Results of the ab initio molecular dynamics calculations of silicon crystals are presented by means of analysis of the velocity autocorrelation function and determination of mean phonon relaxation time. The mean phonon relaxation time is crucial for prediction of the phonon-associated coefficient of thermal conductivity of materials. A clear correlation between the velocity autocorrelation function relaxation time and the coefficient of thermal diffusivity has been found. The analysis of the results obtained has indicated a decrease of the velocity autocorrelation function relaxation time t with increase of temperature. The method proposed may be used to estimate the coefficient of ther-mal diffusivity and thermal conductivity of the materials based on silicon and of other wide-bandgap semiconductors. The correlation between kinetic energy fluctuations and relaxation time of the velocity autocorrelation function has been calculated with the relatively high coefficient of determination R2 = 0.9396. The correlation obtained and the corresponding approach substantiate the use of kinetic energy fluctuations for the calculation of values related to heat conductivity in silicon-based semiconductors (coefficients of thermal conductivity and diffusivity).
The calculation method of the molecular dynamics has been applied to study the correlation of the kinetic energy fluctuations and the relaxation time of the velocity autocorrelation function and the phonon relaxation time in a crystal. On the basis of the molecular dynamics data for silicon crystal obtained at different temperatures in the range 200 K – 1000 K the correlation between the kinetic energy fluctuations and the relaxation time of the velocity autocorrelation function has been calculated with the relatively high coefficient of determination R2 = 0.9396. The correlation obtained and the corresponding approach substantiate a use of the kinetic energy fluctuations for the calculation of values related to the heat conductivity in the silicon based semiconductors (coefficients of thermal conductivity and diffusivity).
PL
Obliczeniowa metoda dynamiki molekularnej została zastosowana do badania korelacji fluktuacji energii kinetycznej i czasu relaksacji autokorelacyjnej funkcji prędkości i czasu relaksacji fononów w krysztale. Na bazie danych dynamiki molekularnej kryształu krzemu otrzymanych w różnych temperaturach w zakresie 200 K – 1000 K została obliczona korelacja fluktuacji energii kinetycznej i czasu relaksacji autokorelacyjnej funkcji prędkości, która cechuje się stosunkowo wysokim współczynnikiem determinacji R2 = 0.9396. Otrzymana korelacja uzasadnia zastosowanie fluktuacji energii kinetycznej do badań obliczeniowych wielkości powiązanych z przewodnością cieplną półprzewodników na bazie krzemu (współczynniki przewodności i dyfuzyjności cieplnej).
Współczynnik załamania n optycznie przezroczystego materiału jest ważną jego charakterystyką, która zależy od elektronowej struktury cząsteczek odpowiedniej substancji. W przypadku olejków roślinnych, zawierających stosunkowo słabo oddziałujące cząsteczki, są jednak własności, które zależą w znacznym stopniu od oddziaływania międzycząsteczkowego. Do takich własności można odnieść krzepnięcie i parowanie olejków. Ostatnie zjawisko wpływa prawdopodobnie w dużym stopniu na natężenie zapachu każdego olejku, który jest ważny w odpowiednich zastosowaniach praktycznych. W związku z tym wyniki badań zależności temperaturowych gęstości r(T) i współczynnika załamania n(T) olejków roślinnych mogą być pomocne w oszacowaniu stopnia oddziaływania międzycząsteczkowego i odpowiednich możliwości ewentualnych zastosowań praktycznych. W niniejszej pracy przedstawiono wyniki badań zależności temperaturowych w zakresie 20-60°C współczynnika załamania nD(T) i gęstości r(T) trzech olejków roślinnych: z pomarańczy, cytryny i grejpfruta. Do pomiarów bezwzględnego współczynnika załamania nD olejków na długości fali świetlnej lD = 589 nm wykorzystano standardowy refraktometr Abbe. Gęstość olejków ρ w temperaturze pokojowej była otrzymana poprzez mierzenie masy m określonej objętości V olejku i następujące obliczenie według wzoru definiującego ρ = m/V. Pomiary zależności temperaturowych współczynnika załamania n(T) i objętości olejków V(T) o określonej masie m wykonano przy pomocy 6-litrowego wodnego termostatu przepływowego typu “PolyScience model 912”. Otrzymane zależności wykorzystano do obliczenia charakterystycznych wielkości refrakcji właściwej i oddziaływania międzycząsteczkowego w olejkach według modelu pola efektywnego zaproponowanego we wcześniejszych pracach autorów (Andriyevsky, B., et al. 2009, Andriyevsky, B., et al. 2010). Na bazie przeprowadzonych badań densymetrycznych i refraktometrycznych olejków roślinnych z pomarańczy, cytryny i grejpfruta w zakresie temperatur 20-60°C sformułowano następujące wnioski.- Zależności temperaturowe gęstości ρ(T) i podatności elektrycznej cD(T) trzech olejków aproksymują się zadowalająco wielomianem pierwszego rzędu, ρ(T)=a+bT, z ujemnymi wartościami współczynników b.-Właściwości optyczne refrakcyjne olejków cytrynowego i grejpfrutowego są zbliżone w porównaniu do właściwości olejku pomarańczy.- Wiązania międzycząsteczkowe w olejkach z cytryny i grejpfruta mogą być słabsze niż w olejku z pomarańczy.
