Wyniki wyszukiwania - BazTech

1

Analysis of Bottom Reverberation Intensity Under Beam-Controlled Emission Conditions in Deep Water

Zheng Guangying, Guo Xiaowei, Zhu Fangwei, Wang Fangyong, Bai Linlang

Archives of Acoustics

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2024

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Vol. 49, nr 2

221--231

EN

A comprehensive understanding of the characteristics and the formation mechanism of reverberation is the key to improving the performance of the active target detection. In response to the challenge of analyzing the intensity of bottom reverberation in typical deep-sea environments, this study proposes a prediction method for the bottom reverberation intensity under beam-controlled emission conditions. It explains the variation law of bottom reverberation intensity under beam-controlled emission conditions in typical deep-sea environments of the South China Sea through theoretical and simulation analyses. Reverberation intensity of the deep-sea bottom under beam-controlled emission conditions exhibits significant fluctuations during the duration of reverberations in the direct sound zone of the seabed. This phenomenon is closely related to the directionality of the source emission, leading to intermittent reverberation masking and detectable areas in the active sonar detection. In addition, the duration of the high-reverberation zone near the cutoff distance of the direct sound from the seabed is longer under the beam-controlled emission conditions of the emission array located within the surface waveguide layer of the deep sea during winter.

2

Analysis of the Collapse Gradient of Deep Water Horizontal Wellbore and the Effects of Mud Chemical Activity and Variation in Water Depth

Dosunmu Adewale, Nwonodi Roland I., Ekeinde Evelyn

Studia Geotechnica et Mechanica

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2020

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Vol. 42, nr 3

232--241

EN

Wellbore collapse is an instability-event that occurs at low mud density and leads to unfavorable economic project, reaching billions of US dollars. Thus, it is important to accurately determine its value, especially in deepwater horizontal wellbores. The main reasons for nontrivial problems with such wellbores are evident: the shale encountered are anisotropic in nature and possess planes of weakness; they react with water-based mud, generate osmotic stresses, swell, and fall unto the wellbore bottom, thereby increasing the non-productive time. To this end, salts are added to reduce the collapse tendency, but it is not currently known what amount of salt addition maintains stability, and does not lead to wellbore fracture; in deepwater, the current trend in global warming means there is a future concern to the industry. As the climate temperature increases, more ice melts from the polar region, the seawater expands and the sea level rises. How to incorporate the corresponding effect on collapse gradient is scarcely known. This study captures the major concerns stated above into wellbore stability analysis. Following the classical approach for geomechanical analysis, Mogi-Coulomb criterion was combined with a constitutive stress equation comprising contributions from mechanical and osmotic potentials of mud and shale. A sophisticated industry model was used to consider the deepwater effect. The results show significant reduction in collapse gradient as the water depth increases, also, larger difference between the mud and shale chemical activities represents higher complexities in the wellbore. In addition, the reduction in the chemical activities of mud limited to 37.5% of the initial value can be practically safe.

3

Increases in the temperature and salinity of deep and intermediate waters in the West Spitsbergen Current region in 1997-2016

Merchel Małgorzata, Walczowski Waldemar

Oceanologia

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2020

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No. 62 (4PA)

501--510

EN

This study investigated the temporal variability in the basic physical properties of deep and intermediate waters in the West Spitsbergen Current region at 76°30’N latitude from 1997 to 2016. Emphasis was placed on quantifying the changes in temperature and salinity and determining the potential drivers of these changes. Hydrographic data were obtained during annual summer cruises aboard the r/v Oceania in the Nordic Seas. The increase in the water temperature, which was especially strong in the western part of the investigated section, was associated with considerable changes in the water layers salinity. The temperature and salinity of the intermediate water increased much faster (0.021°C yr−1 and 0.0022 yr−1, respectively) than those of the deep water (0.009°C yr−1 and 0.0004 yr−1, respectively). The warming rate in the upper 2000 m was also higher than the mean warming rate of the global ocean. The source of the deep water temperature and salinity increases was the deep water inflow from the Arctic Ocean into the Greenland Sea. In contrast, the increase in these properties in the intermediate water was associated with the advection of warmer and more saline Atlantic Water from the North Atlantic to the Nordic Seas.

