Modelling the sources and transport of ammonium nitrogen with the SPARROW model: A case study in a karst basin

Investigations of dissolved oxygen (DO) levels and related water quality in the Petchburi River, a regulated river system in western Thailand, were conducted at 3-month intervals from May 2010 to February 2012. The results indicated generally good water quality with DO levels >4 mg L−1. Variations in water quality, particularly the DO and ammonium nitrogen levels along the river, occurred due to discharge regulation and the natural characteristics of the river. The processes which contribute to DO levels include natural saturation (ca 57–78% in the upper river section and ca 44–76% in the lower river section) and aquatic plant DO production (ca 20–36% in the upper river section and ca 24–50% in the lower river section) which is also significant, while re-aeration would be less effective. The DO contribution from pondweed (family Potamogetonaceae) was of interest because of its successional capacity. Future control of river quality will require suitable management of aquatic plant species for conservation purposes.

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The effect of ecological restoration based artificial reoxygenation on water quality Improvement of urban river water

MATEC Web of Conferences ◽

10.1051/matecconf/201824602037 ◽

2018 ◽

Vol 246 ◽

pp. 02037

Author(s):

Nan Luo ◽

Changying Hu ◽

Weiyu Li ◽

Tao Xie ◽

HuiLi Gong ◽

...

Keyword(s):

Water Quality ◽

Ammonium Nitrogen ◽

Urban River ◽

In Situ Remediation ◽

Quality Degradation ◽

Total Phosphorous ◽

Filter Bed ◽

Microbial Agents

Urban river pollution sources such as Combined Sewer Overflows (CSOs) or Illegally Discharging of Industrial Waste (IDIW) are generally hard to control on-site and cause serious water quality degradation problems across the nation. Therefore developing effective in-situ remediation techniques for urban rivers is of great interest. In this research we combined river reoxygenation, artificial floating island and microbial agents technologies (O-AFI-MA) to developed a comprehensive in-situ remediation technique and obtained water quality data from Sunhe River case study to evaluate its effectiveness. Our discovery indicates that the O-AFI-MA technique effectively improves water quality by reducing chemical oxygen demand (CODCr), total phosphorous (TP), ammonium nitrogen (NH4+-N) level by 45.9%, 61.31, 7.66% respectively and our technique enhances the natural degradation rate by raising the dissolved oxygen (DO) level from 2.8mg/L to 10mg/L upstream. The case study suggests that the sediment accumulation from CSOs and the subsequent internal source release causes great water quality degradation for Sunhe River. We also tested combinatory microbial agents, physical adsorption and multimedia bio-filter bed technologies independently on site to improve the ammonium nitrogen and total phosphorous removal rate of our technique, and the multimedia bio-filter bed is found to be most effective.

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Treatment of high-salt oil produced water based on constructed wetland technology—A case study of a costal oilfield

E3S Web of Conferences ◽

10.1051/e3sconf/202129303019 ◽

2021 ◽

Vol 293 ◽

pp. 03019

Author(s):

Xiaoqing Cao ◽

Xue Gao ◽

Kai Zheng ◽

Shan Wu ◽

Guodong Meng ◽

...

Keyword(s):

Constructed Wetland ◽

Produced Water ◽

Oxygen Demand ◽

Ammonium Nitrogen ◽

Oil Field ◽

Stable Operation ◽

Effluent Water ◽

Good Ability ◽

Operation Period

Aiming at the treatment of large volume of oil produced wastewater, the combined technology based on constructed wetland was applied for produced water treatment in a costal oil field. During the stable operation period, the treatment system maintained removal efficiency of 50.2% for chemical oxygen demand (COD), 100% for oil and 85.1% for ammonium nitrogen (NH3-N) under the gradient increase of salinity along the process. Meanwhile, this system has a good ability to adapt the influent fluctuation. When the oil in the influent fluctuated greatly between 11 mg/L to 147 mg/L, the effluent water quality remained stable. The treated water met the national discharge standard for water pollutants from the oilfield industry and can be used for the saline alkali beach wetland as supplement water.

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The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

Behavioral and Brain Sciences ◽

10.1017/s0140525x13009850 ◽

2014 ◽

Vol 38 (01) ◽

pp. 102-129

Author(s):

ALBERTO MARTÍN ÁLVAREZ ◽

EUDALD CORTINA ORERO

Keyword(s):

Latin America ◽

El Salvador ◽

Early Years ◽

Left Wing ◽

Internal Dynamics ◽

Internal Coherence ◽

The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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Culture and the plasticity of perception

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002887 ◽

2020 ◽

Vol 43 ◽

Author(s):

Michael Lifshitz ◽

T. M. Luhrmann

Keyword(s):

Cultural Context ◽

Sensory Experience ◽

Cultural Learning ◽

The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

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Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

Behavioral and Brain Sciences ◽

10.1017/s0140525x19000451 ◽

2019 ◽

Vol 42 ◽

Author(s):

Daniel J. Povinelli ◽

Gabrielle C. Glorioso ◽

Shannon L. Kuznar ◽

Mateja Pavlic

Keyword(s):

Temporal Reasoning ◽

Higher Order ◽

Important Case ◽

Human Cognition ◽

Relational Reasoning ◽

Dual Systems ◽

First Order ◽

Reasoning System ◽

Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

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Sociocultural memory development research drives new directions in gadgetry science

Behavioral and Brain Sciences ◽

10.1017/s0140525x19000979 ◽

2019 ◽

Vol 42 ◽

Author(s):

Penny Van Bergen ◽

John Sutton

Keyword(s):

Episodic Memory ◽

Autobiographical Memory ◽

Developmental Psychology ◽

Cross Cultural ◽

Memory Development ◽

Development Research ◽

Cultural Research ◽

New Directions ◽

Cross Cultural Research

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.

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Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100165641 ◽

1996 ◽

Vol 54 ◽

pp. 636-637

Author(s):

D. L. Callahan

Keyword(s):

Plastic Deformation ◽

Aluminum Nitride ◽

Mechanical Response ◽

Three Dimensional ◽

Bright Field Image ◽

Perfectly Plastic ◽

Contrast Analysis ◽

Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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