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EN
A high rate of silver nanoparticle formation, effective against the Escherichia coli (E. coli) bacterium, was obtained for the first time by means of a simple, eco-friendly, and low-cost green method in a solution of agave inulin. The study was carried out using the traditional method, in which the effects of the concentration of agave inulin, AgNO3, temperature, and pH on the synthesis were analyzed by UV-Vis spectroscopy and transmission electron microscopy (TEM). Most of the nanoparticles produced were spherical with a size less than 10 nm. In a sample with 20 mg/mL of agave inulin, 1 mM of AgNO3, T = 23°C, and pH = 12, the highest percentage of Ag+ ions available in the solution were reduced for the formation of nanoparticles in less than 40 min, whereas a sample prepared with 60 mg/mL of agave inulin, 10 mM of AgNO3, T = 23°C, pH = 12, and a storage time of 40 min showed a significant bactericidal effect on the E. coli strain. Agave inulin is a good biological compound for the formation of small, spherical silver nanoparticles. A pH of 12 favors a higher production speed of the silver nanoparticles and better use of the available Ag+ ions. In addition to this, the concentration of AgNO3 is a determining factor for increased formation of the nanoparticles necessary to bactericidal effect.
EN
Continuous infusion, as one of the most effective methods of delivering pharmaceuticals to patients, uses infusion pumps to which a syringe and infusion drains are connected. Photosensitive drugs that require UV-VIS protection are delivered to patients with special infusion sets that reduce harmful radiation. However, these drains have different transparencies, which can affect the success of therapy. This study investigated the optical properties of two types of drains used for infusion therapy of photosensitive drugs. UV-VIS spectroscopy studies were carried out, allowing the determination of the absorbance values and absorption coefficient of the two types of drains. The spectrum of their transmittance was also analyzed. The chemical composition of the samples was tested using FTIR-ATR spectroscopy. Furthermore, the roughness and wettability parameters of the drains were determined, which affect not only the kinematics of drug flow in the drains but also the way in which light is transmitted. The results of the study can be used to propose a solution to eliminate the problem of loss of properties of the photosensitive drug in drains, in contact with light. By selecting the appropriate drain thickness, it is possible to reduce the transmission of radiation in the UV-VIS range through the drain.
EN
Artificial neural networks have been shown to be able to approximate any continuous nonlinear functions and have been used to build data based empirical models for nonlinear processes. This work studies primarily the performance of neural networks as a tool for predicting the emission spectra of fluorescent materials from their absorbance, and further, tends to the determination of the optimal topology of the neural network for this purpose. In order to do this, spectral data were initially analyzed by a principal component analysis technique. The first four principal components were used as input nodes of neural networks with various training algorithms – namely cascade- and feed-forward algorithms – and also, various numbers of hidden layers and nodes. The obtained results indicate that the RMS error in a testing data set decreased with increasing the number of neurons and the minimal network architecture for a data prediction problem consists of two hidden layers, respectively with 9 and 1 nodes for both neural networks. Additionally, a better performance was obtained with the cascade-forward neural network, especially in a small number of nodes. The obtained results indicate that the neural networks can be used to provide a relationship between the absorbance as an input and the emission as a target.
EN
The purpose of the present study was to compare the effectiveness of coagulation process conducted using classical non-hydrolyzed coagulant - aluminum(VI)sulfate and pre-hydrolyzed coagulants: Flokor1ASW/B and Flokor 105 V. Water samples subjected to coagulation were collected from selected water treatment plant after pre-ozonation process. Instantaneous samples were taken in winter season. True colour of water amounted 7.0 mg Pt/L and turbidity was 7.29 NTU. The study in laboratory scale was carried out with the usage of a six beaker flocculator. Volumetric coagulation was performed in water samples of the vol- ume of 1 L. In six beakers, rapid-mixing (3 min at the rotational speed of 200 rpm) was followed by 30 min slow mixing (at 30 rpm). After coagulation the samples were subject to 60 min sedimentation. The coagulant dose was optimized for minimum colour, turbidity and UV254 absorbance values using conventional jar testing procedures. The coagulation performance was examined with a range of dosages 0.4-1.4 mg Al/L for pre-hydrolyzed coagulants. In case of alumi- num(VI)sulfate ranged from 1.6-2.6 mg Al/L. The optimum dose for aluminum(VI)sulfate amounted 2.2 mg Al/L. For prehydrolyzed coagulants, the doses were much lower, i.e. 1.4 mg Al/L. Also less wear of water alkalinity was obtained than in case of aluminum(VI)sulfate. The effectiveness of removal of turbidity for ALK, Flokor 1ASW/B and Flokor 105V was 62.6%, 73.0% and 69.0% respectively. Effectiveness of coagulants was compared on the basis of concentration of selected water quality indicators (turbidity, absorbance at 254 nm) after coagulation process (for optimal doses). For the assessment if the differences were statistically significant Student's t test for difference of two independent trials was used. In all examined cases it was found that the use of different types of coagulants is statistically significant for the achieved effects of coagulation. Calculated values were higher than theoretical. (td>tt). The use of pre-hydrolyzed aluminum coagulants improves the efficiency of the coagulation process, and reduce the wear of coagulants in comparison with previously used alumi- num(VI)sulfate. After application of Flokor 1ASW/B the best results (among the investigated coagulants) for the chosen contaminant removal were obtained, more than 46,3% decrease of DOC and 75,0% decrease of UV254 absorbance.
