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Wyszukujesz frazę "Schmidt, R." wg kryterium: Autor


Tytuł:
Występowanie substancji chloroorganicznych w wodzie po procesie utleniania oraz możliwości ich analizy
Occurence of chlororganic substances in water after oxidation and their analysis capabilities
Autorzy:
Schmidt, R.
Powiązania:
https://bibliotekanauki.pl/articles/1819768.pdf
Data publikacji:
2009
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
substancje chloroorganiczne
woda
tlen
utlenianie
chlororganic substances
water
oxidation
Opis:
Chromatographic analysis GC makes several problems during optimisation and separation of analysed substances. Programming of temperature increase,temperature of feeder and temperature of detector are the most common problems. Than it is neccesary to take into consideration other factors, which will have significant impact on retention time, selectivity of separation of analysed compounds or retention index. The chosen results of the research into the influence of various oxidants on forms and quantity of the occurrence of THM, MX-THAT and the Purgeable Halogenoacetic acids in drinking water have been presented in this paper. As a result of conducted research the influence of chemical composition of water, a dose and a sort of applied oxidant on the quantity of the formed chlororganic substances has been shown. It also has been shown that these substances are also formed as a result of oxidation with compounds not containing chlorine.According to the form of the occurring chlororganic compounds and their concentrationafter hydrogen dioxide oxidation, various toxic compounds are possible to beformed. They are cancerogenic and mutagenic ones. The concentration of by-products of oxidation depends on the presence anda sort of precursors, a sort of disinfectant, temperature, season, time of contact and reactionof solution. The kinds and quantity of oxidation by-products also depend on a kindof oxidant and the concentration of the catalyst. Such catalysts in natural waters areinorganic compounds. The capabilities of their quantification using gas chromatographyhave also been presented.Analysis of real samples showed high repeatability and accuracy of conducteddeterminations. Such analysis required accurate sample purification and comparison ofthree extractants because of high concentration of high molecular substances (fulvic acids).
Źródło:
Rocznik Ochrona Środowiska; 2009, Tom 11; 837-848
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Walidacja metod analitycznych chemicznych i mikrobiologicznych
Validation of chemical and microbiological analytic methods
Autorzy:
Schmidt, R.
Michna, D.
Powiązania:
https://bibliotekanauki.pl/articles/1826088.pdf
Data publikacji:
2007
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
analiza chemiczna
zanieczyszczenie środowiska
walidacja
pomiary analityczne
Opis:
Jednym z podstawowych kierunków rozwojowych analityki i monitoringu zanieczyszczeń środowiska jest dążenie do oznaczania coraz mniejszych stężeń składnika w próbkach o złożonej matrycy. Tego typu zadanie jest wielkim wyzwaniem dla analityków i wymaga zwrócenia uwagi na kontrolę i zapewnienie jakości wyników badań [4÷6, 17, 19, 20]. Dokładność oznaczeń można osiągnąć stosując proces walidacji metody analitycznej z różnymi matrycami [3, 7, 22, 23, 28]. Walidacja metody jest procesem ustalenia czy charakterystyki techniczne metody analitycznej są odpowiednie do zamierzonego celu. Dla uzyskania najbardziej wiarygodnych wyników należy przeanalizować metodykę badawczą, w tym procedurę przygotowywania i pobierania próbek. Ważność metody można zweryfikować tylko poprzez badania międzylaboratoryjne [5, 11, 13, 14, 18, 29, 30, 37]. W skład procedury oszacowania jakości wchodzą zazwyczaj następujące elementy: kontrola i ocena dokładności uzyskiwanych wyników poprzez okresowe analizowanie próbek kontrolnych, ocena dokładności metody poprzez: analizę próbek certyfikowanych materiałów odniesienia, porównanie uzyskanych wyników z wynikami uzyskanymi dla tej samej próbki przy zastosowaniu metody odniesienia, wykonanie analiz próbek po dodaniu do nich wzorca, przeprowadzenie porównawczych badań miedzylaboratoryjnych, stosowanie kart kontrolnych, stosowanie odpowiedniego systemu rewizji (auditingu). Ponieważ brak jest dokładnej metodyki przeprowadzenia procesu walidacji metody badawczej dlatego celem pracy jest przedstawienie możliwości przeprowadzenia walidacji z zastosowaniem zarówno metod chemicznych jak i mikrobiologicznych.
