bluuebunny/crossref_metadata_2025 huggingface dataset:
Shaping the light distribution with facet designs in lithium niobate nanowaveguides
Authors: Reig Escalé Marc , Sergeyev Anton , Geiss Reinhard , Grange Rachel
Published: August 2017

The miniaturization of coherent light sources down to the nanoscale demands unrestricted freedom of designs enabled by full control of the material dimensions. One way to transfer bulky applications to the nanoscale is using nanowaveguides, which guide light confined to sub-micron mode sizes. In order to further develop nanowaveguide-based applications such as optical integrated circuits, spectrometers, or local light delivery, it is necessary to have full control of the out-coupled light distribution. Here, we show that the nanowaveguide (NW) facet geometry can be used to shape the light distribution. We experimentally show the influence of the facet in the emission spatial spectrum and, later, we theoretically investigate five different facet designs for shaping the emitted light spatial spectrum. These designs present a diversity of options for manipulating the light distribution. For instance, one design shows large angular light deflection (more than 80° in the radial direction), which is relevant for integrated circuits. A second design shows homogeneous spreading across the normal direction with azimuthal selectivity, which is suitable for local light delivery applications since it acts like a point-source at the facet of the nanowaveguide.
Elastic and thermal properties of free-standing molybdenum disulfide membranes measured using ultrafast transient grating spectroscopy
Authors: Kim Taeyong , Ding Ding , Yim Jong-Hyuk , Jho Young-Dahl , Minnich Austin J.
Published: August 2017

Molybdenum disulfide (MoS2), a member of transition-metal dichalcogenide family, is of intense interest due to its unique electronic and thermoelectric properties. However, reports of its in-plane thermal conductivity vary due to the difficulty of in-plane thermal conductivity measurements on thin films, and an experimental measurement of the in-plane sound velocity has not been reported. Here, we use time-resolved transient grating spectroscopy to simultaneously measure the in-plane elastic and thermal properties of free-standing MoS2 membranes at room temperature. We obtain a longitudinal acoustic phonon velocity of 7000 ± 40 m s−1 and an in-plane thermal conductivity of 74 ± 21 W m−1K−1. Our measurements provide useful insights into the elastic and thermal properties of MoS2 and demonstrate the capability of transient grating spectroscopy to investigate the in-plane vibrational properties of van der Waals materials that are challenging to characterize with conventional methods.
Nanostructure of and structural defects in a Mo2BC hard coating investigated by transmission electron microscopy and atom probe tomography
Authors: Gleich Stephan , Fager Hanna , Bolvardi Hamid , Achenbach Jan-Ole , Soler Rafael , Pradeep Konda Gokuldoss , Schneider Jochen M. , Dehm Gerhard , Scheu Christina
Published: August 2017

In this work, the nanostructure of a Mo2BC hard coating was determined by several transmission electron microscopy methods and correlated with the mechanical properties. The coating was deposited on a Si (100) wafer by bipolar pulsed direct current magnetron sputtering from a Mo2BC compound target in Ar at a substrate temperature of 630 °C. Transmission electron microscopy investigations revealed structural features at various length scales: bundles (30 nm to networks of several micrometers) consisting of columnar grains (∼10 nm in diameter), grain boundary regions with a less ordered atomic arrangement, and defects including disordered clusters (∼1.5 nm in diameter) as well as stacking faults within the grains. The most prominent defect with a volume fraction of ∼0.5% is the disordered clusters, which were investigated in detail by electron energy loss spectroscopy and atom probe tomography. The results provide conclusive evidence that Ar is incorporated into the Mo2BC film as disordered Ar-rich Mo-B-C clusters of approximately 1.5 nm in diameter. Hardness values of 28 ± 1 GPa were obtained by nanoindentation tests. The Young's modulus of the Mo2BC coating exhibits a value of 462 ± 9 GPa, which is consistent with ab initio calculations for crystalline and defect free Mo2BC and measurements of combinatorically deposited Mo2BC thin films at a substrate temperature of 900 °C. We conclude that a reduction of the substrate temperature of 270 °C has no significant influence on hardness and Young's modulus of the Mo2BC hard coating, even if its nanostructure exhibits defects.
Effect of CdS nanocrystals on charge transport mechanism in poly(3-hexylthiophene)
Authors: Khan Mohd Taukeer , Almohammedi Abdullah
Published: August 2017

The present manuscript demonstrates the optical and electrical characteristics of poly(3-hexylthiophene) (P3HT) and cadmium sulphide (CdS) hybrid nanocomposites. Optical results suggest that there is a formation of charge transfer complex (CTC) between host P3HT and guest CdS nanocrystals (NCs). Electrical properties of P3HT and P3HT-CdS thin films have been studied in hole only device configurations at different temperatures (290 K–150 K), and results were analysed by the space charge limited conduction mechanism. Density of traps and characteristic trap energy increase on incorporation of inorganic NCs in the polymer matrix, which might be due to the additional favourable energy states created by CdS NCs in the band gap of P3HT. These additional trap states assist charge carriers to move quicker which results in enhancement of hole mobility from 7 × 10−6 to 5.5 × 10−5 cm2/V s in nanocomposites. These results suggest that the P3HT-CdS hybrid system has desirable optical and electrical properties for its applications to photovoltaics devices.
Constant DI pacing suppresses cardiac alternans formation in numerical cable models
Authors: Zlochiver S. , Johnson C. , Tolkacheva E. G.
Published: August 2017

