Part Of Shell Research Articles

Eight years of passive acoustic monitoring in the Alaskan Beaufort Sea: Lessons learned

Every year during open-water season in 2007–2014, up to 40 passive acoustic recorders with directional capability (DASARs) were deployed in the Beaufort Sea, as part of Shell’s Marine Mammal Monitoring and Mitigation Program. The overarching goal of these deployments was to collect information on the effects of industrial operations, such as seismic exploration and drilling activities, on the behavior of bowhead whales during their fall migration. Recorders were placed on the continental shelf at depths of <55 m, offshore of the North Slope of Alaska, between Barter Island and Harrison Bay. Over the eight-year period, more than 3.1 million bowhead calls were localized. Concurrently, various types of industrial sounds were detected and quantified, such as airgun pulses or the tones produced by machinery. Analyses were then performed by matching—for each recorder—the number of calls localized with the amount of industrial sound detected. These analyses have shown that changes in calling behavior happen at low received levels of anthropogenic sound and lead to complex changes in calling behavior, that are governed by received sound levels, but also other factors, such as distance to the industrial activity or type of industrial sound. [Work sponsored by Shell Exploration and Production Company.]

High - Fidelity Reliability Prediction of a Tube Bundle

The reliability of shell and tube heat exchanger is predicted using a 2-stage physics-based simulation. The first stage uses stochastic porous models of the bundle to estimate operational and environmental uncertainties in flow conditions, such as flow velocity and inlet temperature. The results are used for the second stage, which is the CFD simulation of the sub-model. The most critical part of shell and tube heat exchangers is the tube bundle. The technique integrates stochastic fluid-structure interaction with fatigue and Monte Carlo simulations. Heating loads are transferred between models by mapping of actual temperature distributions. A sensitivity analysis is conducted to determine the significant factors that may lead to failure, as it is impractical to consider all input variables. In the sub-model, which is a tube bank, air flow and heat transfer inter-effects between the three tubes and the fins are measured. Thermal stresses are highest at the bonding regions between the water tubes and the fins, and that is because of the high temperature gradient combined with different material properties. Thermal stress in the model is relatively low, however, it has a high effect on fatigue life, and consequently on reliability result. The presented model can be used as a useful tool for reliability-based design of shell and tube heat exchangers.

The red-eared slider turtle carapace under fatigue loading: The effect of rib-suture arrangement.

Biological structures consisting of strong boney elements interconnected by compliant but tough collagenous sutures are abundantly found in skulls and shells of, among others, armadillos, alligators, turtles and more. In the turtle shell, a unique arrangement of alternating rigid (rib) and flexible (suture) elements gives rise to superior mechanical performance when subjected to low and high strain-rate loadings. However, the resistance to repeated load cycling - fatigue - of the turtle shell has yet to be examined. Such repeated loading could approximately simulate the consecutive high-stress bending loads exerted during (a predator) biting or clawing. In the present study flexural high-stress cyclic loads were applied to rib and suture specimens, taken from the top dorsal part of the red-eared slider turtle shell, termed carapace. Subsequently, to obtain a more complete and integrated fatigue behavior of the carapace, specimens containing a complex alternating rib-suture-rib-suture-rib configuration were tested as well. Although the sutures were found to be the least resistant to repeated loads, a synergistic effect was observed for the complex specimens, displaying improved fatigue durability compared to the individual (suture or even rib) constituents. This study may assist in the design of future high-stress fatigue-resistant materials incorporating complex assemblies of rigid and flexible elements.

A Hybrid statistical mechanics—quantum chemical model for proton transfer in 5‐azauracil and 6‐azauracil in water solution