4

Oznaczanie form specjacyjnych chromu w próbkach wód głębinowych metodą katalityczno-adsorpcyjnej woltamperometrii stripingowej

Ciężkowska Magda, Rudy Aneta

Analit

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2020

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Nr 9

19--26

PL

W pracy opisano metodę oraz wyniki oznaczenia dwóch form specjacyjnych chromu w wodach, pochodzących z sześciu artezyjskich studni głębinowych, znajdujących się na terenie miasta Krakowa. Powodem celowości oznaczenia chromu w wodach głębinowych, przeznaczonych do spożycia są silnie zróżnicowane właściwości jonów chromu (III) i chromu (VI) szczególnie jeżeli chodzi o ich wpływ na organizm ludzki. Chrom(III) jest zaliczany do mikroelementów niezbędnych do prawidłowego funkcjonowania i rozwoju organizmu. Chrom (Vl) ma negatywny wpływ, gdyż przypisuje się mu działanie mutagenne, a nawet kancerogenne. Jako metodę specjacyjnego oznaczania obu form jonów chromu wybrano katalityczno-adsorpcyjną woltamperometrię stripingową (CAdSV) połączoną z rejestracją katodowych woltamogramów techniką impulsej woltamperometrii różnicowej (DPV). Spośród wielu znanych metod instrumentalnych metoda DP CAdSV cechuje się największą precyzją, dokładnością i czułością pomiaru. Co szczególnie ważne próbki wody przeznaczone do analizy woltamperometryczej nie wymagają wstępnego przygotowania, w efekcie metoda spełnia rygorystyczne wymagania zielonej chemii analitycznej (ang. Green Analytical Chemistry).

EN

The publication describes the method and results of determination of chromium speciation forms in deep-water samples. The samples came from six deep wells located in the city of Cracow. The reason for the determination of chromium in water is the different properties of Cr(III) and Cr(Vl) ions, especially their effect on the human body. Chromium (III) is essential for the proper functioning and development of the organism. Chromium (VI) has a negative effect because it acts mutagenically and even carcinogenically. The catalytic adsorptive stripping voltammetry (CAdSV) has been chosen as the method of chromium quantitative determination. Differential pulse voltammetry (DPV) technique was used to record cathodic voltammograms. Among the many instrumental methods, the DP CAdSV is characterized by the highest precision, accuracy, and sensitivity of measurements. It is important that the water samples intended for this analysis do not require any preliminary preparation, so the method meets the requirements of Green Analytical Chemistry.

5

Oszczędność energii w eksploatacji pomp i ujęć głębinowych. Część 3: Stacje prób pomp głębinowych, remonty, gospodarka pompowa

Strączyński Marian, Niezbecki Andrzej, Zatorski Przemysław

Forum Eksploatatora

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2019

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Nr 5 (104)

60-63

PL

W części pierwszej cyklu artykułów (FE 2/2019) podkreślono wpływ metod regulacji parametrów pracy pomp głębinowych na zużycie energii w eksploatacji ujęć. Część druga poświęcona była pracy modeli matematycznych wspomagających podejmowanie właściwych decyzji eksploatacyjnych (FE 3/2019). Trzecia część cyklu artykułów poświęcona będzie znaczeniu diagnozowania stanu technicznego i parametrycznego głębinowych agregatów pompowych badanych na stacjach prób pomp głębinowych, a także organizacji obiegu informacji w remontach oraz w gospodarce pompowej.

6

Decapod crustaceans in benthic habitats of the Turkish Straits System with new records

Bakir A. K., Ateş A. S.

Oceanological and Hydrobiological Studies

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2018

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Vol. 47, No. 4

337--344

EN

The objective of this study was to investigate decapod species occurring in the Turkish Straits System. For this purpose, benthic samples were collected from six different biotopes (photophilic algae, Cystoseira barbata, meadows, Posidonia oceanica, mussel, Mytilus galloprovincialis, meadows, Zostera marina, serpulid reef, and rocks) at depths ranging from 10 to 1000 m. A total of 60 species of decapod crustaceans were identified, including new records for the Turkish Straits System: Processa elegantula, P. modica, Richardina fredericii, Callianassa subterranea, Gourretia denticulata, Inachus parvirostris and Macropodia linaresi. In addition, some information about the spatial and bathymetric distribution as well as biotope preferences of the decapod community is provided.

7

Working rig machines for deep drilling 7500 psi rated drilling equipment for the future

Artymiuk J., Lengersdorf F., Loland J. H., Sokalski M.

Wiertnictwo, Nafta, Gaz

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2010

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T. 27, z. 1--2

67-73

EN

Prospecting with longer drilling wells, at greater depth of water, sets greater and greater technical challenges before designers, producers and users. Especially marine drilling, in new and unprospected areas, where exploration works are planned in the close future, where will necessitate involving higher deadweight capacity of on-water rig construction, machines of higher torque on the string, and more powerful mud pumps. Hence the need of making new equipment capable of performing necessary works safely and effectively.