Cardiac repolarization alternans describe the sequential alternation of the action potential duration (APD) and can develop during rapid pacing. In the ventricles, such alternans may rapidly turn into life risking arrhythmias under conditions of spatial heterogeneity. Thus, suppression of alternans by artificial pacing protocols, or alternans control, has been the subject of numerous theoretical, numerical, and experimental studies. Yet, previous attempts that were inspired by chaos control theories were successful only for a short spatial extent (<2 cm) from the pacing electrode. Previously, we demonstrated in a single cell model that pacing with a constant diastolic interval (DI) can suppress the formation of alternans at high rates of activation. We attributed this effect to the elimination of feedback between the pacing cycle length and the last APD, effectively preventing restitution-dependent alternans from developing. Here, we extend this idea into cable models to study the extent by which constant DI pacing can control alternans during wave propagation conditions. Constant DI pacing was applied to ventricular cable models of up to 5 cm, using human kinetics. Our results show that constant DI pacing significantly shifts the onset of both cardiac alternans and conduction blocks to higher pacing rates in comparison to pacing with constant cycle length. We also demonstrate that constant DI pacing reduces the propensity of spatially discordant alternans, a precursor of wavebreaks. We finally found that the protective effect of constant DI pacing is stronger for increased electrotonic coupling along the fiber in the sense that the onset of alternans is further shifted to higher activation rates. Overall, these results support the potential clinical applicability of such type of pacing in improving protocols of implanted pacemakers, in order to reduce the risk of life-threatening arrhythmias. Future research should be conducted in order to experimentally validate these promising results.
Pulsed characterization of a UV LED for pulsed power applications on a silicon carbide photoconductive semiconductor switch
Authors: Wilson Nicholas , Mauch Daniel , Meyers Vincent , Feathers Shannon , Dickens James , Neuber Andreas
Published: August 2017

The electrical and optical characteristics of a high-power UV light emitting diode (LED) (365 nm wavelength) were evaluated under pulsed operating conditions at current amplitudes several orders of magnitude beyond the LED’s manufacturer specifications. Geared towards triggering of photoconductive semiconductor switches (PCSSs) for pulsed power applications, measurements were made over varying pulse widths (25 ns–100 μs), current (0 A–250 A), and repetition rates (single shot–5 MHz). The LED forward voltage was observed to increase linearly with increasing current (∼3.5 V–53 V) and decrease with increasing pulse widths. The peak optical power observed was >30 W, and a maximum system efficiency of 23% was achieved. The evaluated LED and auxiliary hardware were successfully used as the optical trigger source for a 4H–SiC PCSS. The lowest measured on-resistance of SiC was approximately 67 kΩ.
Fast optical work-function tuning at an organic/metal interface
Authors: Bronsch Wibke , Przyrembel Daniel , Boie Larissa , Gahl Cornelius , Weinelt Martin
Published: August 2017

In a two-color experiment, we demonstrate how light can be used as an external control to continuously tune the work function of a gold substrate functionalized with a dilute azobenzene-based self-assembled monolayer (SAM). The work function is measured by two-photon photoelectron spectroscopy. While in the ground state the azobenzene moiety adopts the trans configuration, illumination with pulsed laser light at a wavelength of 368 nm results in a photostationary state (PSS) mainly comprising cis isomers. An additional 450 nm continuous-wave laser with tunable intensity serves to shift the PSS back towards the ground state. This way the work function is freely adjustable in real time over a range of ∼240 meV between the two PSS extrema. We furthermore relate the change in work function to the average change in dipole moment per azobenzene chromophore. Quantum-chemical calculations that take into account available structural data of the molecules in the SAM must consider at least two different trans and four different cis orientations. The computed respective perpendicular trans-cis dipole-moment changes indicate that in experiment the cis molecules adopt different orientations along with a very high cis azobenzene yield in the UV PSS.
Active control of bright electron beams with RF optics for femtosecond microscopy
Authors: Williams J. , Zhou F. , Sun T. , Tao Z. , Chang K. , Makino K. , Berz M. , Duxbury P. M. , Ruan C.-Y.
Published: August 2017

A frontier challenge in implementing femtosecond electron microscopy is to gain precise optical control of intense beams to mitigate collective space charge effects for significantly improving the throughput. Here, we explore the flexible uses of an RF cavity as a longitudinal lens in a high-intensity beam column for condensing the electron beams both temporally and spectrally, relevant to the design of ultrafast electron microscopy. Through the introduction of a novel atomic grating approach for characterization of electron bunch phase space and control optics, we elucidate the principles for predicting and controlling the phase space dynamics to reach optimal compressions at various electron densities and generating conditions. We provide strategies to identify high-brightness modes, achieving ∼100 fs and ∼1 eV resolutions with 106 electrons per bunch, and establish the scaling of performance for different bunch charges. These results benchmark the sensitivity and resolution from the fundamental beam brightness perspective and also validate the adaptive optics concept to enable delicate control of the density-dependent phase space structures to optimize the performance, including delivering ultrashort, monochromatic, high-dose, or coherent electron bunches.
Attenuation characteristics of electromagnetic waves in a weak collisional and fully ionized dusty plasma
Authors: Dan Li , Guo Li-Xin , Li Jiang-Ting , Chen Wei , Yan Xu , Huang Qing-Qing
Published: August 2017