A hybrid statistical physics—quantum‐chemical methodology was implemented to study the water‐assisted intramolecular proton‐transfer processes in 5‐ and 6‐azauracils in aqueous solutions. The solvent effects were included in the model by explicit inclusion of two pairs of water molecules, which model the relevant part of the first hydration shell around the solute. The position of these water molecules was initially estimated by carrying out a classical Metropolis of dilute water solutions of the title compounds and subsequently analyzing solute–solvent intermolecular interactions in the Monte Carlo‐generated configurations. Sequentially to the statistical physics simulation, ab initio quantum mechanical (QM) level of theory was implemented. The effects of the water as solvent (at ab initio QM level) were introduced at two different levels—using solute–solvent clusters (four‐water molecules) and using the same clusters embedded in an external continuum. Full geometry optimizations of these complexes were carried out at MP2/6–31 + G(d, p) and conductor‐polarizable continuum model (C‐PCM)/MP2/6–31 + G(d, p). Single point calculations were performed at CCSD(T)/6–31 + G(d, p)//MP2/6–31 + G(d, p) computational level to obtain more accurate energies. According to our calculations hydrated azauracils should exist in three forms: mainly dioxo form and two hydroxy forms. The calculated proton transfer activation energies for tautomeric reactions of 5‐azauracil and 6‐azauracil show different pictures for these two compounds. According to C‐PCM/MP2/6–31 +G(d, p) data, water‐assisted proton transfer in 5‐azauracil realizes through two parallel reactions: 1,3,5‐triazine‐2,4(1H,3H)‐dione → 6‐hydroxy‐1,3,5‐triazin‐2(1H)‐one and 1,3,5‐triazine‐2,4(1H,3H)‐dione → 4‐hydroxy‐1,3,5‐triazin‐2(1H)‐one. Tautomeric equilibrium in 6‐azauracil in water could occur by two contiguous reactions: 1,2,4‐triazine‐3,5(2H,4H)‐dione → 5‐hydroxy‐1,2,4‐triazin‐3(2H)‐one and 5‐hydroxy‐1,2,4‐triazin‐3(2H)‐one → 3‐hydroxy‐1,2,4‐triazin‐5(2H)‐one. The proton transfer investigated reactions in 5‐ and 6‐azauracils involve concerted atomic movement. © 2015 Wiley Periodicals, Inc.

Light-Weight Design of the Tubesheet of a High Pressure U-Tube Heat Exchanger Based on Finite Element Analysis

Based on Chinese code GB151 for the design of shell-and-tube heat exchangers, the tubesheets are usually very heavy. The reason is attributed to the oversimplified mechanical model for the calculation of the tubesheet thickness especially the insufficient consideration of the tube support to the tubesheet. In this paper, a 3-D finite element model was established for a U-tube heat exchanger consisting of tubesheet, tube-channel, part of shell and tubes. A static stress analysis was performed under tube-side pressure loading. Optimal computation or light-weight design was carried out for minimum thickness of the tubesheet with the precondition of strength requirements conforming to the design-by-analysis code JB4732-1995. It is found that with the optimization design, the thickness of the tubesheet could be decreased by 31%, meaning that by using finite element method together with the code of design-by-analysis the thickness of the tubesheet can be significantly reduced.

Selective current collecting design for spring-type energy harvesters

We designed and fabricated a high performance spring-type piezoelectric energy harvester that selectively collects current from the inner part of a spring shell.

Discovery of the VHE gamma-ray source HESS J1832-093 in the vicinity of SNR G22.7-0.2

The region around the supernova remnant (SNR) W41 contains several TeV sources and has prompted the H.E.S.S. Collaboration to perform deep observations of this field of view. This resulted in the discovery of the new very high energy (VHE) source HESS J1832-093, at the position $\rm RA=18^h 32^m 50^s \pm 3^s_{stat} \pm 2^s_{syst}, \rm Dec=-9^\circ 22' 36'' \pm 32''_{stat} \pm 20''_{syst} (J2000)$, spatially coincident with a part of the radio shell of the neighboring remnant G22.7-0.2. The photon spectrum is well described by a power-law of index $\Gamma = 2.6 \pm 0.3_{\rm stat} \pm 0.1_{\rm syst}$ and a normalization at 1 TeV of $\Phi_0=(4.8 \pm 0.8_{\rm stat}\pm 1.0_{\rm syst})\,\times\,10^{-13}\,\rm{cm} ^{-2}\,s^{-1}\,TeV^{-1}$. The location of the gamma-ray emission on the edge of the SNR rim first suggested a signature of escaping cosmic-rays illuminating a nearby molecular cloud. Then a dedicated XMM-Newton observation led to the discovery of a new X-ray point source spatially coincident with the TeV excess. Two other scenarios were hence proposed to identify the nature of HESS J1832-093. Gamma-rays from inverse Compton radiation in the framework of a pulsar wind nebula scenario or the possibility of gamma-ray production within a binary system are therefore also considered. Deeper multi-wavelength observations will help to shed new light on this intriguing VHE source.

