Formability Enhancement of Galvanized IF-Steel TWB by Modification of Forming Parameters

Tailor-welded blanks (TWBs) have numerous advantages over traditional blanks used in manufacturing, such as energy conservation and environment protection. Low formability and weld line movement during forming operation are main limitations of these blanks. In this research, the effects of forming parameters including thickness ratio (TR), rolling direction with respect to the weld line and direction of major stress with respect to the weld line, on formability and weld line movement of TWBs made of galvanized Interstitial-Free (IF) steel were investigated experimentally. Also the effect of application of non-uniform blankholder force on weld line movement was studied by FEM simulation. By utilization of ABAQUS software, blankholders with different geometries, namely one-piece and two-pieces were modeled and forming process was simulated. The results revealed that formability maximized when the major stress and rolling direction were along the weld line. The results showed applying different blankholder forces, by application of the two-pieces blankholder, leads to more uniform strain distribution and correspondingly less weld line movement in TWBs with TR greater than 1. It was also concluded that the effect of geometric discontinuities on reducing formability was greater than the effect of the weld region.     

Methylene blue as electron promoters in microbial fuel cell

Microbes and enzymes deliver electrons from carbon sources under anaerobic condition. Electrons are generated as the microorganisms are actively catabolized organic substances. The liberated electrons travel to anode surface. Saccharomyces cerevisiae (PTCC 5269) was implemented as biocatalyst in the anaerobic anode compartment. Glucose was used as carbon source. Also mediator as electron promoter was incorporated in the anode. Among several mediators, methylene blue (MB) as electron promoter with concentration of 50, 100, 200, 300 and 400 μM was selected to shuttle the liberated electron to anode surface. Maximum power and current with MB concentration of 300 μM were obtained. Resistances were applied to control the electron flow from anode to cathode chambers. Data were recorded through an online data-logger. Polarization curves with and without mediator were analyzed in the fabricated cell. MB had good ability to enhance power generation. Maximum open circuit voltage of 250 mV was achieved; the voltage was stabled for the duration of 36 h.     

Investigation on Physicomechanical,Thermal, and Morphological of Dipodal Silane-Modified Walnut Shell Powder-Filled Polyurethane Green Composites and Their Application for Removal of Heavy Metal Ions from Water

Dipodal silane-modified walnut shell powder polyurethane green composites have been prepared with different weight fractions of walnut shell powder viz., 0, 3, 6, and 10?wt% with surface-modified dipodal silane. The properties of dipodal silane-modified walnut shell powder-filled polyurethane green composites was investigated by tensile testing, Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The polyurethane/dipodal silane-modified walnut shell powder has been fabricated based on 3-aminopropyltriethoxysilane and γ-glycidoxypropyl trimethoxysilane. The green composites were analyzed by ultraviolet–visible in two different water solutions with Ni²⁺ and Pd²⁺ ions concentrations.     

Endothelial cell culture model for replication of physiological profiles of pressure, flow, stretch, and shear stress in vitro

The phenotype and function of vascular cells in vivo are influenced by complex mechanical signals generated by pulsatile hemodynamic loading. Physiologically relevant in vitro studies of vascular cells therefore require realistic environments where in vivo mechanical loading conditions can be accurately reproduced. To accomplish a realistic in vivo-like loading environment, we designed and fabricated an Endothelial Cell Culture Model (ECCM) to generate physiological pressure, stretch, and shear stress profiles associated with normal and pathological cardiac flow states. Cells within this system were cultured on a stretchable, thin (～500 μm) planar membrane within a rectangular flow channel and subject to constant fluid flow. Under pressure, the thin planar membrane assumed a concave shape, representing a segment of the blood vessel wall. Pulsatility was introduced using a programmable pneumatically controlled collapsible chamber. Human aortic endothelial cells (HAECs) were cultured within this system under normal conditions and compared to HAECs cultured under static and "flow only" (13 dyn/cm(2)) control conditions using microscopy. Cells cultured within the ECCM were larger than both controls and assumed an ellipsoidal shape. In contrast to static control control cells, ECCM-cultured cells exhibited alignment of cytoskeletal actin filaments and high and continuous expression levels of β-catenin indicating an in vivo-like phenotype. In conclusion, design, fabrication, testing, and validation of the ECCM for culture of ECs under realistic pressure, flow, strain, and shear loading seen in normal and pathological conditions was accomplished. The ECCM therefore is an enabling technology that allows for study of ECs under physiologically relevant biomechanical loading conditions in vitro.     

