scholarly journals Unfixing the Frame: Visualizing Histories of Transcultural Contact, Exchange & Performance in Prince Roland Bonaparte’s Peaux-Rouges (1884)

2017 ◽  
Author(s):  
Emily L. Voelker
Keyword(s):  
Contact Exchange ◽  
Exchange Performance

Experimental research on scavenging process of opposed-piston two-stroke gasoline engine based on tracer gas method

2021 ◽  
pp. 146808742110366
Author(s):  
Fukang Ma ◽  
Wei Yang ◽  
Yifang Wang ◽  
Junfeng Xu ◽  
Yufeng Li
Keyword(s):  
Gas Exchange ◽  
Exchange Process ◽  
Delivery Ratio ◽  
Tracer Gas ◽  
Piston Motion ◽  
Trapped Air ◽  
Exchange Performance ◽  
Gdi Engine ◽  
Gas Exchange Process ◽  
Scavenging Efficiency

The scavenging process of two stroke engine includes free exhaust, scavenging, and post intake process, which clears the burned gas in cylinder and suctions the fresh air for next cycle. The gas exchange process of Opposed-Piston Two-Stroke (OP2S) engine with gasoline direct injection (GDI) engine is a uniflow scavenging method between intake port and exhaust port. In order to investigate the characteristics of the gas exchange process in OP2S-GDI engine, a specific tracer gas method (TGM) was developed and the experiments were carried out to analyze the gas exchange performance under different intake and exhaust conditions and opposed-piston movement rule. The results show that gas exchange performance and trapped gas mass are significantly influenced by intake pressure and exhaust pressure. And it has a positive effect on the scavenging efficiency and the trapped air mass. Scavenging efficiency and trapped air mass are almost independent of pressure drop when the delivery ratio exceeds 1.4. Consequently, the delivery ratio ranges from 0.5 to 1.4 is chosen to achieve an optimization of steady running and minimum pump loss. The opposed piston motion phase difference only affects the scavenging timing. Scavenging performance is mainly influenced by scavenging timing and scavenging duration. With the increased phase difference of piston motion, the scavenging efficiency and delivery ratio increased gradually, the trapping efficiency would increase first and decrease then and reaches its maximum at 14°CA.

scholarly journals Heat exchange performance optimization of a wheel loader cooling system based on computational fluid dynamic simulation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880398 ◽  
Author(s):  
Chao Yu ◽  
Sicheng Qin ◽  
Yang Liu ◽  
Bosen Chai
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Thermal Management ◽  
Cooling System ◽  
Management Model ◽  
Maximum Deviation ◽  
Engine Compartment ◽  
Wheel Loader ◽  
Exchange Performance ◽  
Transmission Oil

This study establishes a thermal management model to improve the heat exchange performance and uniformity of the flow-field distribution in the engine compartment of a wheel loader. Flow-field analyses are performed for an XG956 wheel loader in a virtual wind tunnel using the combined engine compartment thermal management model and computational fluid dynamics. The Fluent calculations revealed various problems. For example, the inlet flow rate at both sides of the engine compartment is small, which accounts for about 8.5% of the total flow, and the flow uniformity of radiator becomes worse with the increase in the air flow. The original cooling system is improved based on the simulation results and then verified by field testing. A comparison of the test data with the simulations indicates that the values obtained using the thermal management model of the engine compartment are largely in agreement with the experimental values, with a maximum deviation of the heat transfer rate at the rated speed of 5.1%. The research method presented in this article could further help to increase the productivity of the non-road mobile machinery cooling system and lower design costs. The temperature of pressurized air, hydraulic oil, transmission oil, and engine cooling fluid decreased by 22.5%, 8.7%, 2.2%, and 8.4% in the improved loader, respectively.

scholarly journals Alterations in Gas Exchange and Oxidative Metabolism in Rice Leaves Infected by Pyricularia oryzae are Attenuated by Silicon

2015 ◽  
Vol 105 (6) ◽  
pp. 738-747 ◽  
Author(s):  
Gisele Pereira Domiciano ◽  
Isaías Severino Cacique ◽  
Cecília Chagas Freitas ◽  
Marta Cristina Corsi Filippi ◽  
Fábio Murilo DaMatta ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Photochemical Efficiency ◽  
Pyricularia Oryzae ◽  
Gas Exchange Parameters ◽  
Photosynthetic Gas Exchange ◽  
Exchange Performance ◽  
Rice Leaves ◽  
Maximum Photochemical Efficiency ◽  
Important Disease ◽  
Exchange Parameters

