scholarly journals Geochemical Characterization and Saturation Index (Si) in the Montebello Lagunar System Liquidamber Lagoon, Chiapas Mexico

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
J. R. Reyes-Santiago ◽  
L. A. García-Villanueva ◽  
G. Fernández-Villagómez ◽  
P. Guzmán-Guadarrama
Keyword(s):  
Water Column ◽  
Saturation Index ◽  
Physicochemical Characterization ◽  
Speciation Analysis ◽  
Water Characteristics ◽  
System A ◽  
A Value ◽  
Foul Smell ◽  
Dead Fish ◽  
Geochemical Speciation

The “Lagunas de Montebello” National Park located in Chiapas, Mexico, is well known for its crystal blue water bodies, some of which, in 2003, started to change color from crystalline to cloudy brown, and occasionally emit a foul smell, contains white-yellowish supernatant debris and dead fish. To determine the causes of the changes in the water characteristics of the “Liquidambar” lagoon of the Montebello lagoon system, a physicochemical characterization was carried out over the first six meters of the water column, together with geochemical speciation analysis and the saturation index calculation for different minerals. Water was classified as calcium-sulfated and the main mechanism that controlled its chemistry was rocks dissolution. Sulfide was found at all sampled depths in the range of 0.11 to 1.13 mg.L-1. The concentration of sulfate in the water column ranged from 249.21 to 298.7 mg.L-1, carbonate ranged from 140.5 to 261.4 mg.L-1, calcium and magnesium ranged from 94.5 to 146.9 mg.L-1 and 34.2 to 38.3 mg.L-1, respectively. Likewise, oxygen was also found to be oversaturated on the surface with a value of 9.32 mg.L-1. The speciation results and SI indicated that the mineral phases calcite, aragonite, and dolomite were oversaturated, being greater on the surface. The results suggested the possibility that the turbidity, the coloration change, and the whitish supernatant were due to the precipitation of carbonate minerals, microbiologically influenced by the photosynthetic activity in the upper layer of the lagoon water.

Hydrochemistry and carbonate sediment characterisation of Bacalar Lagoon, Mexican Caribbean

2019 ◽  
Vol 70 (3) ◽  
pp. 382 ◽  
Author(s):  
Nidia I. Tobón Velázquez ◽  
Mario Rebolledo Vieyra ◽  
Adina Paytan ◽  
Kyle H. Broach ◽  
Laura M. Hernández Terrones
Keyword(s):  
Trace Elements ◽  
Water Column ◽  
Saturation Index ◽  
Major Elements ◽  
Anthropogenic Sources ◽  
Pollution Indices ◽  
Mexican Caribbean ◽  
High Concentrations ◽  
Geochemical Analyses ◽  
Changes Over Time

The aim of the study is to determine the distribution of trace and major elements in the water and in the sediments of the south part of the Bacalar Lagoon and to identify the sources of the trace elements and their changes over time. The western part of the lagoon water column is characterised by high concentrations of Ca2+, HCO3– and Sr2+, derived from groundwater input. In contrast, the eastern part of the lagoon is characterised by high concentrations of Mg2+, Na+ and Cl–. The lagoon is not affected by present-day seawater intrusion. Water column and sediment geochemical analyses performed in Bacalar Lagoon show clear spatial distribution of different parameters. The saturation index of the water column indicates three main groups: (1) a zone oversaturated with regard to aragonite, calcite and dolomite; (2) an undersaturated area where all three minerals are dissolving; and (3) an area with calcite equilibrium and undersaturation with regard to the other minerals. Herein we present the first measurements of trace element (Ba2+, Mn2+, K+, Ni2+, Zn2+) concentrations in carbonates obtained from sediments in Bacalar Lagoon. In order to evaluate whether the trace elements are derived from natural or anthropogenic sources, four pollution indices were calculated. The results confirmed that Bacalar Lagoon sediments are not contaminated with Ni2+, K+, Mn2+ and Ba2+, and that the Zn2+ seems to have a predominantly anthropogenic origin.