PL
W artykule opisano technologię oraz właściwości mikroreaktora chemicznego ze zintegrowanymi elementami optoelektronicznymi. Opracowane urządzenie wykonano w technologii LTCC (Low Temperature Co-fired Ceramics – niskotemperaturowa ceramika współwypalana). Zastosowana technologia mikroelektroniczna umożliwiła integrację elementów mikrofluidycznych (kanały, komory itp.) oraz optoelektronicznych (dioda elektroluminescencyjna, czujnik światła) w jednym wielowarstwowym module ceramicznym. Prezentowany mikroreaktor przeznaczony jest do oznaczania substancji (bio)chemicznych w ciekłych próbkach o bardzo małych objętościach. Detekcja wspomnianych substancji odbywa się na zasadzie pomiaru absorbancji optycznej. Wstępne testy urządzenia przeprowadzono dla kilku roztworów wzorcowych nadmanganianu potasu. Na podstawie otrzymanych wyników stwierdzono dużą amplitudę sygnału wyjściowego oraz liniową odpowiedź urządzenia dla całego zakresu pomiarowego.
EN
The paper presents the technology and performance of the chemical microreactor with integrated optoelectronic components. The device was made using LTCC (Low Temperature Co-fired Ceramics) technology. The applied technology has enabled the integration of electronic, optoelectronic (passives, light emitting diode, light-to-voltage transducer) and microfluidic (channels, chambers, etc.) components in a single multilayer ceramic module. Microreactor with optical detection is designed for the determination of a (bio)chemicals substance in the micro- or nanoliter volume range. Detection of these substances is perforemed by measuring the optical absorbance. Preliminary studies were carried out for a test solutions of potassium permanganate. The obtained results showed a high level of output signal, linear response and good repeatability.
6
Content available remote Study of thin films for application in photovoltaic cells
EN
Purpose: of this paper: The major aim of this paper was describing technical conditions of thermal evaporation method of organic thin film used as active layers for photovoltaic cells. Design/methodology/approach: The organic thin films have been obtained by thermal evaporation process from two sources. The two sources technique alleged to using the mixtures of two kinds of materials on deposited substrate and created the bulk p-n junction. By steering the source temperature the deposited rate of substrates has been changed which has led to changes in the share component in the layer. Findings: The obtained results describe the influence of evaporation process from two sources on optical properties and surface morphology of thin films which consist molecular materials - perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and metal phthalocyanines (NiPc, TiOPc) blends. Research limitations/implications: The morphology and optical properties of thin films films made of organic materials MePc:PTCDA were described. This paper include also influence of physical vapor deposition process conditions on properties of thin films. Practical implications: The obtained results allowed to create the bulk p-n junction. The MePc:PTCDA thin films can be used in photovoltaic applications. Originality/value: The value of this paper is defining the optimal parameters of thermal evaporation from two sources for preparing MePc:PTCDA thin film with the best properties for photovoltaic applications. This paper describes the use of molecular materials for PVD technology. Results of these researches allowed to develop the technology of bulk heterojunction of molecular materials.
PL
Niniejszy artykuł opisuje badania przeprowadzone na odpowiednio zabarwionych (barwnikami: Solvent Red 19, typu Solvent Red 19 oraz Solvent Red 164) i oznakowanych (znacznikiem Solvent Yellow 124) mieszaninach lekkiego oleju opałowego zawierającego dodatki biokomponentów: estrów metylowych kwasów tłuszczowych, oleju rzepakowego, oleju słonecznikowego oraz bioetanolu w celu określenia trwałości ich znakowania i barwienia.
