Improving the polypropylene-clay composite using carbon nanotubes as secondary filler

Problem statement: Current researches have shown that the thermoplastic-clay nanocomposites have failed to live up to the earlier predictions albeit they have found some niche area of applications. This research work therefore aimed at studying the effect of carbon nanotube as secondary filler on the mechanical properties of polypropylene-clay nanocomposite. Approach: Hybrid polypropylene-clay nanocomposite was prepared in the presence of Multiwall Carbon Nanotubes (MWCNTs) as secondary additives using melt intercalation process. The effect of Multiwall Carbon Nanotubes (MWCNTs) on the polypropylene/clay matrix was investigated in terms of dispersion using XRD, tensile test (ASTM D 638) and notched Izod impact test (ASTM D256). These were compared with the conventional polypropylene-clay nanocomposite. Results: The resulting composite shows about 42% increase in the modulus, 26.20% in the tensile strength and 13.30 Kj m-2 impact strength when compared with binary combination of PP/Clay nanocomposite. XRD patterns of PP/Clay and PP/Clay/MWCNT nanocomposites show different diffraction peaks which are indications of intercalation mixed with macromixing. Conclusion: This study showed that MWCNT can successfully address the common shortcomings peculiar to PP/Clay nanocomposite

Development of a wastewater treatment system for chromium removal using chitosan

This study attempts to evaluate the removal of chromium from aqueous solution using chitosan as an adsorbent. The experiment was conducted by varying chitosan dosage (10-30 mg), pH (5-8), contact time (10-90 min) and agitation speed (50-250 rpm). The initial Cr concentration was fixed to 20 mg L-1. The results indicated that pH is the most significant factor that affects the removal of Cr. The R2 of 0.9963 showed that the overall model is good as the experimental values are close to predicted values. The optimized conditions obtained at 28.79 mg chitosan dosage, pH 6.40, 20.20 min contact time and agitation speed of 156.20 rpm. This optimum condition obtained to achieve 0.05 mg L-1 residual Cr concentration or 99.75% removal that meets Department of Environment Malaysia (DOE) effluent discharge requirement. The design of treatment system that consists of rapid mix, sedimentation and filtration unit is based on the optimum operating conditions. Rapid mix tank was designed with surface area of 9.18 m2 and volume of 27.8 m3. Sedimentation basin was designed with surface area of 100 m2 and volume of 83.33 m3. Filtration was designed with surface area of 16.67 m2

Central composite design of zinc removal from model water using chitosan biopolymer

This research project intended to study the performance of chitosan as flocculating agent for removal heavy metal (zinc) from artificial water. Chitosan was used due to its special characteristics such as non-toxic, hydrophilic, biodegradable, biocompatible, and anti-bacterial, biopolymer and very good adsorption of heavy metal which has led to a very diverse range of its applications. The presence of a large number of amine groups on the chitosan chain increases it adsorption capacity. The effect of contact time, dosage of chitosan, agitation speed and pH were observed for optimal absorption of the zinc in synthetic water. Thus, the application of conventional jar test method used for removal of zinc from synthetic water. Thus, the results of this project which is 52.40% of percentage removal of zinc with optimum conditions; pH7, 30mg dosage, 12 minutes of contact time, and 190 rpm agitation speed approved that chitosan competent to be the alternative adsorbent

Development of ternary nanocomposite for civil constraction and fabrication of process vessels

Introduction: Polymer reinforced with Carbon Nanotubes and Nanoclay are receiving research attention for various industrial applications such as automobile interior and exterior accessories, air and space craft, electronics, civil constructions and fabrications of process vessels Problem Statement: Current researches have shown that the thermoplastic-clay nanocomposites have failed to live up to the earlier predictions albeit they have found some niche area of applications. This research work therefore aimed at studying the effect of carbon nanotube as secondary filler on the mechanical properties of polypropylene-clay nanocomposite. Approach: Hybrid polypropylene-clay nanocomposite was prepared in the presence of multiwall carbon nanotubes (MWCNTs) as secondary additives using melt intercalation process. .

