Alstom (United States)

The present study explores the combined effects of diluents (N2, He, and CO2) with polyoxymethylene dimethyl ether 3 (PODE3) addition on soot formation in isooctane inverse diffusion flames to optimize combustion processes. The results indicated that replacing N2 with He diluent in isooctane caused an increase in flame height, temperature, and the mean KL factor (a two-color pyrometry parameter that quantifies soot concentration in flames). In contrast, CO2 acted as an inhibitor, reducing these parameters. Therefore, 20% PODE3/isooctane mixture with CO2 diluent showed the shortest flame height, least flame luminous intensity, and lowest flame temperature, indicating enhanced combustion efficiency, with an almost negligible mean KL factor. Moreover, He dilution produced soot particles with a chain-like morphology, less dense structure, longer fringe length, lower tortuosity, and less disordered, which can be attributed to its higher thermal conductivity and lower heat capacity than N2. Conversely, soot particles generated from pure isooctane with CO2 dilution resulted in smaller fringe length, higher tortuosity, and lower graphitization level compared to N2 and He diluents, even with 20% PODE3 addition. The combined effect of CO2 with 20% PODE3 led to the smallest fringe length, largest tortuosity, and least graphitization with more amorphous soot particles. These findings were supported by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses.

To evaluate the equivalence of immunogenicity, safety and efficacy of Gan & Lee (GL) Glargine (Basalin®; Gan & Lee Pharmaceutical) with that of the reference product (Lantus®) in adult participants with type 2 diabetes mellitus. This was a phase 3, multicenter, open-label, equivalence trial conducted across 57 sites. In total, 567 participants with type 2 diabetes mellitus were randomized in a 1:1 ratio to undergo treatment with either GL Glargine or Lantus® for 26 weeks. The primary endpoint was the proportion of participants in each treatment arm who manifested treatment-induced anti-insulin antibodies (AIA). Secondary endpoints included efficacy and safety metrics, changes in glycated haemoglobin levels, and a comparative assessment of adverse events. Results were analysed using an equivalence test comparing the limits of the 90% confidence interval (CI) for treatment-induced AIA development to the prespecified margins. The percentages of participants positive for treatment-induced glycated haemoglobin by week 26 were similar between the GL Glargine (19.2%) and Lantus® (21.3%) treatment groups, with a treatment difference of -2.1 percentage points and a 90% CI (-7.6%, 3.5%) (predefined similarity margins: -10.7%, 10.7%). The difference in glycated haemoglobin was -0.08% (90% CI, -0.23, 0.06). The overall percentage of participants with any treatment-emergent adverse events was similar between the GL Glargine (80.1%) and Lantus® (81.6%) treatment groups. GL Glargine was similar to Lantus® in terms of immunogenicity, efficacy,and safety, based on the current study.

This work investigates the influence of burnout level on CaO surface areas and intrinsic oxidation rates of partially burned-out coal chars, and then attempts to correlate the two. Three initial chars were made by devolatilizing 63–75 μm size fractions of Dietz (subbituminous B) coal and Beulah Zap lignite in a flat flame methane burner. Three series of partially burned-out chars were then produced by oxidizing (in 5–7% O2) the three initial coal chars to a wide range of conversion degrees (6–97%) in a heated wall drop-tube reactor (DTR) at higher temperatures (1300–1800 K). Intrinsic oxidation rates at lower temperatures were determined by isothermal TGA (573–723 K, 10% O2). CaO surface areas were measured with a selective CO2-chemisorption method. Both intrinsic oxidation rate and CaO surface area decreased as burnout increased for all three char series. Good correlation of CaO surface area with intrinsic oxidation rate has been observed and, subsequently, to normalized rates (per CaO surface area) which were independent of burnout level for all three chars. Such correlation indicates that CaO catalytic behavior is very compelling during oxidation of these low rank coal chars at low temperatures and that rates decreased with increased high-temperature burnout due to increased sintering of the catalytic CaO. Activation energies of the DtzB and Zap series were both independent of burnout and were 32.0 ± 0.9 and 32.9 ± 1.4 kcal/mol, respectively. Regarding the influence of devolatilization conditions on coal char reactivity, normalized and non-normalized oxidation rates of the DtzA chars (prepared at lower temperatures) were as much as 2 times higher than the comparable rates of DtzB and Zap chars. Conversely, values of CaO surface area for DtzA and DtzB chars were similar but consistently less than those for the Zap chars. This suggests that higher temperature preparation decreased the inherent reactivity of the char organic fraction without affecting the CaO surface area.