One of the basic developmental directions of the environment pollution analytics and monitoring is aspiration to determination more and more small concentrations of components in samples with complex matrix. This type of problem is great challenge for analysts and requires turning attention to control and assurance of the quality of investigations results. Accuracy of analysis may be reached by applying process of the validation of the analytic method with various matrices. Validation of method is the process of settlement if technical profile of analytic methods are suitable for the intended aim. In order to obtain the most reliable results research methodology, including procedure of preparing and taking the samples, should be analysed. Validity of method may be verified only by interlaboratory investigations. Procedure of quality estimation usually consists of following elements: o control and evaluation of gained results accuracy by periodical analysing of control samples, o evaluation of method accuracy by: analysis of samples of certified reference materials, comparison of gained results with results obtained for the same sample using reference method, analyse of samples after addition of standard, execution of comparative interlaboratory analyses, application of supervisory cards, application of suitable system of inspection (auditing). Three parameters are inseparably connected with validation of analytic method: o limit of detection (LOD), recommended bottom level of this parameter value is triple value of standard deviation for given method, o reliable detection limit (RDL) - its value should be at least six-time value of standard deviation, o limit of quantitation (LOQ) that is value recognized as the smallest reliable (on the level of probability at least 99%) result of determination using given method. Its value should be between 9 and 10s (s - standard deviation). Validation of chemical and microbiological methods includes testing essential characteristic features of the method. Laboratory, in order to fulfil suitable criteria, should set up, apply, keep and develop quality system, proper for the range of its activity with regard to all undertaken activities and kinds of investigations. Quality system in the laboratory should be suitable for kind and quantity of executed investigations. During samples analysis data should be validated. This process includes both documentation and control of inviolability and idnetifibility of data.
Źródło:
Rocznik Ochrona Środowiska; 2007, Tom 9; 239-257
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
200 years of land - use change and gully erosion : a case study from Małopolska, SE Poland
Autorzy:
Schmidt, R.
Heinrich, J.
Powiązania:
https://bibliotekanauki.pl/articles/295154.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Geomorfologów Polskich
Tematy:
gully erosion
human impact
land-use change
Małopolska
Polska
Opis:
Loess areas are highly affected by human impact since the Neolithic revolution. Within the study in Małopolska we assess the impact of land-use changes on geomorphological processes for the last 200 years. Phases of deforestation and a subsequent intensive agricultural use can be correlated with the appearance of gully erosion.
Źródło:
Landform Analysis; 2011, 17; 167-171
1429-799X
Pojawia się w:
Landform Analysis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ modyfikacji zeolitów na ich właściwości fizykochemiczne
Impact of zeolites modification on their physicochemical properties
Autorzy:
Świderska-Dąbrowska, R.
Schmidt, R.