Icosahedral symmetry breaking: C60to C78, C96and to related nanotubes

Exact icosahedral symmetry of C60is viewed as the union of 12 orbits of the symmetric subgroup of order 6 of the icosahedral group of order 120. Here, this subgroup is denoted byA2because it is isomorphic to the Weyl group of the simple Lie algebraA2. Eight of theA2orbits are hexagons and four are triangles. Only two of the hexagons appear as part of the C60surface shell. The orbits form a stack of parallel layers centered on the axis of C60passing through the centers of two opposite hexagons on the surface of C60. By inserting into the middle of the stack twoA2orbits of six points each and twoA2orbits of three points each, one can match the structure of C78. Repeating the insertion, one gets C96; multiple such insertions generate nanotubes of any desired length. Five different polytopes with 78 carbon-like vertices are described; only two of them can be augmented to nanotubes.

Vaporization dynamics of volatile perfluorocarbon droplets: a theoretical model and in vitro validation.

Perfluorocarbon (PFC) microdroplets, called phase-change contrast agents (PCCAs), are a promising tool in ultrasound imaging and therapy. Interest in PCCAs is motivated by the fact that they can be triggered to transition from the liquid state to the gas state by an externally applied acoustic pulse. This property opens up new approaches to applications in ultrasound medicine. Insight into the physics of vaporization of PFC droplets is vital for effective use of PCCAs and for anticipating bioeffects. PCCAs composed of volatile PFCs (with low boiling point) exhibit complex dynamic behavior: after vaporization by a short acoustic pulse, a PFC droplet turns into a vapor bubble which undergoes overexpansion and damped radial oscillation until settling to a final diameter. This behavior has not been well described theoretically so far. The purpose of our study is to develop an improved theoretical model that describes the vaporization dynamics of volatile PFC droplets and to validate this model by comparison with in vitro experimental data. The derivation of the model is based on applying the mathematical methods of fluid dynamics and thermodynamics to the process of the acoustic vaporization of PFC droplets. The used approach corrects shortcomings of the existing models. The validation of the model is carried out by comparing simulated results with in vitro experimental data acquired by ultrahigh speed video microscopy for octafluoropropane (OFP) and decafluorobutane (DFB) microdroplets of different sizes. The developed theory allows one to simulate the growth of a vapor bubble inside a PFC droplet until the liquid PFC is completely converted into vapor, and the subsequent overexpansion and damped oscillations of the vapor bubble, including the influence of an externally applied acoustic pulse. To evaluate quantitatively the difference between simulated and experimental results, the L2-norm errors were calculated for all cases where the simulated and experimental results are compared. These errors were found to be in the ranges of 0.043-0.067 and 0.037-0.088 for OFP and DFB droplets, respectively. These values allow one to consider agreement between the simulated and experimental results as good. This agreement is attained by varying only 2 of 16 model parameters which describe the material properties of gaseous and liquid PFCs and the liquid surrounding the PFC droplet. The fitting parameters are the viscosity and the surface tension of the surrounding liquid. All other model parameters are kept invariable. The good agreement between the theoretical and experimental results suggests that the developed model is able to correctly describe the key physical processes underlying the vaporization dynamics of volatile PFC droplets. The necessity of varying the parameters of the surrounding liquid for fitting the experimental curves can be explained by the fact that the parts of the initial phospholipid shell of PFC droplets remain on the surface of vapor bubbles at the oscillatory stage and their presence affects the bubble dynamics.

Microstructural Characteristic and its Relation to Mechanical Properties of Clinocardium californiense Shell

The microstructures and mechanical properties of Clinocardium californiense shell were investigated in relation to the different parts of shell. It is found that the shell can be divided into three parts, that is, the dorsal side, body part, and marginal side based on the variation of microstructures along the longitudinal cross section. Specifically, all areas exhibit a cross‐lamellar structure on the dorsal side, and a hierarchical structure comprising three layers including inner (with a cross‐lamellar structure), middle (with a complex cross‐lamellar structure), and outer (with a prismatic structure) layers was observed on the body part, whereas on the marginal side, the orientation of aragonite sheets shows an obvious deflection. The structural architecture, the dimensions of different‐order lamellae in the same kind of structure and the orientation between the indenting direction and aragonite sheet all contribute to the unique mechanical properties of this shell. It is also found that a low value of the ratio of hardness‐to‐Young's modulus (H/E) corresponds to an improved indentation toughness. The middle layer with the densest and most complicated structure on the body part shows the lowest H/E ratio and the highest hardness and Young's modulus.