The expression of complex dielectric permittivity for non-magnetized fully ionized dusty plasma is obtained based on the kinetic equation in the Fokker–Planck–Landau collision model and the charging equation of the statistical theory. The influences of density, average size of dust grains, and balanced charging of the charge number of dust particles on the attenuation properties of electromagnetic waves in fully ionized dusty plasma are investigated by calculating the attenuation constant. In addition, the attenuation characteristics of weakly ionized and fully ionized dusty plasmas are compared. Results enriched the physical mechanisms of microwave attenuation for fully ionized dusty plasma and provide a theoretical basis for future studies.
Integration of a mechanical energy storage system in a road pavement energy harvesting hydraulic device with mechanical actuation
Authors: Duarte Francisco , Ferreira Adelino , Fael Paulo
Published: August 2017

With the growing need for alternative energy sources, research into energy harvesting technologies has increased considerably in recent years. The particular case of energy harvesting on road pavements is a very recent area of research, with different technologies having been developed for this purpose. However, none of them have presented high conversion efficiency rates nor technical or economic viability. Looking at other renewable energy technologies, the inclusion of not only electrical but also in some cases mechanical energy storage units has led to an increase in global efficiency and, consequently, economic viability. This paper deals with the technical study of the integration of mechanical energy storage systems in a road pavement energy harvesting hydraulic device with mechanical actuation in order to evaluate the impact on global efficiency. The main goal is to quantify the efficiency of the energy storage and the overall efficiency of the system, including the harvesting, transmission, and conversion efficiency rate, comparing it to scenarios where no storage system is used. Finally, the conclusions on the performance of each system are presented.
Temperature dependence of the dielectric tensor of monoclinic Ga2O3 single crystals in the spectral range 1.0–8.5 eV
Authors: Sturm C. , Schmidt-Grund R. , Zviagin V. , Grundmann M.
Published: August 2017

The full dielectric tensor of monoclinic Ga2O3 (β-phase) was determined by generalized spectroscopic ellipsometry in the spectral range from 1.0 eV up to 8.5 eV and temperatures in the range from 10 K up to 300 K. By using the oriented dipole approach, the energies and broadenings of the excitonic transitions are determined as a function of the temperature, and the exciton-phonon coupling properties are deduced.
Measuring the kinetic energy of multicharged ions for nanofabrication
Authors: Kim Meeri
Published: August 2017

Physicists at Clemson University characterize the properties of multicharged ions from an electron beam ion source, with implications for nanoprocessing and nanofabrication.
The studies on gas adsorption properties of MIL-53 series MOFs materials
Authors: Jiao Yuqiu , Li Zhenyu , Ma Yue , Zhou Guanggang , Wang Shuangxi , Lu Guiwu
Published: August 2017

Molecular dynamics (MD), grand canonical Monte Carlo (GCMC) and ideal adsorbed solution theory (IAST) were used to study the structures and gas adsorption properties of MIL-53(M)[M=Cr, Fe, Sc, Al] metal organic framework (MOF) materials. The results show that the volumes of those MOF materials increase significantly at high temperature. By analyzing the adsorption isotherms, we found that the temperature had a paramount effect on the gas adsorption behaviors of these MOF materials. For MIL-53(Cr), the orders of the quantities of adsorbed gases were CH4>N2>CO2>H2S, CH4>H2S>CO2>N2 and CH4>CO2>H2S>N2 at 100K, 293K and 623K, respectively. We also calculated the adsorption of several combinations of two gases by MIL-53(Cr) at 293K, the results indicate that the material had selective adsorption of CH4 over CO2, H2S and N2. Our calculations provide microscopic insights into the gas adsorption performances of these MOFs and may further guide the practice of gas separation.
Highly conformal and high-ionic conductivity thin-film electrolyte for 3D-structured micro batteries: Characterization of LiPON film deposited by MOCVD method
Authors: Fujibayashi Takashi , Kubota Yusuke , Iwabuchi Katsuhiko , Yoshii Naoki
Published: August 2017

This paper reports a lithium phosphorus oxynitride (LiPON) thin-film electrolyte deposited using a metalorganic-chemical vapor deposition (MOCVD) method for 3D-structured micro batteries. It is shown that the MOCVD-LiPON film has both highly-conformal step coverage on a patterned substrate with line/space=2μm/2μm and aspect ratio=1 (51±3 nm) and high-ionic conductivity for very thin films deposited at 4.7 nm/min (5.9×10-6 S/cm for 190 nm and 5.3×10-6 S/cm for 95 nm). Detailed material characterization attributes the enhancement in ionic conductivity to a decrease in nanocrystallite size and improvement in chemical-composition uniformity in the film. In addition, electrochemical characterization of an all-solid-state thin-film battery fabricated with the 190 nm-thick LiPON film (Si substrate/Ti/Pt/LiCoO2/LiPON/a-Si:H/Cu) demonstrates that the LiPON film can successfully act as the electrolyte for lithium-ion batteries. Therefore, the MOCVD-LiPON film is a promising candidate material to realize 3D-structured micro batteries in the near future.
Understanding the role of electrostatic and induction effects of water solubility in alkanes
Authors: Dowd Deborah
Published: August 2017