EN
Refractive index n of an optically transparent material is an important its parameter, which depends on the electronic structure of the corresponding substance. In the case of plant oils, consisting of the relatively weak interacting particles, there are properties that however depend greatly on the intermolecular interaction. These properties are the oils coagulation and vaporization. The last phenomenon influences probably greatly the odor intensity of each oil, which can be significant for certain applications. Therefore, results of the temperature dependences of density p(T) and refractive index n(T) of plant oils can be helpful for estimation of the degree of intermolecular interaction and corresponding possibilities of practical applications of oils. In the present paper, the results of study of the temperature dependences of refractive index nD(T) and density p(T) in the range of 20-60 degrees C have been presented for three plant oils obtained from orange, lemon and grapefruit. For measurements of the absolute refractive index nD of oils at the wavelength lambda(D) = 589 nm a standard Abbe refractometer was used. The oil's density p at ambient temperature was obtained by the measurement of the corresponding mass m and volume V, p = m/V. Measurements of the temperature dependences of refractive index n(T) and volume V(T) of the known mass of oil m were performed using the 6-liters water thermostat "PolyScience model 912". The dependences obtained have been used for calculation of the characteristic values of specific refraction and intermolecular interaction of the oils according to the model of the effective electric field proposed in the former publications of the authors (Andriyevsky, B., et al. 2009, Andriyevsky, B., et al. 2010). The following conclusions have been formulated on the basis of investigations of the orange, lemon and grapefruit plant oils done in the temperature range of 20-60 degrees C. 1. The temperature dependences of density p(T) and electric susceptibility X-D(T) are fitted satisfactorily by the first order polynomial, p(T) = a + bT, with negative coefficients b. 2. Refractive properties of the lemon and grapefruit oils are close in comparison to the analogous values for the orange oil. 3. Intermolecular bonds in the lemon and grapefruit oils can be weaker in comparison to the orange oil.
The most important aim of the study was to find the optimum conditions of the process of dewatering of sewage sludge using decanter centrifuge, and also reduce noxiousness of the centrifuge service, by applying orange essential oil as a partial substitute of flocculants. The tests were performed at sewage treatment plant in Tychowo where dewatering process of sewage sludge is carried using decanter centrifuge ALFA LAVAL, type ALDEC with application of different proportions of orange essential oil mixed with ZETAG® 9048FS flocculant for dose C = 76.3 dm3/m3. Water content in the sediment, dry matter content in effluent and concentration of orange essential oil odour in dewatered sediments were assessed. Conducted tests proved that orange essentials oil is a efficient, good flocculant, which may be used as an addition do centrifugal sedimentation process. Addition of orange essential oil has a substantial advantage: it causes the decrease of odorous noxiousness of dewatered sediments. The experiments were conducted on-site in the sewage treatment plant in the centrifuge station. Analysis of odorous noxiousness was conducted in the laboratory using samples collected on-site. Odorous noxiousness was assessed by determination of oudour concentration. Measurements were made using method of dynamic olfactometry according to standard PN-EN 13725:2007 [14] on four station olfactometer T08 (figure 1) equipped with all necessary apparatus. One measurement consisted of four series. Computer software colleted all the measurements results and calculated result of the measurement team (Zite, pan) –geometric mean of all individual measurements. This value is at the same time the concentration of odour in the sample (cod), expressed in european odorous units per cubic meter (ouE/m3) in accordance with PN-EN 13725:2007 [14]. As a result of conducted tests, taking into account good quality of dewatering of sludge with simultaneous, partial, but clear and noticeable reduction of noxious odours emitted from the sediments, both reagents are recommended for dosage that is ZETAG® 9048FS flocculant and orange essential oil, both 50% of the dose volume. It is advisable to conduct further research on the use of essential oils from other plants as flocculants in the broadly defined processes of water and sludge technology, as well as conducting works on the economic production of essential oils form waste materials, also including the logistics of their separation at the selection of waste stage, or their acquisition from fruit processing plants.
