3,260 research outputs found
Recommended from our members
Consolidation of Geologic Studies of Geopressured-Geothermal Resources in Texas
Hydrochemical data obtained from samples of brine produced from the Gladys McCall Zone 8 sandstone reservoir were used to estimate the importance of shale dewatering as a contribution to ultimate reservoir volume. Changes in chloride concentration of produced brines with time were generally small and close to analytical margins of error, but some correlation between production-related pressure drawdown and declining chlorinity was detected. More rigorous analysis of brine composition and source was hindered by nonstandardized sampling and analytical procedures. Geologic data suggest that sandstone interconnection is a more important source of extra reservoir volume than is shale dewatering at the Gladys McCall site. Methods for more definitively determining the effects of shale dewatering and reservoir interconnectedness include direct sampling and chemical analysis of shale water, pressure monitoring and fluid sampling in multiple reservoirs in a single well or a well field, and sidetrack drilling and coring. Petrographic analysis was used to document the effects of experimental compaction on core samples from geopressured-geothermal reservoirs. Experimental compaction simulates the increasing effective stress within these reservoirs as fluid pressures decline during production. Inelastic compaction and brittle failure (fracturing) are closely related to sandstone composition. Sandstones that contain abundant ductile rock fragments and clay minerals undergo large compaction-induced porosity reductions and fracture readily at effective stress levels comparable to those generated in the reservoir during high-volume production. Well-indurated, high-quartz sandstones, such as the Gladys McCall Zone 8, are extremely resistant to both inelastic compaction and brittle failure.Bureau of Economic Geolog
Learning and interaction in groups with computers: when do ability and gender matter?
In the research reported in this paper, we attempt to identify the background and process factors influencing the effectiveness of groupwork with computers in terms of mathematics learning. The research used a multi-site case study design in six schools and involved eight groups of six mixed-sex, mixed-ability pupils (aged 9-12) undertaking three research tasks â two using Logo and one a database. Our findings suggest that, contrary to other recent research, the pupil characteristics of gender and ability have no direct influence on progress in group tasks with computers. However, status effects â pupils' perceptions of gender and ability â do have an effect on the functioning of the group, which in turn can impede progress for all pupils concerned
Vortex line in a neutral finite-temperature superfluid Fermi gas
The structure of an isolated vortex in a dilute two-component neutral
superfluid Fermi gas is studied within the context of self-consistent
Bogoliubov-de Gennes theory. Various thermodynamic properties are calculated
and the shift in the critical temperature due to the presence of the vortex is
analyzed. The gapless excitations inside the vortex core are studied and a
scheme to detect these states and thus the presence of the vortex is examined.
The numerical results are compared with various analytical expressions when
appropriate.Comment: 8 pages, 6 embedded figure
Sensory motor systems of artificial and natural hands
The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person
Current driven rotating kink mode in a plasma column with a non-line-tied free end
First experimental measurements are presented for the kink instability in a
linear plasma column which is insulated from an axial boundary by finite sheath
resistivity. Instability threshold below the classical Kruskal-Shafranov
threshold, axially asymmetric mode structure and rotation are observed. These
are accurately reproduced by a recent kink theory, which includes axial plasma
flow and one end of the plasma column that is free to move due to a
non-line-tied boundary condition.Comment: 4 pages, 6 figure
Conductance distribution between Hall plateaus
Mesoscopic fluctuations of two-port conductance and four-port resistance
between Hall plateaus are studied within a realistic model for a
two-dimensional electron gas in a perpendicular magnetic field and a smooth
disordered potential. The two-port conductance distribution is concave
between and and is nearly flat between and . These
characteristics are consistent with recent observations. The distribution is
found to be sharply peaked near the end-points and . The
distribution functions for the three independent resistances in a four-port
Hall bar geometry are, on the other hand, characterized by a central peak and a
relatively large width.Comment: 11 pages, 5 ps figures, submitted to Phys. Rev.
Co-design and robots: A case study of a robot dog for aging people
© Springer International Publishing AG 2016. The day-to-day experiences of aging citizens differ significantly from young, technologically savvy engineers. Yet, well-meaning engineers continue to design technologies for aging citizens, informed by skewed stereotypes of aging without deep engagements from these users. This paper describes a co-design project based on the principles of Participatory Design that sought to provide aging people with the capacity to co-design technologies that suit their needs. The project combined the design intuitions of both participants and designers, on equal footing, to produce a companion robot in the form of a networked robotic dog. Besides evaluating a productive approach that empowers aging people in the process of co-designing and evaluating technologies for themselves, this paper presents a viable solution that is playful and meaningful to these elderly people; capable of enhancing their independence, social agency and well-being
The integrated academic information system support for education 3.0 in higher education institution: lecturer perspective
Education 3.0 has been implemented in many higher education institutions (HEIs). Education 3.0 has been directed the institution toward better educational experience. But on the other hands, the implementation of Education 3.0 also caused some problems. Previous research has found administrative problem experienced by the lecturer. This research explores deeper from the lecturer and suggested the solution from lecturer perspective, combined with information technology capabilities owned by the HEIs. The research used a case study as the method and conducted a qualitative research with a semi-structured interview. The interview analysis has found that the increase of the administrative processes is caused by online and offline administrative activities. The online activities are from e-learning and the offline activities are from traditional learning (face-to-face). The administrative processes also involved the academic information system (AIS). Simplified all of the administrative processes are more preferred. To overcome the problems, integrating the AIS and e-learning become necessary. This research suggests transforming the existing AIS into an integrated AIS and hopes the solution can simplify the administration process
Mosquitoes Collected In South And East Kalimantan
Pengumpulan nyamuk dalam waktu singkat di sembilan tempat di Kalimantan Timur dan Selatan menghasilkan 57 species dari 11 genera. Species yang terbanyak dikumpulkan ialah dari genus Culex 27 percent Mansonia 16 percent. Anopheles 16 percent, Aedes 12 percent, Armigeres 7 percent, Mimomia 7 percent, Uranotaenia 7 percent, Hodgesia. Tripteroides, Heizmania dan Culiseta masing-masing 2 percent
Secondary user relations in emerging mobile computing environments
Mobile technologies are enabling access to information in diverse environ.ments, and are exposing a wider group of individuals to said technology. Therefore, this paper proposes that a wider view of user relations than is usually considered in information systems research is required. Specifically, we examine the potential effects of emerging mobile technologies on end-Ââuser relations with a focus on the âsecondary userâ, those who are not intended to interact directly with the technology but are intended consumers of the technologyâs output. For illustration, we draw on a study of a U.K. regional Fire and Rescue Service and deconstruct mobile technology use at Fire Service incidents. Our findings provide insights, which suggest that, because of the nature of mobile technologies and their context of use, secondary user relations in such emerging mobile environments are important and need further exploration
- âŠ