Powiązania:
https://bibliotekanauki.pl/articles/1819297.pdf
Data publikacji:
2012
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
ion exchange
natural clinoptilolite
removal
cations
metals
Cr3+
cu2+
pb2+
Fe3+
Opis:
Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth metals (Na, K, Mg, Ca, Sr, Ba), in which the pore size is 0.3-1.2 nm and depends on the structure of the zeolite. They consist of tetrahedrons of [AlO4]-5- and [SiO4]4-, which make ordered crystal lattice of rings, channels and chambers. Variable degree of oxidation of silicon (IV) and aluminum (III) causes their electronegative character. The size of the charge may determine the adsorption, ion exchange and catalytic capacities of zeolite. The structure made of ring tetrahedron units contains open tunnels, making zeolites also molecular sieves. Zeolites are mostly used for adsorption of ammonium ions from aqueous solutions, removal of radioactive elements and heavy metals, and recent studies suggest the possibility of application of zeolites for removal of chloroorganic compounds and oily pollutants. The most widely used zeolite in practice for water and wastewater treatment is clinoptilolite, which is characterized by large ion exchange and adsorption capacity. Authors of many works explain the adsorption process with ion exchange. But when interpreting the results the authors do not consider that the zeolites have also tunnels that make them also molecular sieves. As a result of ion adsorption on clinoptilolite in hydrogen or sodium form, pH of the solution decreases, resulting in possible formation of electropositive, electronegative complexes and dissociated ions which make up aquaions, increasing or decreasing the effectiveness of their removal. During usage of modified zeolites for the adsorption of ions from aqueous solutions, many accompanying processes take place, such as precipitation, coprecipitation and catalytic adsorption. The influence of the physicochemical properties of natural zeolite and zeolite in the hydrogen form on an aqueous solution in the process of washing out is presented in the paper. Presented results clear prove that the decisive factor affecting the quality of the aqueous solution after the washing out process is initial pH of the solution. Depending on method of modification, physicochemical properties of zeolites can vary considerably. Transformation of natural zeolite into the hydrogen form increases its acidity and physical and chemical resistance. Modification of zeolite with HCl may also increase the content of pure zeolite by dissolution of other, non-zeolite materials. Zeolite H has a greater content of of silicon and aluminum compounds in relation to total mass which is a result of introduction of protons into the zeolite. This is confirmed by lower content of alkali metals and alkaline earth metals (sodium, calcium and potassium) in ZH. Exchange of ions of sodium, potassium, calcium for protons is a result of modification of ZN with HCl. Examination of washing out process showed that there is a small migration of impurities (Fe and Ca) from ZH as compared to ZN. At the same time increase of iron content in the solution increases its turbidity. And also turbidity depends on the initial pH of the solution. It's highest value was observed when the initial pH was equal to 6. Significant increase of turbidity as a function of pH is mainly caused by abrasion of zeolite grains in the process of shaking and by formation of precipitable complexes of iron and calcium. The paper presents also the results of zeta potential measurements. potential of H zeolite in the investigated range of pH has a much higher absolute values compared to ZN and vary in the range from -20 mV to -30 mV. H zeolite has a higher electrostatic activity than natural zeolite. Potential creating ions such as H+ and OH- have decisive influence on the zeolite surface charge.
Źródło:
Rocznik Ochrona Środowiska; 2012, Tom 14; 460-470
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Sedimentation Supported by Coagulation Process on Effectiveness of Separation of the Solid Phase from Wastewater Stream
Autorzy:
Maciołek, P.
Szymański, K.
Schmidt, R.
Powiązania:
https://bibliotekanauki.pl/articles/123962.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
wastewater treatment
coagulation
flocculation
separation
Opis:
The objective of this work was to test the impact of coagulant and flocculant at the stage of mechanical wastewater treatment on the wastewater treatment plant operation, performed in the A2O process. In this paper, the principles of correct conduct of coagulation in wastewater treatment have been discussed. It appears from the research performed that significant elimination of BOD5 such as 20÷30%, total suspended matter up to 90%, COD up to 50% and total nitrogen at 30% level was achieved supported by the coagulation process in the pre-settling tanks. Approximately 50% of phosphorus was eliminated after the mechanical part. Additionally, a significant impact of Superfloc flocculant on the effectiveness of the solid phase separation (activated sludge) in the secondary settling tank was noted under diversified flow conditions.
Źródło:
Journal of Ecological Engineering; 2018, 19, 6; 81-87
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości fizykochemiczne zeolitu modyfikowanego jonami żelaza
Physicochemical properties of modified with iron ions zeolite
Autorzy:
Świderska-Dąbrowska, R.
Schmidt, R.
Sikora, A.
