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1.
Sensors (Basel) ; 14(4): 7049-65, 2014 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-24759109

RESUMEN

Dempster-Shafer evidence theory (DSET) is a flexible and popular paradigm for multisource data fusion in wireless sensor networks (WSNs). This paper presents a novel and easy implementing method computing masses from the hundreds of pieces of data collected by a WSN. The transfer model is based on the Mahalanobis distance (MD), which is an effective method to measure the similarity between an object and a sample. Compared to the existing methods, the proposed method concerns the statistical features of the observed data and it is good at transferring multi-dimensional data to belief assignment correctly and effectively. The main processes of the proposed method, which include the calculation of the intersection classes of the power set and the algorithm mapping MDs to masses, are described in detail. Experimental results in transformer fault diagnosis show that the proposed method has a high accuracy in constructing masses from multidimensional data for DSET. Additionally, the results also prove that higher dimensional data brings higher accuracy in transferring data to mass.


Asunto(s)
Redes de Comunicación de Computadores , Modelos Teóricos , Tecnología Inalámbrica , Algoritmos , Gases/análisis
2.
Sensors (Basel) ; 14(6): 9562-81, 2014 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-24887039

RESUMEN

There is continuously increasing interest in research on multi-sensor data fusion technology. Because Dempster's rule of combination can be problematic when dealing with conflicting data, there are numerous issues that make data fusion a challenging task, including the exponential explosion, Zadeh Paradox, and one-vote veto. These issues lead to a great difference between the fusion results and real results. This paper applies the idea of analyzing distance-based evidence conflicts, introduces the concept of vector space, and proposes a new cosine theorem-based method of identifying and expressing conflicting data. In addition, this paper proposes a new data fusion algorithm based on the degree of mutual support between beliefs, which is based on the Jousselme distance-based combination rule proposed by Deng et al. Simulation results demonstrate that the presented algorithm achieves great improvements in both the accuracy of identifying conflicting data and that of fusing conflicting data.

3.
Gels ; 8(6)2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35735724

RESUMEN

Selective extraction of low-concentration thorium (Th(IV)) from wastewater is a very important research topic. In this paper, amidoxime cellulose was synthesized, and its composition and structure were characterized by FT-IR, SEM, XPS, and elemental analysis. The adsorption experiment results showed that the adsorption reaction was a spontaneous exothermic process. When the solid-liquid ratio was 0.12 g/L and the pH value was 3.5, the adsorption percentage of the Th(IV) in water onto amidoxime-functionalized cellulose (AO-CELL) could reach over 80%. The maximum adsorption capacity can reach to 450 mg/g. At the same time, the adsorption selectivity, desorption process and reusability of the material were also studied. The results showed that the AO-CELL had a good selectivity for Th(IV) in the system with Sr2+, Cu2+, Mg2+, Zn2+, Pb2+, Ni2+, and Co2+ as co-ions. In the nitric acid concentration of 0.06 mol/L system, the AO-CELL desorption rate of Th(IV) can reach 95%, and the adsorption rate of Th(IV) in aqueous solution of AO-CELL is still above 60% when the AO-CELL is reused four times. The above results show that the amidoxime cellulose adsorption material synthesized by our research group has good selective adsorption performance for Th(IV) of a low concentration in an aqueous solution and has a good practical application value.

4.
Chemosphere ; 292: 133401, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34953880

RESUMEN

Efficient and cost-effective removal of radioactive iodine anions from contaminated water has become a crucial task and a great challenge for waste treatment and environmental remediation. Herein, we present hexadecylpyridinium chloride monohydrate modified bentonite (HDPy-bent) for the efficient and selective removal of iodine anions (I- and IO3-) from contaminated water. Batch experiments showed that HDPy-bent could remove more than 95% of I- and IO3- within 10 min, and had maximum I- and IO3- adsorption capacities of 80.0 and 50.2 mg/g, respectively. Competitive experiments indicated that HDPy-bent exhibited excellent I- and IO3- selectivity in the excessive presence of common concomitant anions including PO43-, SO42-, HCO3-, NO3-, Cl- (maximum mole ratio of anions vs iodine anions was ∼50,000). An anion exchange mechanism was proposed for the selective adsorption of iodine anions. Optimal adsorption structure of HDPy+/I- (IO3-) at atomic level and driving forces of the I- (IO3-) adsorption were calculated by density functional theory (DFT) simulations. Moreover, the good durability and reusability of the HDPy-bent has been demonstrated with 5 adsorption-desorption cycles. Dynamic column experiment also demonstrated that HDPy-bent exhibited excellent removal and fractional recovery capabilities towards I- and IO3- from simulated groundwater and environmental water samples. In conclusion, this work presents a promising adsorbent material for the decontamination of radioactive iodine anions from wastewater on a large scale.


