Optimum Experimental Design applied to MEMS accelerometer calibration for 9-parameter auto-calibration model

© 2015 IEEE. Optimum Experimental Design (OED) is an information gathering technique used to estimate parameters, which aims to minimize the variance of parameter estimation and prediction. In this paper, we further investigate an OED for MEMS accelerometer calibration of the 9-parameter auto-calibration model. Based on a linearized 9-parameter accelerometer model, we show the proposed OED is both G-optimal and rotatable, which are the desired properties for the calibration of wearable sensors for which only simple calibration devices are available. The experimental design is carried out with a newly developed wearable health monitoring device and desired experimental results have been achieved

Online auto-calibration of triaxial accelerometer with time-variant model structures

© 2017 Elsevier B.V. In this paper, an online auto-calibration method for MicroElectroMechanical Systems (MEMS) triaxial accelerometer (TA) is proposed, which can simultaneously identify the time-dependent model structure and its parameters during the changes of the operating environment. Firstly, the model as well as its associated cost function is linearized by a new proposed linearization approach. Then, exploiting an online sparse recursive least square (SPARLS) estimation, the unknown parameters are identified. In particular, the online sparse recursive method is based on an L1-norm penalized expectation-maximum (EM) algorithm, which can amend the model automatically by penalizing the insignificant parameters to zero. Furthermore, this method can reduce computational complexity and be implemented in a low-cost Micro-Controller-Unit (MCU). Based on the numerical analysis, it can be concluded that the proposed recursive algorithm can calculate the unknown parameters reliably and accurately for most MEMS triaxial accelerometers available in the market. Additionally, this method is experimentally validated by comparing the output estimations before and after calibration under various scenarios, which further confirms its feasibility and effectiveness for online TA calibration

Nonparametric dynamical model of cardiorespiratory responses at the onset and offset of treadmill exercises

© 2018, International Federation for Medical and Biological Engineering. This paper applies a nonparametric modelling method with kernel-based regularization to estimate the carbon dioxide production during jogging exercises. The kernel selection and regularization strategies have been discussed; several commonly used kernels are compared regarding the goodness-of-fit, sensitivity, and stability. Based on that, the most appropriate kernel is then selected for the construction of the regularization term. Both the onset and offset of the jogging exercises are investigated. We compare the identified nonparametric models, which include both impulse response models and step response models for the two periods, as well as the relationship between oxygen consumption and carbon dioxide production. The result statistically indicates that the steady-state gain of the carbon dioxide production in the onset of exercise is bigger than that in the offset while the response time of both onset and offset are similar. Compared with oxygen consumption, the response speed of carbon dioxide production is slightly slower in both onset and offset period while its steady-state gains are similar for both periods. The effectiveness of the kernel-based method for the dynamic modelling of cardiorespiratory response to exercise is also well demonstrated. [Figure not available: see fulltext.]

Antiproliferative activity of recombinant human interferon-λ2 expressed in stably transformed BmN cells

This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector pIZT/V5-His harboring the human IFN-λ2 gene. After the BmN cells were transfected with the pIZT/V5- His- hIFN-λ2 vector, the stably transformed BmN cells expressing hIFN-λ2 gene were selected using Zeocin. Following two months of screening, the transformed BmN cell line was obtained. Stable transformed BmN cell line can be maintained at a lower Zeocin concentration. The representing 26 kDa protein band of IFN-λ2 was detected by SDS-PAGE and Western blotting. The expression level of hIFN- λ2, determined by ELISA, was about 8.142 ng in 4 × 105 cells. The antiproliferative activity of hIFN-λ2 was determined by MTT assay. The 50% inhibitory concentrations (IC50) of the recombinant hIFN-λ2 on A549 (lung cancer cells), HL60 (acute promyelocytic leukemia cells), BEL-7402 (liver cancer cells) and M231 cells (breast cancer cells) were approximately 3.21, 2.84, 6.29 and 9.32 ng/ml, respectively. In summary, Human IFN-λ2 can be stably expressed in the transformed BmN cell line, and the expressed recombinant hIFN-λ2 demonstrated antiproliferative activity to tumor cells in vitro.Key words: Human interferon-λ2 protein, gene expression, antiproliferative activity

Feasibility study on a double chamber microbial fuel cell for nutrient recovery from municipal wastewater

© 2018 Elsevier B.V. Microbial fuel cell (MFC) is currently considered a promising technology for wastewater treatment. This study aims to evaluate the feasibility of a double-chamber MFC in terms of: (i) operating mode (batch mode, self-circulation mode, single-continuous mode) of anolyte on the nutrient accumulation in the catholyte, (ii) aeration conditions (anode effluent with aeration supplied in catholyte; anode effluent without aeration supplied in catholyte; cathode effluent with aeration supplied in catholyte and cathode effluent without aeration supplied in catholyte) on the nutrient recovery and (iii) types of separators (cation exchange membrane (CEM), forward osmosis (FO), and nonwoven (NW)) to remove nutrients toward their recovery from municipal wastewater. Results showed that there was no negligible increase in the phosphate concentration of the catholyte at the three different modes but accumulation of ammonium. At different aeration conditions, nutrients can be recovered by chemical precipitation at high pH generated by the MFC itself. Basically, phosphate was removed by microbial absorption and recovered by chemical precipitation while ammonium was accumulated by current generation and recovered as precipitates. It was found that double-chamber MFC with the CEM as the separator reported the best nutrients removal with >97.58% of NH4+-N and >94.9% of PO43−-P removed/recovered, followed by the MFC with the nonwoven and FO membrane, respectively. Thus, the double-chamber MFC is feasible for recovering nutrients in a comprehensive bioelectrochemical system