Powiązania:
https://bibliotekanauki.pl/articles/400983.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
katalizator heterogeniczny
naturalne zeolity
modyfikacja zeolitów
potencjał elektrokinetyczny
rozmywalność
heterogeneous catalyst
natural zeolites
zeolites modification
elektrokinetic potential
elution test
Opis:
W dobie wzrastającego zanieczyszczenia środowiska naturalnego istotne jest poszu-kiwanie coraz efektywniejszych metod ich usuwania. W szczególności zastosowanie tanich i łatwo dostępnych katalizatorów "proekologicznych" - naturalnych zeolitów, pozwala na intensyfikację wielu procesów, a ponadto nie są wnoszone do środowiska dodatkowe zanieczyszczenia. Szerokie zastosowanie naturalnych zeolitów - uwodnionych glinokrzemianów, wynika z ich wyjątkowej struktury przestrzennej, nadającej im właściwości molekularno-sitowe, jonowymienne i sorpcyjne oraz dużą aktywność katalityczną. Ich powierzchnię można łatwo modyfikować jonami metali. Stąd mogą one być z powodzeniem stosowane jako heterogeniczny katalizator w procesie Fentona, do utleniania zanieczyszczeń organicznych w wodzie i ściekach. W pracy opisano właściwości fizykochemiczne zeolitu naturalnego modyfikowanego jonami żelaza (II), który następnie poddano prażeniu w temperaturze 450°C. W wyniku modyfikacji ziarna zeolitu pokryte zostały czerwonobrunatnymi tlenkami żelaza (III), które stanowiły ok. 5% masy zeolitu. Powstała powłoka była stabilna mechanicznie i chemicznie - do roztworu przechodziły niewielkie ilości Fe, nie przekraczające 70 /
Currently, when the pollution of natural environment increases, the search for more effective methods of pollutant removal is essential. Application of cheap and easy to get pro-ecological catalysts - natural zeolites - allows to intensify many processes. These minerals do not bring any additional pollutant to the environment. Wide application of natural zeolites, the hydrated alumino-silicates results from their unique spatial structure. Such structure of zeolites gives them molecular sieve properties, ionic exchange and sorption properties, and high catalytic activity. The surface of zeolites can be easily modified with metal ions, therefore they can be used as heterogeneous catalyst in the Fenton process. In this paper physicochemical properties of natural zeolites modified with Fe(II) ions, calcinated at 450°C are presented. As a result of modification, zeolite grains were covered by red-seal iron (III) oxides, which were about 5% of zeolite mass. Coating was mechanically and chemically stable -from zeolite to solution leached only small amounts of Fe, not exceeding 70 /
Źródło:
Inżynieria Ekologiczna; 2011, 24; 195-204
2081-139X
2392-0629
Pojawia się w:
Inżynieria Ekologiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementation of continuum damage in elasto- viscoplastic constitutive equations
Autorzy:
Ambroziak, A.
Kłosowski, P.
Nowicki, M.
Schmidt, R.
Powiązania:
https://bibliotekanauki.pl/articles/1955210.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska
Tematy:
elasto-viscoplastic constitutive models
damage
finite element method
Opis:
Modelling of the continuum damage framework, is developed for application in the elasto-viscoplastic Chaboche constitutive model. A brief description of the basic variant of the Chaboche model equations is given, followed by a discussion of the most important assumptions necessary to obtain evolution of the continuum damage model and its appli-cation to the open FE commercial program. A consistent presentation of the two proposed approaches is followed by numerical examples.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2006, 10, 2; 207-220
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biofilter model development for the removal of pollutants from feedlot runoff
Autorzy:
Wan, H.
Wilson, B. N.
Schmidt, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/207193.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
biofilters
parameter estimation
pollution
runoff
biofiltr
usuwanie zanieczyszczeń
MinnFARM
Opis:
Biofilters are a potential treatment option for removing pollutants from feedlot runoff but little research has been done on their use and design. In this study, two mechanism -based models were developed to simulate biofilter processes: a first-order model and a logistic model. The two models were calibrated and evaluated using nitrogen (N) and phosphorus (P) data collected from rainfall events for an experimental biofilter at Melrose, Minnesota, USA. The first-order model predicted removal efficiencies better than the logistic model. The sensitivity analysis suggested that the predictions of the first-order model are more sensitive to parameter. In addition, the uncertainty analysis suggested that the range in predictive errors could be a consequence of uncertainty of estimating parameter from the limited data set for the first-order model. In contrast, the uncertainty analysis for the logistic model of N suggested that reasons other than the uncertainty in parameter estimation are needed to explain predictive errors. Overall, the study provides a useful tool for assessing biofilter performance that can easily be improved with larger observed data sets. The biofilter model has been implemented in the most recent version of the Minnesota feedlot annualized runoff model (MinnFARM).