New research demonstrates electrostatics and induction are decisive in capturing water solubility in alkanes.
Novel poling method in piezoelectric ceramics opens the door to the next-generation large-strain actuators
Authors: Zhang Zhengzheng
Published: August 2017

Chinese scientists for the first time realize giant actuation strain of nearly 0.6% via reversible domain switching—about four times larger than that of conventional PZT actuators.
NEOGENE TECTONICS IN SE AUSTRALIA: IMPLICATIONS FOR PETROLEUM SYSTEMS
Authors: Dickinson J.A. , Wallace M.W. , Holdgate G.R. , Daniels J. , Gallagher S.J. , Thomas L.
Published: August 2017

The influence of Neogene tectonics in the SE Australian basins has generally been underestimated in the petroleum exploration literature. However, onshore stratigraphic and offshore seismic data indicates that significant deformation and exhumation (up to one km or more) has occurred during the late Tertiary-Quaternary. This tectonism coincides with a change in the dynamics of the Australian plate, beginning at around 12 Ma, resulting in a WNW–ESE compressional regime which has continued to the present day.Significant late Miocene tectonism is indicated by a regional angular unconformity at around the Mio-Pliocene boundary in the onshore and nearshore successions of the SE Australian basins.Evidence of on going Pliocene- Quaternary tectonism is widespread in all of the SE Australian basins. Late Tertiary tectonism has produced structures in the offshore SE Australian basins which have been favourable targets for petroleum accumulation (e.g. Nerita structure, Torquay Sub-basin; Cormorant structure, Bass Basin). In the offshore Gippsland Basin, most of the oil- and gas-bearing structures have grown during Oligocene-Recent time. Some Gippsland Basin structures were largely produced prior to the mid- Miocene, while others have a younger structural history. In areas of intense late Tertiary exhumation and uplift (e.g. proximal to the Otway and Strzelecki Ranges), burial/maturation models of petroleum generation may be significantly affected by Neogene uplift.Many structures produced by late Miocene-Pliocene deformation are dry. These relatively young structures may post-date the major maturation episodes, with the post-structure history of the basins dominated by exhumation and cooling.
NATURAL FRACTURES OF THE SOUTHERN COOPER AND EASTERN WARBURTON BASINS, SOUTH AUSTRALIA
Authors: Sun X.
Published: August 2017

A study of the southern Cooper and eastern Warburton Basins has resulted in classifying natural fractures and delineating regional fracture systems and orientations of open and partially open fractures. Firstly, natural fractures have been identified from selected lithological units in 44 wells of the southern Cooper Basin. Open fractures are developed mainly within the brittle Tirrawarra Sandstone. These open fractures are mostly high angle to subvertical, with measured apertures of up to 2 mm. Secondly, natural fractures have been characterised in Warburton Basin cores from 91 wells, 27 of which have dipmeter and/or FMS (Formation Micro- Scanner) logs. Fractures more commonly occur within brittle sandstone, dolomite, grainy limestone and ignimbrite.Two systems of orthogonal, high-angle, regional fracture sets (four fractures) have been identified. They extend across local structures in both basins in South Australia. System I is comprised of a pair of orthogonal fractures, striking NNE–SSW (20–200°) and ESE–WNW (110–290°), while a second pair of orthogonal fracture sets, striking NE–SW (60–240°) and NW–SE (150–330°), characterises System II. Open, steeply dipping SW fractures striking WNW and NW within Systems I and II have been interpreted from core and FMS data in several wells. The results indicate that an optimum well trajectory designed to maximise intersection with open natural fractures should be 200–210° and 240–250°, and possibly also 270–290°. The deviation angle should be 30° from horizontal in the fracture zone due to the high-angle and subvertical fracture dips. A semi-quantitative estimate of fracture density from cores in both basins has been determined: the greatest fracture density is located within major fault zones and structural culminations.
DYNAMIC FAULT/FRACTURE SEAL BEHAVIOUR AND GEOMECHANICAL ANALYSIS OF THE GREATER GOBE AREA, SOUTHERN HIGHLANDS PROVINCE, PAPUA NEW GUINEA
Authors: Daniels M.C. , Moffat D.T. , Castillo D.A.
Published: August 2017

The Gobe Main and SE Gobe Fields were discovered in the early 1990s in the Papuan Fold Belt in the Highlands of Papua New Guinea. Heavily karstified Darai Limestone at the surface and heli-supported drilling made field appraisal problematic and expensive. With initial well spacing upwards of several kilometres, these fields were thought to be ‘tank’ type models, with field-wide extrapolations of gas-oil and oil-water contacts.The main Iagifu Sandstone reservoir in the Gobe fields comprises several fluvial and near-shore sand bodies, which are readily correlatable across the fields. The reservoir units display discrete coarsening upward sequences containing medium (~17%) porosity, medium to high permeability (>100 mD) sandstones. Although several different depositional facies are interpreted within the Iagifu reservoir, sand units are extensive on the scale of the Gobe structures and do not appear to be producing significant lateral boundaries or reservoir compartmentalisation.Geomechanical analysis has enabled the calculation of in-situ stress magnitudes and establishment of a geomechanical model for Gobe. Locally, the Gobe Main Field appears to be in a strike-slip stress regime (SHmax>Sv>Shmin). SHmax directions vary from NNE– SSW to NE–SW. Stress magnitudes indicate the structure is near frictional equilibrium, with a high proportion of natural fractures and faults critically stressed for shear failure. Since first oil in early 1998, performance results have indicted pressure segregation of many of the wells in both the Gobe Main and SE Gobe fields. Although only one fault has been positively identified at the reservoir level, the mapped faults appear to have sand-on-sand juxtaposition with minimal (
HYDRODYNAMIC ANALYSIS OF FLOW SYSTEMS AND FAULT SEAL INTEGRITY IN THE NORTH WEST SHELF OF AUSTRALIA
Authors: Otto C.J. , Underschultz J.R. , Hennig A.L. , Roy V.J.
Published: August 2017

