Aerobic methane-oxidizing bacteria (MOB) play an important role in reducing methane emissions in nature. Most current researches focus on the natural habitats (e.g., lakes, reservoirs, wetlands, ...paddy fields, etc.). However, methanotrophs and the methane-oxidizing process remain essentially unclear in artificial habitat, such as the urban water cycle systems. Here, high-throughput sequencing and qPCR were used to analyze the community structure and abundance of MOB. Six different systems were selected from Yunyang City, Chongqing, China, including the raw water system (RW), the water supply pipe network system (SP), the wastewater pipe network system (WP), the hospital wastewater treatment system (HP), the municipal wastewater treatment plant system (WT) and the downstream river system (ST) of a wastewater treatment plant. Results clearly showed that the MOB community structure and network interaction patterns of the urban water cycle system were different from those of natural water bodies. Type I MOB was the dominant clade in HP. Methylocysis in Type II was the most abundant genus among the whole urban water cycle system, indicating that this genus had a high adaptability to the environment. Temperature, dissolved oxygen, pH and concentration significantly affected the MOB communities in the urban water cycle system. The network of MOB in WT was the most complicated, and there were competitive relationships among species in WP. The structure of the network in HP was unstable, and therefore, it was vulnerable to environmental disturbances. Methylocystis (Type II) and Methylomonas (Type I) were the most important keystone species in the entire urban water cycle system. Overall, these findings broaden the understanding of the distribution and interaction patterns of MOB communities in an urban water cycle system and provide valuable clues for ecosystem restoration and environmental management.
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•Initial exploration of the MOB communities in an urban water cycle system.•Methylocysis has the highest abundance in the entire urban water cycle system.•Methylomonas has a high adaptability to the environment of hospital wastewater.•Network interaction indicates that low-abundance species had an irreplaceable role.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Methane-oxidizing bacteria (MOB), a unique group of Gram-negative bacteria utilizing methane as a sole source of carbon and energy, have been proved to be a biological indicator for gas prospecting. ...Field and cultivation-free detection of MOB is important but still challenging in current microbial prospecting of oil and gas (MPOG) system. Herein, SERS was used for the first time to our knowledge to investigate two species of methanotrophs and four closely relevant bacteria that universally coexisted in the upper soil of natural gas. A special but very simple approach was utilized to make silver nanoparticles (Ag NPs) sufficiently contact with every single bacterial cell, and highly strong and distinct Raman signals free from any native fluorescence have been obtained, and successfully utilized for distinguishing MOB from other species. A more convincing multi-Raman criterion based on single Raman bands, and further the entire Raman spectrum in combination with statistical analysis (e.g., principal component analysis (PCA)), which were found capable of classifying MOB related bacterial cells in soil with an accuracy of 100%. This study therefore demonstrated sensitive and rapid SERS measurement technique accompanied by complete Raman database of various gas reservoirs related bacteria could aid field exploration of natural gas reservoir.
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•Label-free SERS used for the first time to the microbial prospecting of oil and gas.•A very simple and rapid procedure for making silver nanoparticles sufficiently contact with bacteria was obtained.•Six MOB related bacterial species were successfully discriminated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Mo(Si,Al)2-MoB composite coatings were deposited on TZM alloy by a single-step pack cementation process. The microstructure development of the coatings and the influence of deposition temperature on ...the coating structure are investigated. The coatings form via a sequence manner of first Al depositing and then Al-Si-B or Si-B co-depositing, while increasing the deposition temperature will move Al-Si-B or Si-B co-depositing ahead during the process. The coatings prepared at 1250 °C for more than 4 h consist of thick Mo(Si,Al)2 outer layer with dispersed MoB particles and thin MoB inner layer. The oxidation-resistant performance and degradation mechanism for the coatings during oxidation at 1400 °C are discussed.
•Mo(Si,Al)2-MoB composite coatings were prepared on TZM alloy.•Elements deposition sequence for the coating preparation was elucidated.•Effect of deposition temperature on the coating structure was studied.•The coatings exhibited excellent oxidation resistance at 1400 °C.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Safe environment contact, and high-performance motion control are typically conflicting design goals. Admittance control can improve safety and stability in contact with a stiff environment but ...remains challenging on industrial robots. Typically, high-performance motion control is achieved by low-admittance systems, which can give high transient forces or instability in contact with high-stiffness environments. This article proposes a linear admittance control framework from which a multifunction observer (MOB)-based control scheme that succeeds in directly improving the motion control accuracy by suppressing disturbances, while achieving better loop shaping in the outer-loop admittance control is designed. By using the task space force and position measurement of the robot, combined with linearized position-controlled robot and payload models to design the MOB, the outer-loop controller can render improved interactive dynamics. In addition, a methodology to design the proposed MOB based on the reduced-order model is developed. Furthermore, the bounded-magnitude frequency-domain uncertainty in the linear model is identified at a variety of robot poses. Theoretical evaluations and experiments verify the effectiveness of the proposed MOB-based control method, in contact with a very stiff environment and with a 7-kg payload.
Very large floating structures (VLFS) are typically made up of several modules of offshore platforms, such as semi-submersibles, connected by mechanical connectors. The proposed Truss Pontoon Mobile ...Offshore Base (TP-MOB) is a new type of offshore platform based on the truss pontoon semi-submersible design. The design of the connectors is crucial for the functionality of the structure. In this study, the flexible connectors are modeled with a 3D source distribution method and the wave forces are estimated with 3D linear potential theory. The open-source finite element-based numerical model, HYDRAN-XR, is used to analyze the structural responses and connector forces in both regular and irregular wave conditions. The results indicate significant differences in responses between single and multi-module cases, especially in extreme waves. Loads on the connector change greatly for three- and five-module cases, with maximum values at specific wave angles.