Źródło:
Environment Protection Engineering; 2017, 43, 3; 61-80
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fossil thrips of the family Uzelothripidae suggest 53 million years of morphological and ecological stability
Autorzy:
Nel, P.
Schmidt, A.R.
Bassler, C.
Nel, A.
Powiązania:
https://bibliotekanauki.pl/articles/22508.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
fossil
thrip
morphological stability
ecological stability
Arthropoda
Thysanoptera
Uzelothripidae
fungi
Ascomycota
Capnodiales
sooty mould
amber
Eocene
France
Opis:
The new fossil thrips Uzelothrips eocenicus P. Nel and A. Nel sp. nov. (Thysanoptera: Uzelothripidae) is described from two lowermost Eocene amber−preserved specimens (one macropterous and one apterous). The family Uzelothripidae is only known so far from a single extant species, Uzelothrips scabrosus. The fossils differ from the extant species only by the antennal segments III and IV, which appear distinctly separated instead of being fused as in the in the extant U. scabrosus. Dark−coloured hyphae and conidia of the Dothideomycetes (Ascomycota) which are likely to belong to the sooty moulds (Capnodiales) are attached to the apterous fossil specimen. We consider this arthropod−fungus association not to be accidental since these fungi are also found in extant specimens of these uzelothripids, suggesting very specific long−term interactions and strong habitat specificity.
Źródło:
Acta Palaeontologica Polonica; 2013, 58, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Upper Sinemurian ammonite succession in the Sierra Madre Oriental (Mexico)
Autorzy:
Meister, Ch.
Blau, J.
Dommergues, J-L.
Schlatter, R.
Schmidt-Effing, R.
Powiązania:
https://bibliotekanauki.pl/articles/2061407.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
Early Jurassic
Sinemurian
biostratigraphy
Mexico
Sierra Madre Oriental
Opis:
In the Sierra Madre Oriental (Mexico), the biostratigraphic subdivision of the Upper Sinemurian can be refined. It has been possible to differentiate 11 horizons from the upper Obtusum Zone to the top of the Raricostatum Zone which are correlated with the NW European standard zonation. The index species of each horizon is figured.
Źródło:
Volumina Jurassica; 2009, 7, 1; 31-36
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of parametric methods of power spectrum estimation in passive sonar signals classification
Autorzy:
Schmidt, J.
Salamon, R.
Powiązania:
https://bibliotekanauki.pl/articles/332824.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents the signals classification method based on the parametric spectral analysis as applied to the passive sonar. The system's structure is discussed special emphasis is given to the procedure of features selection in which true poles are chosen. Attached are results of tests carried out to evaluate the applicability of parametric methods of spectral estimation for the purpose of creating acoustic portraits and their classification.
Źródło:
Hydroacoustics; 1999, 2; 145-150
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Code signals transmission using MFSK modulation in shallow waters
Autorzy:
Zachariasz, K.
Schmidt, J.
Salamon, R.
Powiązania:
https://bibliotekanauki.pl/articles/332705.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents an acoustic system for the transmission of digital data in shallow coastal waters of which multi-path propagation and intense reverberations are characteristic. To ensure a small error probability of moderate speed transmission, the system uses corrective codes and a technique of incoherent modulation MFSK (Mufti Frequency Shift Keying). To synthesise the transmission signal, estimate the spectrum of the signal received and code and decode the channels, a DSP processor was used. The paper includes the results of a computer simulation in which the system was put to work in the presence of Gaussian noise. The system was tested in shallow coastal waters and the results are discussed in the paper.
Źródło:
Hydroacoustics; 2001, 4; 261-264
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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