scholarly journals WUJUD BUDAYA DALAM NOVEL TEGUH ANAK JADAH KARYA A.D. DONGGO (KAJIAN ANTROPOLOGI SASTRA)

EDU-KATA ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 159-168
Author(s):  
Amiruddin Amiruddin
Keyword(s):  
New Order ◽  
Physical Culture ◽  
The Novel ◽  
Value System ◽  
System A ◽  
A Value ◽  
The Family ◽  
Anthropological Literature ◽  
The Impact

This research-oriented culture and a form of resistance against the culture of power in the novel Teguh Anak Jadah by A.D. Donggo studied from anthropological literature review. Interdisciplinary between anthropology and literature provide new understanding of the phenomenon of human culture in literature. The method used in this study using hermeneutic methods. This method outlined understand the text and the text intended for a review of literature. Hermeneutical suitable for reading literature for the study of literature, whatever its form, related to an activity that interpretation.  In general, the study found a form of culture and a form of resistance against the culture of power in the novel Teguh Anak Jadah by A.D. Donggo. Cultural manifestation in the form of a value system, a system of norms, physical culture, specific rules, politics cultural activities, and the work. Novel Teguh Anak Jadah by A.D. Donggo It also shows the impact of the New Order regime and its cronies make public mindset when it becomes depressed, silent habit deeply ingrained during the New Order government has given rise to a new habit that is easy to forget. Forgetting the role of self, the role of the organization, the role of the family, against fellow citizens of different ideologies.

scholarly journals Adaptando el Lean Project Delivery System a la elaboración o actualización de un plan de estudios de ingeniería civil incorporando BIM, Realidad Virtual y Fotogrametría = Adapting Lean Project Delivery System to the elaboration or updating of the Civil Engineering Undergraduate Degree Plan, incorporating BIM, Virtual Reality and Photogrammetry

2020 ◽  
Vol 4 (3) ◽  
pp. 35
Author(s):  
Xavier Brioso ◽  
Diego Fuentes Hurtado
Keyword(s):  
Virtual Reality ◽  
Delivery System ◽  
Civil Engineering ◽  
Project Delivery ◽  
Lean Principles ◽  
System A ◽  
Catholic University ◽  
A Value ◽  
Management Area

El Lean Project Delivery System (LPDS) es un sistema que implementa principios y herramientas Lean en todo el ciclo de vida de un proyecto de construcción. El LPDS es adaptativo pues es flexible para especificar las entradas y salidas de los procesos y tiene la libertad de elegir herramientas, técnicas y tecnologías acorde a las últimas tendencias. El propósito principal de este artículo es presentar un marco de generación de valor a través de la adaptación del LPDS al proceso de revisión de un plan de estudios. Este trabajo adapta el modelo del LPDS al proyecto de elaboración o actualización de un plan de estudios de la especialidad de ingeniería civil, incorporando BIM, realidad virtual y fotogrametría a lo largo de las asignaturas del área de gestión de la construcción. Se incluyen herramientas blandas y competencias tecnológicas que potencian la empleabilidad del egresado. Como estudio de caso se presenta la aplicación del modelo en la Pontificia Universidad Católica del Perú.ABSTRACTLean Project Delivery System (LPDS) is a system that implements Lean principles and tools throughout the life cycle of a construction project. The LPDS is adaptive because it's flexible enough to specify the inputs and outputs of each process and allows the freedom to choose tools, techniques and technologies according to the latest trends. The main purpose of this paper is to present a value-generation framework through the adaptation of the LPDS to the Undergraduate Degree Plan process. This work adapts the LPDS model to the current project, elaboration or updating of the civil engineering curriculum, incorporating BIM, virtual reality and photogrammetry in the construction management area subjects. Soft tools and technological skills are included, and as such, enhancing the employability of the undergraduate. As a case study, the application of the model is presented at the Pontifical Catholic University of Peru.