Bone Anchors—A Preliminary Finite Element Study of Some Factors Affecting Pullout

Bone anchors (or suture anchors) are used to provide attachment points for sutures to connect tissue such as tendons or ligaments to bone, and work by engaging a threaded portion—sometimes tapered—to the cancellous and/or cortical bone. Such repair is often needed after trauma, or as part of reconstructive surgery. This paper uses the finite element method to compare the pullout characteristics of one common type of bone anchor in different cancellous bone structures. Finite element models are created by using computed tomography (CT) scans of cancellous bone and building computer-aided design (CAD) models to define the cancellous bone geometry. Orthopedic surgeons will sometimes remove parts of the cortical shell and this paper also examines the mechanical effects of decortication. Furthermore, the importance of the connection between anchor and cortical layer is examined. One of the key outcomes from the model is that the coefficient of friction between bone and anchor determines potential mechanisms of pullout. The stiffness of anchors and the effect of the cortical layer are presented for different pullout angles to obtain the theoretical response. The results show the detailed modeling that includes the micro-architecture of the cancellous bone is necessary to capture the large variations that can exist.

Analysis of possible causes of cracks initiation on barking drum

During operation of barking drum equipment the cracks were identified on the input part of drums cylindrical shell’. On the basis of operator request the analysis of reasons of possible causes of crack initiation on drum shell has been realized. The analysis includes numerical computations of stress fields in the locations of stress concentrators resulting from loading of drum during operation as well as influence of vertical offset of drives to the stress state in drum shell. The residual stresses in selected locations of drum shell were determined by the hole-drilling method. On the basis of analysis new concept of drum shell strengthening has been proposed in order to ensure its further safe operation.

Managing water quality under drought conditions in the Llobregat River Basin

The primary effects of droughts on river basins include both depleted quantity and quality of the available water resources, which can render water resources useless for human needs and simultaneously damage the environment. Isolated water quality analyses limit the action measures that can be proposed. Thus, an integrated evaluation of water management and quality is warranted.In this study, a methodology consisting of two coordinated models is used to combine aspects of water resource allocation and water quality assessment. Water management addresses water allocation issues by considering the storage, transport and consumption elements. Moreover, the water quality model generates time series of concentrations for several pollutants according to the water quality of the runoff and the demand discharges. These two modules are part of the AQUATOOL decision support system shell for water resource management. This tool facilitates the analysis of the effects of water management and quality alternatives and scenarios on the relevant variables in a river basin.This paper illustrates the development of an integrated model for the Llobregat River Basin. The analysis examines the drought from 2004 to 2008, which is an example of a period when the water system was quantitative and qualitatively stressed. The performed simulations encompass a wide variety of water management and water quality measures; the results provide data for making informed decisions. Moreover, the results demonstrated the importance of combining these measures depending on the evolution of a drought event and the state of the water resources system.

Molecular simulation study on Hofmeister cations and the aqueous solubility of benzene.

We study the ion-specific salting-out process of benzene in aqueous alkali chloride solutions using Kirkwood-Buff (KB) theory of solutions and molecular dynamics simulations with different empirical force field models for the ions and benzene. Despite inaccuracies in the force fields, the simulations indicate that the decrease of the Setchenow salting-out coefficient for the series NaCl > KCl > RbCl > CsCl is determined by direct benzene-cation correlations, with the larger cations showing weak interactions with benzene. Although ion-specific aqueous solubilities of benzene may be affected by indirect ion-ion, ion-water, and water-water correlations, too, these correlations are found to be unimportant, with little to no effect on the Setchenow salting-out coefficients of the various salts. We further considered LiCl, which is experimentally known to be a weaker salting-out agent than NaCl and KCl and, therefore, ranks at an unusual position within the Hofmeister cation series. The simulations indicate that hydrated Li(+) ions can take part of the benzene hydration shell while the other cations are repelled by it. This causes weaker Li(+) exclusion around the solute and a resulting, weaker salting-out propensity of LiCl compared to that of the other salts. Removing benzene-water and benzene-salt electrostatic interactions in the simulations does not affect this mechanism, which may therefore also explain the smaller effect of LiCl, as compared to that of NaCl or KCl, on aqueous solvation and hydrophobic interaction of nonpolar molecules.

