Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Miska, A." wg kryterium: Autor


Wyświetlanie 1-5 z 5
Tytuł:
Wieści ze świata feromonów ludzkich
Autorzy:
Miska, A.
Powiązania:
https://bibliotekanauki.pl/articles/854855.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Przyrodników im. Kopernika
Tematy:
czlowiek
substancje zapachowe
feromony
percepcja zapachow
relacje miedzyludzkie
substancje aromatyczne zob.substancje zapachowe
Źródło:
Wszechświat; 2011, 112, 07-09
0043-9592
Pojawia się w:
Wszechświat
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How copper excess influences homeostasis of the bank vole (Myodes glareolus)
Autorzy:
Miska-Schramm, A.
Zakrzewska, M.
Hajduk, J.
Kruczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/1189831.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:
copper
iron
zinc
bank vole
homeostasis
Opis:
Copper is a physiologically occurring trace element, the availability of which to wild small mammals is constantly increasing. This research deals with the questions of how copper in doses equivalent to those found in the natural environment from polluted areas (Cu I – 150 mg kg-1, Cu II – 600 mg kg-1) influences homeostasis of small rodents. The following were used as indicators: ratios of organs to body mass, blood parameters (haematocrit, haemoglobin), copper, iron and zinc concentrations in selected tissues and in excrements. The bank vole was used as a model species (n = 72). Haematocrit was assessed using a haematocrit reader, while haemoglobin was determined with a spectrophotometer. The content of Cu, Fe and Zn was analyzed using the flame method. Ratios of the liver and kidneys to body mass were significantly lower in animals exposed to 600 mg kg-1 Cu than in the control. Copper accumulated in the liver, kidneys, brain and excrements of the Cu II animals of both sexes. It also influenced the iron and zinc homeostasis by decreasing the iron concentration in the kidneys of both sexes, in the liver of females and in male testes. Additionally, it caused a decline in iron excretion in females. Compared to the control, the zinc concentration was significantly higher in the liver and brain of animals exposed to copper solutions as well as in the kidneys of copper treated males. Along with an increase in copper, the zinc concentration in faeces decreased significantly. In conclusion, copper pollution influences negatively the homeostasis of small mammals. Consequently it may interfere with trophic chains, which could affect adversely the degree of biodiversity.
Źródło:
Journal of Elementology; 2017, 22, 2; 617-628
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How copper excess influences homeostasis of the bank vole (Myodes glareolus)
Autorzy:
Miska-Schramm, A.
Zakrzewska, M.
Hajduk, J.
Kruczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/961456.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Opis:
Copper is a physiologically occurring trace element, the availability of which to wild small mammals is constantly increasing. This research deals with the questions of how copper in doses equivalent to those found in the natural environment from polluted areas (Cu I – 150 mg kg-1, Cu II – 600 mg kg-1) influences homeostasis of small rodents. The following were used as indicators: ratios of organs to body mass, blood parameters (haematocrit, haemoglobin), copper, iron and zinc concentrations in selected tissues and in excrements. The bank vole was used as a model species (n = 72). Haematocrit was assessed using a haematocrit reader, while haemoglobin was determined with a spectrophotometer. The content of Cu, Fe and Zn was analyzed using the flame method. Ratios of the liver and kidneys to body mass were significantly lower in animals exposed to 600 mg kg-1 Cu than in the control. Copper accumulated in the liver, kidneys, brain and excrements of the Cu II animals of both sexes. It also influenced the iron and zinc homeostasis by decreasing the iron concentration in the kidneys of both sexes, in the liver of females and in male testes. Additionally, it caused a decline in iron excretion in females. Compared to the control, the zinc concentration was significantly higher in the liver and brain of animals exposed to copper solutions as well as in the kidneys of copper treated males. Along with an increase in copper, the zinc concentration in faeces decreased significantly. In conclusion, copper pollution influences negatively the homeostasis of small mammals. Consequently it may interfere with trophic chains, which could affect adversely the degree of biodiversity.
Źródło:
Journal of Elementology; 2017, 22, 2
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the use of a down-hole mechanical cleaning device for efficient wellbore cleaning
Analiza wykorzystania wgłębnych mechanicznych urządzeń czyszczących do skutecznego oczyszczania otworu
Autorzy:
Qureshi, A.
Miska, S.
Miska, W.