PL

Prowadzenie prac poszukiwawczych coraz dłuższymi otworami wiertniczymi i przy coraz większej głębokości wody, stawia przed konstruktorami, producentami i użytkownikami coraz wyższe wyzwania techniczne. Szczególnie w wierceniach morskich, na nowych obszarach, nieobjętych dotychczas poszukiwaniami, (a tam w najbliższej przyszłości będą koncentrować się prace poszukiwawcze), wymagana będzie większa nośność nawodnej konstrukcji urządzenia wiertniczego, maszyny o znacznie większych momentach obrotowych przekazywanych na przewód wiertniczy oraz pompy płuczkowe o większej mocy od stosowanych obecnie. Stąd konieczność budowy sprzętu, który będzie w stanie zapewnić bezpieczne i efektywne wykonanie koniecznych prac.

8

Compressibilité des sédiments marins grande profondeur a tres fortes limites de liquidité

Hattab M., Favre J. L.

Studia Geotechnica et Mechanica

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2008

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Vol. 30, nr 1-2

234-244

EN

The progressive transition from the non-remoulded behaviour (natural soil) to remoulded behaviour is here investigated. Tests were performed on a deepwater clay sediments from the Gulf of Guinea characterized by a very high liquid limit. The results are analysed and compared on one hand with the reference behaviour of remoulded normally consolidated mineral clays established by BIAREZ and FAVRE [1], and on the other hand with intrinsic compression (ICL) curve proposed by BURLAND [4]. The study is supplemented with a local approach of microstructural analysis, using mercury porosimetry method.

9

Ventilation of the Baltic Sea deep water : A brief review of present knowledge from observations and models

Meier H. E. M., Feistel R., Piechura J., Arneborg L., Burchard H., Fiekas V., Golenko N., Kuzmina N., Mohrholz V., Nohr C., Paka V. T., Sellschopp J., Stips A., Zhurbas V.

Oceanologia

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2006

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No. 48 (S)

133-164

EN

The ventilation of the Baltic Sea deep water is driven by either gale-forced barotropic or baroclinic salt water inflows. During the past two decades, the frequency of large barotropic inflows (mainly in winter) has decreased and the frequency of medium-intensity baroclinic inflows (observed in summer) has increased. As a result of entrainment of ambient oxygen-rich water, summer inflows are also important for the deep water ventilation. Recent process studies of salt water plumes suggest that the entrainment rates are generally smaller than those predicted by earlier entrainment models. In addition to the entrance area, the Słupsk Sill and the Słupsk Furrow are important locations for the transformation of water masses. Passing the Słupsk Furrow, both gravity-driven dense bottom flows and sub-surface cyclonic eddies, which are eroded laterally by thermohaline intrusions, ventilate the deep water of the eastern Gotland Basin. A recent study of the energy transfer from barotropic to baroclinic wave motion using a two-dimensional shallow water model suggests that about 30% of the energy needed below the halocline for deep water mixing is explained by the breaking of internal waves. In the deep water decade-long stagnation periods with decreasing oxygen and increasing hydrogen sulphide concentrations might be caused by anomalously large freshwater inflows and anomalously high mean zonal wind speeds. In different studies the typical response time scale of average salinity was estimated to be between approximately 20 and 30 years. The review summarizes recent research results and ends with a list of open questions and recommendations.

10

Zastosowanie reaktorów membranowych w ochronie środowiska

Bohdziewicz J.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Śląska

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2003

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z. 48

129-138

PL

W artykule omówiono przykłady możliwości zastosowania reaktorów membranowych do uzdatniania wody głębinowej przeznaczonej do celów pitnych oraz do oczyszczania ścieków. Skojarzenie mikrofiltracji, ultrafiltracji i odwróconej osmozy z procesami biologicznymi (złoże zatopione, metoda osadu czynnego) pozwoliły we wszystkich przebadanych układach na uzyskanie lepszej efektywności oczyszczania w porównaniu z wynikami uzyskanymi w stosowanych dotychczas rozwiązaniach konwencjonalnych.

EN

The paper presents applications of membrane reactors to the treatment of wastewater as well as deep water intended for drinking. A combination of microfdtration, ultrafiltration, reverse osmosis and biological processes (deep bed fdtration, activated sludge technique) demonstrated better effectiveness than the traditional methods used in all the systems tested.