Towards a Lining Integrated Active Structural Acoustic Control System

For future aircraft counter-rotating open rotor (CROR) engines are a promising technology to reduce their CO2 footprint. Since the contribution of CROR engines to the cabin noise is higher than for jet engines, new strategies for the reduction of noise transmissions for frequency bands below 500 Hz are necessary. Active structural acoustic control (ASAC) systems are capable to reduce sound transmission of lining structures in this bandwidth. Sensors measure the vibrations of the lining to estimate its sound emission into the cabin. Based on these signals a controller calculates force signals for actuators on the lining. The actuator forces change the vibration behaviour of the lining in order to reduce its sound emission. For the realization of such a system in a real aircraft, manufacturing and maintenance issues have to be addressed. Within work package 3 of the EU project ACASIAS an aircraft lining with an integrated ASAC system is developed. The size of the lining is app. 1300 x 1690 mm2 (W x H) and it is simply curved. The radius of 2980 mm makes it relevant for a twin-aisle aircraft like the Airbus A350. The focus of research activities lies on the integration of components and the industrial manufacturing process of the lining. The components to be integrated are sensors, actuators and the corresponding wiring. A concept is proposed where each actuator and sensor is encapsulated in a kind of insert. The inserts smoothly integrate into the manufacturing process of the lining while they protect the actuators and sensors from humidity, dust, etc. The maintenance aspect is covered by the option to change each actuator or sensor upon insert level. The integrated wiring of the lining is left unaffected during an actuator or sensor replacement since connectors in each insert allow a nearly tool-free assembly/disassembly. In this paper the progress of work package 3 is presented at a detailed design review (DDR) stage. Finally, the lining will be manufactured and equipped with a full ASAC system. Experiments will be conducted in the acoustic transmission loss facility at the DLR

Deep Borehole Heat Exchangers -A Conceptual Review

ABSTRACT Borehole heat exchangers are used for transforming a rock mass into an underground heat storage. Usually, their depth does not exceed 200 m, but some extend to a depth of almost 3000 m. Underground heat storages can operate as part of heating and cooling systems, often economically. In winter they extract heat from the rock mass for space heating, while in summer the cooled rock mass is used for air conditioning. The heat extracted from buildings via air conditioning is transferred into the rock mass, thereby regenerating its condition for winter time. Deep borehole exchangers also may operate only in the heating mode. Then, the rock resource conditions are regenerated via heat transfer through neighboring rocks. If a groundwater flow is present, the heat can also be removed and the source conditions regenerated through convection. Here, an overview is provided of the use and operation of deep borehole heat exchangers around the world. Special emphasis is placed on the Carpathians, where numerous analyses of geothermal heat use have been performed since 1999. Examples of calculations for old oil and gas wells as well as negative exploration boreholes are given. Such analyses have been performed for boreholes in Poland and the Ukraine. However little research has been published on this subject to date, for reasons described herein

Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis.

OBJECTIVE: To determine the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline, Embase, and Cochrane databases (until December 2015). REVIEW METHODS: Databases were searched without language restrictions for studies of women with uncomplicated twin pregnancies that reported rates of stillbirth and neonatal outcomes at various gestational ages. Pregnancies with unclear chorionicity, monoamnionicity, and twin to twin transfusion syndrome were excluded. Meta-analyses of observational studies and cohorts nested within randomised studies were undertaken. Prospective risk of stillbirth was computed for each study at a given week of gestation and compared with the risk of neonatal death among deliveries in the same week. Gestational age specific differences in risk were estimated for stillbirths and neonatal deaths in monochorionic and dichorionic twin pregnancies after 34 weeks' gestation. RESULTS: 32 studies (29 685 dichorionic, 5486 monochorionic pregnancies) were included. In dichorionic twin pregnancies beyond 34 weeks (15 studies, 17 830 pregnancies), the prospective weekly risk of stillbirths from expectant management and the risk of neonatal death from delivery were balanced at 37 weeks' gestation (risk difference 1.2/1000, 95% confidence interval -1.3 to 3.6; I(2)=0%). Delay in delivery by a week (to 38 weeks) led to an additional 8.8 perinatal deaths per 1000 pregnancies (95% confidence interval 3.6 to 14.0/1000; I(2)=0%) compared with the previous week. In monochorionic pregnancies beyond 34 weeks (13 studies, 2149 pregnancies), there was a trend towards an increase in stillbirths compared with neonatal deaths after 36 weeks, with an additional 2.5 per 1000 perinatal deaths, which was not significant (-12.4 to 17.4/1000; I(2)=0%). The rates of neonatal morbidity showed a consistent reduction with increasing gestational age in monochorionic and dichorionic pregnancies, and admission to the neonatal intensive care unit was the commonest neonatal complication. The actual risk of stillbirth near term might be higher than reported estimates because of the policy of planned delivery in twin pregnancies. CONCLUSIONS: To minimise perinatal deaths, in uncomplicated dichorionic twin pregnancies delivery should be considered at 37 weeks' gestation; in monochorionic pregnancies delivery should be considered at 36 weeks. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42014007538

