The role of the flow pattern in wastewater aeration tanks

Reactor hydraulics is one of the key factors for plant performance and plant control. The residence time distribution is a good but limited indicator of reactor hydraulics. A more detailed view is obtained by direct observations within the reactor. Two different techniques (conservative tracer, reactive tracer) are discussed to detect major anomalies in the flow field of a wastewater aeration tank. Experiments with conservative tracers give valuable information over a very limited period of time making the analysis of the flow field difficult. On the other hand, reactive tracers can be monitored long term which helps identifying the flow pattern provided that a high spatial and temporal resolution of the measurements is applied. Experimental data is used to determine the structure and the parameters of a compartment model that corresponds well with the measurements.

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Lyell, the Geikies and Croll's observations on terrestrial glacial sediments and landforms

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s1755691021000116 ◽

2021 ◽

pp. 1-14

Author(s):

James ROSE

Keyword(s):

Climate Change ◽

High Quality ◽

Glacial Sediments ◽

Direct Observations ◽

The Social ◽

The Status ◽

Social And Physical Environment ◽

Glacial Landforms

ABSTRACT Within the context of the work and achievements of James Croll, this paper reviews the records of direct observations of glacial landforms and sediments made by Charles Lyell, Archibald and James Geikie and James Croll himself, in order to evaluate their contributions to the sciences of glacial geology and Quaternary environmental change. The paper outlines the social and physical environment of Croll's youth and contrasts this with the status and experiences of Lyell and the Geikies. It also outlines the character and role of the ‘Glasgow School’ of geologists, who stimulated Croll's interest into the causes of climate change and directed his focus to the glacial and ‘interglacial’ deposits of central Scotland. Contributions are outlined in chronological order, drawing attention to: (i) Lyell's high-quality observations and interpretations of glacial features in Glen Clova and Strathmore and his subsequent rejection of the glacial theory in favour of processes attributed to floating icebergs; (ii) the significant impact of Archibald Geikie's 1863 paper on the ‘glacial drift of Scotland’, which firmly established the land-ice theory; (iii) the fact that, despite James Croll's inherent dislike of geology and fieldwork, he provided high-quality descriptions and interpretations of the landforms and sediments of central Scotland in order to test his theory of climate change; and (iv) the great communication skills of James Geikie, enhanced by contacts and evidence from around the world. It is concluded that whilst direct observations of glacial landforms and sediments were critical to the long-term development of the study of glaciation, the acceptance of this theory was dependent also upon the skills, personality and status of the Geikies and Croll, who developed and promoted the concepts. Sadly, the subsequent rejection of the land-ice concept by Lyell resulted in the same factors challenging the acceptance of the glacial theory.

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Changes in Foliar Functional Traits of S. pyrenaicus subsp. carpetanus under the Ongoing Climate Change: A Retrospective Survey

Plants ◽

10.3390/plants9030395 ◽

2020 ◽

Vol 9 (3) ◽

pp. 395

Author(s):

Rosina Magaña Ugarte ◽

Adrián Escudero ◽

Daniel Sánchez Mata ◽

Rosario G. Gavilán

Keyword(s):