The paper presents exploratory examinations on possibility of pre-treatment of wastewater containing gasoline and diesel fuel, that is wastewater “produced” in each car service and repair workshop and in gas station. It is a vast number of service points, which, though daily produce small amounts of wastewater but in the scale of the whole country amount of wastewater is substantial. Such wastewater is usually piped off into the sewage system. Often oily wastewater does not meet requirements set by local companies which own the municipal sewage treatment plants. Therefore, authors made have undertaken considerations on the concept of use the flotation process for pre-treatment of wastewater containing oil and gasoline, as a small wastewater treatment plant that could be installed in a separate room of garage or gas station. Example diagram is shown in Figure 5. This paper presents preliminary testing of a pilot-distinctive nature. Laboratory tests of flotation process were carried out in two independent study groups, ie. one with use of model wastewater and second with the use of real wastewater. Conducted examinations and analysis of the results allow to draw certain conclusions: 1. Wastewater from car service stations, mechanical garages and also gas stations are contaminated with oil derived compound, and although individual garage produces small amounts of wastewater, the sum of all wastewater in the scale of the whole country each day is substantial. 2. Proposed small installation for pre-treatment of oily wastewater, when implemented In the car service station or gas station will improve quality of wastewater daily inputted to sewage system. 3. The flotation process which is the first node of proposed technological installation does not treat wastewater sufficiently, but noticeably, and thus it allows to extend the life of an important node of the installation, that is sorption process. 4. Research should be continued on a small experimental plant installed in the car or gas station.
The main objective of this study was to provide a method for reducing odor nuisance and checking to what extent the essential oil affects the quality of the mechanical dewatering of municipal sewage sludge. Pine essential oil was used as a substitute of the flocculant in the process of centrifugal sedimentation of sewage sludge. The study was divided into two stages. In the first stage of the research was essential oil from pine needles was produced in the process of steam distillation. In the second part of the research process of mechanical dewatering of municipal sewage sludge on a laboratory sedimentation centrifuge MPW-350 was carried out with the use for this process pine essential oil (produced in the first stage of the study) and flocculant ZETAG® 9048FS. Constant parameters of centrifugal sedimentation were: centrifugation time was t [min.] (assumed centrifugation time t = 1 min.) and centrifuge speed n [1/min.] (assumed n = 2400 1/min.). Independent variable parameters were: dose of flocculant C [ml of flocculant solution /dm3 of sludge] and the dose of essential oil D [cm3 /100 cm3 of sludge]. Based on extensive investigations carried out, it was found that the pine essential oil effectively neutralizes unpleasant odors emitted in the process of mechanical dewatering of municipal sewage sludge during laboratory centrifuge sedimentation. With increasing doses of the pine essential oil time of effective neutralization of unpleasant odors increases, both in the dewatered sludge and effluent. Dose of added flocculant affects the time of effective neutralization of odors by pine essential oil. Together with an increase of flocculant dose, duration of odor neutralization in sludge and effluent decreases. With the increase in the dose of essential oil water content in the sludge decreases. This relationship is maintained for all used concentrations of flocculant dose. With the increase in the dose of essential oil solids concentration in effluent decreases. This relationship is maintained for all used concentrations of flocculant dose. Application of the results of this study requires a technical and economic analysis and determination of the feasibility of the proposed method. This will be the subject of aseparate publication.
