The effect of CO2-loaded amine solvents on the corrosion of a carbon steel stripper

The corrosive behaviour of loaded amine solvents was evaluated under stripper operating conditions, for post-combustion carbon capture, to determine the feasibility of using carbon steel in plant construction. In addition to monoethanolamine, three alternative amine solvents: methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), 1-(2-aminoethyl)piperazine (AEPZ), and the common additive K2CO3 were studied when in contact with carbon steel (C1018) over a 28-day period. Corrosive behaviour was evaluated using carbon steel coupons: gravimetric method for weight change, surface imaging (SEM) and analytical techniques (EDX and XRD), and Fe ion concentration in solution (ICP–OES). The results demonstrated that MDEA and AMP as well as K2CO3 develop a significant siderite (FeCO3) layer on the carbon steel surface. The presence of this layer is attributed to the preferred reaction pathway with CO2 for tertiary and sterically hindered amines. The FeCO3 layer formed in the case of MDEA provides superior protection from continued corrosion of the carbon steel. By contrast, MEA and AEPZ show significant corrosion to the carbon steel surface. In conclusion, MDEA, AMP, and K2CO3 can preferentially produce sufficient surface FeCO3 layers to reduce corrosion levels in carbon steels for use under stripper conditions in post-combustion carbon capture plants

FREQ-Seq2: a method for precise high-throughput combinatorial quantification of allele frequencies

The accurate determination of allele frequencies is crucially important across a wide range of problems in genetics, such as developing population genetic models, making inferences from genome-wide association studies, determining genetic risk for diseases, as well as other scientific and medical applications. Furthermore, understanding how allele frequencies change over time in populations is central to ascertaining their evolutionary dynamics. We present a precise, efficient, and economical method (FREQ-Seq2) for quantifying the relative frequencies of different alleles at loci of interest in mixed population samples. Through the creative use of paired barcode sequences, we exponentially increased the throughput of the original FREQ-Seq method from 48 to 2,304 samples. FREQ-Seq2 can be targeted to specific genomic regions of interest, which are amplified using universal barcoded adapters to generate Illumina sequencing libraries. Our enhanced method, available as a kit along with open-source software for analyzing sequenced libraries, enables the detection and removal of errors that are undetectable in the original FREQ-Seq method as well as other conventional methods for allele frequency quantification. Finally, we validated the performance of our sequencing-based approach with a highly multiplexed set of control samples as well as a competitive evolution experiment in Escherichia coli and compare the latter to estimates derived from manual colony counting. Our analyses demonstrate that FREQ-Seq2 is flexible, inexpensive, and produces large amounts of data with low error, low noise, and desirable statistical properties. In summary, FREQ-Seq2 is a powerful method for quantifying allele frequency that provides a versatile approach for profiling mixed populations

Large-scale monocular SLAM by local bundle adjustment and map joining

This paper first demonstrates an interesting property of bundle adjustment (BA), "scale drift correction". Here "scale drift correction" means that BA can converge to the correct solution (up to a scale) even if the initial values of the camera pose translations and point feature positions are calculated using very different scale factors. This property together with other properties of BA makes it the best approach for monocular Simultaneous Localization and Mapping (SLAM), without considering the computational complexity. This naturally leads to the idea of using local BA and map joining to solve large-scale monocular SLAM problem, which is proposed in this paper. The local maps are built through Scale-Invariant Feature Transform (SIFT) for feature detection and matching, random sample consensus (RANSAC) paradigm at different levels for robust outlier removal, and BA for optimization. To reduce the computational cost of the large-scale map building, the features in each local map are judiciously selected and then the local maps are combined using a recently developed 3D map joining algorithm. The proposed large-scale monocular SLAM algorithm is evaluated using a publicly available dataset with centimeter-level ground truth. ©2010 IEEE

Studies on hemorrhagic pneumonia in Moschus sifanicus

A series of investigations were carried out including epidemiology, etiology and pathology on hemorrhagic pneumonia in Moschus sifanicus, which had prevailed in Xinglong Mountain National Nature Reserve District in Gansu province of China. The results indicated that the prevalence of thisdisease could be correlated with local humidity in Xinglong Mountain in Gansu province of China. The disease is caused by single infection of Pasteurella multocida or mix of P. multocida, Escherichia coli and Pseudomonas aeruginosa, and is a contagious disease. The pathological changes were mainly manifested in the vessel wall of bronchia and bronchiole appeared congested, bleeding, edemic with infiltration of inflammatory cells, mucosa of bronchiole degenerates, with the presence of necrosis and exfoliation, pulmonary alveolus generated suppuration, disaggregation and necrosis. It was concluded that the diseases are mainly caused by local bacteria and affected M. sifanicus finally die of hemorrhagic or purulent, necrotic pneumonia

Quantum dissipation and broadening mechanisms due to electron-phonon interactions in self-formed InGaN quantum dots

Quantum dissipation and broadening mechanisms in Si-doped InGaN quantum dots are studied via the photoluminescence technique. It is found that the dissipative thermal bath that embeds the quantum dots plays an important role in the photon emission processes. Observed spontaneous emission spectra are modeled with the multimode Brownian oscillator model achieving an excellent agreement between experiment and theory for a wide temperature range. The dimensionless Huang-Rhys factor characterizing the strength of electron-LO-phonon coupling and damping constant accounting for the LO-phonon-bath interaction strength are found to be ∼0.2 and 200 cm-1, respectively, for the InGaN QDs. © 2006 American Institute of Physics.published_or_final_versio

Large autologous ilium with periosteum for tibiotalar joint reconstruction in Rüedi-Allgöwer III or AO/OTA type C3 pilon fractures: a pilot study.