EN
This article describes a study carried out on appropriately dyed (Solvent Red 19, Solvent Red19 sim and Solvent Red164 dyes) and marked (Solvent Yellow 124 marker) mixtures of heating oil containing the bio-components: FAME, rapeseed oil, sunflower oil and bioethanol with the aim of determining the stability of their marking and dyeing.
PL
Przedstawiono wyniki badań usuwania zanieczyszczeń ze ścieków przemysłowych w układzie hybrydowym koagulacja-odwrócona osmoza. Obiektem badań była przepracowana wodno-olejowa ciecz chłodząco-smarująca stosowana w ubytkowej obróbce detali. Celem wykonanych badań była ocena wpływu wstępnej koagulacji przepracowanej cieczy chłodząco-smarującej na skuteczność usuwania pozostałości organicznych i jonowych z wód poemulsyjnych w procesie odwróconej osmozy. Proces koagulacji przeprowadzono za pomocą koagulantów o jednakowej reszcie anionowej, tj.: siarczanu glinu(III) oraz siarczanu żelaza(II) z nadtlenkiem wodoru. Z uzyskanej wody poemulsyjnej usuwano zanieczyszczenia organiczne i jonowe za pomocą odwróconej osmozy. Zastosowano komercyjną membranę poliamidową o symbolu technicznym RO 75GPD wyprodukowaną przez GE Osmonics. Proces filtracji membranowej prowadzono przy stałym ciśnieniu, wynoszącym 9 bar. Zmiany właściwości fizykochemicznych permeatu rejestrowano w ciągu pięciogodzinnych badań. Przeprowadzony monitoring pozwolił na określenie optymalnego czasu trwania procesu, umożliwiającego skuteczne usunięcie zanieczyszczeń z wody. Proces filtracji membranowej prowadzono w układzie półotwartym, tzn. uzyskany permeat odprowadzano na zewnątrz, bez uzupełniania nadawy. Przeprowadzone badania wykazały, że skuteczność usuwania zanieczyszczeń z wody poemulsyjnej w procesie odwróconej osmozy zależy od rodzaju zastosowanego koagulantu w etapie deemulgacji przepracowanej wodno-olejowej cieczy chłodząco-smarującej. Większą skuteczność, a także wydajność procesu uzyskano w przypadku zastosowania podczas koagulacji siarczanu żelaza(II), wspomaganego nadtlenkiem wodoru.
EN
This paper presents test results of contaminants removal from industrial wastewater in a hybrid system involving coagulation and reversed osmosis. Used oil-in-water cutting fluid operated in detailed machining was the object of this study. The purpose of conducted research was to assess the influence of preliminary coagulation of waste cutting fluids on the effectiveness of organic and ionic residues removal from post demulsification water in the process of reversed osmosis. The coagulation process was conducted by means of coagulants with equal anion radicals such as: aluminum sulfate and iron sulfate with hydrogen peroxide. Organic and ionic residues were removed from obtained post demulsification water by means of reversed osmosis. The tests were performed using a commercial polyamide membrane (RO 75GPD - GEOsmonics). Membrane filtration process was carried out at constant pressure of 9 bar. Physicochemical changes in the permeate were recorded during multiple five hour tests. Conducted monitoring enabled to determine the optimal duration of the process for contaminants removal. The process of membrane filtration was performed in a semi-opened system. Obtained permeate was drained out without feed refill. Conducted research showed that the effectiveness of contaminants removal from post demulsification water in the process of reversed osmosis depends on the kind of used coagulant during demulsification stage of waste cutting fluid. Greater effectiveness and efficiency of the process was possible when using iron sulfate with hydrogen peroxide for coagulation.
EN
Investigations on integration of optoelectronic components with LTCC (low temperature co-fired ceramics) microfluidic module are presented. Design, fabrication and characterization of the ceramic structure for optical absorbance is described as well. The geometry of the microfluidic channels has been designed according to results of the CFD (computational fluid dynamics) analysis. A fabricated LTCC-based microfluidic module consists of an U-shaped microchannel, two optical fibers and integrated light source (light emitting diode) and photodetector (light-to-voltage converter). Properties of the fabricated microfluidic system have been investigated experimentally. Several concentrations of potassium permanganate (KMnO4) in water were used for absorbance/transmittance measurements. The test has shown a linear detection range for various concentrations of heavy metal ions in distilled water. The fabricated microfluidic structure is found to be a very useful system in chemical analysis.