Trace determination of cadmium in water using anodic stripping voltammetry at a carbon paste electrode modified with coconut shell powder

AbstractBackgroundIncreasing awareness on the environmental impact of heavy metals has increased a considerable interest in the determination of metals in natural water bodies. The present paper describes the development and electrochemical application of carbon paste electrode modified with fibrous part of coconut shell for the determination of cadmium in water samples.MethodsDetermination was carried out using anodic stripping voltammetry. It is a two-step process. First, the metal ions get accumulated at the electrode surface at open-circuit potential, followed by a potential scan for voltammetric determination of cadmium.ResultsDifferent parameters affecting the determination of Cd (II) were optimized and are as follows: HCl as stripping solvent, acetate buffer of pH 5 as accumulating solvent, and 15-min accumulation time. Triton X-100, cetyltrimethylammonium bromide, and sodium dodecyl sulfate were used as representative for neutral, cationic, and anionic surfactants, respectively, to see the effect of surface active macromolecules. Interference caused by other metal ions on the determination of cadmium was also studied.ConclusionsThe method shows the development of a sensor for the sensitive determination of cadmium with limit of detection at 105 μg L−1. This technique does not use mercury and, therefore, has a positive environmental benefit.

Enhanced surface electron transfer by fabricating a core/shell Ni@NiO cluster on TiO2 and its role on high efficient hydrogen generation under visible light irradiation

A Ni@NiO core/shell cluster was fabricated on TiO2 surface (Ni@NiO/TiO2) and its roles on surface electron transfer and the enhancement on hydrogen evolution under visible light irradiation were investigated. For a comparison, the Ni/TiO2 and NiO/TiO2 catalysts were fabricated, respectively. By photosensitization using Eosin Y as an antenna molecule, (1.6 wt%)Ni@NiO/TiO2 exhibited the highest activity (364.1 μmol h−1) in comparison with (1.6 wt%)Ni/TiO2 and (1.6 wt%)NiO/TiO2 and the corresponding apparent quantum efficiency reached 28.6% at 460 nm. The photoluminescence spectra and photoelectrochemical characterization results confirmed that the Ni@NiO core/shell structure could promote the photogenerated electrons transferring from TiO2 conduction band to Ni@NiO clusters, resulting in the quicker separation of electron–hole pairs. In addition, part of NiO shell can be reduced into metallic Ni during the photoreaction and vice versa. Cyclic voltammogram characterization verified that the transformation between Ni and NiO was a dynamic balance process, which can not only provide reacting channels for electrons and protons but also ensure the photocatalytic hydrogen evolution proceeding continuously. This study discloses structure-dependent effect of non-noble metal cocatalyst on semiconductor photocatalysts in photocatalytic water reduction, and gives an insight into designing high-efficient non-noble metal/semiconductor hybrid photocatalysts.

A relationship between reduced nucleus accumbens shell and enhanced lateral hypothalamic orexin neuronal activation in long-term fructose bingeing behavior.

Fructose accounts for 10% of daily calories in the American diet. Fructose, but not glucose, given intracerebroventricularly stimulates homeostatic feeding mechanisms within the hypothalamus; however, little is known about how fructose affects hedonic feeding centers. Repeated ingestion of sucrose, a disaccharide of fructose and glucose, increases neuronal activity in hedonic centers, the nucleus accumbens (NAc) shell and core, but not the hypothalamus. Rats given glucose in the intermittent access model (IAM) display signatures of hedonic feeding including bingeing and altered DA receptor (R) numbers within the NAc. Here we examined whether substituting fructose for glucose in this IAM produces bingeing behavior, alters DA Rs and activates hedonic and homeostatic feeding centers. Following long-term (21-day) exposure to the IAM, rats given 8–12% fructose solutions displayed fructose bingeing but unaltered DA D1R or D2R number. Fructose bingeing rats, as compared to chow bingeing controls, exhibited reduced NAc shell neuron activation, as determined by c-Fos-immunoreactivity (Fos-IR). This activation was negatively correlated with orexin (Orx) neuron activation in the lateral hypothalamus/perifornical area (LH/PeF), a brain region linking homeostatic to hedonic feeding centers. Following short-term (2-day) access to the IAM, rats exhibited bingeing but unchanged Fos-IR, suggesting only long-term fructose bingeing increases Orx release. In long-term fructose bingeing rats, pretreatment with the Ox1R antagonist SB-334867 (30 mg/kg; i.p.) equally reduced fructose bingeing and chow intake, resulting in a 50% reduction in calories. Similarly, in control rats, SB-334867 reduced chow/caloric intake by 60%. Thus, in the IAM, Ox1Rs appear to regulate feeding based on caloric content rather than palatability. Overall, our results, in combination with the literature, suggest individual monosaccharides activate distinct neuronal circuits to promote feeding behavior. Specifically, long-term fructose bingeing activates a hyperphagic circuit composed in part of NAc shell and LH/PeF Orx neurons.

