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11.
Gizem Yanalak Abdalaziz Aljabour Emre Aslan Faruk Ozel Imren Hatay Patir 《International Journal of Hydrogen Energy》2018,43(36):17185-17194
The efficiencies of a series of hydrogen evolving catalysts based on metal oxide nanofibers (NiO, Co3O4, Mn3O4) are investigated for the photocatalytic hydrogen evolution from water without using any co-catalyst under the visible light irradiation by using triethanolamine (TEOA) as an electron donor and Eosin-Y (EY) dye as a photosensitizer. It is found that the photocatalytic hydrogen evolution activities follow the order as: Mn3O4<Co3O4<NiO (196 μmolg?1h?1, 5552 μmolg?1h?1, 7757 μmolg?1h?1, respectively). Moreover, the catalytic behavior of these nanofibers on the hydrogen production has been also compared to bulk forms of NiO, Co3O4 and Mn3O4 by producing hydrogen 937 μmolg?1h?1, 901 μmolg?1h?1 and 135 μmolg?1h?1, respectively. The nanofiber structures demonstrated much higher photocatalytic activity than bulk forms due to the effect of the increased surface to volume ratio deduced from the fibrous character. The photocatalytic plausible pathway for the hydrogen production is also discussed. 相似文献
12.
Ramazan Gürkan Halil brahim Ulusoy Mehmet Akay Pinar Bulut Ramazan Gurkan Halil ibrahim Ulusoy Mehmet Akcay Pmar Bulut 《稀有金属(英文版)》2011,30(5):477-487
A novel catalytic kinetic method is proposed for the determination of Se(IV), Se(VI), and total inorganic selenium in water
based on the catalytic effect of Se(IV) on the reduction of Celestine blue by sodium sulfide at pH 7.0 phosphate buffer. The
fixed-time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the
two calibration graphs are linear with a good correlation coefficient in the range 2–20 and 20–200 μg·L−1 of Se(IV) for the fixed-time method at 30°C. The experimental and theoretical detection limits of the developed kinetic method
were found to be 0.21 and 2.50 μg·L−1 for the fixed-time method (3 min). All of the variables that affect the sensitivity at 645 nm were investigated, and the
optimum conditions were established. The interference effect of various cations and anions on the Se(IV) determination was
also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange
resin such as Amberlite IR120 plus as long as chelating agents of thiourea and thiosulphate. The proposed kinetic method was
validated statistically and through recovery studies in natural water samples. The relative standard deviations (RSDs) for
ten replicate measurements of 2, 10, and 20 μg·L−1 of Se(IV) change between 0.35% and 5.58%, while the RSDs for ten replicate measurements of 3, 6, and 12 μg·L−1 of Se(VI) change between 0.49% and 1.61%. Analyses of a certified standard reference material (NIST SRM 1643e) for selenium
using the fixed-time method showed that the proposed kinetic method has good accuracy. The Se(IV), Se(VI), and total inorganic
selenium in lake and river water samples have been successfully determined by this method after selective reduction of Se(VI)
to Se(IV). 相似文献
13.
Critical assessment of extracellular polymeric substances extraction methods from mixed culture biomass 总被引:3,自引:0,他引:3
Extracellular polymeric substances (EPS) have a presumed determinant role in the structure, architecture, strength, filterability, and settling behaviour of microbial solids in biological wastewater treatment processes. Consequently, numerous EPS extraction protocols have recently been published that aim to optimize the trade off between high EPS recovery and low cell lysis. Despite extensive efforts, the obtained results are often contradictory, even when analysing similar biomass samples and using similar experimental conditions, which greatly complicates the selection of an extraction protocol. This study presents a rigorous and critical assessment of existing physical and chemical EPS extraction methods applied to mixed-culture biomass samples (nitrifying, nitritation-anammox, and activated sludge biomass). A novel fluorescence-based method was developed and calibrated to quantify the lysis potential of different EPS extraction protocols. We concluded that commonly used methods to assess cell lysis (DNA concentrations or G6PDH activities in EPS extracts) do not correlate with cell viability. Furthermore, we discovered that the presence of certain chemicals in EPS extracts results in severe underestimation of protein and carbohydrate concentrations by using standard analytical methods. Keeping both maximum EPS extraction yields and minimal biomass lysis as criteria, it was identified a sonication-based extraction method as the best to determine and compare tightly-bound EPS fractions in different biomass samples. Protein was consistently the main EPS component in all analysed samples. However, EPS from nitrifying enrichments was richer in DNA, the activated sludge EPS had a higher content in humic acids and carbohydrates, and the nitritation-anammox EPS, while similar in composition to the nitrifier EPS, had a lower fraction of hydrophobic biopolymers. In general, the easily-extractable EPS fraction was more abundant in carbohydrates and humic substances, while DNA could only be found in tightly bound EPS fractions. In conclusion, the methodology presented herein supports the rational selection of analytical tools and EPS extraction protocols in further EPS characterization studies. 相似文献
14.