Źródłem nieprzyjemnych zapachów są zarówno procesy naturalne, jak i działalność człowieka. Naturalne odory pochodzą głównie z procesówwulkanicznych, pożarów lasów i stepów, emisji z terenów bagnistych oraz rozkładu materii przez mikroorganizmy. Działalność antropogeniczna emitująca największe ilości odorów związana jest z przemysłem chemicznym, energetycznym, papierniczym, farmaceutycznym, spożywczym, a także wytwarzaniem ścieków i odpadów.Emisja tych złowonnych gazów stanowi dużą uciążliwość szczególnie dla ludności zamieszkującej na obszarach ich oddziaływania. W chwili obecnej brak polskich norm w zakresie metod oceny intensywności odorów i przepisów określających ich oddziaływanie na środowisko - co uniemożliwia zarówno nakazanie ograniczenia emisji odorów, jak i egzekwowania nakazów przez organy ochrony środowiska - przyczynia się do podejmowania stosownych środków zaradczych. Zróżnicowanie charakteru emisji odorów, a także cech odorantów, sprawia, że stosuje się różnego rodzaju środki zaradcze. W wypadku niewielkich emisji, gdy stężenia odorantów są małe, choć z racji niskich progów wyczuwalności węchowej powodują istotną uciążliwość, możliwe jest stosowanie środków maskujących.
EN
Investigations on use of ethereal oils for masking of odours were divided into two stages:Stage I - in laboratory from plant materials that is: geranium leaves, dry carawayseeds, coneberries of juniper, dry fruits of anise and dry seeds of black cumin ethereal oils were obtained in the process of distillation with water steam. Quantity of obtained ethereal oil Vo and following parameters: pH, total suspension Zo, dissolved substances SR, dry residues SP chlorine content, density ? and refraction coefficient nD depending on the temperature (in the range 10÷60°C) and aromatic extract gain index Wuz were determined after their producing. Stage II - test of decrease of noxiousness of emitted odours was executed in SUPERFISH plant by application of obtained in the first stage of investigations ethereal oils. Produced aromatic solutions had been sprayed using sprinkler in hall of postproduction wastewater pretreatment plant in fish processing plant SUPERFISH, located in Kukinia near Ustronie Morskie, northern Poland. After spraying time of fragrance duration was measured in two zones, i.e. in the distance 0.6 m and 1.2 m from the spot of spreading the substance, that is Dorr settlers no. III and V. It must be stressed, that the source of noxious odours processing plant are post-production suspension wastewater collected in the buffer reservoir and coming from following processes: flotation, sedimentation with coagulation, sorption and sedimentation in radial settler. Conducted investigations showed that all obtained aromatic substances had neutralized unpleasant odours effectively. The best masking proprieties has extract from caraway, because time of fragrance duration of sprayed solution from caraway in distance 0.6 m from the spot of spread of substance was 42 min. and fragrance duration of sprayed solution of carnation extract, in the distance 1.2 m was 27 min. Conducted investigations also allow to state that, density of oils is in functional relation to refraction coefficient nD. The higher density of oil is, the higher refraction coefficient value nD, a also the longer masking properties maintains extract under given desodorisation conditions.