scholarly journals Full-scale operation of a novel two-pipe active beam system for simultaneous heating and cooling of office buildings

2019 ◽  
Vol 111 ◽  
pp. 01073
Author(s):  
Alessandro Maccarini ◽  
Göran Hultmark ◽  
Niels C. Bergsøe ◽  
Alireza Afshari
Keyword(s):  
Room Temperature ◽  
Energy Performance ◽  
Physical Parameters ◽  
Heating And Cooling ◽  
System A ◽  
A Value ◽  
Beam System ◽  
Simultaneous Heating ◽  
Simultaneous Heating And Cooling ◽  
Cooling Loads

This paper presents an investigation on the operation of a novel active beam system installed in an office building located in Jönköping, Sweden. The system consists of two parts: a dedicated outdoor air system (DOAS) to satisfy latent loads and ventilation requirements, and a water circuit to meet sensible heating and cooling loads. The novelty of the system is in relation to the water circuit, which is able to provide simultaneous heating and cooling through a single water loop that is near the room temperature. The energy performance of the system is currently being monitored through a number of sensors placed along the water circuit. Relevant physical parameters are being measured and data are available through a monitoring system. A preliminary analysis shows that the system is performing as designed. Results are shown for a typical week in winter, spring and summer. In particular, the supply water temperature in the circuit was between 20°C (in summer) and 23.2°C (in winter). The maximum supply/return temperature difference was found in summer and it assumed a value of 1.5 K. It is noticed that in spring supply and return water temperatures almost overlap.

Summer–winter transitions in Antarctic ponds: III. Chemical changes

2011 ◽  
Vol 24 (2) ◽  
pp. 121-130 ◽  
Author(s):  
Jenny Webster-Brown ◽  
Ian Hawes ◽  
Karl Safi ◽  
Brian Sorrell ◽  
Nathaniel Wilson
Keyword(s):  
Trace Elements ◽  
Water Column ◽  
Ice Shelf ◽  
Toxic Trace Elements ◽  
Mineral Phases ◽  
Show Evidence ◽  
Speciation Modelling ◽  
Geochemical Speciation ◽  
Inorganic Solutes ◽  
High Concentrations

AbstractObservations were made of water column chemistry in four Na-Cl dominated ponds on the McMurdo Ice Shelf from the end of January to early April in 2008. During that time the ponds went from ice-free to predominantly frozen, with only a small volume of residual hypoxic, saline liquid trapped at the base of each pond. Changes in the concentrations of inorganic solutes with time distinguished Na, Cl, Mg, K, SO4, As, U and Mn as ions and trace elements that behave mainly conservatively during freezing, from those which are affected by biological processes (removing HCO3) and the precipitation of mineral phases such as calcite (removing Ca and more HCO3). Dissolved Fe, Mo, Cu and Zn also show evidence of precipitation from the water column during freezing; geochemical speciation modelling predicts the formation of stable insoluble mineral phases such as Fe oxides and oxyhydroxides while conditions are oxic, and Fe-, Cu-, Mo- and Zn-sulphide minerals in the presence of H2S. Consequently, under winter conditions, residual liquid beneath the ice in such ponds is anticipated to be an anoxic Na-Cl brine with the capacity to develop high concentrations of toxic trace elements such as As and U.

Redox speciation of chromium in the oceanic water column of the Lesser Antilles and offshore Otago Peninsula, New Zealand

2003 ◽  
Vol 54 (6) ◽  
pp. 745 ◽  
Author(s):  
Sylvia Sander ◽  
Andrea Koschinsky ◽  
Peter Halbach
Keyword(s):  
New Zealand ◽  
Water Column ◽  
Effective Means ◽  
Stripping Voltammetry ◽  
Speciation Analysis ◽  
Hydrothermal Activity ◽  
Lesser Antilles ◽  
Species Determination ◽  
Seafloor Hydrothermal Activity ◽  
Redox Speciation