Rice blast, caused by Pyricularia oryzae, is the most important disease in rice worldwide. This study investigated the effects of silicon (Si) on the photosynthetic gas exchange parameters (net CO2 assimilation rate [A], stomatal conductance to water vapor [gs], internal-to-ambient CO2 concentration ratio [Ci/Ca], and transpiration rate [E]); chlorophyll fluorescence a (Chla) parameters (maximum photochemical efficiency of photosystem II [Fv/Fm], photochemical [qP] and nonphotochemical [NPQ] quenching coefficients, and electron transport rate [ETR]); concentrations of pigments, malondialdehyde (MDA), and hydrogen peroxide (H2O2); and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and lypoxigenase (LOX) in rice leaves. Rice plants were grown in a nutrient solution containing 0 or 2 mM Si (−Si or +Si, respectively) with and without P. oryzae inoculation. Blast severity decreased with higher foliar Si concentration. The values of A, gs and E were generally higher for the +Si plants in comparison with the −Si plants upon P. oryzae infection. The Fv/Fm, qp, NPQ, and ETR were greater for the +Si plants relative to the −Si plants at 108 and 132 h after inoculation (hai). The values for qp and ETR were significantly higher for the –Si plants in comparison with the +Si plants at 36 hai, and the NPQ was significantly higher for the –Si plants in comparison with the +Si plants at 0 and 36 hai. The concentrations of Chla, Chlb, Chla+b, and carotenoids were significantly greater in the +Si plants relative to the –Si plants. For the –Si plants, the MDA and H2O2 concentrations were significantly higher than those in the +Si plants. The LOX activity was significantly higher in the +Si plants than in the –Si plants. The SOD and GR activities were significantly higher for the –Si plants than in the +Si plants. The CAT and APX activities were significantly higher in the +Si plants than in the –Si plants. The supply of Si contributed to a decrease in blast severity, improved the gas exchange performance, and caused less dysfunction at the photochemical level.

Li4Mn5O12 Lithium Ion Sieve Preparation and Adsorption Properties

2014 ◽  
Vol 1004-1005 ◽  
pp. 670-674 ◽  
Author(s):  
Dian Quan Dong ◽  
Hong Bo Dai ◽  
Jian Guo Zheng
Keyword(s):  
High Selectivity ◽  
Colloidal Crystal ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Precursor Solution ◽  
Exchange Capacity ◽  
Average Pore ◽  
Exchange Performance ◽  
Roasting Condition

Polystyrene microspheres with 120nm diameter were synthesized by emulsion polymerization and three-dimensionally ordered colloidal crystal templates were obtained by centrifugal sedimentation.Three dimensionally ordered nanopore (3DON) manganese oxide lithium ion-sieve was prepared after filtration, two heated roasting and acid modified by using precursor solution filling the colloidal crystal templates, which was prepared by Lithium salt, manganese salt and citric acid. SEM, XRD, and saturated exchange capacity test were used to characterize the roasting condition, appearance, structure, and ion exchange performance of the oxide. The results showed that, the optimum roasting condition of preparing lithium ion-sieve precursors were found as follows: heating rate at 2°C/min, 300 °C roasting 4h and 800 °C roasting 8h, The 3DON Li4Mn5O12lithium ion sieve precursor has the shape of three-dimensional cross-linked connected into the network structure. Li4Mn5O12was regularly arranged and the hole wall was integrity,average pore size of approximately 90nm.3DON Li4Mn5O12 showed good stability for acid and the retrofit of lithium ion-sieve showed a high selectivity for Li+. The saturated exchange capacity of Li+is 51.98mgLi+/g.

scholarly journals Mexican Stock Exchange Performance after the Crisis of 2008: Application of Data Mining

2020 ◽  
Vol 18 ((1)) ◽  
Author(s):  
Eliseo Ramírez Reyes ◽  
Arturo Morales Castro ◽  
Néstor Juan Sanabria Landazábal
Keyword(s):  
Neural Networks ◽  
Default Risk ◽  
Regression Models ◽  
Prediction Models ◽  
Stock Exchange ◽  
Sovereign Default ◽  
Linear Regression Models ◽  
Exchange Performance ◽  
Sovereign Default Risk ◽  
Dow Jones Industrial Average

