scholarly journals Accuracy Improvement of the 14C Method Applied in Biomass and Coal Co-Firing Power Stations

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 994
Author(s):  
Yuxing Tang ◽  
Zhongyang Luo ◽  
Chunjiang Yu

The 14C method is an approach used to determine the proportion of carbon derived from biomass and fossil fuel in the co-fired flue gas. Its accuracy is mainly limited by the deviations between the applied biomass fuels’ 14C activity reference value and virtual value. To enrich the theoretical basis of the 14C method when applied to a Chinese biomass and coal co-firing power station, this study performed field sampling experiments and established a new evaluation method based on domestic literature. Unlike previous studies, this study revealed that the 14C activity of biomass far away from fossil carbon sources was 0.7–1.3 pMC lower than the local atmosphere. The 14C activity laws between tree rings and barks, specifically between eucalyptus bark and poplar bark were different, due to different growth models and different bark regeneration cycles, respectively. According to the test results and renewal conclusions, this study proposed a reasonable idea for constructing the prediction equation of referential biomass fuels’ 14C activity. Following this equation, the biomass fuels’ 14C activities of biomass direct-fired power stations at different Chinese cities were obtained.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun Zhao ◽  
Xumei Chen

An intelligent evaluation method is presented to analyze the competitiveness of airlines. From the perspective of safety, service, and normality, we establish the competitiveness indexes of traffic rights and the standard sample base. The self-organizing mapping (SOM) neural network is utilized to self-organize and self-learn the samples in the state of no supervision and prior knowledge. The training steps of high convergence speed and high clustering accuracy are determined based on the multistep setting. The typical airlines index data are utilized to verify the effect of the self-organizing mapping neural network on the airline competitiveness analysis. The simulation results show that the self-organizing mapping neural network can accurately and effectively classify and evaluate the competitiveness of airlines, and the results have important reference value for the allocation of traffic rights resources.


Author(s):  
Shigeru Takaya ◽  
Yuji Nagae ◽  
Tai Asayama

This paper describes a creep–fatigue evaluation method for modified 9Cr–1Mo steel, which has been newly included in the 2012 edition of the JSME code for design and construction of fast reactors. In this method, creep and fatigue damages are evaluated on the basis of Miner’s rule and the time fraction rule, respectively, and the linear summation rule is employed as the failure criterion. Investigations using material test results are conducted, which show that the time fraction approach can conservatively predict failure life if margins on the initial stress of relaxation and the stress relaxation rate are embedded. In addition, the conservatism of prediction tends to increase with time to failure. Comparison with the modified ductility exhaustion method, which is known to have good failure life predictability in material test results, shows that the time fraction approach predicts failure lives to be shorter in long-term strain hold conditions, where material test data is hardly obtained. These results confirm that the creep–fatigue evaluation method in the code has implicit conservatism.


2020 ◽  
Vol 27 (3) ◽  
pp. 228-235
Author(s):  
Rafael Santiago Floriano ◽  
Alexandre Fenley ◽  
Daniel Sobral Teixeira ◽  
Leonardo da Costa Silva ◽  
Hugo Valverde Reis ◽  
...  

ABSTRACT Cardiopulmonary exercise testing (CPX) is a noninvasive method for assessing physiological changes during physical exercise. Functional capacity has been evaluated using prediction equations. However, this evaluation method may yield different outcomes when applied to a healthy male population and patients with chronic heart failure (HF). This study aimed to compare the estimated and obtained values of oxygen consumption (VO2) during CPX both at the ventilatory anaerobic threshold (VAT) and at peak exercise for healthy men and HF patients. For that, 56 men were divided into 3 groups: (1) 18 young and healthy (YG) (27±6.01 years); (2) 14 healthy older adults (OG) (61±6.3 years); and (3) 24 chronic HF patients (HFG) (53±13.6 years). CPX in cycle ergometer was administered to all individuals for determining VO2 at the VAT and peak exercise. Then, VO2 was estimated at the two moments using a prediction equation, and estimated values were compared to those obtained. Estimated VO2 was significantly higher than obtained VO2 in OG (16.9±1.8 vs. 13.1±2.1mL/kg/min) and HFG (12±6.9 vs. 8.7±2.5mL/kg/min). We found no difference between estimated and obtained VO2 for the YG (22,6±5,5 vs. 23,1±8,7mL/kg/min). The prediction equation overestimated VO2 values for older adults and HF patients. However, the YG obtained similar values than those estimated.


2013 ◽  
Vol 785-786 ◽  
pp. 191-198
Author(s):  
Li Jun Li ◽  
Feng Li ◽  
Ze Jiang Zhang

Different flame retardant contents of polyurethane rigid foam (PRF) were prepared in this paper. Combustion performances of PRF were tested by cone calorimeter (CONE). Fire risk of PRF was evaluated based on Analytic Hierarchy Process (AHP). The evaluation results were compared with the traditional LOI results. It was found that the evaluation method based on AHP combined with CONE test results for evaluating fire hazard of thermal insulation material for exterior walls of buildings is more accurate and objective compared with the method of the traditional LOI.