Chromium redox speciation analysis was carried out onboard ship in several water column profiles off the islands of Dominica, St Lucia and Grenada (Lesser Antilles), and at two stations offshore from the Otago Peninsula (New Zealand). The catalytic adsorptive stripping voltammetry with diethylenetriaminepentaacetic acid as complexing reagent and a hanging mercury drop as a working electrode were used. In the samples from the Lesser Antilles, Cr(VI) concentrations ranged around a relatively constant background of 1.5–2.5 nM, except for one higher value of 4.3 nM, whereas Cr(III) was highly variable and reached maximum concentrations of 12 nM. Variable environmental influences, such as hydrothermal activity and atmospheric input, are probable sources for reduced chromium species. In contrast, the Cr(III) contribution was less than 50% of total Cr in subantarctic non-hydrothermal water offshore from the Otago Peninsula and the presence of Cr(III) was restricted to the upper 100 m of the water column. In these depth profiles, Cr (VI) (up to 3.7 nM) was clearly the dominating species.Onboard ship redox speciation was shown to be an effective means to avoid storing artefacts in species determination. We conclude that seafloor hydrothermal activity contributes significantly to the reduced Cr species chemistry of the surrounding seawater.

scholarly journals Plankton composition of Hakaluki Haor of Moulvibazar, Bangladesh

2021 ◽  
Vol 30 (1) ◽  
pp. 69-78
Author(s):  
Mohammad Azmal Hossain Bhuiyan ◽  
Mahin Mohid ◽  
SAM Shariar Islam ◽  
Abu Kowser ◽  
Md Rasikul Islam ◽  
...  
Keyword(s):  
Aquatic Organisms ◽  
Co2 Concentration ◽  
Mass Scale ◽  
Fish Kill ◽  
Secchi Disc ◽  
Biological Variables ◽  
A Value ◽  
Gross Α And Β ◽  
Standard Value ◽  
Dead Fish

In the present study, physicochemical and biological variables related to the water quality of Hakaluki Haor were studied. Three study stations viz. Bakshimul, Jalabeel and Dudhai were investigated because of an event of mass scale of dead fish and other aquatic organisms were reported. The stations had water depths from 2.74 - 5.13 m and Secchi Disc Transparency were 0.74 - 1.91 m. The air and water temperature among the three stations ranged from 28.2 - 30.4°C and 21.8 - 28.8°C, respectively. TDS ranged from 35 - 42 mg/l, while the electric conductivity of water showed 40 - 50 μS/cm. SRP, nitrate and SRS ranged from 10.68 - 12.32 μg/l, 0.116 - 0.122 mg/l and, 16.08 - 35.42 mg/l, respectively. The concentration of DO was very poor which ranged from 2.8 - 5.4 mg/l. In all the three studied stations, the free CO2 concentration was 0.096 mg/l. Chlorophyll-a value was moderate in all the three stations (ranged within 34.67 and 40.60 μg/l). The phaeopigment concentration was low and ranged from 1.51- 8.72 μg/l among the studied stations. Concentration of ammonia was much higher (1.03 - 1.72 mg/l) than the standard value for Bangladesh (0.5 mg/l). From this analysis, it is observed that during fish kill event the concentration of ammonia was higher with low DO content which might have resulted because of the decomposition of upper foliar parts of the rice plant due to the sudden inundation. Gross α and β counts were found to be 0.01 and 0.10 Bq/l in the Haor water at the time of fish kill. From the planktonic community, 16 phytoplanktons from green algae, 14 euglenoids, 5 diatoms, 5 dinoflagellates and 12 zooplankton species were recorded. A shift in the pH of the Haor water from acidic to alkaline might have occurred during the last 3 decades. A detailed limnological study covering the climatic seasons of Bangladesh has been recommended to be carried out for Hakaluki Haor. Dhaka Univ. J. Biol. Sci. 30(1): 69-78, 2021 (January)

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