Preparation and Characterization of Carvacrol Loaded Polyhydroxybutyrate Nanoparticles by Nanoprecipitation and Dialysis Methods

In this investigation, preparation of carvacrol loaded polyhydroxybutyrate (PHB) nanoparticles was performed by nanoprecipitation and dialysis methods. PHB particles were obtained by nanoprecipitation method without and with low concentration of Tween 80 or pluronic as surfactant. Nano‐ and micro‐sized particles were formed with trimodal distribution and large aggregates. Size and distribution of nanoparticles were decreased when concentration of Tween 80 was increased to 1% (v/v) in water as polar phase. PHB nanoparticles had narrow size (157 nm) with monomodal distribution. Nanoparticles, which were prepared by dialysis method had 140 nm in diameter with monomodal distribution. Carvacrol was used as a lipophilic drug and entrapped in optimized nanoparticles formulation by nanoprecipitation and dialysis methods. Entrapment efficacy was 21% and 11%, respectively. Morphology of PHB nanoparticles was spherical. The results of kinetic release study showed that carvacrol was released for at least 3 days. Release kinetic parameters showed a simple Fickian diffusion behavior for both formulations. Carvacrol loaded PHB nanoparticles had good dispersion into the agar medium and antimicrobial activity against Escherichia coli. This study describes the 1st work on loading of carvacrol into the PHB nanoparticles by nanoprecipitation and dialysis methods.     

An Omniphobic Spray Coating Created from Hierarchical Structures Prevents the Contamination of High-Touch Surfaces with Pathogens

Engineered surfaces that repel pathogens are of great interest due to their role in mitigating the spread of infectious diseases. A robust, universal, and scalable omniphobic spray coating with excellent repellency against water, oil, and pathogens is presented. The coating is substrate-independent and relies on hierarchically structured polydimethylsiloxane (PDMS) microparticles, decorated with gold nanoparticles (AuNPs). Wettability studies reveal the relationship between surface texturing of micro- and/or nano-hierarchical structures and the omniphobicity of the coating. Studies of pathogen transfer with bacteria and viruses reveal that an uncoated contaminated glove transfers pathogens to >50 subsequent surfaces, while a coated glove picks up 10⁴ (over 99.99%) less pathogens upon first contact and transfers zero pathogens after the second touch. The developed coating also provides excellent stability under harsh conditions. The remarkable anti-pathogen properties of this surface combined with its ease of implementation, substantiate its use for the prevention of surface-mediated transmission of pathogens.     

Functional Nanomaterials for the Diagnosis of Alzheimer's Disease: Recent Progress and Future Perspectives

Alzheimer's disease (AD) is one of the main causes of dementia worldwide, whereby neuronal death or malfunction leads to cognitive impairment in the elderly population. AD is highly prevalent, with increased projections over the next few decades. Yet current diagnostic methods for AD occur only after the presentation of clinical symptoms. Evidence in the literature points to potential mechanisms of AD induction beginning before clinical symptoms start to present, such as the formation of amyloid beta (Aβ) extracellular plaques and neurofibrillary tangles (NFTs). Biomarkers of AD, including Aβ₄₀, Aβ₄₂, and tau protein, amongst others, show promise for early AD diagnosis. Additional progress is made in the application of biosensing modalities to measure and detect significant changes in these AD biomarkers within patient samples, such as cerebral spinal fluid (CSF) and blood, serum, or plasma. Herein, a comprehensive review of the emerging nano-biomaterial approaches to develop biosensors for AD biomarkers’ detection is provided. Advances, challenges, and potential of electrochemical, optical, and colorimetric biosensors, focusing on nanoparticle-based (metallic, magnetic, quantum dots) and nanostructure-based biomaterials are discussed. Finally, the criteria for incorporating these emerging nano-biomaterials in clinical settings are presented and assessed, as they hold great potential for enhancing early-onset AD diagnostics.