Asunto(s)
Neoplasias de la Tiroides , Contaminantes Químicos del Agua , Adsorción , Aniones , Bentonita , Humanos , Yoduros , Radioisótopos de Yodo , Modelos Teóricos , Aguas Residuales , Contaminantes Químicos del Agua/análisis
5.
Front Med (Lausanne) ; 9: 898650, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36330070

RESUMEN

Background and object: Heart failure is one of the common complications in patients with end-stage renal disease (ESRD) and a major cause of death in these patients. The choice of dialysis modality for ESRD patients with congestive heart failure (CHF) is still inconclusive. The purpose of this study was to compare the prognosis of hemodialysis (HD) and peritoneal dialysis (PD) among ESRD patients with CHF and provide a basis for clinical decision-making. Materials and methods: This was a retrospective study conducted at Guangdong Provincial Hospital of Traditional Chinese Medicine that included patients with CHF requiring long-term renal replacement therapy between January 1, 2012 and December 31, 2017. The end of follow-up was December 31, 2020. All patients were divided into HD and PD groups and sub grouped by age, and we used univariate and multifactorial Cox regression analyses to calculate the relative hazard ratios (HR) of the different dialysis types and adjusted for differences in baseline data using propensity score matching (PSM). Result: A total of 121 patients with PD and 156 patients with HD were included in this study. Among younger ESRD patients (≤65 years of age) with CHF, the prognosis of HD was worse than that of PD [HR = 1.84, 95% confidence interval (CI) = 1.01-3.34], and this disadvantage remained significant in the fully adjusted model [sex, age at dialysis initiation, Charlson comorbidities index, body mass index, prealbumin, hemoglobin, and left ventricular ejection fraction (LVEF)] and after PSM. In the older group (>65 years of age), the prognosis of HD was better than that of PD (HR = 0.46, 95% CI = 0.25-0.85), and the protective effect remained in the fully adjusted model and after PSM. The aforementioned survival differences across the cohort were maintained in patients with preserved LVEF (>55%), but could not be reproduced in patients with reduced LVEF (≤55%). Conclusion: In southern China, PD is a better choice for younger patients with ESRD, CHF and preserved LVEF, and HD is the better option for older patients.

8.
Sci Total Environ ; 737: 139705, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32783821

RESUMEN

Since the establishment of the world-class Three Gorges Dam (TGD) across the Yangtze River, China, the downstream reach has experienced a long-term adjustment with regard to the river morphology and hydrodynamics, imposing a profound impact on the environmental conditions of human living and aquatic ecosystem. This study presents an investigation on the river channel morphological characteristics and hydrodynamic environment of a large bifurcation-confluence complex downstream of the TGD through detailed field survey and numerical modeling. Results show that the main stem, before being bifurcated into two sub-channels (the North Channel and the South Channel), experiences a meander, leading to the severe bed scouring near the outer bank (pools) resulted from a high flow mass flux and bed shear stress. Because of being bifurcated, the river width with largely growing may result in the reduction of flow velocity and sediment deposition (riffles), and thereby two plugbars are formed near the entrance of two sub-channels. In the meantime, the velocity-reversal phenomenon (flow velocity and friction velocity) is identified when low flows are transited into high flows. The flow mass flux, however, is always larger in pool regions, which is highly related to water depth. As a result, the topographic steering of flows by riffles, bars and floodplains may have more impact on flow path under low flow conditions, while the bankline shape would become more important under high flows. Furthermore, the topographic steering could play a key role in the pattern of flow separations near the confluence. More interestingly, the confluence flow separation only occurs under low flow conditions and its occurring location shifts upwards the tributary (the North Channel), which differs from observations in previous studies. The visualized numerical results of friction velocity distribution indicate that sediment is more likely to deposit in the North Channel (entrance) with lower friction velocity, implying the potential closure of the sub-channel.