Stomatal Density ◽

Weather Conditions ◽

Plant Performance ◽

Adaptive Plasticity ◽

Mountain Areas ◽

Stomatal Size ◽

Physiological Approach ◽

Stomatal Traits

The sensitivity of stomatal behavior and patterning (i.e., distribution, density, size) to environmental stimuli, renders them crucial for defining the physiological performance of leaves. Thus, assessing long-term modifications in stomatal traits in conserved specimens arises as a valuable eco-physiological approach to predict how the rising trend of warmer, drier summers could affect plant fitness; particularly in mountain areas already experiencing climate aggravation and lacking the related monitoring schemes like Mediterranean high-mountains. Variations in foliar and stomatal traits were studied in conserved specimens of Senecio pyrenaicus subsp. carpetanus from Sierra de Guadarrama over the past 71 years. Our findings revealed decreasing trends in leaf width, stomatal size, and increasing tendency in stomatal density, all correlated with the recent 30-year climate exacerbation in these mountains. This evidenced a positive selection favoring traits that allow safeguarding plant performance under drier, hotter weather conditions. The significant relation between stomatal traits and climatic variables upholds the role of stomatal patterning in sensing environmental cues in this species, feasibly optimizing physiological responses involved in the growth–water loss trade-off. The transition to smaller, densely packed stomata observed in recent decades could indicate local-adaptive plasticity in this species, enhancing stomatal response, as coarser environmental conditions take place in Sierra de Guadarrama.

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Specific Features of Luxury Products Branding

Elektronički zbornik radova Veleučilišta u Šibeniku ◽

10.51650/ezrvs.15.3-4.3 ◽

2021 ◽

Vol 15 (3-4) ◽

pp. 29-38

Author(s):

Aleksandra Krajnović ◽

Jurica Bosna ◽

Sara Grubišić

Keyword(s):

Competitive Advantage ◽

Rapid Change ◽

Modern World ◽

Key Factors ◽

Market Strategy ◽

Luxury Goods ◽

Optimal Balance ◽

Luxury Products

In this modern world characterized by rapid change, the role of marketing is increasingly important. Developing a brand is one way in which a competitive advantage can be achieved. The work defines the concept of luxury through the prism of marketing, shows the specifics of marketing in the luxury products market and the key factors that influence the demand for luxury products. The paper found that the key to success is to effectively create a market strategy whose main goal is to create a strong and emotional long-term relationship between the brand and the consumer. Also, the new trend of "abundant rarity" has led companies in the luxury goods sector to strive to strike an optimal balance between exclusivity and affordability.

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Experiments with the long-term rumen simulation technique (Rusitec); use of soluble food and an inert solid matrix

British Journal Of Nutrition ◽

10.1079/bjn19790110 ◽

1979 ◽

Vol 42 (2) ◽

pp. 229-245 ◽

Cited By ~ 29

Author(s):

J. W. Czerkawski ◽

Grace Breckenridge

Keyword(s):

Dilution Rate ◽

Solid Phase ◽

Compartment Model ◽

Solid Food ◽

Solid Matrix ◽

Fermentation Pattern ◽

Micro Organisms ◽

Reaction Vessels

1. The role of soluble nutrients and of the solid matrix in rumen fermentation was investigated in some detail, and experiments designed to explore the possibility of using a balanced soluble diet and an inert solid matrix, are described.2. The use of a balanced soluble substrate as the only source of nutrients in the presence of an inert solid phase in the reaction vessels results in vigorous fermentation but is accompanied by disappearance of protozoa from the effluent.3. In the absence of digestible solid phase, the rate of fermentation and the fermentation pattern depends mainly on the amount and type of nutrients supplied and to a smaller extent on the dilution rate, the variations being greatest at low dilution rates.4. The solid matrix in the form of wood shavings or the residue remaining after prolonged digestion of hay could sequestrate micro-organisms and could be used as solid phase, but the defined mixture of soluble substrates used resulted in somewhat abnormal fermentation compared with fermentation obtained with solid food.5. When the solid food included some hay extract and when the dilution rate was not too great a reduced output of protozoa could be maintained. At high dilution rate the outflow of protozoa was negligible and yet considerable numbers of protozoa were found in the solid matrix and associated liquid.6. A three-compartment model was developed to describe the flow of liquid and microbial matter within the simplified system.

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Large-Volume Intrathecal Administrations: Impact on CSF Pressure and Safety Implications

Frontiers in Neuroscience ◽

10.3389/fnins.2021.604197 ◽

2021 ◽

Vol 15 ◽

Author(s):

Vasily Belov ◽

Janine Appleton ◽

Stepan Levin ◽

Pilar Giffenig ◽

Beata Durcanova ◽

...