Clinically Applicable Segmentation of Head and Neck Anatomy for Radiotherapy: Deep Learning Algorithm Development and Validation Study

BACKGROUND: Over half a million individuals are diagnosed with head and neck cancer each year globally. Radiotherapy is an important curative treatment for this disease, but it requires manual time to delineate radiosensitive organs at risk. This planning process can delay treatment while also introducing interoperator variability, resulting in downstream radiation dose differences. Although auto-segmentation algorithms offer a potentially time-saving solution, the challenges in defining, quantifying, and achieving expert performance remain. OBJECTIVE: Adopting a deep learning approach, we aim to demonstrate a 3D U-Net architecture that achieves expert-level performance in delineating 21 distinct head and neck organs at risk commonly segmented in clinical practice. METHODS: The model was trained on a data set of 663 deidentified computed tomography scans acquired in routine clinical practice and with both segmentations taken from clinical practice and segmentations created by experienced radiographers as part of this research, all in accordance with consensus organ at risk definitions. RESULTS: We demonstrated the model's clinical applicability by assessing its performance on a test set of 21 computed tomography scans from clinical practice, each with 21 organs at risk segmented by 2 independent experts. We also introduced surface Dice similarity coefficient, a new metric for the comparison of organ delineation, to quantify the deviation between organ at risk surface contours rather than volumes, better reflecting the clinical task of correcting errors in automated organ segmentations. The model's generalizability was then demonstrated on 2 distinct open-source data sets, reflecting different centers and countries to model training. CONCLUSIONS: Deep learning is an effective and clinically applicable technique for the segmentation of the head and neck anatomy for radiotherapy. With appropriate validation studies and regulatory approvals, this system could improve the efficiency, consistency, and safety of radiotherapy pathways

Cholinesterase Inhibitors and Hospitalization for Bradycardia: A Population-Based Study

Laura Park-Wyllie and colleagues examined the health records of more than 1.4 million older adults and show that initiation of cholinesterase inhibitor therapy is associated with a more than doubling of the risk of hospitalization for bradycardia

Anti-Arthritic Effects of Magnolol in Human Interleukin 1β-Stimulated Fibroblast-Like Synoviocytes and in a Rat Arthritis Model

Fibroblast-like synoviocytes (FLS) play an important role in the pathologic processes of destructive arthritis by producing a number of catabolic cytokines and metalloproteinases (MMPs). The expression of these mediators is controlled at the transcriptional level. The purposes of this study were to evaluate the anti-arthritic effects of magnolol (5,5′-Diallyl-biphenyl-2,2′-diol), the major bioactive component of the bark of Magnolia officinalis, by examining its inhibitory effects on inflammatory mediator secretion and the NF-κB and AP-1 activation pathways and to investigate its therapeutic effects on the development of arthritis in a rat model. The in vitro anti-arthritic activity of magnolol was tested on interleukin (IL)-1β-stimulated FLS by measuring levels of IL-6, cyclooxygenase-2, prostaglandin E2, and matrix metalloproteinases (MMPs) by ELISA and RT-PCR. Further studies on how magnolol inhibits IL-1β-stimulated cytokine expression were performed using Western blots, reporter gene assay, electrophoretic mobility shift assay, and confocal microscope analysis. The in vivo anti-arthritic effects of magnolol were evaluated in a Mycobacterium butyricum-induced arthritis model in rats. Magnolol markedly inhibited IL-1β (10 ng/mL)-induced cytokine expression in a concentration-dependent manner (2.5–25 µg/mL). In clarifying the mechanisms involved, magnolol was found to inhibit the IL-1β-induced activation of the IKK/IκB/NF-κB and MAPKs pathways by suppressing the nuclear translocation and DNA binding activity of both transcription factors. In the animal model, magnolol (100 mg/kg) significantly inhibited paw swelling and reduced serum cytokine levels. Our results demonstrate that magnolol inhibits the development of arthritis, suggesting that it might provide a new therapeutic approach to inflammatory arthritis diseases