BackgroundManagement of Rüedi-Allgöwer III or AO/OTA type C3 pilon fracture presents numerous challenges to the orthopaedic surgeon. A joint preservation technique using a large autologous ilium with periosteum in combination with internal implant fixation was reported to improve the outcome of reconstruction.MethodsTwenty-five patients according to Tscherne/Oestern FxCO-I closed fracture and FxOI open fractures classification after Rüedi-Allgöwer III or AO/OTA type C3 pilon fracture received a large autologous ilium with periosteum for tibiotalar joint reconstruction and open reduction and internal fixation (ORIF), between March 2015 and September 2018. The visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) score, and Burwell and Charnley criteria were used for outcome analysis.ResultsTwenty patients with an average age of 45.2 years were followed for an average of 18.3 months. The VAS and AOFAS scores, and Burwell and Charnley ratings were recorded at the last follow-up after reconstructive surgery. Two patients developed redness and swelling at the wound site, but recovered after local care and dressing changes. No patient displayed deep surgical site infection, donor site complication, non-union or local complication during the final follow-up. The average bone union time was 18.3 months (range 3-36).ConclusionsLarge autologous ilium with periosteum in combination with ORIF can be performed for tibiotalar joint reconstruction. This experimental procedure reduces the risk of post-operative complications following articular reconstruction for Rüedi-Allgöwer III or AO/OTA type C3 pilon fractures in short follow-up.Level of evidenceLevel III, retrospective cohort study

Structural phase transition in IrTe2_2: A combined study of optical spectroscopy and band structure calculations

Ir$_{1-x}$Pt$_x$Te$_2$ is an interesting system showing competing phenomenon between structural instability and superconductivity. Due to the large atomic numbers of Ir and Te, the spin-orbital coupling is expected to be strong in the system which may lead to nonconventional superconductivity. We grew single crystal samples of this system and investigated their electronic properties. In particular, we performed optical spectroscopic measurements, in combination with density function calculations, on the undoped compound IrTe$_2$ in an effort to elucidate the origin of the structural phase transition at 280 K. The measurement revealed a dramatic reconstruction of band structure and a significant reduction of conducting carriers below the phase transition. We elaborate that the transition is not driven by the density wave type instability but caused by the crystal field effect which further splits/separates the energy levels of Te (p$_x$, p$_y$) and Te p$_z$ bands.Comment: 16 pages, 5 figure

Chemical characterization of PM2.5 from a southern coastal city of China:applications of modeling and chemical tracers in demonstrationof regional transport

An intensive sampling campaign of airborne fine particles (PM2.5) was conducted at Sanya, a coastal city in Southern China, from January to February 2012. Chemical analyses and mass reconstruction were used identify potential pollution sources and investigate atmospheric reaction mechanisms. A thermodynamic model indicated that low ammonia and high relative humidity caused the aerosols be acidic and that drove heterogeneous reactions which led to the formation of secondary inorganic aerosol. Relationships among neutralization ratios, free acidity, and air-mass trajectories suggest that the atmosphere at Sanya was impacted by both local and regional emissions. Three major transport pathways were identified, and flow from the northeast (from South China) typically brought the most polluted air to Sanya. A case study confirmed strong impact from South China (e.g., Pearl River Delta region) (contributed 76.8% to EC, and then this result can be extended to primary pollutants) when the northeast winds were dominant. The Weather Research Forecasting Black carbon model and trace organic markers were used to apportion local pollution versus regional contributions. Results of the study offer new insights into the atmospheric conditions and air pollution at this coastal city

Violet electroluminescence of AlInGaN-InGaN multiquantum-well light-emitting diodes: Quantum-confined stark effect and heating effect

Electroluminescence (EL) from AlInGaN-InGaN multiquantum-well violet light-emitting diodes is investigated as a function of forward bias. Two distinct regimes have been identified: 1) quantum-confined Stark effect at low and moderately high forward biases; 2) heating effect at high biases. In the different regimes, the low-temperature EL spectra exhibit different spectral features which are discussed in detail. © 2007 IEEE.published_or_final_versio

Comparative study on microstructure and surface properties of keratin- and lignocellulosic-based activated carbons

© 2015 Elsevier B.V. All rights reserved. The paper probed the preparation of activated carbon by potassium silicate (K2SiO3) activation from keratin waste (cowhair waste, CW) and lignocellulosic materials (Cyperus alternifolius, CA) and the comparisons of physicochemical properties of the resulting carbons. These impregnation conditions were as follows: one impregnated at room temperature for 12 h then dipped at high temperature for 30 min; the other was only impregnated at room temperature for 12 h, producing four activated carbons CWAC-1, CWAC-2, CAAC-1, and CAAC-2. The influence of activation time, K2SiO3/precursor weight ratio, and the pre-process on properties of activated carbons was discussed. The CWAC-1 produced at 700°C with the K2SiO3/precursor weight ratio of 2:1 possessed the Brunauer-Emmet-Teller (BET) surface area of 1965 m2/g and total pore volume of 1.345 cm3/g, while CAAC-1 prepared at the same conditions attained the BET surface area of 1710 m2/g and total pore volume of 0.949 cm3/g. The surface area and total pore volume of CAAC increased with the impregnation ratio. Moreover, CWAC-1, CWAC-2, CAAC-1, and CAAC-2 exhibited high portion of micropores, illustrating the role of K2SiO3. The analysis with a Fourier transform infrared spectrometer indicates that CWAC has more functional groups than CAAC, as well as CWAC-1 and CWAC-2 which possess similar functional groups