Umit Bulut Angeliki Menegaki 《Energy Sources, Part B: Economics, Planning, and Policy》2020,15(5):297-310
ABSTRACT This paper investigates the relationship between solar energy production and economic growth for top 10 countries with the highest installed solar energy production capacity as of 2017 (China, the USA, Japan, Germany, Italy, India, the UK, France, Australia, and Spain, respectively) using data over the period 1999–2015. For this purpose, the paper employs panel cointegration and causality methods that are robust to cross-sectional dependence. The findings imply that the coefficient of solar energy is insignificant in the empirical model and that there is no causality between solar energy and GDP, indicating the neutrality hypothesis prevails for solar energy. Theoretical and practical implications are also discussed. 相似文献
15.
Sleep scheduling, which is putting some sensor nodes into sleep mode without harming network functionality, is a common method
to reduce energy consumption in dense wireless sensor networks. This paper proposes a distributed and energy efficient sleep
scheduling and routing scheme that can be used to extend the lifetime of a sensor network while maintaining a user defined
coverage and connectivity. The scheme can activate and deactivate the three basic units of a sensor node (sensing, processing,
and communication units) independently. The paper also provides a probabilistic method to estimate how much the sensing area
of a node is covered by other active nodes in its neighborhood. The method is utilized by the proposed scheduling and routing
scheme to reduce the control message overhead while deciding the next modes (full-active, semi-active, inactive/sleeping)
of sensor nodes. We evaluated our estimation method and scheduling scheme via simulation experiments and compared our scheme
also with another scheme. The results validate our probabilistic method for coverage estimation and show that our sleep scheduling
and routing scheme can significantly increase the network lifetime while keeping the message complexity low and preserving
both connectivity and coverage. 相似文献
16.
Opar Ekin Alpakut Gizem Parlatan Uğur Yavaş Seydi Yüksel Bahar Ünlü M. Burçin Buyru H. Faruk Baştu Ercan Ferhanoğlu Onur 《Instruments and Experimental Techniques》2022,65(3):444-451
Instruments and Experimental Techniques - With its elongated depth of focus, Bessel beams offer rapid and high aspect ratio ablation capability, in contrast to Gaussian beam counterparts. In this... 相似文献
17.
In a training center, 1,131 inguinal hernias were repaired in 1,000 consecutive patients in 6 years. The documents of these patients were reviewed retrospectively for surgical complications. A total of 38 complications were encountered in 35 patients, including wound infection (1.9%), recurrence (0.9%), tethered testis (0.3%), bladder injury (0.3%), was deferens injury (0.2%), iatrogenic orchiectomy (0.1%), and postoperative death. Most of them occurred in the early years of the clinic, and nearly one-half were technical in nature. Careful training, stressing the importance of gentle handling of the tissues, and meticulous dissection with emphasis on learning groin anatomy should reduce the incidence of such complications. 相似文献
18.
Focusing on a process where a designer embeds herself in craftspeople’s workshops with the intention of ‘learning from inside’ and ‘making together’; this paper proposes pathways for considering collaboration between designers and craftspeople via digital fabrication and weaving. The tension of forces that make weaving possible, act as an analogy for this collaboration as well as providing the title of the project as ‘One Over, One Under’. The project proposes a mode of working and a spectrum of outcomes where the designer has a first-hand experience of production techniques, engages in a serious and continuous dialogue through making, and develops an intervention that also brings forth her own skill set (introducing digital fabrication and structural variations), thus transforming the conventions and boundaries between established roles and manufacturing techniques. An experiment that resulted in a series of objects considering both the technologies of production and the input of the designer, this process not only increases the potentials that crafts hold for the field of design, but it also offers possibilities of collaboration and a further articulation of the design act. 相似文献
19.
Engineering with Computers - In this study, we established a wavelet method, based on Haar wavelets and finite difference scheme for two-dimensional time fractional reaction–subdiffusion... 相似文献
20.
Neural Computing and Applications - In this paper, we establish exact solutions of coupled Higgs equation and Nizhnik-Novikov-Veselov (NNV) system. We apply generalized Kudryashov method (GKM) to... 相似文献