9.
Membranes (Basel) ; 10(10)2020 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-33096651

RESUMEN

Graphene oxide (GO) and its composite membranes have exhibited great potential for application in water purification and desalination. This article reports that a novel graphene oxide membrane (GOM) of ~5 µm thickness was fabricated onto a nylon membrane by vacuum filtration and cross-linked by amino acids (L-alanine, L-phenylalanine, and serine). The GOM cross-linked by amino acids (GOM-A) exhibits excellent stability, high water flux, and high rejection to metal ions. The rejection coefficients to alkali and alkaline earth metal ions through GOM-A were over 94% and 96%, respectively. The rejection coefficients decreased with an increasing H+ concentration. Metal ions (K+, Ca2+, and Fe3+) can be inserted into GOM-A layers, which enlarges the interlayer spacing of GOM-A and neutralizes the electronegativity of the membrane, resulting in the decease in the rejection coefficients to metal ions. Meanwhile, GOM-A showed quite high antibacterial efficiency against E. coli. With the excellent performance as described above, GOM-A could be used to purify and desalt water.

10.
J Biomol Struct Dyn ; 26(3): 293-300, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18808195

RESUMEN

Four novel water-soluble complexes of Ln(III) with gatifloxacin (HGA), [La(HGA)3Cl3] x 2H2O, [Nd(HGA)3Cl3] x 2H2O, [Eu(HGA)3Cl3] x 2H2O, [Tb(HGA)3Cl3] x 2H2O, have been synthesized and characterized by elemental analyses, molar conductivities, IR spectra, fluorescence spectra, and thermogravimetry/differential thermal analysis (TG-DTA). In addition, the DNA-binding properties of the ligand and its complexes have been investigated by absorption, fluorescence spectra, and viscosity measurements. The experimental results indicated that the complexes and ligand bind to DNA via groove binding mode.


Asunto(s)
Antiinfecciosos , ADN , Fluoroquinolonas , Lantano/química , Antiinfecciosos/química , Antiinfecciosos/metabolismo , ADN/química , ADN/metabolismo , Fluoroquinolonas/química , Fluoroquinolonas/metabolismo , Gatifloxacina , Estructura Molecular , Espectrometría de Fluorescencia , Viscosidad
11.
Artículo en Inglés | MEDLINE | ID: mdl-17919971

RESUMEN

(Z)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its solid rare earth complexes LnL3.2H2O (Ln=La, Eu, Tb) were synthesized and characterized by means of MS, elemental analysis, FTIR, 13C NMR and TG-DTA. The IR and 13C NMR results show that the carboxylic groups in the complexes coordinated to the rare earth ions in the form of a bidentate ligand, but the ester carboxylic groups have not taken part in the coordination. The luminescence spectra of Eu(III) and Tb(III) complexes in solid state were also studied. The strong luminescence emitting peaks at 616nm for Eu(III) and 547nm for Tb(III) can be observed, which could be attributed to the ligand has an enhanced effect to the luminescence intensity of the Eu and Tb.


Asunto(s)
Butiratos/síntesis química , Elementos de la Serie de los Lantanoides/química , Luminiscencia , Butiratos/química , Ligandos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Estructura Molecular , Éteres Fenílicos , Espectrometría de Fluorescencia , Espectrofotometría Infrarroja , Temperatura
12.
Polymers (Basel) ; 10(3)2018 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-30966271