Powiązania:
https://bibliotekanauki.pl/articles/299975.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
wiercenie
oczyszczanie dna otworu
otwory horyzontalne
drilling
down-hole mechanical cleaning
horizontal wells
Opis:
Field evidence indicates that in highly deviated and horizontal wells, cuttings tend to accumulate on the lower side of the annulus under the influence of gravity and eventually may form a non moving bed. This leads to considerable increase in equivalent circulating density (ECD) and drag/torque as well may result in a differential pipe sticking and wellbore stability problems. A good control of drilling fluid rhelogical properties, flow rate and drillpipe rotational speed may not be sufficient in some instances. Also, the commonly used techniques of circulation at high flow rates, using sweeps of high/low viscosity and high density may not be possible and, at times, prove to be ineffective. To overcome this difficulty, a down hole cleaning subs (mechanical cleaning devices - MCDs) are incorporated in the drill string to agitates the cuttings bed by bringing the cuttings into suspension for subsequent carrying out by the drilling fluid to the surface. These devices are furnished with "blades" which produce the desired hydrodynamic effects as the drill string is rotated and helps to dislodge the cuttings from the bed. The hole cleaning is thus governed primarily by the agitation created by the device, the rheological properties of the mud and the drilling fluid flow rate. Taking these factors into account, a study was conducted at Tulsa University Drilling Research Projects' (TUDRP) large scale wellbore simulator to experimentally determine the cleaning efficiency of a Mechanical Cleaning Device (MCD). From the database generated through the experiments, correlations were obtained by performing regression modeling to extend the results to field applications. These correlations are based on dimensionless parameters and predict reasonably accurately the in-situ cuttings concentration when the MCD is installed in the drill string. The results are useful for designing of the optimal hydraulic program for extended reach, high angle and horizontal wells.
Z danych terenowych wynika, że w silnie odchylonych i poziomych otworach wiertniczych zwierciny gromadzą się w dolnej części przestrzeni pozarurowej pod wpływem siły grawitacji. Prowadzi to do znacznego wzrostu ECD oraz momentu; może również spowodować zablokowanie rury oraz problemy z zachowaniem stabilności otworu. Właściwa kontrola właściwości reologicznych, wielkości przepływu i prędkości obrotowej w niektórych przypadkach może okazać się niewystarczająca. Również powszechnie stosowane techniki intensywnej cyrkulacji, a także z wykorzystaniem cieczy o wysokiej/niskiej lepkości oraz dużej gęstości mogą okazać się niemożliwe lub nieskuteczne. Do pokonania tej trudności na przewodzie zastosowano mechaniczne wgłębne urządzenie czyszczące w celu pobudzenia zwiercin i utworzenia zawiesiny, która zostanie wyniesiona na powierzchnię wraz z płuczką wiertniczą. Urządzenia tego typu wyposażone są w ostrza, które wywołują pożądany efekt hydrodynamiczny w trakcie obrotu przewodu wiertniczego, i w wyniku czego zwierciny zostają podniesione z miejsca gromadzenia się. Główne mechanizmy związane z czyszczeniem otworu polegają na wzbiciu osadu, odpowiednich właściwościach reologicznych płuczki wiertniczej oraz hydrauliki.
Źródło:
Wiertnictwo, Nafta, Gaz; 2007, 24, 1; 401-413
1507-0042
Pojawia się w:
Wiertnictwo, Nafta, Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of layouts of PDC cutters in core bit drilling
Autorzy:
Buitrago Gomez, L. A.
Miska, S. Z.
Ziaja, M. B.
Powiązania:
https://bibliotekanauki.pl/articles/299255.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
PDC cutter
cutters layout
PDC bit
coring
drilling efficiency
Opis:
Over the past two decades, various single cutter force models have been developed that consider formation properties and bit characteristics. These models have been extensively used to describe the interaction of a Polycrystalline Diamond Compact (PDC) bit with formation rocks; however, their use to predict bit drilling efficiency is usually inadequate. There is an ample of field evidence that the density and layouts of PDC cutters affect drilling efficiency. Still, however, there is no reliable model of the PDC bit performance allowing determination of these bit design features for a specific bit's applications. In order to better understand the relationship between rock properties and PDC cutter layouts for different bit applications, laboratory drilling tests were performed with PDC core bits. The concept of an eight-blade PDC core bit was used to build a bit with a common body and replaceable heads. Core-bit design features such as: bit, cutter size, and cutter geometry were constant. In this study, the full-scale test rig facility at the University of Tulsa was used to obtain consistent data for six different layouts of PDC cutters. Operating parameters, such as the rate per minute (RPM) and weight on bit (WOB), were varied and performance parameters (rate of penetration (ROP) and bit torque (TQB)), were measured at each time step with the frequency of 10 Hz. The ROP were calculated as a function of bit displacement over time. All operating parameters were recorded as part of the data acquisition platform. Depth of Cut (DOC) was calculated from ROP, and the average WOB and TQB were estimated at each depth of cut. Tests were performed on two different rocks: Bedford and Carthage Limestones. For the purpose of comparing performance among different cutter layouts, we experiment with a maximum of four different depths of cut, which corresponded to four different weights on bit. The tested layouts allowed a constant maximum DOC per cutter of 0.25 in. Water was the drilling fluid for the entire experimental phase. The results showed that under the same drilling parameters, the cutter layout plays a key role in drilling efficiency. Strong linear relationships were found between DOC, WOB and TQB at different conditions that were characteristic of the specific bit design. Also, the PDC cutter layouts affected the relative drilling performance differently for different rock properties.
Źródło:
AGH Drilling, Oil, Gas; 2016, 33, 2; 341-360
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies