612 research outputs found
Entropic competition in polymeric systems under geometrical confinement
Using molecular dynamics simulation, we investigate the effect of confinement
on a system that comprises several stiff segmented polymer chains where each
chain has similar segments, but length and stiffness of the segments vary among
the chains which makes the system inhomogeneous. The translational and
orientational entropy loss due to the confinement plays a crucial role in
organizing the chains which can be considered as an entropy-driven segregation
mechanism to differentiate the components of the system. Due to the
inhomogeneity, both weak and strong confinement regimes show the competition in
the system and we see segregation of chains as the confining volume is
decreased. In the case of strong spherical confinement, a chain at the
periphery shows higher angular mobility than other chains, despite being more
radially constrained.Comment: 16 pages, 11 figure
Protein Fouling of Cellulose Acetate Microfiltration Membranes Modified by the Deposition of Amino Acid L-DOPA
An Enhanced Adaptive Algorithm to Mitigate Mis-coordination Problem of the Third Zone of Distance Relays
ABSTRACT Cascaded tripping of power lines due to mal-operation of zone 3 distance relays is one of the main causes of many blackouts worldwide. The improved protection technique for zone 3 can help to prevent such mal-operation and, thus, more reliable power systems can be envisaged. This paper presents a novel zone-3 setting scheme based on impedance seen by distance relays in order to calculate zone-3 setting of the relays when faults are simulated on the reach of zone-2 of primary distance relays. The new technique is also enhanced to be used in an adaptive protection system. Since three phase fault rarely occurs in the system and in order to have better demonstration of effectiveness of the proposed scheme, it is tested for various type of faults such as, two phase (AB), single phase to ground (AG) and two phase to ground (ABG) as well as three-phase (ABC) using data simulated through DIgSILENT in the IEEE 30-bus test system during different topologies. The simulation results show that the novel zone 3 distance relay elements using the proposed method operate correctly for various events
Adaptive Fuzzy Synergetic PSS Design to Damp Power System Oscillations
This paper presents a novel indirect adaptive Power System Stabilizer (PSS) via a developed synergetic control methodology and fuzzy systems. Fuzzy system is utilized in an adaptive scheme to estimate the system using a nonlinear model. The synergetic control guarantees robustness of the controller and makes the controller easy to implement because of using a chatter free continuous control law. Additionally, the parameters of the controller are optimized by Imperialist Competitive Algorithm (ICA). The effectiveness of the proposed scheme is confirmed on a single machine power system while the stability is guaranteed through Lyapunov synthesis
Risk assessment of sari fatemeh zahra hospital using failure mode effect analysis, individualized rapid assessment tool, and preliminary hazard analysis
Abstract
Background and purpose:
Identification of risk in hospital waste management have a major role in reducing the cost of surplus and preventing the spread of diseases. In this quantitative analysis, we aimed at determining waste components, evaluating hospital waste management, and prioritizing the risks in Sari Fatemeh Zahra Hospital.
Materials and methods:
We performed a descriptive-cross-sectional study in 2015.
Tchobanoglous method was used for quantitative-physical analysis of the waste. The individualized rapid assessment tool was applied to evaluate waste management. Preliminary Hazard Analysis and failure
mode and effect analysis models were used to identify and prioritize the risks.
Results:
Total waste production, general waste, infectious wastes, and sharp objects were 1011.54, 600.45, 384.94, and 26.15 kg/day, respectively. Plastics, organic materials, and textiles constituted the highest amount of waste products. According to the individualized rapid assessment tool, the score obtained by the hospital was 82.15% indicating an excellent waste management. In preliminary hazard analysis, failure mode, and effect analysis models, 23 errors were observed, of which 9 had a priority number greater than 100.
Conclusion:
The models studied showed that mixing the sharp waste material with other garbage, disposal of non-infectious and semi-household waste in infectious bins and vice versa are of high risk and need corrective measures.
Keywords:
hospital waste management,quantitative analysis,
risk assessment,preliminary hazard analysis, Hazard Analysis
and Failure mode
Catalytic decomposition of 2-chlorophenol using an ultrasonic-assisted Fe3O4-TiO2@MWCNT system: Influence factors, pathway and mechanism study.