The North West Shelf hydrodynamics pressure database, developed as part of the North West Shelf Hydrodynamics Project, currently contains 7,780 pressure data points and hundreds of stress, temperature and water salinity data. All data have been ranked using a newly developed quality-control system. Equivalent hydraulic head mapping (fluid potential energy analysis) to interpret fluid migration pathways, hydraulic barriers and conduits was shown to be a valid technique despite lateral and vertical fluid density variations. Pressureelevation analysis identified six major aquifer systems (hydrostratigraphic units) in the regional North West Shelf. On a regional scale, the general flow direction in the North West Shelf is from the basins’ depocentres towards the onshore and upwards to the shallower aquifer systems. Compaction-driven flow is the main driving force for fluid flow in the North West Shelf. Overpressured compartments in the Carnarvon Basin are leaking, not hydraulically isolated from the regional flow field, thus generating their own local flow system. In general, fluid flow within the hydrostratigraphic units is parallel to the trend of major fault systems, which act as barriers in the horizontal plane of the aquifer. However, local-scale hydrodynamic analysis has shown that faults can act as fluid conduits between hydrostratigraphic units providing vertical hydraulic communication (e.g. Mardie to Barrow aquifers). Case studies in the Harriet, Gorgon, Griffin, Goodwyn and Vulcan areas have shown that the migration paths can be very complex due to the hydraulic nature of the faults and the presence of overpressured compartments
POST-RIFT TECTONIC SUBSIDENCE AND PALAEO-WATER DEPTHS IN THE NORTHERN CARNARVON BASIN, WESTERN AUSTRALIA
Authors: Kaiko A.R. , Tait A.M.
Published: August 2017

The subsidence history of the Northern Carnarvon Basin has been dominated by simple thermal sag following the creation of the Exmouth, Barrow and Dampier Sub-basins by Early to Middle Jurassic rifting. This conclusion follows from the recognition of vitrinite reflectance suppression, which removes the need for recent heating events, and from the use of seismic stratigraphy, rather than only palynology and micro-palaeontology, to determine palaeo-water depths.The simple thermal-sag model, related to Jurassic rifting, accounts for the post-rift sedimentary architecture of the Northern Carnarvon Basin, especially in areas of sediment starvation. It also has implications for the timing of hydrocarbon generation and the reconstruction of migration pathways. This work has re-emphasised the theoretical possibility of determining palaeo-water depths by adjusting one-dimensional basin models to fit simple thermal sag tectonic subsidence curves.Miocene uplift, in the order of several hundred metres, has caused local basin inversion, accentuated some preexisting structures and re-activated some faults causing hydrocarbon remigration, but has otherwise not affected the thermal history of the sediments.
THE MIDDLE CRETACEOUS TO RECENT SEQUENCE STRATIGRAPHIC EVOLUTION OF THE EXMOUTH-BARROW MARGIN, WESTERN AUSTRALIA
Authors: Young H.C. , Lemon N.M. , Hull J.N.F
Published: August 2017

Five supersequences have been revealed by a regional sequence stratigraphic study conducted in the Albian (109 Ma) to Recent section of the Exmouth-Barrow passive margin. The interpretation utilises a new sequence stratigraphic model developed for mixed siliciclasticcarbonate lithofacies. A high degree of resolution is brought to the study by identification of 37 regional sequence boundaries controlled by biostratigraphic, wireline and seismic data. Ditch cutting analysis, integrated into the new chronostratigraphic framework, provided detailed lithofacies maps.The five supersequences, named the Gallic, Senonian, Palaeogene, Middle Neogene and Pliocene, are based upon regional lowstand, transgressive and highstand phases. The Gallic Supersequence (late Tithonian–latest Cenomanian) represents a marine incursion of siliciclastic sediments coincident with the rifting and accelerated movement of India away from Australia. A Senonian Supersequence (latest Cenomanian–middle Maastrichtian) truncates the previous supersequence with incised canyons developed on the outer shelf. The evolution of the Senonian section corresponds to the Australian separation from Antarctica and the first appearance of carbonates.The Palaeogene Supersequence (middle Maastrichtian– late Early Miocene) dominates much of the Tertiary and is identified by a basinward shift of facies following a Maastrichtian–Paleocene sea level fall. Enhanced subsidence on the outer shelf during the Eocene created a forced transgression with carbonate mudstonesiltstone deposition. A highstand during the Oligocene– Early Miocene formed the distinctive prograding carbonate shelf recognised throughout the North West Shelf.A Middle Neogene Supersequence (late Early Miocene– Early Pliocene) is identified by an erosive base and the development of a thin lowstand fan on the outer shelf. The supersequence is largely characterised by backstepping reefs following a Middle Miocene transgression. A Late Miocene eustatic stillstand restricted reef development to the inner shelf, generating coarsegrained carbonate progrades from highstand-shedding. The final Pliocene Supersequence (Pliocene–Recent) was initiated by a eustatic fall during the Early Pliocene and was followed by the development of a transgressive, aggrading shelf.
APPLICATION OF GUIDELINE CHARTS IN DECISIONMAKING ON WELL TRAJECTORY AND MUD WEIGHT PROGRAM
Authors: Chen X. , Tan C.P. , Haberfield C.M.
Published: August 2017