Wplyw substancji humusowych na wzrost i rozwoj siewek salaty

W doświadczeniu z kiełkowaniem nasion sałaty na szalkach Petriego badano wpływ substancji humusowych na wzrost i rozwój siewek sałaty. Po 5 i 10 dniach eksperymentu oznaczono wagę siewek oraz długość łodyg i korzeni. Stwierdzono, że działanie substancji humusowych zależy przede wszystkim od odmiany testowanej sałaty, a następnie rodzaju preparatu. Stwierdzono wpływ substancji humusowych na rozwój liści i korzeni bocznych siewek.In experiment with seed germination of lettuce in Petri-dishes, effects of humic substances on growth of seedlings was observed. After 5 and 10 days weight and length of seedlings stems and roots were determined. It was found, that the effect of humic substances depend mainly on variety of lettuce and on type of humus preparation. The effect of humic substances on development of seedling leaves and roots was also observed

Optymalizacja trajektorii otworu kierunkowego dla kryterium minimalizacji kosztu jego wykonania

New drilling technical and technological solutions enhance the development of directional drilling, enabling better control of direction of drilling and real-time 3D information about the position of the bit in the borehole rendered by the control and measurement apparatuses. The 2D and 3D method of designing the trajectory of a borehole axis has been modified in this paper. In both cases the minimum cost of drilling of a borehole in an interval from the beginning of its deflecting (KOP) up to the ultimate destination point was assumed to be the optimization criterion. Another assumption says that the admissible dogleg will never be exceeded over the entire interval of the borehole axis. Commonly more and more boreholes are performed from one place or one drilling platform. Such drilling is aimed at, e.g. developing unconventional deposits of natural gas or improving the depletion factor by injecting water or CO2. In such cases the boreholes are located densely, which may result in their colliding. Hence, attention was drawn to the fact that in such cases inaccuracies of apparatuses measuring the angle of deflection of the borehole, azimuth, length of the borehole and formation of error ellipsoids around a given point should be accounted for. The assumed method of positioning the borehole axis is also important. For a considerable length of the borehole axis the calculations are simple but time-consuming, therefore specialist computer programs are recommended. The trajectories of directional boreholes should be designed taking into account the position of the neighboring boreholes and inaccuracy of measuring equipment, as in this way the level of risk of potential collisions of boreholes axes can be determined.Wprowadzanie najnowszych rozwiązań technicznych i technologicznych do wiertnictwa sprzyja rozwojowi wierceń kierunkowych. Jest to możliwe dzięki szerokim możliwościom sterowania kierunkiem wiercenia i aparaturze kontrolno-pomiarowej mogącej w czasie rzeczywistym przekazywać informacje o położeniu świdra w przestrzeni trójwymiarowej. W artykule zmodyfikowano projektowanie w przestrzeni dwu i trójwymiarowej trajektorii osi otworu kierunkowego. Założono, że kryterium optymalizacji w obu przypadkach jest minimum kosztu wykonania otworu w interwale od początku jego kierunkowania (KOP) aż do końcowego celu. Przyjęto także ograniczenie mówiące o tym, że na całym analizowanym interwale osi otworu nie zostanie przekroczona dopuszczalna krzywizna. W praktyce wiertniczej obserwuje się coraz to więcej otworów wykonywanych z jednego placu lub z jednej platformy wiertniczej. Przykładowo są to wiercenia mające na celu udostępniania złóż gazu niekonwencjonalnego lub poprawienie współczynnika sczerpania złóż poprzez zatłaczanie do nich wody lub CO2. W takich przypadkach zazwyczaj zwiększa się zagęszczenie otworów, co może w niekorzystnych przypadkach prowadzić do ich kolizji. Z tego powodu zwrócono uwagę, że w takich sytuacjach wskazane jest uwzględnienie niedokładności przyrządów mierzących kąt odchylenia osi otworu i jej azymut oraz długość otworu i tworzenie wokół danego punktu pomiarowego elipsoidy błędu. Tutaj istotna jest także przyjęta metodyka określania przestrzennego położenia osi otworu. Dla znacznej długości osi otworu obliczenia są proste lecz bardzo czasochłonne i dlatego warto skorzystać z programów komputerowych. Zatem zaleca się projektować trajektorie osi otworów kierunkowych z uwzględnieniem położenia sąsiednich otworów i niedokładności przyrządów pomiarowych, co umożliwia określenie poziomu ryzyka w zakresie potencjalnych kolizji osi otworów