A critical review on ammonium recovery from wastewater for sustainable wastewater management

© 2018 Elsevier Ltd The growing global population's demand for ammonium has triggered an increase in its supply, given that ammonium plays a crucial role in fertilizer production for the purpose of food security. Currently, ammonia used in fertilizer production is put through what is known as the industrial Haber Bosch process, but this approach is substantially expensive and requires much energy. For this reason, looking for effective methods to recover ammonium is important for environmental sustainability. One of the greatest opportunities for ammonium recovery occurs in wastewater treatment plants due to wastewater containing a large quantity of ammonium ions. The comprehensively and critically review studies on ammonium recovery conducted, have the potential to be applied in current wastewater treatment operations. Technologies and their ammonium recovery mechanisms are included in this review. Furthermore the economic feasibility of such processes is analysed. Possible future directions for ammonium recovery from wastewater are suggested

Microbial fuel cell for nutrient recovery and electricity generation from municipal wastewater under different ammonium concentrations

© 2019 Elsevier Ltd In the present study, a dual-compartment microbial fuel cell (MFC) was constructed and continuously operated under different influent concentrations of ammonium-nitrogen (5–40 mg/L). The impacts of ammonium on organics removal, energy output and nutrient recovery were investigated. Experimental results demonstrated that this MFC reactor achieved a CDO removal efficiency of greater than 85%. Moreover, excess ammonium concentration in the feed solution compromises the generation of electricity. Simultaneously, the recovery rate of phosphate achieved in the MFC was insignificantly influenced at the wider influent ammonium concentration. In contrast, a high concentration of ammonium may not be beneficial for its recovery

Inertial sensor based post fall analysis for false alarming reduction

One of the major public health problems among elderly people is falling injury. This study investigates fall detection and prevention by using inertial sensors for which the major existing challenging is how to significantly reduce false alarming in order to enhance the acceptance of elderly users during rehabilitation and daily exercises. Different from most existing approaches in the literature, the behavior after falling will be analyzed in details, which can not only greatly reduce false alarming, but also significantly improves the accuracy of the assessment of the severity of falling injuries

Effect of organic loading rate on the recovery of nutrients and energy in a dual-chamber microbial fuel cell

© 2019 Elsevier Ltd This study aimed to assess the impacts of organic loading rate (OLR) (435–870 mgCOD/L·d) on nutrients recovery via a double-chamber microbial fuel cell (MFC) for treating domestic wastewater. Electricity generation was also explored at different OLRs, including power density and coulombic efficiency. Experimental results suggested the MFC could successfully treat municipal wastewater with over 90% of organics being removed at a wider range of OLR from 435 to 725 mgCOD/L·d. Besides, the maximum power density achieved in the MFC was 253.84 mW/m2 at the OLR of 435 mgCOD/L·d. Higher OLR may disrupt the recovery of PO43−-P and NH4+-N via the MFC. The same pattern was observed for the coulombic efficiency of the MFC and its highest value was 25.01% at the OLR of 435 mgCOD/L·d. It can be concluded that nutrients and electrical power can be simultaneously recovered from municipal wastewater via the dual-chamber MFC

Polymorphism of the pig-implantation protein 3 (preis3) gene and its association with litter size traits

The pre-implantation protein 3 (prei3), which might play a role in pre-implantation embryogenesis, is one of the promising candidate genes for litter size traits in pigs. In this study, a single nucleotide polymorphism (SNP: T802G) in intron 6 of the pig prei3 gene was detected and a genotyping assay for this SNP was developed. An association study for this SNP with litter size was performed in two independent populations. One population consisted of crossbred sows derived from Landrace, Large White, Chinese Tongcheng and/or Chinese Meishan (Line DIV). The other population constituted of crossbred animals derived from Chinese Qingping and Duroc (QD). Statistical analysis demonstrated that, in first parity, 2.65 more piglets were born and 3.82 more piglets were born alive in sows in Line DIV with genotype TT than with genotype GG. For second and subsequent litters, in both the DIV and QD lines there were significant differences in the number of piglets born alive between TG and GG sows, with the TG sows producing more piglets born alive than the GG sows. These results suggest that the prei3 SNP is significantly associated with litter size in the two populations studied, and could be useful in selection for increasing litter size in pigs. Further investigations on more pig populations with large sample sizes are needed to confirm this. South African Journal of Animal Science Vol. 36(3) 2006: 209-21