As a reusable sonocatalyst, magnetically separable Fe3O4-TiO2@MWCNT (FMT) was synthesized by an ultrasound-assisted wet impregnation method and was evaluated in the removal of 2-chlorophenol (2CP). Physical and chemical properties of the catalyst composite materials were investigated by all catalysts were systematically characterized using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), Dynamic light scattering (DLS), and N2-physisorption. The efficiency and kinetics of 2CP removal by FMT-assisted sonocatalysis (FMT-US) was systematically investigated under various operational parameters i.e. pH, FMT and 2CP concentration, temperature and ultrasonic power. The results indicated that 0.4gL-1 FMT dosage, pH 5, temperature of 35°C as well as 50 w ultrasound power are the most favorable conditions for the degradation of the 2CP. Furthermore, both of the superoxide and hydroxyl radicals were produced in the reaction, however, superoxide radicals were assumed to be the dominating reactive species for the 2CP degradation, according to the scavenging tests and electron paramagnetic resonance tests. Moreover, the FMT catalyst exhibited a high reusability and stability in the US/FMT system during the five repetitive experiments. The intermediate products were identified by GC-MS, thereby a possible degradation pathway is proposed. The chemical oxygen demand (COD) and corresponding total organic carbon (TOC) removal efficiencies were 64.9% and 56.7%, respectively. Finally, toxicity tests showed that the toxicity of the solution increased during the first 5min and then decreased significantly with the progress of the oxidation. The mechanisms of ultrasound irritation enhanced FMT activation were also proposed.
Copyright © 2017 Elsevier Inc. All rights reserved
Zinc- and Copper-Doped Mesoporous Borate Bioactive Glasses: Promising Additives for Potential Use in Skin Wound Healing Applications
In this study, zinc (Zn)- and copper (Cu)-doped 13-93B3 borate mesoporous bioactive glasses (MBGs) were successfully synthesized using nitrate precursors in the presence of Pluronic P123. We benefited from computational approaches for predicting and confirming the experimental findings. The changes in the dynamic surface tension (SFT) of simulated body fluid (SBF) were investigated using the Du Noüy ring method to shed light on the mineralization process of hydroxyapatite (HAp) on the glass surface. The obtained MBGs were in a glassy state before incubation in SBF. The formation of an apatite-like layer on the SBF-incubated borate glasses was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The incorporation of Zn and Cu into the basic composition of 13-93B3 glass led to changes in the glass transition temperature (Tg) (773 to 556 °C), particle size (373 to 64 nm), zeta potential (−12 to −26 mV), and specific surface area (SBET) (54 to 123 m2/g). Based on the K-means algorithm and chi-square automatic interaction detection (CHAID) tree, we found that the SFT of SBF is an important factor for the prediction and confirmation of the HAp mineralization process on the glasses. Furthermore, we proposed a simple calculation, based on SFT variation, to quantify the bioactivity of MBGs. The doped and dopant-free borate MBGs could enhance the proliferation of mouse fibroblast L929 cells at a concentration of 0.5 mg/mL. These glasses also induced very low hemolysis (<5%), confirming good compatibility with red blood cells. The results of the antibacterial test revealed that all the samples could significantly decrease the viability of Pseudomonas aeruginosa. In summary, we showed that Cu-/Zn-doped borate MBGs can be fabricated using a cost-effective method and also show promise for wound healing/skin tissue engineering applications, as especially supported by the cell test with fibroblasts, good compatibility with blood, and antibacterial properties
Fabrication and characterization of cobalt- and copper-doped mesoporous borate bioactive glasses for potential applications in tissue engineering
Developing novel compositions of bioactive glasses (BGs) is key for accelerating tissue repair and regeneration. In this work, we developed a series of cobalt (Co)- and copper (Cu)-doped mesoporous bioactive glasses (MBGs) based on borate 13-93B3 composition using nitrate precursors. We took benefit from data science algorithms to predict and assess the physico-chemical and biological properties of the samples. The results showed that the presence of the dopants (Co and Cu) in the MBGs could change the glass transition temperature (Tg) (from 773 to 539 °C), the zeta potential (from -12 to -43 mV), and surface area (from 54 to 194 m2/g). However, the presence of 2.5 mol% of dopants in the composition led to just a slight decrease in their bioactivity. In vitro biocompatibility assays confirmed that all the glass samples were biocompatible. Furthermore, the doped MBGs exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. In addition, these glasses could induce the mobility of human umbilical vein endothelial cells (HUVECs) and enhance new blood vessel formation in ovo. According to the obtained data, it can be stated that this type of doped borate MBGs held great promise in tissue engineering applications
Data mining for prediction of length of stay of cardiovascular accident inpatients
The healthcare sector generates large amounts of data on a daily basis. This data holds valuable knowledge that, beyond supporting a wide range of medical and healthcare functions such as clinical decision support, can be used for improving profits and cutting down on wasted overhead. The evaluation and analysis of stored clinical data may lead to the discovery of trends and patterns that can significantly enhance overall understanding of disease progression and clinical management. Data mining techniques aim precisely at the extraction of useful knowledge from raw data. This work describes an implementation of a data mining project approach to predict the hospitalization period of cardiovascular accident patients. This provides an effective tool for the hospital cost containment and management efficiency. The data used for this project contains information about patients hospitalized in Cardiovascular Accident’s unit in 2016 for having suffered a stroke. The Weka software was used as the machine learning toolkit.Fundação para a Ciência e a Tecnologia (UID/CEC/00319/2013
Fructose reprogrammes glutamine-dependent oxidative metabolism to support LPS-induced inflammation
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