Bubble–particle collision and attachment probability on fine particles flotation

Particle size is an important parameter in flotation and has been the focus of flotation research for decades. The difficulty in floating fine particles is attributed to the low probability of bubble–particle collision. In this research, the influence of hydrodynamic parameters on collision probability of fine particles was investigated. Collision probability was obtained using Stokes, intermediate I and intermediate II and potential equations. Maximum collision probability was 5.65% obtained with impeller speed of 1100 rpm, air flow rate of 30 l/h and particle size of 50 μm. Also, attachment probability under Stokes flow, turbulent and potential flow conditions was calculated 100, 99.49 and 81.87% respectively. Maximum attachment probability was obtained with impeller speed of 700 rpm, contact angle of 90°, particle size of 20 μm and air flow rate of 15 l/h. Collision angles were obtained between 60.71° and 60.18° and attachment angles were obtained between 9.15° and 59.83°.     

A new energy harvester using a cross-ply cylindrical membrane shell integrated with PVDF layers

In this paper, we proposed a smart cylindrical membrane shell panel (SCMSP) model for vibration-based energy harvester. The SCMSP is made of an orthotropic elastic core covered by outer PVDF layers with transverse polarization vector. Electrodynamics governing equations of motion are derived by applying extended Hamilton’s principle. The governing equations are based on Donnell’s linear thin shell theory. The SCMSP displacement fields are expanded by means of double Fourier series satisfying immovable edges with free rotation boundary conditions and coupled system of linear partial differential equations are obtained. The discretized linear ordinary differential equations of motion are obtained using Galerkin method. The output power is taken as an indicating criterion for the generator. A parametric study for MEMS applications is conducted to predict the power generated due to radial harmonic ambient vibration. Optimal resistance value is also obtained for the particular electrode distribution that gives maximum output power. A low vibration amplitude (5?Pa), and a low-frequency (471.79?Hz) vibration source is targeted for the resonance operation, in which the output power of 0.4111?μW and peak-to-peak voltage of 0.2952?V are predicted.     

Estimation of froth flotation recovery and collision probability based on operational parameters using an artificial neural network

An artificial neural network and regression procedures were used to predict the recovery and collision probability of quartz flotation concentrate in different operational conditions. Flotation parameters, such as dimensionless numbers (Froude, Reynolds, and Weber), particle size, air flow rate, bubble diameter, and bubble rise velocity, were used as inputs to both methods. The linear regression method shows that the relationships between flotation parameters and the recovery and collision probability of fl...     

Improving adaptive receivers performance in molecular communication via diffusion

Forthcoming applications for molecular communications (MC) such as drug‐delivery and health monitoring will require robust receiver capabilities to mitigate channel memory and inter symbol interference caused by previous transmitted symbols. Here, the authors introduce an adaptive weighted algorithm to reduce the influence of these factors. This novel signal detection is deployed on to a concentration‐based MC system with absorbing receiver which is based on the so‐called first passage time concept. The proposed detector has low complexity and does not require explicit channel knowledge. To evaluate authors’ proposed algorithm, a theoretical approach is developed to derive the bit error rate (BER). Numerical results also carried out to verify the accuracy of these formulations and establish that the new detector will achieve better performance in comparison with other common low‐complex detectors under certain scenarios. Additionally, the authors propose a simple pre‐coding technique to combat the sequence of consecutive ones in low ISI scenarios. Also a comparison between detectors is given, which is based on the variation of distance, symbol period, signal‐to‐noise ratio (SNR), and number of molecules.Inspec keywords: radio receivers, error statistics, signal detection, intersymbol interferenceOther keywords: low‐complex detectors, low ISI scenarios, symbol period, signal‐to‐noise ratio, adaptive receivers performance, molecular communication, drug‐delivery, health monitoring, robust receiver capabilities, channel memory, inter symbol interference, previous transmitted symbols, adaptive weighted algorithm, novel signal detection, concentration‐based MC system, absorbing receiver, passage time concept, low complexity, explicit channel knowledge, authors, theoretical approach, bit error rate, numerical results     

X-Ray Measurement and Enhancement of SBUPF1 Plasma Focus Device in Different Ar Pressures and Operating Voltages

