scholarly journals Technical note: A time-integrated sediment trap to sample diatoms for hydrological tracing

2020 ◽  
Author(s):  
Jasper Foets ◽  
Carlos E. Wetzel ◽  
Núria Martinez-Carreras ◽  
Adriaan J. Teuling ◽  
Jean-François Iffly ◽  
...  
Keyword(s):  
Sampling Method ◽  
Water Quality Assessment ◽  
Technical Note ◽  
Terrestrial Environment ◽  
Run Off ◽  
Algal Groups ◽  
Sediment Data ◽  
Almost All ◽  
Diatom Community Composition ◽  
Representative Samples

Abstract. Diatoms, microscopic, single-celled algae, are present in almost all habitats containing water (e.g. streams, lakes, soil, rocks) and form one of the most common and diverse algal groups in both freshwaters and marine ecosystems. In the terrestrial environment, their diversified species distributions are mainly controlled by physiographical factors and anthropic disturbances. This makes them useful tracers in catchment hydrology. In their use as a hydrological tracer, diatoms are generally sampled in streams by means of an automated sampling method and as a result many samples are collected to cover a whole storm run-off event. As diatom analysis is labour intensive, a trade-off has to be made between the number of sites and the amount of samples per site. A potential way to reduce this number is by using a time-integrated mass-flux sampler. Here, we explored the potential for the Phillips sampler to provide a representative sample of the diatom assemblage of a whole storm run-off event. We addressed this by comparing the diatom community composition of the Phillips sampler to the composite community collected by the automatic samplers for three events. Our results indicate that during two events the Phillips sampler sampled representative samples, whereas significantly different communities were collected during the third event. However, sediment data of this event, which was sampled with automatic samplers, showed much noise meaning that we could not verify if the Phillips sampler sampled representative communities or not. Nevertheless, we believe that this sampler could not only be applied in hydrological tracing using terrestrial diatoms, but may also be a useful tool in water quality assessment.

scholarly journals Technical note: A time-integrated sediment trap to sample diatoms for hydrological tracing

2020 ◽  
Vol 24 (10) ◽  
pp. 4709-4725
Author(s):  
Jasper Foets ◽  
Carlos E. Wetzel ◽  
Núria Martínez-Carreras ◽  
Adriaan J. Teuling ◽  
Jean-François Iffly ◽  
...  
Keyword(s):  
Water Quality Assessment ◽  
Technical Note ◽  
Sampling Effort ◽  
Terrestrial Environment ◽  
The Third ◽  
Run Off ◽  
Analysis Of Similarity ◽  
Sediment Data ◽  
Almost All ◽  
Diatom Community Composition

Abstract. Diatoms, microscopic single-celled algae, are present in almost all habitats containing water (e.g. streams, lakes, soil and rocks). In the terrestrial environment, their diversified species distributions are mainly controlled by physiographical factors and anthropic disturbances which makes them useful tracers in catchment hydrology. In their use as a tracer, diatoms are generally sampled in streams by means of an automated sampling method; as a result, many samples must be collected to cover a whole storm run-off event. As diatom analysis is labour-intensive, a trade-off has to be made between the number of sites and the number of samples per site. In an attempt to reduce this sampling effort, we explored the potential for the Phillips sampler, a time-integrated mass-flux sampler, to provide a representative sample of the diatom assemblage of a whole storm run-off event. We addressed this by comparing the diatom community composition of the Phillips sampler to the composite community collected by automatic samplers for three events. Non-metric multidimensional scaling (NMDS) showed that, based on the species composition, (1) all three events could be separated from each other, (2) the Phillips sampler was able to sample representative communities for two events and (3) significantly different communities were only collected for the third event. These observations were generally confirmed by analysis of similarity (ANOSIM), permutational multivariate analysis of variance (PERMANOVA), and the comparison of species relative abundances and community-derived indices. However, sediment data from the third event, which was sampled with automatic samplers, showed a large amount of noise; therefore, we could not verify if the Phillips sampler sampled representative communities or not. Nevertheless, we believe that this sampler could not only be applied in hydrological tracing using terrestrial diatoms, but it might also be a useful tool in water quality assessment.

scholarly journals Water Quality Assessment of West Tarum Canal for Drinking Water Supply

2021 ◽  
Vol 277 ◽  
pp. 04003
Author(s):  
Ayu Widya Utami ◽  
Dwi Nowo Martono ◽  
Haruki Agustina
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Integrated Management ◽  
Water Quality Assessment ◽  
Polluted Water ◽  
Infrastructure Development ◽  
Raw Water ◽  
Agriculture Industry ◽  
The Government ◽  
Almost All