Keyword(s):

Large Volume ◽

Biological Effects ◽

Dependent Manner ◽

Key Factors ◽

Contributing Factors ◽

Csf Pressure ◽

The Central Nervous System ◽

Different Levels

The increasing number of studies demonstrates the high potency of the intrathecal (IT) route for the delivery of biopharmaceuticals to the central nervous system (CNS). Our earlier data exhibited that both the infused volume and the infusion rate can regulate the initial disposition of the administered solute within the cerebrospinal fluid (CSF). This disposition is one of key factors in defining the subsequent transport of the solute to its intended target. On the other hand, fast additions of large volumes of liquid to the CSF inevitably raise the CSF pressure [a.k.a. intracranial pressure (ICP)], which may in turn lead to adverse reactions if the physiologically delimited threshold is exceeded. While long-term biological effects of elevated ICP (hydrocephalus) are known, the safety thresholds pertaining to short-term ICP elevations caused by IT administrations have not yet been characterized. This study aimed to investigate the dynamics of ICP in rats and non-human primates (NHPs) with respect to IT infusion rates and volumes. The safety regimes were estimated and analyzed across species to facilitate the development of translational large-volume IT therapies. The data revealed that the addition of a liquid to the CSF raised the ICP in a rate and volume-dependent manner. At low infusion rates (<0.12 ml/min in rats and <2 ml/min in NHPs), NHPs and rats displayed similar tolerance patterns. Specifically, safe accommodations of such added volumes were mainly facilitated by the accelerated pressure-dependent CSF drainage into the blood, with I stabilizing at different levels below the safety threshold of 28 ± 4 mm Hg in rats and 50 ± 5 mm Hg in NHPs. These ICPs were safely tolerated for extended durations (of at least 2–25 min). High infusion rates (including boluses) caused uncompensated exponential ICP elevations rapidly exceeding the safety thresholds. Their tolerance was species-dependent and was facilitated by the compensatory role of the varied components of craniospinal compliance while not excluding the possibility of other contributing factors. In conclusion, large volumes of liquids can safely be delivered via IT routes provided that ICP is monitored as a safety factor and cross-species physiological differences are accounted for.

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Restoring lions Panthera leo to northern KwaZulu-Natal, South Africa: short-term biological and technical success but equivocal long-term conservation

Oryx ◽

10.1017/s003060530700172x ◽

2007 ◽

Vol 41 (2) ◽

pp. 196-204 ◽

Cited By ~ 63

Author(s):

L.T.B. Hunter ◽

K. Pretorius ◽

L. C. Carlisle ◽

M. Rickelton ◽

C. Walker ◽

...

Keyword(s):

South Africa ◽

Home Ranges ◽

Large Carnivores ◽

Key Factors ◽

Short Term ◽

Kwazulu Natal ◽

Release Area ◽

Methodological Considerations

AbstractThe success of efforts to re-establish mammalian carnivores within their former range is dependent on three key factors: methodological considerations, the biological requirements of the target species, and the involvement of local human communities for whom large carnivores pose a threat. We consider the role of these factors in the first 13 years of an effort to re-establish wild lions in northern KwaZulu-Natal Province, South Africa. We employed soft-release methods to mitigate the characteristic problems associated with restoration of large carnivores. A pre-release captivity period facilitated acclimatization of reintroduced lions and promoted long-term bonding of unfamiliar individuals into cohesive groups. All individuals remained in the release area and established enduring, stable home ranges. Reintroduced lions successfully reproduced and raised 78% of their cubs to independence. Human activity was the cause of all post-release mortality. Despite rapid population growth and the re-establishment of the species at Phinda Private Game Reserve, the population is small and isolated with little prospect for re-colonizing additional areas where the species has been extirpated, or for connecting with other isolated lion populations in the region. Accordingly, although we essentially overcame the short-term technical and biological challenges facing lion reintroduction, the long-term value of the Phinda population for addressing the conservation issues facing the species remains equivocal.

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