Zanieczyszczenie powietrza spowodowane jest nie tylko emisją zanieczyszczeń toksycznych, ale również i uciążliwych - czasem bardzo uciążliwych, a mianowicie emisją nieprzyjemnych zapachów zwanych odorami. Źródłem pochodzenia gazów złowonnych są procesy zachodzące zarówno w naturze jak i w działalności człowieka. Wchodzące w ich skład lotne związki chemiczne, należą do połączeń nieorganicznych i organicznych. Naturalne odory są wprowadzane do środowiska w wyniku działalności wulkanicznej planety, rozkładu materii przez mikroorganizmy, pożarów lasów i stepów, emisji gazów złowonnych przez tereny bagniste, a także w wyniku erozji słonecznej i wietrznej materiałów. Gazy pochodzenia antropogenicznego swoje źródło mają w procesach produkcyjnych, w których powstają dobra materialne (przemysł chemiczny, energetyczny, papierniczy, farmaceutyczny, metalurgiczny, przetwórstwa węgla i ropy, spożywczy i in.) oraz w wyniku spalania paliw, a także wytwarzania odpadów bytowych i ścieków. Badania nad maskowaniem tych złowonnych gazów prowadzone są m.in. w Politechnice Koszalińskiej w Katedrze Techniki Wodno-Mułowej i Utylizacji Odpadów w której od kilku lat trwają prace nad wyprodukowaniem skutecznego i taniego środka zmniejszającego uciążliwość zapachów [10, 11, 15]. Opracowywana metoda polega na zastępowaniu zapachu niepożądanego przyjemniejszym. Jako środki maskujące wykorzystywane są naturalne olejki eteryczne, pozyskiwane ze świeżych surowców roślinnych w procesie destylacji. Dotychczas badaniom poddano olejki eteryczne pozyskiwane z takich surowców jak: igliwie tui i sosny , mięty pieprzowej, róży dzikiej oraz skórek pomarańczy, cytryny i grejpfruta. Przedmiotem niniejszej publikacji jest opis i analiza wyników badań, będących kontynuacją wcześniejszych badań w pozyskiwaniu z roślin olejków eterycznych i ich zastosowania w celu maskowania odorów w zakładzie SUPERFISH w Kukini koło Ustronia Morskiego.
EN
Processes taking place both in the nature and in the human activities are the source of bad smelling gases (odours). Odours contain volatile chemical compounds, which belong to inorganic and organic connections. Natural odours are introduced to the environment as a result of volcanic activities of the planet, degradation of matter by microorganisms, fires of forests and grasslands, release of odours by boggy terrains, and also in the result of the sun and wind erosion of materials. Gases of anthropogenic origin have their source in production processes, in which they come into being material goods (chemical, energetic, paper, pharmaceutical, metallurgical, processing of coal and oil, food and other industries) and as a result of burning fuels, and also production of municipal wastes and sewage. The working of ethereal oils is many-sided, i.e. antibacterial, disinfe antiinflammatory, and even antivirus, additionally stimulating immunological system of the organism, improving circulation and acting anaglesically [13]. Ethereal oils also found their use for neutralization of odours and decrease of their noxiousness as a result of bigger and bigger contamination of the environment by still developing industry. Methods of odours masking have been used for many years in such branches of economy like wastewater treatment, landfills of wastes, paper-mills, fish and fish wastes processing plants, meat and fat processing plants. Area of use grows gradually, along with working out new preparations compensating odours [12]. The object of this paper is description and analysis of results of investigations, being continuation of earlier investigations on extracting ethereal oils from plants and their use in order to mask of odours in institution SUPERFISH fish processing plant in Kukinia near Ustronie Morskie, northern Poland. Badania nad zastosowaniem olejków eterycznych do maskowania odorów zostały podzielone na dwa etapy: Investigations on use of ethereal oils for masking of odours were divided into two stages: Stage I - in laboratory from plant materials that is: orange, lemon and grapefruit skins, ginger roots and dried flower buds of carnation ethereal oils were obtained in the process of distillation with water steam. Quantity of obtained ethereal oil Vo and following parameters: pH, total suspension Zo, dissolved substances SR, dry residues SP and aromatic extract gain index Wodz were determined after their producing. Stage II - test of decrease of noxiousness of emitted odours was executed in SUPERFISH plant by application of obtained in the first stage of investigations ethereal oils. Produced aromatic solutions had been sprayed using sprinkler in hall of postproduction wastewater pretreatment plant in fish processing plant SUPERFISH, located in Kukinia near Ustronie Morskie, northern Poland. After spraying time of fragrance duration was measured in two zones, i.e. in the distance 0.6 m and 1.2 m from the spot of spreading the substance, that is Dorr settlers no. III and V. It must be stressed, that the source of noxious odours processing plant are post-production suspension wastewater collected in the buffer reservoir and coming from following processes: flotation, sedimentation with coagulation, sorption and sedimentation in radial settler. Conducted investigations showed that all obtained aromatic substances had neutralized unpleasant odours effectively. The best masking proprieties has extract from grapefruit and carnation, because time of fragrance duration of sprayed solution from grapefruit in distance 0.6 m from the spot of spread of substance was 27 min. and fragrance duration of sprayed solution of carnation extract, in the distance 1.2 m was 12 min.
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