To prevent or minimise wellbore instability problems, it is critical to determine the optimum wellbore profile and to design an appropriate mud weight program based on wellbore stability analysis. It is a complex and iterative decisionmaking procedure since various factors, such as in-situ stress regime, material strength and poroelastic properties, strength and poroelastic anisotropies, initial and induced pore pressures, must be considered in the assessment and determination.This paper describes the methodology and procedure for determination of optimum wellbore profile and mud weight program based on rock mechanics consideration. The methodology is presented in the form of guideline charts and the procedure of applying the methodology is described. The application of the methodology and procedure is demonstrated through two field case studies with different in-situ stress regimes in Australia and Indonesia.
ROLE OF TERRESTRIAL SEQUESTRATION IN MEETING KYOTO TARGETS
Authors: Noble I.R.
Published: August 2017

There is strong scientific consensus that the concentration of greenhouse gases in the atmosphere is increasing due to human activities and that this is leading to changes in the Earth’s climate. Fluxes between terrestrial ecosystems and the atmosphere are a significant component of the global carbon cycle and actions to increase net storage in terrestrial ecosystems (often called sinks) will delay the build up of greenhouse gases in the atmosphere. There is still political debate as to which sinks may be accounted in compliance with the Kyoto Protocol. The decisions made will affect the total costs of compliance with the Kyoto Protocol by a factor or two to four. Geological sequestration may also reduce emissions by an amount of the same order as sequestration in terrestrial sinks. Biological and geological sequestration offer a significant opportunity to buy several decades of time to make an efficient transition to technologies and economies that release less greenhouse gasses to the atmosphere from energy production and industrial processes.
THE SEARCH FOR SITES FOR GEOLOGICAL SEQUESTRATION OF CO2 IN AUSTRALIA: A PROGRESS REPORT ON GEODISC
Authors: Rigg A.J. , Allinson G. , Bradshaw J. , King J. Ennis- , Gibson-Poole C.M. , Hillis R.R. , Lang S.C , Streit J.E.
Published: August 2017

The APCRC GEODISC research program has encountered many challenges looking for geological sequestration sites for CO2, but has also found some solutions. Challenges already faced have been in effectively searching databases, developing uniform terminology and evaluation methodology, establishing comparative quality assessment of Australia’s sequestration sites against each other and against those from overseas, improving our understanding of the injection and trapping properties of CO2 and predicting its effects on reservoirs/seals, and developing economic and reservoir models.Pilot research projects at the regional and site specific levels have been used to address these issues, as well as developing generic models, before building site specific models. Issues such as storage efficiency and the use of carbonates as CO2 sequesrationt reain challenges for the future.Preliminary conclusions reached from the regional study of Australia suggest that suitable deep saline formations will be widespread, have the largest sequestration volumes, and are likely to be the most economically attractive option currently available. In the future, some depleted oil and gas fields and enhanced coalbed methane production sites may also represent local high-volume options. It is considered unlikely that sequestration into voids/cavities or associated with enhanced oil recovery (EOR) will represent attractive options other than in exceptional circumstances. Despite these limitations, it is expected that many of Australia’s sedimentary basins will have excellent sequestration sites. The GEODISC program will provide an assessment of the critical factors required for success at each site.Several of the highest-ranking saline formations are currently undergoing site-specific study. Early indications are that the petrophysical data required for models of injection, migration, and trapping is of limited availability. Various methods are required to estimate the distribution and likely variability of these parameters across any site.These and other uncertainties in the distribution, quantity and quality of data required for predictive modelling necessitate an innovative and thorough approach to handling both risk and uncertainty. This will also be a challenge to be addressed during the GEODISC program.From the GEODISC work to date, it appears that it will be technically feasible to sequester large quantities of CO2 in geological formations in Australia for long periods of time. What is less clear is whether this can be done at a cost that would not impose an unreasonable economic burden on Australian industry. The future results for GEODISC will be highly relevant to answering this key question.
GEOGRAPHICAL AND TEMPORAL MOVEMENTS OF HUMPBACK WHALES IN WESTERN AUSTRALIAN WATERS
Authors: Jenner K.C.S. , Jenner M-N.M. , McCabe K.A.
Published: August 2017

Through compilation of historical whaling data, together with recent aerial and boat-based survey data, a general framework for the overall peaks of migration has been estimated for the temporal and spatial movements of Group IV humpback whales along the Western Australian coast.The migratory paths of humpback whales along the Western Australian coast lie within the continental shelf boundary or 200 m bathymetry. Major resting areas along the migratory path have been identified at Exmouth Gulf (southern migration only) and at Shark Bay. The northern endpoint of migration and resting area for reproductively active whales in the population appears to be Camden Sound in the Kimberley. A 6,750 square km2 area of the Kimberley region, inclusive of Camden Sound, has also been identified as a major calving ground. The northern and southern migratory paths have been shown to be divergent at the Perth Basin, Dampier Archipelago and Kimberley regions. In all cases the northern migratory route is further off-shore.
RECENT DEVELOPMENTS IN OCEAN ENGINEERING EDUCATION
Authors: Renilson M. , Soholt J.E. , Macfarlane G.
Published: August 2017