EN
In water treatment plants (WTP), flocculation is carried out on the base of jar testing which is the basic method to determine optimum operating conditions, i.e. the range of effective doses of reagents, times of rapid and slow mixing and mixing gradients. However, the procedure for these tests, although of high technological reliability, also reveals some defects. One of the most important is that it is time-consuming. This means that we get all results with several hours' delay. The problem also concerns the hydraulic parameters of flocculation and separation. Jar test procedures and technical limitations of the equipment used in these tests only allow for a very approximate assessment of the required intensity and time of rapid mixing and flocculation. Taking into consideration the above limitations of jar tests so to get full control over the coagulation system, it is necessary to apply the system which allows to obtain full information about the course of all unit processes. The main element of the proposed system structure is a Stream Current Analyzer (SCA) cooperating with a pH analyzer. Taking into consideration measurement used in determination of treatment effectiveness, the most useful are spectrophotometric measurements of absorbance UV254 as an indicator of organic matter and particle number analyses as an indicator of suspended particles concentration.
PL
W praktyce wodociągowej proces ustalania parametrów technologicznych koagulacji realizowany jest na drodze testów zlewkowych, które stanowią podstawową metodę określania optymalnych warunków prowadzenia procesu tj. zakres skutecznych dawek reagentów, czasy szybkiego i wolnego mieszania oraz gradienty mieszania. Jednak procedura tych testów, mimo dużej wiarygodności technologicznej ma także pewne wady. Do najważniejszych należy zaliczyć to, że jest ona czasochłonna. Oznacza to, że ewentualne wyniki uzyskujemy czasami z kilkugodzinna zwłoką. Istotnym problemem jest również prawidłowy dobór parametrów hydraulicznych procesu flokulacji i separacji zawiesiny pokoagulacyjnej. Procedury testów zlewkowych i ograniczenia techniczne urządzeń stosowanych w tych testach pozwalają jedynie na bardzo przybliżoną ocenę wymaganej intensywności oraz czasów szybkiego mieszania oraz flokulacji. Biorąc pod uwagę powyższe ograniczenia testów zlewkowych, aby uzyskać pełną kontrolę nad przebiegiem procesu koagulacji wymagane jest zastosowanie systemu pozwalającego na uzyskanie możliwie pełnej informacji o przebiegu poszczególnych procesów jednostkowych. Głównym elementem proponowanego systemu jest Analizator Prądu Strumieniowego (SCA) współpracujący z analizatorem pH. W zakres pomiarów wejdą pomiary absorbancji w nadfiolecie przy długości fali 254 nm jako wskaźniki zawartości materii organicznej (UV254) oraz mętność (M) lub alternatywnie liczba i wielkość cząstek (LC) jako wskaźnik zawartości cząstek zawieszonych.
PL
W artykule opisano właściwości promieniowania terahercowego oraz techniki pomiarów spektrometrycznych - Fourierowskiej (FTIR) i czasowej (TDS-THz). Następnie przedstawiono metodykę wyznaczania ze zmierzonego widma - współczynnika absorpcji, współczynnika załamania i emisyjności, które są charakterystycznymi parametrami materiałowymi. Opisano sposób wykonania próbki heksogenu, wyniki pomiarów transmisyjnych metodą FTIR oraz wyznaczono wymienione wyżej współczynniki.
EN
This paper presents advantages of terahertz radiation and describes spectrometric techniques for this region - Fourier Transform Infrared Spectroscopy (FTIR) and Time Domain Spectroscopy (TDS). Next, a methodology of determination of some parameters of a material like absorption coefficient, refractive index and emmisivity form a mesured spectrum is presented. Preparation of a sample of RDX, its FTIR spectrum and calculation of the above mentioned parameters is also presented.
12
Content available remote Studying of spin-coated oxad-Si properties
EN
Purpose: The major aim of this paper was describing technical conditions of polymer thin film deposition by spin-coating techniques. Design/methodology/approach: Thin films of about nanometres thickness were prepared by spin-coating and their properties were studied. As a material for preparing polymer thin films oxad-Si was used. The thin films were deposited with various spinning velocity from solution of different concentration. Thin films were deposited on BK7 glass and quartz substrates. Findings: The obtained results describe influence of the solution concentration and spinning velocity on morphology and optical properties of spin-coated oxad-Si thin films. Research limitations/implications: The obtained results confirm the oxad-Si availability for optoelectronic application to be stipulated. Practical implications: The morphology and optical properties of Oxad-Si polymer thin films were described. This paper include also description of the influence of deposition conditions on properties of polymer thin films. Originality/value: The value of this paper is defining the optimal parameters of spin-coating technology for preparing oxad-Si thin film with the best properties for optoelectronics appliances. This paper describes new experimental polymeric material for spin coating technology. Results of these researches enable to develop the spin-coating technology.