West Tarum Canal (WTC) is a canal that drains raw water from the Jatiluhur Dam. Nearly 81% of the raw water for drinking water used by Jakarta’s people comes from this canal. However, various land uses such as agriculture, industry, settlements, and infrastructure development impact WTC’s water quality. This research aims to assess WTC’s water quality in 2016-2020 based on water quality standards set by the Government and using the STORET method. The results of this research indicate that the concentrations of TDS (142-351 mg/L), Fe (0.1-0.15 mg/L), Mn (0.03-0.1 mg/L) are meet the standards, while DO (3.6-4.9 mg/L), BOD (4-10 mg/L), COD (13-30 mg/L) are not meet the standards. Almost all monitoring points have pH values between 5.75-7.68 that are meet the standards. The STORET score of WTC is from -26 to -38 with an average of -30, which indicates that WTC’s water quality is moderately polluted. Water contamination in WTC will burden the drinking water processing and ultimately affect the community’s ability to pay for drinking water. This research also shows the need for integrated management of WTC from upstream to downstream and the need to increase collaboration between stakeholders in carrying out this management.

scholarly journals Association Between Serum Albumin And The Success Of Fluid Resuscitation In Children Hospitalizen In Cipto Mangunkusumo Hospital Burn Center

2019 ◽  
Vol 5 (2) ◽  
pp. 226-233
Author(s):  
Rismala Dewi ◽  
Karina Kaltha ◽  
Aditya Wardhana ◽  
Piprim B. Yanuarso
Keyword(s):  
Serum Albumin ◽  
Fluid Resuscitation ◽  
Sampling Method ◽  
Burn Injury ◽  
Significant Loss ◽  
Mortality And Morbidity ◽  
Burn Center ◽  
Pediatric Resuscitation ◽  
Almost All ◽  
Burn Patient

Background : Burn injury has a great impact on mortality and morbidity in children. Significant loss of albumin (hypoalbuminemia) in burn patient often leads to serious complications. However, it is still unclear whether serum albumin has a role in the success of fluid resuscitation in children with burn injury. Method : This is a retrospective cohort study based on medical record of children hospitalized with burn injury at Cipto Mangunkusumo Hospital Burn Centre from January 2012-March 2018. The subjects collected with the total sampling method. Result : Most burn injury happen because of scalds, and have grade 2 burn injury with PELOD score<10. Almost all subjects was succesfully resuscitated in the first 24 hour (95,1%). No association was found between the success of fluid resuscitation with either serum albumin [RR 1,175(95%CI 0,3-4,4) p=0,812], or with ureum, creatinin, lactate level, weight and the degree/extent of the burn injury. Conclusion: The success rate of fluid resuscitation in pediatric burn injury was quite high in Cipto Mangunkusumo Hospital Burn Centre. No association was found between serum albumin and the success of fluid resuscitation during the first 24 hour period. Keywords: albumin, burn, pediatric, resuscitation  

CFD Simulation of Fin-and-Tube Heat Exchanger with Louvered Fin Configuration: Technical Note

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
M. Sabari ◽  
D. Channankiah ◽  
D. Shivalingappa
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Cfd Simulation ◽  
Calculated Data ◽  
Technical Note ◽  
Operating Conditions ◽  
Tube Heat Exchanger ◽  
Louvered Fin ◽  
Almost All

Heat exchanger plays a major role in almost all mechanical industries. Enhancement of heat transfer surface plays major role in numerous applications such as in heat exchangers, refrigeration and air conditioning systems etc. This paper examines the fluid flow and heat exchange on the air side of a multi-row fin-and-tube heat exchanger. A brief comparison is given between fin-and-tube heat exchanger attributes with louvered fins in a wider range of operating conditions defined by inlet air velocities. The brief representation on the calculated data for the louvered heat exchanger shows better heat transfer characteristics with a slightly higher pressure drop. The CFD procedure is validated by comparing the numerical simulation results with different inlet air velocities. Best combination of higher heat transfer and minimum pressure drop are occurred in inlet air velocity of 2.5 m/s.

Seasonal variation in the diet of a population of Hyla arborea from Romania

2007 ◽  
Vol 28 (4) ◽  
pp. 485-491 ◽  
Author(s):  
Diana Cupsa ◽  
Tibor Hartel ◽  
Severus-Daniel Covaciu-Marcov ◽  
István Sas ◽  
Éva-Hajnalka Kovács ◽  
...  
Keyword(s):  
Dietary Diversity ◽  
Diversity Index ◽  
Stomach Contents ◽  
Activity Period ◽  
Feeding Intensity ◽  
Terrestrial Environment ◽  
Hyla Arborea ◽  
Plant Remains ◽  
Almost All ◽  
Prey Items

Abstract We examined the diet of Hyla arborea over its entire activity period (March to late September, 2004), and analysed a total of 585 adult samples. From the stomach contents we identified plant remains, shed-skin fragments, and animals. We identified a total of 2976 prey items, almost all of which originated from the terrestrial environment. Adult araneans and coleopterans were the most abundant prey items in the diet of the studied tree frogs. Some of the prey items become abundant in certain parts of the year (e.g. Homoptera, Lepidoptera larvae, Trichoptera). The dietary diversity index is high and exhibits seasonal changes. During the period of study an important seasonal change was observed in feeding intensity and in the type of consumed prey. Our results show that Hyla arborea has a broad dietary diversity which was expected as a consequence of exploiting the habitat both vertically and horizontally, possibly allowing access to a broader spectrum of prey.