Different prediction models are explored to analyze the performance of the Mexican Stock Exchange (PQI) after the 2008 crisis. These models have demonstrated a good prognostic capacity for both multivariable and univariable approaches given their non-parametric characteristics. The selected variables were: Dow Jones Industrial Average Index (DJIA), CPI, International Reserves (IR), CETES28, USDMX exchange rate, (M1) and the sovereign default risk of Mexico (MRDS). The models were evaluated with MAPE and compared with linear regression models (LR) and neural networks (NN). The results show that the models have a similar performance according to the percentages of error they presented.

scholarly journals The Effect of Gamma Irradiation on the Physiochemical Properties of Caesium-Selective Ammonium Phosphomolybdate-Polyacrylonitrile (AMP-PAN) Composites

2019 ◽  
Author(s):  
Alistair Holdsworth ◽  
Harry Eccles ◽  
daniel rowbotham ◽  
Adam Brookfield ◽  
David Collison ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Gamma Irradiation ◽  
Fuel Cycle ◽  
Radioactive Isotopes ◽  
Limited Attention ◽  
Spent Fuel ◽  
Physiochemical Properties ◽  
Exchange Performance ◽  
Effects Of Radiation ◽  
By Products

Managing certain by-products of the nuclear fuel cycle, such as the radioactive isotopes of caesium: Cs-134, Cs-135 and Cs-137 is challenging due to their environmental mobility and radioactivity. While a great many materials can isolate Cs<sup>+</sup> ions from neutral or basic aqueous solutions via ion exchange, few of these, with the exception of ammonium phosphomolybdate (AMP), function effectively in acidic media. The use of AMP, and its porous composite in polyacrylonitrile (PAN) for management of Cs radioisotopes in various nuclear wastes have been known for decades and are well studied, yet the effects of radiation on the physiochemical properties of such composites have only received limited attention to date. In a previous publication, we demonstrated that a 100 kGy gamma irradiation dose has negligible effect on the ion exchange performance of AMP and AMP-PAN with respect to capacity or kinetics under the Cs<sup>+</sup> concentrations and acidity found in spent fuel recycling. As a continuation of this prior study, in this publication we explore the effects of gamma irradiation on the physiochemical properties of AMP and AMP-PAN using a range of characterisation methods. The effects of the same gamma dose on the oxidation state of Mo in AMP and AMP-PAN, the thermal degradation of both AMP and AMP-PAN, combined with a first study into the high-temperature degradation AMP, are reported. The implications of irradiation, its possible mechanism, the conditions present in SNF recycling, and for the end-of-life disposal or recycling of these materials are also discussed.

scholarly journals Media Exchange Performance Test Using the Bradford Assay in an Automated Bioreactor Engineering Model for Space Experiments

2018 ◽  
Vol 24 (2) ◽  
pp. 222-232
Author(s):  
Jong-Won Lee ◽  
Kyoung-Bong Ha ◽  
Youn-Kyu Kim ◽  
Joo-Hee Lee ◽  
In-Ho Choi ◽  
...  
Keyword(s):  
Exchange Rate ◽  
Human Body ◽  
Performance Test ◽  
Performance Testing ◽  
Space Environment ◽  
Engineering Model ◽  
Exchange Performance ◽  
Space Experiments ◽  
The Media ◽  
Bradford Assay

Life science research has been actively carried out in space for a long time using bioreactor equipment, in anticipation of manned space exploration and space tourism. Such studies have reported that the microgravity environment has a negative effect on the human body, including the musculoskeletal system, nervous system, and endocrine system. Bone loss and muscular atrophy are issues that need to be resolved before long-term exposure of the human body to a space environment. To address this problem, Y. K. Kim et al. designed a system in 2015 and performed an evaluation of an automated bioreactor development model (DM) for space experiments. In this study, we developed an automated bioreactor engineering model (EM) based on the previous literature, and conducted media exchange performance testing using the Bradford assay. We used a novel method that allowed quantitative assessment of the media exchange rate versus the conventional assessment method using visual observation with a camera. By measuring the media exchange rate of the automated bioreactor EM, we attempted to verify applicability for the system for space experiments. We expect that the experimental method proposed in this study is useful for logical determination of liquid exchange or circulation in different closed systems.

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