Design and energy absorption enhancement of vehicle hull under high dynamic loads

V-shape hulls are widely used in peacekeeping efforts such as demining vehicles in order to deflect the blast energy and reduce the effects of mine blast. Blast resistant design and energy absorption enhancement of V-shape plates were carried out using finite element analysis package ABAQUS. Various geometries of V-shape plates with and without interlayer of materials like Al-foams and honeycomb were employed to analyze their effects on the deformation of the plate and applied stresses and strains. The results obtained show that application of metallic foams leads to better response of the plate and consequently results in more energy dissipation, less dame to vehicle and enhances crew survivability.     

“Fe doped Ni–Co spinel protective coating on ferritic stainless steel for SOFC interconnect application”

In an attempt to reduce the oxidation and Cr evaporation rates, various protective coating layers with a nominal composition of NiCo_2−xFe_xO₄ (x = 0, 0.5, 1) were deposited on the SUS 430 ferritic stainless steel substrate, as interconnect for solid oxide fuel cell application, by sol-gel dip coating method. Then, the coated samples were soaked at 750 °C for 2.5 h in N₂ and subsequently for 2.5 h in air. Phase composition and microstructure of the coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, long-term isothermal oxidation experiment and area specific resistance (ASR) measurement were also carried out on the coated samples. Results showed that the addition of 1 mol of Fe into Ni–Co spinel (x = 1), led to a parabolic rate constant of 5.16 × 10⁻¹⁵(g² cm⁻⁴ s⁻¹) and an ASR of 17 mΩ cm².     

POLAROGRAPHIC CHARACTERIZATION OF AROMATIC STRUCTURES IN COAL LIQUID PRODUCTS

Reducible aromatic species in coal liquid products from five major processes (Synthoil, FMC COED, HRI H-Coal, PAMCO SRC, and Catalytic Inc. SRC) together with solvent elution chromatography fractions of a selected asphaltene has been evaluated. The half-wave potentials measurments are found to be consistant with other methods. The total polarographic reduction of measurement per average molecule for Synthoil solvent fractions, as measured by diffusion constant (i_d/C), increases in the following manner: gas oil → resin → asphaltene → carbene → carboid. The same trend was observed when color indices (I) and refractive indices (n₂₅) were individually studied.     

Combined cerium oxide nanocapping and layer-by-layer coating of porous silicon containers for controlled drug release

Local drug release in close vicinity of solid tumors is a promising therapeutic approach in cancer therapy. Implantable drug delivery systems can be designed to achieve controlled and sustained drug release. In this study, ultrathin porous membranes of silicon wafer were employed as compatible drug reservoir models. An anticancer model drug, curcumin (CUR), was successfully loaded into porous silicon containers (8.94?±?0.72% w/w), and then, cerium oxide nanocapping was performed on the open pores for drug protection and release rate prolongation. Next, layer-by-layer surface coating of the drug container with anionic (alginate) and cationic (chitosan) polymers rendered pH-responsivity to the device. The drug release profile was studied using reflectometric interference Fourier transform spectroscopy at different pH conditions. It was determined that faster decomposition of the polymeric layers and subsequent CUR release occur in acidic buffer (pH 5.5) compared to a neutral buffer. Various characterization studies, including dynamic light scattering, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy, contact angle measurement, ultraviolet–visible spectroscopy, and X-ray powder diffraction revealed that our system has the required physicochemical properties to serve as a novel pH-sensitive drug delivery implant for cancer therapy.     

Investigation on cristobalite crystallization in silica-based ceramic cores for investment casting

In this work, cristobalite crystallization and its effects on mechanical and chemical behaviour of injection moulded silica-based ceramic cores were investigated. In order to simulate casting process condition, the sintered samples at 1220 °C were also heated up to 1430 °C. Flexural strength test was carried out on both sintered and heat treated samples. Chemical resistance of the cores was evaluated by leaching the samples inside 43 wt% KOH solution at its boiling point. Phase evolution and microstructure were investigated by thermal analyses (DTA and DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM). Results showed that cristobalite was crystallized on the surface of fused silica grains at about 1380 °C. Flexural strength of the sintered cores was decreased after simulated casting heat treatment due to cristobalite phase transformation. The formed cristobalite on the surface of fused silica grains dramatically decreased the leachability of ceramic cores.     

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.     

A least-squares support vector machine approach to predict temperature drop accompanying a given pressure drop for the natural gas production and processing systems

Precise estimation of temperature variations throughout gas production systems can enhance designing the production amenities. Routine methods for determining the temperature profiles in gas production systems are based on the gas composition and flash calculations. However, if the gas compositions are not available, the gas production system can be modelled by employing a black-oil approach, which is also a method for calculating the oil/gas resources and for modelling the gas reservoir operation. Accordingly, for black-oil models and when the natural gas compositions are not accessible, applying robust predictive tools in this research is of high interest in natural production systems. The current study places emphasis on applying the predictive model based on the least- squares support vector machine (LSSVM) to estimate precisely the proper temperature drop associated with a given pressure drop throughout the natural gas production systems based on the black-oil approach to acquire an accurate result for the temperature drop of natural gas streams. Genetic algorithm was used to optimise hyper-parameters (γ and σ²) which are embedded in the LSSVM model. Using this method is simple and it accurately determines the temperature drop through the natural gas stream with minimum uncertainty.     

Investigation of Cs(I) and Sr(II) removal using nanoporous bentonite

ABSTRACT

Bentonites are types of clays made up the dominant constituent of montmorillonite. Four types of nano-porous and nano-structured commercial bentonite clays were studied in detail for their physicochemical and mineralogical properties vs. Cs and Sr adsorption. The instrumental analyses to study samples were X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) surface area measurements, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetry (TG). The XRF and peaks of XRD patterns at 2θ?=?8, 19.9, 35, 55, and 62 clearly indicated that the main component of the bentonite samples was montmorillonite. The BET analysis showed that B1 has the highest specific surface area among the other samples which its single and multiple point BET surface area were equal to 84.85 and 85.94?m²?g^?1, respectively. These values represents the amount of montmorillonite and adsorption capacity of samples. The physicochemical, structural and morphological characteristics of different samples were investigated through instrumental analysis. The results of separation processes of Cs(I) and Sr(II) showed 59.75 and 45.5% adsorption capacities for B3 and B2 which were the highest values among the others. The results lead to the conclusion that samples B3 had a good adsorption capacity to remove Cs(I) and Sr(II).     

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.     

β-Amyloid Targeting with Two-Dimensional Covalent Organic Frameworks: Multi-Scale In-Silico Dissection of Nano-Biointerface

Cytotoxic aggregation of misfolded β-amyloid (Aβ) proteins is the main culprit suspected to be behind the development of Alzheimer's disease (AD). In this study, Aβ interactions with the novel two-dimensional (2D) covalent organic frameworks (COFs) as therapeutic options for avoiding β-amyloid aggregation have been investigated. The results from multi-scale atomistic simulations suggest that amine-functionalized COFs with a large surface area (more than 1000 m²/gr) have the potential to prevent Aβ aggregation. Gibb's free energy analysis confirmed that COFs could prevent protofibril self-assembly in addition to inhibiting β-amyloid aggregation. Additionally, it was observed that the amine functional group and high contact area could improve the inhibitory effect of COFs on Aβ aggregation and enhance the diffusivity of COFs through the blood-brain barrier (BBB). In addition, microsecond coarse-grained (CG) simulations with three hundred amyloids reveal that the presence of COFs creates instability in the structure of amyloids and consequently prevents the fibrillation. These results suggest promising applications of engineered COFs in the treatment of AD and provide a new perspective on future experimental research.