scholarly journals Australasian Public Awareness and Belief in Conspiracy Theories: Motivational Correlates

2021 ◽  
Author(s):  
Mathew Marques ◽  
Mathew Ling ◽  
Matt Williams ◽  
John Kerr ◽  
Jim McLennan
Keyword(s):  
Political Ideology ◽  
Public Awareness ◽  
Belief System ◽  
Systematic Investigation ◽  
Analytic Thinking ◽  
Conspiracy Theories ◽  
Nationally Representative ◽  
The Government ◽  
Almost All ◽  
Representative Samples

Conspiracism is not restricted to the fringe dwellers of society. International research suggests that such beliefs are quite common and that conspiracy theories may serve three basic psychological motives (i.e., epistemic, existential, and relational) for individuals. Yet, little is known about conspiracy theory awareness or conspiracism in Australasia. We report the first large systematic investigation of system justifying motives using two nationally representative samples of Australians (n = 1,011) and New Zealanders (n = 754). Our findings show that almost all are aware of local and international conspiracies, and the majority endorse one or more. Also, that all three psychological motives consistently relate to conspiracism but not to awareness. In a series of hierarchical multiple regressions, we find that epistemic (i.e., decreased analytic thinking), existential (i.e., less trust in others, and socially conservative political ideology and increased religiosity), and relational motives (i.e., increased anomie and disillusionment with the government) were all significant unique predictors of increased local and international conspiracism. Findings are discussed in terms of the importance of understanding conspiracism as an ideological belief system that may function to serve underlying psychological motives.

scholarly journals On the verification of climate reconstructions

2007 ◽  
Vol 3 (3) ◽  
pp. 397-409 ◽  
Author(s):  
G. Bürger
Keyword(s):  
A Priori ◽  
Inverse Regression ◽  
Limited Sample ◽  
Climate Reconstructions ◽  
Skill Scores ◽  
Calibration Sets ◽  
Significance Levels ◽  
Complete Set ◽  
Almost All ◽  
Representative Samples

Abstract. The skill of proxy-based reconstructions of Northern hemisphere temperature is reassessed. Using an almost complete set of proxy and instrumental data of the past 130 years a multi-crossvalidation is conducted of a number of statistical methods, producing a distribution of verification skill scores. Among the methods are multiple regression, multiple inverse regression, total least squares, RegEM, all considered with and without variance matching. For all of them the scores show considerable variation, but previous estimates, such as a 50% reduction of error (RE), appear as outliers and more realistic estimates vary about 25%. It is shown that the overestimation of skill is possible in the presence of strong persistence (trends). In that case, the classical "early" or "late" calibration sets are not representative for the intended (instrumental, millennial) domain. As a consequence, RE scores are generally inflated, and the proxy predictions are easily outperformed by stochastic, a priori skill-less predictions. To obtain robust significance levels the multi-crossvalidation is repeated using stochastic predictors. Comparing the score distributions it turns out that the proxies perform significantly better for almost all methods. The scores of the stochastic predictors do not vanish, nonetheless, with an estimated 10% of spurious skill based on representative samples. I argue that this residual score is due to the limited sample size of 130 years, where the memory of the processes degrades the independence of calibration and validation sets. It is likely that proxy prediction scores are similarly inflated and have to be downgraded further, leading to a final overall skill that for the best methods lies around 20%. The consequences of the limited verification skill for millennial reconstructions is briefly discussed.

scholarly journals Seasonal Variation of Solute Concentration in Melt Waters Draining from an Alpine Glacier

1981 ◽  
Vol 2 ◽  
pp. 11-16 ◽  
Author(s):  
D.N. Collins
Keyword(s):  
Electrical Conductivity ◽  
Seasonal Variation ◽  
Solute Concentration ◽  
Alpine Glacier ◽  
Annual Variations ◽  
Solids Concentration ◽  
Run Off ◽  
Melt Water ◽  
Discharge Regime ◽  
Almost All

Electrical conductivity of melt waters draining from the portal of Gornergletscher, Switzerland, was recorded continuously for extended periods during the 1978‐79 hydrological year. Conductivity was used as a surrogate measure of the total dissolved solids concentration in melt water to describe the seasonal variation of solute, and its relation to discharge, in an attempt to use melt-water hydrochemistry as an indicator of the nature of subglacial processes within an alpine glacier. In winter, conductivity was 2 to 10 times higher than during the summer ablation season. and also showed considerable diurnal and annual variations independent of discharge. The transition from winter to summer discharge regime was preceded by falling solute concentration. A distribution shaped as a “triangle-with-spike” describes the complex relationship between discharge and electrical conductivity for the annual cycle of run-off. Almost all the solute load from beneath Gornergletscher is evacuated during summer. Melt-water hydrochemistry provides some insight into the nature of sub-glacial chemical processes, but, since melt waters do not appear to have access to all areas of the glacier bed, it probably under-estimates total chemical activity.

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