•Investigated the Truss Pontoon - MOB using open-source finite-element-based code (HYDRAN-XR tool).•Implemented Rigid Module Flexible Connector (RMFC) for the Truss Pontoon - MOB.•Single and multi-module interactions of Truss Pontoons - MOBs are considered under regular/irregular wave conditions.•Responses and forces acting on the connectors of Truss Pontoon - MOB modules are reported.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Anti-press sentiment based on negative emotions of disgust and hatred has prevailed in Korea since the mid-2010s. Through in-depth interviews with ten journalists working for Korean news ...organizations, supplemented with an analysis of self-reflective articles, this study investigates how journalists experience this audience hostility and harassment, how they cope with it, and how their practices are influenced by it. The analysis reveals that, combined with the dualistic views of populist politics and the influence of misogynic narratives, journalists who cover topics, such as politics and gender, are more likely to become targets of anti-press violence. Moreover, it shows that anti-press violence induces negative emotions, such as discomfort, anger, lethargy, and fear, among journalists. To cope with these emotions, with little support from their news organizations, journalists tend to pursue emotion-focused coping strategies, such as striving for perfection in the newswork process, building emotional boundaries between the audience and themselves, counter-hating readers, and blaming other journalists. Finally, the paper suggests that anti-press violence in Korea promotes a chilling effect in news organizations that, consequently, may infringe on individual journalists' autonomy and editorial independence.
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BFBNIB, NUK, PILJ, SAZU, UL, UM, UPUK
Erosion of sink rolls by molten zinc is one of the most prominent and persistent problems occurring in hot-dip galvanizing industry. MoB–CoCr as an alternative to WC–12Co for stainless steel ...protective coating resistance to molten zinc was deposited by high velocity oxygen fuel (HVOF). Microstructure and mechanical characterization of the coatings were carried out by SEM, XRD and micro-hardness test. Resistance to thermal shock and molten zinc corrosion of the coatings were also conducted. Results showed that MoB–CoCr coating exhibited a better resistance property to thermal shock than that of WC–12Co. At the same time, the corrosion test showed that lifetime of samples with MoB–CoCr coatings in molten zinc appeared to be longer than that of WC coating. The corrosion resistance of MoB–CoCr coating may be ascribed to non-wettability of MoB–CoCr in molten zinc, which can delay the molten zinc penetration into substrates along the micro-cracks of the coating.
•MoB–CoCr as alternative to WC–12Co for stainless steel protective coating was deposited by HVOF.•MoB–CoCr coating exhibited a better resistance property to thermal shock than WC–12Co coating.•Lifetime of MoB–CoCr coatings in molten zinc was also longer than that of WC–12Co coating.•The excellent corrosion resistance of MoB–CoCr coating may be ascribed to non-wettability property of the coating.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Transition metal diborides in hexagonal AlB2 type structure typically form stable MB2 phases for group IV elements (M = Ti, Zr, Hf). For group V (M = V, Nb, Ta) and group VI (M = Cr, Mo, W) the ...stability is reduced and an alternative hexagonal rhombohedral MB2 structure becomes more stable. In this work we investigate the effect of vacancies on the B-site in hexagonal MB2 and its influence on the phase stability and the structure for TiB2, ZrB2, HfB2, VB2, NbB2, TaB2, CrB2, MoB2, and WB2 using first-principles calculations. Selected phases are also analyzed with respect to electronic and bonding properties. We identify trends showing that MB2 with M from group V and IV are stabilized when introducing B-vacancies, consistent with a decrease in the number of states at the Fermi level and by strengthening of the B-M interaction. The stabilization upon vacancy formation also increases when going from M in period 4 to period 6. For TiB2, ZrB2, and HfB2, introduction of B-vacancies have a destabilizing effect due to occupation of B-B antibonding orbitals close to the Fermi level and an increase in states at the Fermi level.
This article contributes to our understanding of the notion of mob censorship from the Ugandan context by examining the nature and consequences of harassment targeting women journalists on social ...media. Drawing on research about online harassment and censorship, we link mob violence in physical spaces to harassment encountered on social media from the perspectives of women journalists. We illustrate that the different forms of harassment enabled by online platforms present serious challenges for individual journalists, and the journalism profession. Our findings suggest that online attacks on reporters include comments that denigrate women's bodies, and discredit journalists' reportage. The harassment compels women journalists to engage in online hibernation and censorship.
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BFBNIB, NUK, PILJ, SAZU, UL, UM, UPUK
The online harassment of journalists is a phenomenon which has been on the rise in Europe over the last decade and it affects journalists' working lives. As an expression of mob censorship, online ...harassment raises questions about how media organisations react to online aggressions targeting their journalists, the consequences on the victims' well-being and on the role of journalism in society. Yet, previous research has shown the lack of support mechanisms provided by journalists' employers. In this article, we explore the hypothesis that the lack of organisational support towards targeted journalists is partly due to the challenges faced by media managers when trying to make sense of the phenomenon. This article offers a unique viewpoint on how 22 Belgian media managers from five media organisations struggle to define what online harassment is and how to respond to it. In turn, it shows that the vague understanding of what online harassment is seems to favour case-by-case organisational responses. Missing words and unstructured actions related to online harassment impede media managers from addressing online harassment as a collective issue in journalism and its consequences on the democratic debate.
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BFBNIB, NUK, PILJ, SAZU, UL, UM, UPUK
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