PL
W artykule przedstawiono wyniki badań elektrooptycznych wybranych luminoforów z grupy układów azaheterocyklicznych. Zbudowano jednowarstwowe diody ITO/MOL+PVK/Ca/Al, w których warstwę aktywną stanowiła mieszanina luminofory z tej grupy oraz polimeru matrycowego PVK. Zebrano i omówiono właściwości fotofizyczne molekuł.
EN
In this paper the synthesis of some new chromophores which could be used in organic LED fabrication are presented. All of them are pyrazoloquinoline derivatives. They were characterized by absorption and photoemission spectroscopy. Some were used, dispersed in poly(N-vinylcarbazole) (PVK) matrix, as the emissive layer in LED structure.
14
Content available remote Dissolved organic carbon (DOC) in water samples from livestock farms
EN
The main objective of this work was to recognize the magnitude and sources of pollution with DOC in various kinds of water from farms located in different parts of Poland. Four kinds of water samples were analysed: water from farm wells, groundwater from under grasslands, groundwater from farmsteads, and surface water from streams and ditches adjacent to the farm area. The highest concentrations of DOC (mean = 75 mg C dm-³) and nutrients were found in samples of groundwater from farmstead, the lowest in samples of well water. Potassium and phosphorus concentrations were significantly correlated with DOC in all analysed kinds of water. That evidenced that the three components had the same transport mechanism though the active medium was DOC which bound potassium or phosphate ions or protected them from sorption onto surrounding soil materials. The absorbance at 280 or 472 μm wavelengths was significantly correlated with DOC concentration and can be used to estimate the DOC content in water sample. However, same differences in the slopes of regression equation require a calibration be performed for every kind of analysed waters bodies.
PL
Celem prezentowanych badań było rozpoznanie zakresu i źródeł zanieczyszczania rozpuszczalnym węglem organicznym (RWO) różnych rodzajów wody z gospodarstw usytuowanych w różnych częściach Polski. Badano próbki wody ze studni gospodarskich, wodę gruntową spod użytków zielonych oraz z terenu zagrody, a także z rowów i cieków przyległych do gospodarstwa. Największe stężenia RWO (średnie = 72 mg C·dm-³) i składników nawozowych stwierdzono w próbkach wody gruntowej z terenu zagrody, a najmniejsze w wodzie ze studni. Stężenie RWO było istotnie skorelowane ze stężeniem potasu i fosforu we wszystkich badanych rodzajach wody. To wskazuje na wspólny mechanizm przemieszczania się tych trzech substancji. Jednakże, aktywnym czynnikiem jest RWO, który wiąże jony fosforanów lub potasu albo też chroni je przed sorpcją na otaczającym materiale. Absorbancja mierzona przy długości fali 280 lub 472 μm była istotnie skorelowana z RWO i można by ją stosować do określania stężenia RWO w próbkach wody. Jednakże, stwierdzone duże różnice w nachyleniu krzywych regresji wymagają osobnej kalibracji dla każdego rodzaju badanej wody.
PL
W pracy przedstawiono oryginalną metodykę określania stężenia nasycenia glukozy w roztworze wodnym. Oparto ją na wykorzystaniu pomiaru absorbancji roztworów i zawiesin α-D glukozy w obszarze bliskiej podczerwieni a dokładnie przy liczbie falowej 8000 cm-1 i 9000 cm-1. W przyjętej metodyce wartość stężenia nasycenia określał punkt przecięcia prostej otrzymanej z aproksymacji wartości absorbancji zawiesin o różnym stężeniu z wartością A=0. Wyniki pomiarów porównano z danymi opublikowanymi w literaturze światowej.
EN
Paper presented an original method to determine the solubility – concentration of glucose saturation in water solutions. The method was based on measuring the absence of prepared α-D glucose solutions and suspensions in near infrared area, i.e. at the wave numbers 8000 and 9000 cm-1. According to assumed method the value of saturation concentration was determined by intersection point of the straight line resulted from linear approximation the absorbance for suspensions of different concentrations, with value A=0. Obtained measurement results were compared with the data published in world literature.