This paper presents complete mass and energy balance of a novel installation for thermal utilization of the sewage sludge. Calculations were performed for the typical output of a wastewater processing plant in a middle size Polish town. Overall, the proposed configuration seems to be advantageous, as the proposed installation is fully sustainable and does not need external energy sources, due to maximized heat recovery from many different sources. Optimization of the heat use is performed, by utilizing all the available heat sources, including low-quality heat, such as the latent heat of water vapors, present in wet air after drying. Despite using plasma gasification system, the installation is able to generate surplus electricity, which can be used as a power source for all of the auxiliary devices, such as fans, augers and PLC systems. The proposed system can be implemented in the water treatment plants, in towns with the total amount of inhabitants ranging from a couple of thousand up to 40 thousand. System does not require anaerobic digestion of the sewage sludge. Nonetheless, the use of anaerobic digestion brings some advantages as the producer gas from the gasification installation can be mixed with biogas.

Considered is double wall cooling, with full-coverage effusion-cooling on the hot side of the effusion plate, and a combination of impingement cooling and cross flow cooling, employed together on the cold side of the effusion plate. Data are given for a main stream flow passage with a contraction ratio (CR) of 4 for main stream Reynolds numbers Rems and Rems,avg of 157,000–161,000 and 233,000–244,000, respectively. Hot-side measurements (on the main stream flow or hot side of the effusion plate) are presented, which are measured using infrared thermography. Using a transient thermal measurement approach, measured are spatially resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficient. For the same Reynolds number, initial blowing ratio (BR), and streamwise location, increased thermal protection is often provided when the effusion coolant is provided by the cross flow/impingement combination configuration, compared to the cross flow only supply arrangement. In general, higher adiabatic effectiveness values are provided by the impingement only arrangement, relative to the impingement/cross flow combination configuration, when compared at the same Reynolds number, initial BR, and x/de location. Data for one streamwise location of x/de = 60 show that the highest net heat flux reduction line-averaged net heat flux reduction (NHFR) values are produced either by the impingement/cross flow combination configuration or by the impingement only arrangement, depending upon the particular magnitude of BR, which is considered.

Abstract As the result of a leak detected in a plate-formed header at PENELEC'S Shawville Unit No. 3, an extensive failure investigation was initiated to determine the origin of cracking visible along the longitudinal weld seam. Fabricated from SA387-D material and designed for a superheater outlet temperature of 566 deg C, the 11.4 cm thick header had operated for approximately 187,000 h at the time of the failure. Discussion focuses on the results of a metallographic examination of boat samples removed from the longitudinal seam weldment in the vicinity of the failure and at other areas of the header where peak temperatures were believed to have been reached. The long-term mechanical properties of the service-exposed base metal and creep-damaged weld metal were determined by creep testing. Based on the utility's decision to replace the header within one to three years, an isostress overtemperature lead specimen approach was taken, whereby failure of a test specimen in the laboratory would precede failures in the plant. These tests revealed approximately a 2:1 difference in life for the base metal as compared to weld metal.

<div class="section abstract"><div class="htmlview paragraph">The combustion process in a homogeneous charge compression ignition (HCCI) engine is mainly governed by ignition wave propagation. The in-cylinder pressure, heat release rate, and the emission characteristics are thus largely driven by the chemical kinetics of the fuel. As a result, CFD simulation of such combustion process is very sensitive to the employed reaction mechanism, which model the real chemical kinetics of the fuel. In order to perform engine simulation with a range of operating conditions and cylinder-piston geometry for the design and optimization purpose, it is essential to have a chemical kinetic mechanism that is both accurate and computational inexpensive. In this paper, we report on the evaluation of several chemical kinetic mechanisms for methanol combustion, including large mechanisms and skeletal/reduced mechanisms. These mechanisms are evaluated in terms of homogeneous ignition delay time, laminar flame speed, and multi-phase simulations of HCCI heavy-duty engine. The results are compared with experimental data and evaluated in terms of the accuracy and computational cost. It was found that scattering of ignition delay time predicted from different chemical kinetic mechanisms reported in the literature under homogeneous mixture ignition conditions give rise to a high sensitivity of the engine in-cylinder pressure prediction to the selected mechanism.</div></div>

Rail switches are critical infrastructure components of a railroad network, that must maintain high-levels of reliable operation. Given the vast number and variety of switches that can exist across a rail network, there is an immediate need for robust automated methods of detecting switch degradations and failures without expensive add-on equipment. In this work, we explore two recent machine learning frameworks for classifying various switch degradation indicators: (1) a featureless recurrent neural network called a Long Short-Term Memory (LSTM) architecture, and (2), the Deep Wavelet Scattering Transform (DWST), which produces features that are locally time invariant and stable to time-warping deformations. We describe both methods as they apply to rail switch monitoring and demonstrate their feasibility on a dataset captured under the service conditions by Alstom Corporation. For multiple categories of degradation types, the baseline models consistently achieve near-perfect accuracies and are competitive with the manual analysis conducted by human switch-maintenance experts.