RESUMEN

The ß-cyclodextrin-graft-(maleic anhydride-co-acrylonitrule) copolymer (ß-CD-g-(MAH-co-AN)) synthesized through radical polymerization reactions of ß-cyclodextrin (ß-CD) with maleic anhydride (MAH) and acrylonitrule (AN) in the special monomer proportion, chemically modify with amidoxime groups to obtained the new adsorbent, which was terms as amidoxime-functionalized ß-cyclodextrin-graft-(maleic anhydride-co-acrylonitrule) copolymer (ß-CD-g-(MAH-co-AO)). Based on the characteristic results of Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), X-ray Diffraction (XRD), and thermalgravity analysis (TGA) techniques, the grafted nitrile groups were successfully converted to amidoxime groups by reaction with hydroxylamine. In this report, the influence of different factors such as pH value and ionic strength, solid-liquid ratio, contact time, initial U(VI) concentration, and temperature on adsorption was investigated by a batch adsorption experiment. The adsorption process fitting results show that the adsorption followed the Langmuir isotherm model and the maximum adsorption capacity was 0.747 g/g at pH 4.0. In addition, the regeneration performance was investigated by varying the concentration of eluent, temperature, and contact time. Under the desorption condition of 0.10 M HNO3, the adsorbents can be reused 12 times in the case that the adsorption capacity was not significantly reduced. The functionalized copolymer exhibits high selectivity under circumstance of other co-existing ions is present in the solution.

13.
J Colloid Interface Sci ; 497: 385-392, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28301832

RESUMEN

A 2-picolylamine functionalized poly(styrene-co-maleic anhydride) resin was synthesized and characterized by FT-IR, elemental analysis, SEM and XPS. To recover uranium from aqueous solution, the influence factors such as pH values, contact time, temperature and initial uranium concentration were optimized. Adsorption kinetics fitted well with the pseudo-second-order model, whereas adsorption isotherm matched well with the Langmuir isothermal adsorption model, with the maximum sorption capacity of 518.39mgg-1 at pH 5.30 and 298K. The uptake of uranium could be implied in 0.01M coexisted ions environment. Besides, the resin could be regenerated by 0.1M HNO3 and repeatedly utilized in circles. The study proved that the resin has potential application prospects for disposal of uranium(VI).

14.
Polymers (Basel) ; 9(6)2017 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-30970880

RESUMEN

In this report, the ß-CD(AN-co-AA) hydrogel was used to remove the thorium(IV) [Th(IV)] from the water system, and the new adsorbent was characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The influences of contact time, pH value, ionic strength, solid-liquid ratio, initial Th(IV) concentration, and temperature on Th(IV) adsorption onto the functional hydrogel were researched. The results showed that the experimental data followed the Langmuir isotherm and the maximum adsorption capacity (qmax) for Th(IV) was 692 mg/g at pH 2.95, which approached the calculated (qe) 682 mg/g. The desorption capacity of Th(IV) in different HNO3 concentrations ranging from 0.005 to 0.5 M was also studied, and the percentage of the maximum desorption was 86.85% in the condition of 0.09 M HNO3. The selectivity of ß-CD(AN-co-AA) hydrogel was also be studied, the results indicated that this material retained the good adsorption capacity to Th(IV) even when the Ca2+, Mg2+, or Pb2+ existed in the system. The findings indicate that ß-CD(AN-co-AA) can be used as a new candidate for the enrichment and separation of Th(IV), or its analogue actinides, from large-volume solution in practical application.

15.
Artículo en Inglés | MEDLINE | ID: mdl-19758837

RESUMEN

2-((4-Methoxyphenoxy) carbonyl) benzoic acid, 2-(1-methoxyvinyl) benzoic acid and their rare earth complexes LnL(2)(OH).3H(2)O (Ln=La, Eu, Tb) were synthesized and characterized by means of elemental analysis, FTIR, (1)H NMR, UV and luminescence spectroscopy. The FTIR and (1)H NMR results show that the carboxylic groups in the complexes coordinated to the rare earth ions in the form of one dentate, and the ester carboxylic groups have taken part in the coordination. Among these complexes, Eu(III) complexes and Tb(III) complexes exhibit characteristic fluorescence with comparatively high brightness and good monochromaticity, which indicated that the ligands of HL(I) and HL(II) are good organic chromophore to absorb and transfer energy to metal ions.


Asunto(s)
Ácido Benzoico/síntesis química , Elementos de la Serie de los Lantanoides/síntesis química , Luminiscencia , Ácido Benzoico/química , Elementos de la Serie de los Lantanoides/química , Espectroscopía de Resonancia Magnética , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta
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