Heat transfer efficiency analysis in different constructions of borehole heat exchangers

W publikacji opisano realizacje otworowych wymienników ciepła na świecie i w Polsce. Zaprezentowano podstawowe konstrukcje wymienników otworowych. Przedstawiono możliwości wymiany ciepła. Podano obliczenia przewodności cieplnej efektywnej wymienników otworowych Laboratorium Geoenergetyki WWNiG AGH w Krakowie, a także wartości oporności termicznej wymienników, które mają wpływ na efektywność energetyczną.There are described in the paper drilling of borehole heat exchangers (BHE) on the world and in Poland. The most popular constructions of BHE are described with possibility of heat extraction. There are also showed results of calculation of effective heat transfer coefficient of the Laboratory of Geoenergetics of Drilling, Oil and Gas Faculty of AGH University of Science and Technology BHEs with its heat resistivity. This parameters decided for energetic efficiency of the BHEs

Concept of making use of closed wells in field Turaszówka for heat recovery and heating an indoor swimming pool

Odwierty służące kiedyś do eksploatacji węglowodorów znajdujące się niejednokrotnie w niewielkiej odległości od obiektów budowlanych mogą służyć do pozyskiwania niskotemperaturowej energii zawartej w górotworze i za pośrednictwem pomp ciepła dostosowanej do potrzeb odbiorcy. W artykule przedstawiono koncepcję zagospodarowania zlikwidowanych odwiertów złoża ropy naftowej Turaszówka poprzez ich adaptację na otworowe wymienniki ciepła. Niewielka odległość od krytej pływalni daje możliwość wykorzystania ciepła przez odbiorcę, który wymaga całorocznego obciążenia źródła energii o korzystnej charakterystyce. Przedstawiona propozycja obejmuje wykorzystanie zlikwidowanych pięciu odwiertów, a także wskazuje na możliwość wykorzystania innych, które są jeszcze eksploatowaneClosed wells used for hydrocarbon production, frequently are located close to buildings, therefore can be used for the recovery of low-temperature energy of the rock mass, which can be then delivered to the heat pumps and finally to the end user. A concept of managing closed wells in the field Turaszówka, their adaptation to heat exchangers is presented in the paper. A small distance to an indoor swimming pool creates a possibility of using the heat by a customer who requires a reliable energy source of good characteristic all year long. Having assumed heat deliveries for heating water in the swimming pool, a high efficiency of heat pump is possible. This concept was analysed in view of 5 closed wells, and also perhaps the already operational one

Dynamics of some phisical and chemical properites of sandy soil with changed mechanical composition and its effect on crop yields

Микроделяночный опыт был заложен в 1971 г. на почве образованной из рыхлого песка. Из этой почвы, в результате её измельчения получали субстрат, содержащий 87% илистых частиц, который добавляли в количествах: 0%, 5%, 10%, 15% и 30% веса в слое 0 - 25 см. Применяли два уровня органического удобрения, а с 1976 г. дифференцировали также минеральное удобрение (1 NPK, 20 т/га стойлового навоза и 2 NPK 40 т/га стойлового навоза). Целью исследований являлось сравнение приданных почве свойств и полученных урожаев непосредственно после докладки опыта и через продолжительное время её использования. Установлено, что приданный почве механический состав верхнего слоя и водный режим не изменились. Выступили значительные изменения химических свойств, а за 12 лет увеличилось содержание гумуса с 0,94% до 1,25%. Отмечено также обеднение почвы питательными элементами. Урожаи растений в зависимости от прибавки измельченной почвы были выше на 10,0% до 18,6% (зерновых от 18,4% до 22,9% и кормовых культур от 17% до 41%).The microplot experiment was established in 1971 on a soil developed from loose sand. From this soil, as the result of grounding the substratum containing 87% of clay fraction was obtained and added in the amount of: 0, 5, 10, 15, 30 per cent weight to the layer 0 - 25 cm. Two levels of organic fertilization were applied and from 1976 mineral fertilization was differentiated as well(lNPK, 20 t/ha farmyard manure and 2 NPK, 40 t/ha farmyard manure). The aim of the investigations was to compare the given soil properties and yields directly after establishment of the experiment, and after longer period of the soil utilization. It has been confirmed that the given mechanical composition of the surface layer of the soil and hydrological properties underwant no changes. Great changes in chemical properties were observed. After 12 years, the humus content increased from 0,94 to 1,25 per cent. Also impoverishment of soil in mineral elements took place. The yields of plants increased from 10,0% to 18,6% (cereals from 8,4% to 22,9% and forage plants from 17% to 41%)