Q&A: Qatar's Oil and Gas R&D Push

Youssif Saleh, general manager of Qatar Shell Research and Technology Centre in the Qatar Science and Technology Park, discusses the R&D strategy of the center and in Qatar. What are the main drivers behind the decision to establish an R&D center in the Middle East? We are pleased about the role that Qatar plays in Shell’s overall technology strategy through our world-class research and development program based at the Qatar Shell Research and Technology Centre (QSRTC). This makes QSRTC a member of Shell’s wider R&D community, which includes technology centers in cities such as Amsterdam and Houston. QSRTC’s mandate is to provide a home for research that adds value both to the state of Qatar, to Shell, and to our partners. Therefore, our work is focused on the development and implementation of technologies that support Qatar’s specific needs, as well as support Qatar’s role as the world’s largest liquefied natural gas exporter and the gas-to-liquids (GTL) capital of the world. Moreover, we work with many of Qatar’s universities and academic institutions abroad, and provide training in R&D to Qatari national staff as part of Shell’s support for Qatar’s journey toward a knowledge-based economy. When was QSRTC established and on what specific areas of R&D does it focus its efforts? We have been an anchor tenant at the Qatar Science and Technology Park (QSTP), a home for technology-based companies from around the world, since 2008 with a USD-100-million funding commitment over 10 years. That was also the year we became the first tenant of QSTP to file a patent based on research conducted in Qatar. The center’s current activities build upon Shell’s extensive experience in the GTL field and focuses specifically on catalyst testing, product development, and GTL byproduct research, including water treatment and reuse. Catalysts are a key focus area since they are essential to the process that converts natural gas into liquid fuels and other products at our Pearl GTL facility, the largest GTL plant in the world. Our researchers have also worked on developing new uses for sulfur, a coproduct of the GTL process, and are collaborating with scientists from around the world on improving the understanding of carbonate reservoirs.

Electrical Properties of Garut Citrus Fruits at Low Alternating Current Signal and its Correlation with Physicochemical Properties During Maturation

In this research, local citrus fruits, namely Garut citrus, were analyzed for electrical properties related to physicochemical properties. Electrical measurement on fruit was done by using low alternating current with a frequency varying from 50 Hz to 1 MHz. The fruits are placed between two plate electrodes and treated as dielectric material. Electrical parameters per unit of weight were used in this study to compensate variations in weight. Electrical impedance, resistance, and reactance per weight of citrus fruits will decrease if the frequency is increased. Electrical circuit models have been constructed to describe the internal conditions of citrus fruits. To indicate the fruit maturity, the physicochemical properties were used, i.e., firmness, total soluble solids, pH, and hydrogen ion concentration. The value of resistance, impedance, and reactance per weight declined during citrus fruits maturation. The correlations between electrical and physicochemical properties are investigated too. The highest consistency of correlations happens at a frequency of 1 MHz. Based on the model of an electrical circuit, the highest value of electrical resistance is outer shell and the lowest is seed. And then, the highest value of electrical capacitance is albedo and the lowest is segment. Resistance values of the parts of citrus fruits, i.e., seed, segment, segment wall, and outer shell, were decreased during maturation. While capacitance value of segment, albedo, and flavedo were increased.

Domes, pits, and small chaos on Europa produced by water sills

AbstractPits, domes, and small chaos on Europa's surface are quasi‐circular features a few to a few tens of kilometers in diameter. We examine if injection of water sills into Europa's ice shell and their subsequent evolution can induce successive surface deformations similar to the morphologies of these features. We study the dynamics of water spreading within the elastic part of the ice shell and show that the mechanical properties of ice exert a strong control on the lateral extent of the sill. At shallow depths, water makes room for itself by lifting the overlying ice layer and water weight promotes lateral spreading of the sill. In contrast, a deep sill bends the underlying elastic layer and its weight does not affect its spreading. In that case, the sill lateral extent is limited by the fracture toughness of ice and the sill can thicken substantially. After emplacement, cooling of the sill warms the surrounding ice and thins the overlying elastic ice layer. As a result, preexisting stresses in the elastic part of the ice shell increase locally to the point that they may disrupt the ice above the sill (small chaos). Disruption of the surface also allows for partial isostatic compensation of water weight, leading to a topographic depression at the surface (pit), of the order of ~102 m. Complete water solidification finally causes expansion of the initial sill volume and results in an uplifted topography (dome) of ~102m.