PL
Przebadano wpływ ozonu na odbarwianie wodnych roztworów wybranych barwników gryfacidowych i grylalanowych, produkowanych przez Zakłady Chemiczne "Organika-Zachem" w Bydgoszczy. Obie grupy barwników poddano działaniu ozonu o stężeniu: 0,153;0,04 i 0,02 cm3 xO3min4. Przebadano także jak na proces dekoloryzacji barwników wpływa zakwaszanie i alkalizowanie środowiska reakcji. Ubytek stężenia barwników obserwowano za pomocą zmian absorbancji w czasie.
EN
An effect of ozone on decolourization of water solutions of the selected gryfacid and gryfalane dyes (Chemical Plants "Organika-Zachem" in Bydgoszcz, Poland) has been studied. Both groups of dyes were subjected to the action of ozone at concentrations of 0,153; 0,04 and 0,02 cm3 of O3/dm3. The effect of the process of dye decolourizationon acidification or alkalization of the reaction medium has also been investigated. The decrement in dye concentration was determined by the changes of absorbance in time.
EN
The content of low molecular weight LMW (<1000 Da) dissolved organic substances was determined by ultrafiltration (concentration factor of 2) in different water samples collected in the Gulf of Gdańsk. The proportion of this fraction (based on organic carbon concentration) ranged from 24 to 57%. The lowest percentage was detected in riverine samples. The DOC concentrations in ultrafiltrates was similar in all the samples analysed. The absorbance proportion (at 250 nm) due to the low molecular fraction in the overall absorbance ranged from 14 to 45% and in all but one sample was lower than the DOC percentage. There was no relationship between DOC and absorbance in the LMW fractions (r2 = 0.08), in contrast to the characteristics of the "bulk" samples (r2 = 0.88).
PL
W pracy przedstawiono wyniki badań wpływu różnych utleniaczy oraz promieniowania UV na odbarwienie wodnych roztworów 5 barwników. Do badań wybrano utleniacze, które redukują się na związki nietoksyczne dla środowiska. Przebadano wpływ różnych stężeń nadtlenku wodoru i nadtlenodisiarczanu(VI) amonu, obu wyżej wymienionych utleniaczy obok siebie oraz każdego z nich w obecności jonów wodorowych, pochodzących od kwasu siarkowego(VI). Roztwory wodne barwników naświetlano również promieniami UV. Promieniowanie UV zastosowano także dla roztworów zawierających już nadtlenek wodoru. Ponadto barwniki rozkładano ozonem. Na podstawie otrzymanych wyników stwierdzono, że najlepiej w roztworach wodnych badane barwniki rozkładają się pod wpływem ozonu oraz układu H2O2 + UV. Z wybranych barwników najmniej odporne na większość zastosowanych układów utleniających okazały się: Szkarłat Bezpośredni Trwały 4BS i Róż Helionowy 2B.
EN
The results of the studies on an effect of the various oxidants and UV radiation on the decolouration of water solutions of 5 dyes have been presented. The oxidants which are reduced to the compounds non-toxic for environment have been selected for our investigations. An effect of the various concentrations of hydrogen peroxide, ammonium peroxysulfate(VI), combination of both oxidants mentioned above and each of them separately in the presence of sulfuric(VI) acid has been studied. The water solutions of dyes have also been exposed to UV radiation. The UV radiation have been applied for solutions containing hydrogen peroxide and, moreover, the dyes have been decomposed using ozone. Basing on the results obtained, it has been found that the destruction of the dyes in water solutions proceeds with the best results under the action of ozone and the system: H2O2 + UV.
EN
The preparation of sol-gel derived materials in the form of bulk and thin films as well as bulks with entrapped urease as an organic dopant is described. The absorbance spectra of urease solutions and sol-gel matrices were recorded in the transmission mode. The absorbance of sol-gel matrices with embedded enzyme was measured in the reflection mode.
EN
Various factors influencing the quality of UVVIS spectra obtained for sea water (in 100 mm cells) have been tested. The spectrophometer instability and baseline drift introduced absorbance error of ~ 0.0002 and ~ 0.001, respectively. Deviations caused by improper blanks reached 0.005 ab-sorbance units. Standard deviation of absorbance values determined for samples collected in the Gulf of Gdansk during repetitive casts (0.008-0.022) significantly exceeded the detection limit based on variability of the blank sample (0.002).
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