One-pot preparation of alumina-modified polysulfone-graphene oxide nanocomposite membrane for separation of emulsion-oil from wastewater

In recent years, polysulfone-based nanocomposite membranes have been widely used for contaminated water treatment because they comprise properties such as high thermal stability and chemical resistance. In this study, a polysulfone (PSf) nanocomposite membrane was fabricated using the wet-phase inversion method with the fusion of graphene oxide (GO) and alumina (Al2O3) nanoparticles. We also showed that GO-Al2O3 nanoparticles were synthesised successfully by using a one-pot hydrothermal method. The nanocomposite membranes were characterised by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and water contact angle. The loading of GO and Al2O3 was investigated to improve the hydrophilic and oil rejection of the matrix membrane. It was shown that by using 1.5 wt.% GO-Al2O3 loaded in polysulfone, ~74% volume of oil was separated from the oil/water emulsion at 0.87 bar and 30 min. This figure was higher than that of the process using the unmodified membrane (PSf/GO) at the same conditions, in which only ~60% volume of oil was separated. The pH, oil/water emulsion concentration, separation time, and irreversible fouling coefficient (FRw) were also investigated. The obtained results suggested that the GO-Al2O3 nanoparticles loaded in the polysulfone membrane might have potential use in oily wastewater treatment applications

Risk factors associated with mechanical ventilation, autonomic nervous dysfunction and physical outcome in Vietnamese adults with tetanus.

BACKGROUND: Tetanus remains common in many low- and middle-income countries, but as critical care services improve, mortality from tetanus is improving. Nevertheless, patients develop severe syndromes associated with autonomic nervous system disturbance (ANSD) and the requirement for mechanical ventilation (MV). Understanding factors associated with worse outcome in such settings is important to direct interventions. In this study, we investigate risk factors for disease severity and long-term physical outcome in adults with tetanus admitted to a Vietnamese intensive care unit. METHODS: Clinical and demographic variables were collected prospectively from 180 adults with tetanus. Physical function component scores (PCS), calculated from Short Form Health Survey (SF-36), were assessed in 79 patients at hospital discharge, 3 and 6 months post discharge. RESULTS: Age, temperature, heart rate, lower peripheral oxygen saturation (SpO2) and shorter time from first symptom to admission were associated with MV (OR 1.03 [ 95% confidence interval (CI) 1.00, 1.05], p = 0.04; OR 2.10 [95% CI 1.03, 4.60], p = 0.04; OR 1.04 [ 95% CI 1.01, 1.07], p = 0.02); OR 0.80 [95% CI 0.66, 0.94], p = 0.02 and OR 0.65 [95% CI 0.52, 0.79, p < 0.001, respectively). Heart rate, SpO2 and time from first symptom to admission were associated with ANSD (OR 1.03 [95% CI 1.01, 1.06], p < 0.01; OR 0.95 [95% CI 0.9, 1.00], p = 0.04 and OR 0.64 [95% CI 0.48, 0.80], p < 0.01, respectively). Median [interquartile range] PCS at hospital discharge, 3 and 6 months were 32.37 [24.95-41.57, 53.0 [41.6-56.3] and 54.8 [51.6-57.3], respectively. Age, female sex, admission systolic blood pressure, admission SpO2, MV, ANSD, midazolam requirement, hospital-acquired infection, pressure ulcer and duration of ICU and hospital stay were associated with reduced 0.25 quantile PCS at 6 months after hospital discharge. CONCLUSIONS: MV and ANSD may be suitable endpoints for future research. Risk factors for reduced physical function at 3 months and 6 months post discharge suggest that modifiable features during hospital management are important determinants of long-term outcome

Functional outcome and muscle wasting in adults with tetanus.

BACKGROUND: In many countries, in-hospital survival from tetanus is increasing, but long-term outcome is unknown. In high-income settings, critical illness is associated with muscle wasting and poor functional outcome, but there are few data from resource-limited settings. In this study we aimed to assess muscle wasting and long-term functional outcome in adults with tetanus. METHODS: In a prospective observational study involving 80 adults with tetanus, sequential rectus femoris ultrasound measurements were made at admission, 7 days, 14 days and hospital discharge. Functional outcome was assessed at hospital discharge using the Timed Up and Go test, Clinical Frailty Score, Barthel Index and RAND 36-item Short Form Health Survey (SF-36) and 3 and 6 months after discharge using the SF-36 and Barthel Index. RESULTS: Significant muscle wasting occurred between hospital admission and discharge (p70 y of age, functional recovery at 6 months was reduced compared with younger patients. Hospital-acquired infection and age were risk factors for muscle wasting. CONCLUSIONS: Significant muscle wasting during hospitalization occurred in patients with tetanus, the extent of which correlates with functional outcome

Social Determinants of Long Lasting Insecticidal Hammock-Use Among the Ra-Glai Ethnic Minority in Vietnam: Implications for Forest Malaria Control

