25 research outputs found
Detailed modeling of the effects of K/Na additives on the thermal DeNO(x) process
No full textA reduced mechanism simplified from a detailed chemical kinetics mechanism containing N/H/O/K/Na elements was developed and validated in this paper. When the reduced mechanism was integrated into computational fluid dynamics (CFD) software, the effect of potassium and sodium additives on the selective non-catalytic reduction (SNCR) thermal DeNO(x) process was simulated. The simulation results were compared to those of experiments under different oxygen concentrations, normalized stoichiometric ratios (NSRs) of the N agent/NO, and alkali metal additive concentrations within the temperature range from 1023 to 1523 K, and the simulation results coincided qualitatively with those of the experiment in an entrained flow reactor. The alkali metal additives did not change the effects of the oxygen concentration and NSR on the SNCR process: a conversion temperature point exists at about 1173-1223 K; below the conversion temperature point, a higher oxygen concentration can promote the effect of SNCR, while above the conversion temperature point, the efficiency will be reduced; and a higher NSR is beneficial for NO reduction, but its effect becomes less obvious with the increase of the reducing agent. The alkali metal additives extend the "temperature window" toward a lower temperature by about 50-100 K with more OH and NH2 radical production, and the effect of K additives is less obvious than that of Na. However, the promoting effect of the K additive cannot be well-simulated because of the lack of a suitable mechanism. A K chemistry mechanism should be optimized on the basis of its effect on the SNCR process. The K or Na concentration almost has no influence on the effect of alkali metal additives on the thermal DeNO(x) process when the K or Na concentration is beyond a certain value
Pengaruh Penggunaan Variasi Jenis Busi Dan Variasi Bahan Bakar Terhadap Emisi Gas Buang HC, CO, CO2 Dan O2 Pada Sepeda Motor Honda Beat FI Tahun 2016
No full textThe purpose of this research are (1) Knowing and obtaining the results of the investigation of the effect of variations in spark plug types on exhaust emissions of HC, CO, CO2 and O2 on Beat FI 2016 motorbikes (2) Knowing and obtaining the results of investigating the effect of variations in fuel on exhaust emissions HC, CO, CO2 and O2 on Beat FI 2016 motorbikes (3) Knowing and obtaining the results of the investigation of the effect of spark plug types and fuel variations on exhaust emissions of HC, CO, CO2 and O2 on Beat FI 2016 motorbikesThis research uses descriptive quantitative research with experimental research methods. Measurement of exhaust emissions in accordance with SNI 09-7118.3-2005. The population in this study was a Honda Beat FI motorcycle. The sample in this study was a Honda Beat FI motorbike in 2016. The data collection technique was using purposive sampling. The research was conducted at Dishubkominfo Surakarta city using the gaz analyzer technotest.Results of this research is (1) The use of a combination of pertalite fuels and iridium plugs generates the lowest HC rate of 118.67 ppm or a decrease of 32.58% (2) The use of pertalite fuel with platinum plugs decreases by producing the lowest CO rate of 0.487% or decrease 3.31% (3) pertamax fuel with standard plugs resulted in the lowest CO2 exhaust emission of 10.5% with a difference of 2.27 or decrease 17.75% (4) use of pertalite fuel with standard plugs capable of producing O2 exhaust gas emissions of 1.057% or the lowest
Effects after starting or switching from bisphosphonate to romosozumab or denosumab in Japanese postmenopausal patients
No full textPurpose We aimed to investigate the longitudinal changes in bone metabolic markers and bone mineral density (BMD) after starting or switching from bisphosphonate (BP) to romosozumab (ROMO) or denosumab (DENO) therapies over 12 months and to determine predictors that establish associations with changes in BMD among the patients received the ROMO therapy. Methods Postmenopausal osteoporosis patients with a high risk of fracture-154 in total-were recruited; their therapies were switched to ROMO or DENO from BP/naive or vitamin D (ND) (ND-ROMO: 43, BP-ROMO: 38, ND-DENO: 38, and BP-DENO: 35). Longitudinal changes in bone metabolic markers and BMD were evaluated. Results ROMO groups showed significant increases in BMD of the lumbar spine at 6 and 12 months and femoral neck at 12 months compared to the DENO groups. Although BP-ROMO showed significant increase in the lumbar spine BMD compared to BP-DENO, there were no significant differences in femoral neck and total hip BMDs between BP-ROMO and BP-DENO. Among the ROMO groups, % changes of BMD from baseline to 12 months were associated with bone metabolic markers at baseline and changes in TRACP-5b from baseline to 3 months. Conclusions ROMO continuously increased BMD for 12 months and performed better than DENO. On the other hand, effects of ROMO switched from BP on BMD of femoral neck and total hip were almost same with DENO. Bone metabolic markers at baseline and changes in TRACP-5b from baseline to 3 months may predict the efficacy of ROMO after 12 months of administration
Comparison of server runtime environments
No full textRad obrađuje razvojno okruženje „Deno“ koji se smatra novom verzijom vrlo popularnog „Node.js“ okruženja. Teorijska usporedba ističe nedostatke „Node.js-a“ od strane brojnih korisnika, ali i od samog autora „Node.js-a“ koji predstavlja novi alat „Deno“. „Deno“, prema autoru, pokriva sve nedostatke. Temeljne razlike između ovih alata obrađene su i u praktičnom dijelu rada gdje se kroz kodiranje jednostavnih aplikacija prikazuju različiti pristupi koje ova okruženja imaju. Isto tako rad sa alatom „Deno“ pobliže je opisan kroz izradu serverske strane 'To do' aplikacije (aplikacije popisa obaveza) gdje je pokazan rad „Deno-a“ sa „NoSQL“ bazom „MongoDB“.This graduation thesis deals with the “Deno” development environment, which is considered a new version of the very popular “Node.js” environment. The theoretical comparison highlights the shortcomings of “Node.js” from the side of numerous users, but also from the author of “Node.js” himself, who presents the new “Deno” tool. “Deno”, according to the author, covers all the shortcomings. The fundamental differences between these tools are also covered in the practical part of the work, where the different approaches that these environments have are shown through the coding of simple applications. Likewise, the work with the “Deno” tool is described in more detail through the creation of the backend of the 'To do' application (to-do list application), where the work of “Deno” with the “NoSQL” database “MongoDB” is shown