Ocean engineering is a broad branch of engineering covering all aspects of engineering associated with the design, construction and operation of fixed and floating structures in the marine environment. It differs from naval architecture which traditionally focusses on ships and related ocean vehicles, and is of relevance to engineers in the offshore oil and gas industry.The Australian Maritime College (AMC) commenced running Australia’s first Bachelor of Engineering (Ocean Engineering) degree in 1997, with the first students graduating in 2000. The program was designed to meet the growing need of the Australian offshore oil and gas industry for graduate engineers skilled in the analysis and design of structures and facilities capable of operating in ever-increasing water depths. It builds on the already successful naval architecture degree offered by AMC, and has the first year completely in common.AMC makes use of its uniquely maritime focus and its wide variety of specialist facilities to produce graduates with a strong hands-on approach to complement their theoretical studies. The program features a unique blend of traditional marine and ocean-related subjects with a thorough grounding in hydrodynamics, wave theories, reservoir engineering, drilling technology, well design, offshore operations, oil and gas production technology and sub-sea engineering. As such, it is believed that the syllabus has a composition that is basically unique in the world.To support this new degree, AMC has commissioned the construction of a new Model Test Basin to complement its existing towing tank. This will have a plan form of 35 x 12 m and will be equipped with multi-directional wavemakers, making it ideal for student use, as well as consulting and staff research.The aim of the program is to produce engineering graduates with a broad theoretical background and a practical approach to problem solving. The ocean engineering graduates from AMC will be exceptionally well equipped to pursue successful careers within the international oil and gas industry.This paper describes briefly the various subjects that are unique to the ocean engineering degree and shows how the subject syllabi come together into a coherent program which will produce systems engineers rather than specialists. The course has just recently received Full Accreditation from The Institution of Engineers, Australia (IEAust).
UNITISATION OF PETROLEUM FIELDS UNDER THE PSLA
Authors: Griffiths J.
Published: August 2017

Unitisation is a commercial agreement between the titleholders of a shared petroleum pool that extends across two (or more) title boundaries.In 1998, a working group involving government and industry representatives was formed, with the intent of drafting a guideline on unitisation. However, work on the guideline was put on hold until after resolution of the Perseus Athena unitisation issue. During the intervening period, a number of new unitisation cases have arisen and a further number are on the horizon.A workshop was held in Perth on 22 February 2001 to canvass opinions and options on unitisation. Around 30 representatives from government (Commonwealth, Western Australia, Victoria, Northern Territory and the Timor Gap Joint Authority) and industry (APPEA, Agip, Apache, BHP, ExxonMobil, MIMI, Phillips, Santos, Shell and Woodside) attended and contributed to the Workshop.There is general agreement among industry and government representatives that there is a range of unitisation issues under the Petroleum (Submerged Lands) Act 1967 (PSLA) that need to be clarified. In response, the Commonwealth is examining those parts of the Act that deal with property rights with respect to shared pools and when government should direct unitisation. This could lead to changes to the PSLA depending on consultations with interested parties on these matters.The aim of this paper is to canvas a number of options with regards to property rights and government direction. These options could also help resolve a range of other issues relating to unitisation, including information sharing and secondary taxation of unitised fields.
LEGAL ISSUES RELATING TO UNDERGROUND GAS STORAGE
Authors: Rose P. , Turner L.
Published: August 2017

This paper addresses various legal issues associated with underground gas storage, including the potential for commercial underground gas storage, legislative developments in relation to underground gas storage, specific legal issues in relation to commercial underground gas storage, matters to address in a commercial underground gas storage agreement, and the potential application of third party access regimes to underground gas storage reservoirs and facilities.
THE INTEGRATED USE OF PETROPHYSICAL, AVO, SEISMIC INVERSION AND 3D VISUALISATION TOOLS FOR RESERVOIR CHARACTERISATION
Authors: Sena A.G. , Smith T.M.
Published: August 2017

The successful exploration for new reservoirs in mature areas, as well as the optimal development of existing fields, requires the integration of unconventional geological and geophysical techniques. In particular, the calibration of 3D seismic data to well log information is crucial to obtain a quantitative understanding of reservoir properties. The advent of new technology for prestack seismic data analysis and 3D visualisation has resulted in improved fluid and lithology predictions prior to expensive drilling. Increased reservoir resolution has been achieved by combining seismic inversion with AVO analysis to minimise exploration risk.In this paper we present an integrated and systematic approach to prospect evaluation in an oil/gas field. We will show how petrophysical analysis of well log data can be used as a feasibility tool to determine the fluid and lithology discrimination capabilities of AVO and inversion techniques. Then, a description of effective AVO and prestack inversion tools for reservoir property quantification will be discussed. Finally, the incorporation of the geological interpretation and the use of 3D visualisation will be presented as a key integration tool for the discovery of new plays.
NEW ZEALAND’S TARANAKI BASIN: GIANTS IN THE GRABEN?
Authors: Hart A.W.
Published: August 2017

