312,532 research outputs found
Tertiary nitrification of wastewater in trickling filters
No full textThis study was designed to investigate, at laboratory and pilot scale, the effects of
various loading and climatic factors on the nitrification perfon-nance of four media, and
to undertake a comparative assessment of the media. The media used were blast furnace
slag and three random plastic media: Flocor RS, Etapak 160 and a new medium, Etapak
210.
Laboratory experiments using pure cultures of Nitrosomonas europaea have determined
the effect on nitrification of temperature, pH and substrate, BOD and inhibitor
concentrations. Optimal values have been resolved for the temperature and pH and half-
saturation constants for the substrate and inhibition are calculated for pure culture
conditions. The presence of glucose and glutamic acid has been shown to have a
beneficial effect on nitrification, although this observation could not be adequately
explained.
Pilot scale research, conducted over a two year period, has provided an accurate
representation of a nitrifying trickling filter by using effluent from Cranfield STW in
filters exposed to the full climadc variation. Data obtained from these filters have
indicated the superior performance of the blast furnace slag media due mostly to its
ability to maintain a large active bacterial Population without excessive accumulation.
Results have been used to support or challenge previous publications, and to generate
a set of desion curves.
Conclusions from this research have been used in the design of a full scale nitrifying
trickling filter which has been constructed at Cranfield STW, early data from which are
presented
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
Ability of local species plant in surface flow constructed wetland to reduce biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in sasirangan wastewater
No full textAbstract
Sasirangan wastewater has characteristics of high pH as well as high level of biochemical oxygen demand(BOD)and chemical oxygen demand(COD). Sasirangan industries produce large amount of wastewater, which then is directly discarded around the environment without treatment processes. The effect afterward is the oxygen supply in the water diminishes and eventually triggers the activity of anoxic-anaerobic microorganisms that produces odors. Constructed wetlands are able to become the alternative to waste treatment technology at the economical household scale industries. This study was conducted to determine the ability of the removal of BOD and COD in the sasirangan effluent with constructed wetlands (CW) surface flow system using the batch method. Plants used in CW is Hydrilla verticillata, purun tikus (Eleocharis dulcis) and lotus (Nelumbo nucifera). CW was running for 0, 3, 6, 9 and 12 days. This study shows that the best removal of BOD dan COD in CW occurred on 12th days. BOD and COD removal for 12 days at the CW reactor that planted with H. verticillata, E. dulcis, N. nucifera, and the combination of all plant, respectively is 98.19% and 98.41%; 98.74% and 98.73%; 98.48% and 98.61%; 98.89% and 98.83%. It can be concluded that CW planted with H. verticillata, E. dulcis, N. nuciferacan remove BOD and COD on liquid waste sasirangan with the greatest efficiency at CW with combination of plants with retention time of 12 day
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Sulla dinamica stocastica del BOD lungo un corso d'acqua
No full textIl BOD è una delle grandezze chiave per caratterizzare le qualità dell'acqua nei fiumi. A questo proposito la nota tratta il problema in cui siano presenti sorgenti puntuali e casuali di BOD, ciascuna delle quali con una propria funzione densità di probabilità. Risultato del lavoro è la descrizione dell'evoluzione, lungo il corso d'acqua, della probabilità della concentrazione di BOD. La cinetica di decadimento è modellata in modo sia lineare sia non lineare ed un'eventuale incertezza già presente nella condizione iniziale è anche contemplata. Il problema è modellato come un processo differenziale stocastico e viene risolto analiticamente per qualsivoglia distribuzione probabilistica delle immission
Explaining New Phenomena in Terms of Previous Phenomena
No full textIt has become increasingly clear that natural phenomena cannot be formally deduced from laws but that almost every phenomenon has its own particular way of being linked to higher-level generalizations, usually via approximations, normalizations and corrections. This article deals with the following problem: if there are no general principles to link laws to phenomena, and if each phenomenon has its own way of being explained, how can we -- or how can a theory -- explain any new phenomenon? I will argue that while particular explanations only apply to the specific phenomena they describe, parts of such explanations can be productively reused in explaining new phenomena. This leads to a view on theory, which I call maximalism, according to which new phenomena are understood in terms of previous phenomena. On the maximalist view, a theory is not a system of axioms or a class of models, but a dynamically updated corpus of explanations. New phenomena are explained by combining fragments of explanations of previous phenomena. I will give an instantiation of this view, based on a corpus of phenomena from classical and fluid mechanics, and show that the maximalist approach is not only used but also needed in scientific practice
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