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JNDS, Volume 14, Number 2
No full textArticle discussing "dark matter," the discovery of which may provide the key to an age-old mystery concerning the nature of humanity. The author suggests that "dark matter" is the matter of mysticism, which constitutes the subtle bodies and was present before (and responsible for) the Big Bang that created visible matter
Predicting student success: using curriculum based measurements of reading to predict student success on Minnesota's statewide assessments
No full textIncludes bibliographical references
Securing javascript runtime of OPC UA deployments
No full textOPC UA is a commonly used machine-to-machine communication protocol. As it is used in industrial critical infrastructure, its security is vital. OPC UA has several proprietary and open-source implementations in different programming languages. Among them, a JavaScript implementation node-opcua stands out due to advantages such as ease of use, code maturity etc. JavaScript is a just-in-time compiled programming language that is executed by a runtime system. Node.js is the most common runtime environment to run JavaScript programs. Deno is it a potential and unofficial successor as it is developed by the original author of Node.js. One promised improvement of Deno is the focus on higher security, such as having a restricted file system and network access by default. Since (1) not all libraries have been adopted yet for for Deno, since (2) this new runtime comes with a compatibility mode featured first in version v1.15, since (3) there is very few research literature yet and since (4) there is no current dedicated OPC UA implementation for Deno so far, we present and evaluate measures to overcome errors when running node-opcua on Deno in this paper
Promotional Effect of La in the Three-Way Catalysis of La-Loaded Al2O3-Supported Pd Catalysts (Pd/La/Al2O3)
No full textLa-loaded Al2O3 (La/Al2O3) is a practical support for three-way catalysis (TWC) reactions. Although it has been reported that the addition of La to Al2O3 results in improved thermal stability to retain high specific surface areas, its effect on the catalytic reduction of NOx (DeNO(x)) has not been studied systematically. Herein, we describe the role of La in La/Al2O3-supported Pd catalysts (Pd/La/Al2O3) for TWC reactions. For that purpose, we employed various in situ spectroscopic studies, including infrared (IR), X-ray absorption fine structure (XAFS), and near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) in combination with density functional theory (DFT) calculations. The obtained results revealed that Pd-0 species supported on La/Al2O3 are more electron-deficient compared to those on pristine Al2O3 without La(Pd/Al2O3). Kinetic studies using powdered catalysts revealed that the addition of La suppresses the poisoning effect by CO during the DeNO(x) reactions. In addition to the catalytic tests with powdered catalysts, monolithic honeycomb forms of the catalysts were prepared and employed for TWC reactions, which showed that Pd/La/Al2O3 exhibits higher DeNO(x) activity than Pd/Al2O3. In this study, we also reexamined the effective loading amount of La, which has traditionally been similar to 3-5 wt % of La for TWC processes in order to retain the high specific surface area of the La/Al2O3 supports. Our investigations showed that an increased La loading (15 wt %) is even more effective for the DeNO(x) reactions tested in this study due to the higher reactivity toward NO and the greater suppression of the poisoning effect of CO. The developed catalyst Pd/La(15)/Al2O3 has also been tested in a commercial vehicle and has been evaluated on a practical driving mode test cycle (LA-4; city cycle of U.S. Federal and California), where it showed a better catalytic performance than the conventionally used Pd/La(3-5)/Al2O3 catalysts. Our study suggests that the loading amount of La in Pd/La/Al2O3 catalysts needs to be adjusted depending on the application systems, considering not only the support stability (surface areas) but also the promotional effect in the TWC process
The achievement gap: comparing children's reading trend lines by socioeconomic status over time
No full textIncludes bibliographical references
Next Generation Automotive DeNO<sub>X</sub> Catalysts: Ceria What Else?
No full textNitrogenoxides (NOx, including NO and NOx) are a group of hazardous, toxic and harmfulgasses, which have an adverse effect on both environment and human health,e.g., acid rain, photochemical smog, and affecting the human respiratorysystem. The NOx concentration in most of the EUcities exceeds the EU annual limit value (40 μg/m3). Around40% of the emitted NOx is attributedto transport related emissions. In currently applicable Euro 6, the real NOx emissionfrom a diesel car is on average 400% than the Euro 6 regulation limit allows ifmeasured under more realistic driving conditions. Although NSR and SCR DeNOx systemshave been broadly investigated and commercially applied with the aim to reduceNOx emissions from lean burn engines,some common problems still exist, e.g., a narrow temperature window and a lowgas hourly space velocity (up to 50.000 L/L/h)in order to convert the NOx selectivelyinto Nx. Due to the in practice high NOxemissionfrom September 2017 additional legislation will be in force to arrive at a morerealistic determination of the highly dynamic NOxemissionby among others the introduction of the real driving emission (RDE) test in thecertification procedure. The Di-Air (Diesel NOxaftertreatment by Adsorbed Intermediate Reductants) system was developed by Toyota(2011-2012) and is still under development. This Di-Air system showed promiseby yielding a high NOx conversion,especially at high temperature (up to 600 ∘C) and high gas hourly space velocity (up to 125.000 L/L/h).This system opts to meet the future stringent NOxreductionrequirements under RDE test conditions (Chapter 1)