In this paper, best condition of filling gas pressure and operating voltage for SBUPF1 plasma focus device to have maximum intensity of hard and soft X-ray emission has been reported. For time resolved X-ray detection, PIN detector and fast plastic Scintillator detector with appropriate filters have been used and for time integrated X-ray emission measurement, radiography films with appropriate filter masks have been used. Rogowski coil has been used for pinch detection. The highest hard X-ray emission has been observed at the pressure of 0.45 mbar of Argon and discharge voltage about 23.5 kV. The highest Soft X-ray emission has been observed at the pressure of 0.35 mbar of Argon and discharge voltage about 23.5 kV. For enhancement of hard X-ray emission intensity, lead disk was placed in copper anode tip and measurements were repeated. Results have shown that hard X-ray emission has been enhanced about 23% and soft X-ray emission has been enhanced about 33% with inserting a high atomic number metal disk like lead. Results from integral X-ray measurement have shown presence of dominant peaks in ranges 13.2–15, 21–21.9 and 23.4–24.3 keV with significant spectral components in the range of 0–50 keV. Pinch size has measured with pin hole camera and it is about 0.6 mm × 2.12 mm. Captured images with SBUPF1 have confirmed that it is a suitable source for introspective imaging with capability of showing very fine details.     

Surface Decoration of Peptide Nanoparticles Enables Efficient Therapy toward Osteoporosis and Diabetes

A versatile surface decoration strategy to efficiently encapsulate water-soluble peptides is developed. By assembling peptide molecules into nanoparticles, diverse physiochemical properties of these compacted molecules are equalized to the surface properties of nanoparticles. Primarily driven by the generic electrostatic attractions, the surface of as-prepared peptide nanoparticles is decorated with charged amino acids-grafted poly(lactic-co-glycolic acid). This adsorbed polymer layer versatilely blocks the phase transfer of peptide nanoparticles by increasing their affinity to the dispersed phase solvent molecules. Attributed to the ultrahigh encapsulation efficiencies (> 96%), the peptide mass fraction inside the obtained microcomposites is higher than 48%. The plasma calcium level has been efficiently reduced for ≈3 weeks with only one single injection of salmon calcitonin-encapsulated microcomposite in osteoporotic rats. Similarly, one single injection of exenatide-encapsulated microcomposites efficiently controls the glycemic level in type 2 diabetic rats for up to 3 weeks. Overall, the developed versatile surface decoration strategy efficiently encapsulates peptides and improves their pharmacokinetic features, regardless of the molecular structure of peptide cargos.     

Enhancing Apoptosome Assembly via Mito-Biomimetic Lipid Nanocarrier for Cancer Therapy

Apoptosis is the natural programmed cell death process, which is responsible for abnormal cell clearance. However, many cancer cells develop various mechanisms to escape apoptosis through interrupting apoptosome assembly, which is a key step to initiate apoptosis. This promotes tumorigenesis and drug resistance, and thus, poses a great challenge in cancer treatment. Herein, a biomimetic lipid nanocarrier mimicking mitochondrial Cytochrome C (Cyt C) binding is developed. Cardiolipin, the major phospholipid of mitochondrial inner membrane, is introduced as the main component in biomimetic liposomal formulation. With the help of cardiolipin, Cyt C is sufficiently loaded in liposome based on electrostatic and hydrophobic interaction with cardiolipin. Lonidamine (LND) is added in hydrophobic phase of liposome to modulate the metabolic activity within cancer cells and sensitize the cells to Cyt C-induced apoptosis. The results suggest that LND reduces ATP level and creates favorable environment for Cyt C induced apoptosome assembly, exhibiting higher apoptosis level and anti-tumor efficacy in vitro and in vivo. The conjugation of a tumor-homing peptide, LinTT1, on the nanovesicle, increases the efficacy due to enhanced tumor accumulation. Overall, this biomimetic lipid nanocarrier proves to be an efficient delivery system with great potential of pro-apoptosis cancer therapy.     

Immunomodulatory Hydrogels: Advanced Regenerative Tools for Diabetic Foot Ulcer

Diabetic foot ulcer (DFU) is one of the most common complications of diabetes, bringing physical and mental challenges for patients due to the lack of efficient curative therapy. Despite considerable advances in pharmacological and surgical approaches, clinical trials for DFU patients remain disappointing due to the local overactive and excessive inflammation. Immunomodulatory hydrogels has significant advantages to overcome the clinical challenge of DFUs therapy. Here, recent fabrication and regenerative advances in the utilization of functional hydrogels for altering the immune microenvironment of DFUs are comprehensively reviewed. The pathological features and the healing processes of DFUs, followed by summarizing the physicochemical properties essential for the design of regenerative hydrogels for immunomodulation in DFUs, are briefly introduced. Then, the potential immuno-therapeutic modalities of hydrogels and emerging trends used to treat DFUs via multitherapeutic approaches and enhanced efficacy and safety are discussed. Taken together, by linking the structural properties of hydrogels to their functions in DFU therapy with a particular focus on immunomodulatory stimuli, this review can promote further advances in designing advanced hydrogels for DFUs, resulting in improved diabetic wound repair through translation into clinical setting in the near future.