BACKGROUND: Long-lasting insecticidal hammocks (LLIHs) are being evaluated as an additional malaria prevention tool in settings where standard control strategies have a limited impact. This is the case among the Ra-glai ethnic minority communities of Ninh Thuan, one of the forested and mountainous provinces of Central Vietnam where malaria morbidity persist due to the sylvatic nature of the main malaria vector An. dirus and the dependence of the population on the forest for subsistence - as is the case for many impoverished ethnic minorities in Southeast Asia. METHODS: A social science study was carried out ancillary to a community-based cluster randomized trial on the effectiveness of LLIHs to control forest malaria. The social science research strategy consisted of a mixed methods study triangulating qualitative data from focused ethnography and quantitative data collected during a malariometric cross-sectional survey on a random sample of 2,045 study participants. RESULTS: To meet work requirements during the labor intensive malaria transmission and rainy season, Ra-glai slash and burn farmers combine living in government supported villages along the road with a second home at their fields located in the forest. LLIH use was evaluated in both locations. During daytime, LLIH use at village level was reported by 69.3% of all respondents, and in forest fields this was 73.2%. In the evening, 54.1% used the LLIHs in the villages, while at the fields this was 20.7%. At night, LLIH use was minimal, regardless of the location (village 4.4%; forest 6.4%). DISCUSSION: Despite the free distribution of insecticide-treated nets (ITNs) and LLIHs, around half the local population remains largely unprotected when sleeping in their forest plot huts. In order to tackle forest malaria more effectively, control policies should explicitly target forest fields where ethnic minority farmers are more vulnerable to malaria

A generation step for force reflecting control of a pneumatic excavator based on augmented reality environment

Nowadays, excavators play an important role in construction machinery. Among them, pneumatic excavators are suitable selections for some specific applications, because of their advantages. As a new trend, automation of excavation helps improving productivity, safety, and reducing of operation costs, consequently, making construction works become feasible even in hostile environment. In traditional auto-operating methods, excavators are controlled by joysticks through a so-called virtual environment in which the excavation performance is determined by some sensors attached to the real machines. However, the control accuracy by using these methodologies is reduced proportionally to the number of used sensors. The aim of this paper is to develop a mathematic model to apply to force reflecting control method basedaugmented reality environment for a pneumatic excavator. Here, the mathematic model was constructed and optimized by practical excavation data. Once, the optimized model is obtained, it can be used in a combination with potential meters attached on the excavator to estimate loading forces without using any force sensor as well as to monitor current states of the excavator in the virtual environment. By using the estimated force to create a reflecting force to the joysticks, the driver can feel the real working conditions as directly-driving method. A mini-scaled pneumatic excavator was used in this study for investigating the proposed modeling method

A study on force reflecting joystick control using virtual force sensor for applications to excavators.

Nowadays, tele-operation robotic systems, especially in construction machinery such as automated excavators become an urgent demand which help improving productivity, safety, and reducing of operation costs. The aim of this paper is to develop a novel force reflecting joystick control (FRJC) method using virtual force sensor for applications to excavators. Here, the suggested system is a combination of a master system – force reflecting joystick mechanism (FRJM) and a slave system – real excavator which is integrated with potentiometers at its active joins. Two non-linear black box models (NBBM) are proposed for identifying dynamic behaviors of the excavator and FRJM. Once, the optimized models are obtained, they can be used in a combination with potentiometers to estimate loading forces without using any force sensor as well as to monitor current states of the excavator in the virtual environment. A test rig employing a pneumatic actuator was used in this study for investigating the proposed NBBM models

A study on wave energy harvesting using hydrostatic transmission

A pneumatic actuator is a device that is capable of converting energy from a pressurized gas into motion. While motion can be created through other means, such as a hydraulic or electric motor, pneumatic actuators are safer, cheaper, and cleaner. Therefore, pneumatic actuators have been used widely in the field of industry automation. However, the compressibility of air and the inherent non-linearity of pneumatic actuators cause challenges in controlling accurately position of pneumatic actuators. This paper presents an accurate non-linear back-box model (NBBM) for identifying the dynamic behavior of pneumatic actuators. Once the optimized NBBM of the pneumatic actuator is obtained, it can give a generation of an effective solution for designing a position controller of that. Here, the NBBM is a multi-player perceptron neural network (MLPNN), whose parameters are optimized by using the Lervenberg-Marquardt Back Propagation (LMBP) algorithm. For the model verification, a pneumatic actuator was set up to investigate the dynamics of it as well as to generate the training data. Next, the advanced NBBM for the pneumatic actuator is performed with suitable inputs to estimate the cylinder piston displacement. Finally, the NBBM ability is evaluated by a comparison of the estimated and real pneumatic actuator performance

Design of an advanced time delay measurement and a smart adaptive unequal interval grey predictor for real-time nonlinear control systems

This paper is a generation step for developing a novel control methodology based on a variable sampling period (VSP) approach to deal with nonlinear systems containing random delays. The proposed VSP is constructed from an advanced time delay measurement (TDM) method and a novel time delay prediction (TDP) method. The TDM is built to measure real working time of the controlled system, consequently observing a set of actual system delays. Next, the TDP is based on a so-called Smart Adaptive Unequal Interval Grey Model with single-variable first-order - SAUIGM(1,1) to forecast the system delay in the next working step for adjusting the sampling period in order to eliminate bad effects of time delays on the control performance. The SAUIGM(1,1) model was developed from the GM(1,1) model with four significant improvements. It can be easily applied to any practical prediction problem and achieve high prediction accuracy even in case of sparse or largely noisy data. Real-time delay measurements and predictions have been carried out with several examples to verify the proposed TDM and TDP methods. The results indicate that the designed TDM and TDP have strong potential to be applied to the suggested VSP methodology for nonlinear control systems

Theoretical investigation of a variable displacement vane-type oil pump

Variable displacement vane-type oil pumps represent one of the most innovative pump types for industrial applications, especially for engine lubrication systems. This article deals with a mathematical modeling method for theoretical performance investigation of a typical variable displacement vane-type oil pump. This theoretical model is based on the pump geometric design and dynamic analyses. It can be considered as a generation step for a deeper understanding of the pump operation as well as for effectively implementing the pump control mechanisms to satisfy the urgent demands of engine lubrication systems. The developed theoretical pump model is finally illustrated by numerical simulations