Radiocarbon ◽  
2019 ◽  
Vol 61 (5) ◽  
pp. 1229-1238
Author(s):  
C Matthias Hüls ◽  
Ingo Petri ◽  
Helmut Föll

ABSTRACTLuristan Iron Mask Swords have been recovered mostly from illegal diggings in the 1920s. The about 90 known objects are characterized by a disk-shaped pommel on the top of the handle with two mounted bearded heads on two sides. According to the similarity in form and radiocarbon (14C) measurements on two swords from museum collections, an overall short production period was assumed around 1000 BC (Moorey 1991; Rehder 1991). Here we present the results of metallurgical analysis and 14C measurements for three newly acquired Luristan swords, which were donated to the Royal Museums of Art & History, Brussels. Metallurgical analysis indicates an iron production via the bloomary furnace technique. Analyzed samples show large slag inclusions (Fayalite, Wüstite, glass) within a mostly ferritic and pearlitic iron. The carbon contents varied between 0.2 wt% to around 0.8 wt%). 14C measurements on thermally extracted carbon give 14C ages between 2800 BP–3360 BP (calibrated ∼1745 BC–900 BC). The reliability of the 14C measurements are discussed with respect to external (contamination during handling) and intrinsic contamination (e.g. fossil carbon sources during manufacture).


2011 ◽  
Vol 138-139 ◽  
pp. 962-966 ◽  
Author(s):  
Kai Liu ◽  
Li Xu

Experimental study on combustor outlet temperature field of heavy-duty gas turbine had been finished on high-pressure test system. Experimental results indicate: The OTDF is sensitive to diameter of dilution holes, and the RTDF is sensitive to location of dilution holes. The test results have important guiding significance and reference value to design, commission and working about the similar combustor.


Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2120
Author(s):  
Chang-Pyo Chung ◽  
Su-Young Choi ◽  
Dong-Bum Kim ◽  
Wan-Goo Park ◽  
Byoung-Il Kim ◽  
...  

Sheet-coated composite waterproofing (SCCW) have been developed to overcome the natural weakness of singly-ply coating or sheet waterproofing systems for roofing, but there are currently multiple types of SCCW joints. Conventional standard tensile strength testing results show that all SCCW joint types seem to pass the minimum requirement and current selection of SCCW type is dictated on the principle of ‘higher tensile strength is better’, but it has not been experimentally studied as to which type is the optimal to respond to environmental degradation while under the effect of zero-span tensile stress occurring during concrete joint displacement. In this study, five types of SCCW joints were tested: Overlap Bond (OB) type, Overlap Heated-Air Welding (OH) type, Butt Joint I Type (BI), Butt Joint T Type (BT), and Butt Joint Separation Movement Type (BS). These types of joint designs were subjected to Alkali, NaCl, and H2SO4 exposure, and temperature change (60 °C and −20 °C) for determining changes to tensile strength in the joint section. Tensile strength change results are compared to joint displacement resistance test results of specimens that were treated with chemical and temperature degradation. With the exception of chemical exposure conditioning, the Overlap type joints generally had higher tensile strength compared to the butt joint types, but joint displacement test results showed the opposite results, suggesting that complex joints found in SCCW require new evaluation method for quality assessment.


2013 ◽  
Vol 11 ◽  
pp. 177-182
Author(s):  
S. Miropolsky ◽  
S. Frei

Abstract. Many investigations have been published on the transferability of RF immunity test results between system and IC-levels. The RF signal level at DUT (Device under Test) inputs, i.e. either RF voltage amplitude or RF input current, is used as a reference value for the load on the DUT. Existing approaches analyze the DUT response as a function of the RF signal level at a single input pin, e.g. supply voltage. Sufficient accuracy of such an approach could be shown in several cases, but results are not sufficient as a general solution for complex DUT. This paper proposes both theoretical analysis and practical implementation of a DPI setup, where a disturbance, equivalent to system-level BCI setup, can be delivered to multiple DUT input ports.


2014 ◽  
Vol 584-586 ◽  
pp. 1192-1196
Author(s):  
Xiao Wen Liu ◽  
Xiao Yan Chen

Through lots of triaxial and a single-line wetting path experiments for slaking deformation of the remolded laterite , behaviors of stress-strain and volumetric strain-axial strain are studied at different level values of wetting stress.The test results indicate that the modulus of deformation and the strength of samples are reduced by wetting, that the value of wetting deformation is relation to the stress state and that the logarithmic relationship between wetting axial strain of the type of laterite and wetting stress levels meets . The test results obtained have an important reference value for actual projects in Jiangxi laterite area.


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