During the past 50 years of utilising modern techniques in New Zealand’s Taranaki Basin, explorers have both been rewarded by its bountiful accumulations and frustrated by its complicated morphology. Numerous superimposed sub-basins, depocentres, areas of uplift, interbedded volcanic edifices and recent volcanism contribute to the complexity of New Zealand’s only producing province. Exploration has been successful along the flanks of the basin, but the time has come to focus on the numerous grabens forming the Taranaki Basin.The basin is a Late Cretaceous rift more than twice the size of the North Sea’s prolific Viking graben, but only 120 wildcats have been drilled since 1955, with only 50 offshore. Horst, tilted fault block, inversion features and thrust anticlines have been the traditional targets, but companies are showing increased interest in relatively more difficult plays involving turbiditic, volcaniclastic and diagenetic reservoirs.The axis of the 6,000 km2 Northern Taranaki graben, the northern part of the Taranaki Basin, has not been penetrated by the drill bit and offers numerous exploration opportunities for basin floor and slope fans of Eocene and Miocene age. Acoustic scattering, diffraction and absorption within a chain of buried Miocene stratovolcanoes inhibit seismic energy from passing into the older sequences, which consist of numerous basin floor fan sequences. Long avoided by exploration programs, volcanic edifices were found to possess good reservoir characteristics and entrap hydrocarbons at Kora–1. The 7000+ km3 of layered extrusive volcanic rock in the graben cannot therefore be discounted as potential reservoir. Another play developed by Miocene magmatism is the doming of potential turbidite reservoirs by underlying igneous feeder dyke systems. In addition, the wells drilled at Kora identified a more elusive play concept—that of potentially large petroleum accumulations stratigraphically trapped downdip from diagenetically altered reservoirs, serving as sealing lithologies, near the igneous feeder dyke systems.As most seismic records in the Northern Taranaki graben were acquired more than a decade ago, modern seismic acquisition and processing technologies are needed to penetrate the buried volcanic edifices and unlock the basin’s story. A better understanding of the basin’s complexities, more cost-effective drilling techniques and a willingness to explore for targets in the source kitchens may finally expose the true potential of the Taranaki Basin.
THE PETROLEUM POTENTIAL OF EAST TIMOR
Authors: Charlton T.R.
Published: August 2017

The hydrocarbon prospectivity of East Timor is widely considered to be only moderate due to Timor island’s well-known tectonic complexity, but in the present study a much higher potential is interpreted, with structures capable of hosting giant hydrocarbon accumulations. High quality source rocks are found in restricted marine sequences of Upper Triassic-Jurassic age. The most likely reservoir target is shallow marine siliciclastics of Upper Triassic-Middle Jurassic age encountered in the Banli–1 well in West Timor, comparable to the Malita and Plover Formations of the northern Bonaparte Basin, and sealed by Middle Jurassic shales of the Wai Luli Formation. The Wai Luli Formation also forms a major structural décollement level which detaches shallow level structural complexity from a simpler structural régime beneath.The principal exploration targets are large, structurally simple inversion anticlines developed beneath the complex shallow-level fold and thrust/mélange terrain. Eroded-out examples of inversion anticlines, such as the Cribas, Aitutu and Bazol anticlines, are typically several tens of kilometres long and up to 10 km broad. Comparable structures in the subsurface of southern East Timor are interpreted north of Betano, and probably also near Suai, Beaco, Aliambata and Iliomar. Other potential targets include a possible non-inverted rollover anticline at Pualaca, stratigraphic and structural traps in the south coast syn/postorogenic basins, and possibly large structural domes beneath extensive Quaternary reef plateaux in the extreme east of the island.
EVIDENCE FOR A NEW OIL FAMILY IN THE NANCAR TROUGH AREA, TIMOR SEA
Authors: George S.C. , Volk H. , Ruble T.E. , Brincat M.P.
Published: August 2017

Geochemical evidence is presented for a previously unrecognised oil generative source rock in the Nancar Trough area. This source rock supplements the middle to late Jurassic source rocks, which have previously been shown to have generated most of the oils in the northern Bonaparte Basin and the Vulcan Sub-basin. Fluids with a strong contribution from this new source rock, defined here as the Nancar oil family, have an unusually high abundance of mid-chain substituted monomethylalkanes. In comparison, oils from the Vulcan Sub-basin contain mostly terminally substituted monomethylalkanes and the overall abundance is much lower. Oils from the Laminaria High and some from the northern Vulcan Sub-Basin show intermediate characteristics and may be co-sourced. Evidence from the analysis of fluid inclusion oils was important in establishing the presence of the new oil family because interference from drilling mud contaminants could be excluded. The detailed geochemistry of Ludmilla–1 fluid inclusion oil suggests the source rock for the Nancar oil family was deposited in a marine environment under sub-oxic conditions with limited sulphur content, a low contribution of terrestrial organic matter and a high contribution of organic matter from bacterial activity. Since monomethylalkanes are typical biomarkers of cyanobacteria, the source rock that gave rise to the new oil family may be rich in cyanobacterial organic matter. Further studies on sediment extracts are needed to establish an explicit oil-source rock correlation and to identify the stratigraphic location/palaeo-environment of the source rock. Such information will be valuable in determining the prospectivity of the large and relatively unexplored province draining the Nancar Trough kitchen.