bluuebunny/crossref_metadata_2025 huggingface dataset:
Ambient Assisted Living Technologies for Aging Well: A Scoping Review
Authors: Blackman Stephanie , Matlo Claudine , Bobrovitskiy Charisse , Waldoch Ashley , Fang Mei Lan , Jackson Piper , Mihailidis Alex , Nygård Louise , Astell Arlene , Sixsmith Andrew
Published: March 2015

Ambient assisted living (AAL) technology is of considerable interest in supporting the independence and quality of life of older adults. As such, it is a core focus of the emerging field of gerontechnology, which considers how technological innovation can aid health and well-being in older age. For this scoping review, a comprehensive search of databases and key journals was conducted from January to April of 2013 in order to identify AAL technologies that have the potential to help deal with some of the challenges associated with aging. In particular, we focused on technologies that could potentially be used by people living with some degree of cognitive impairment, ranging from normal cognitive aging to mild cognitive impairment up to earlier stages of dementia. Options currently available and those still under development were both included in our search. Fifty-nine technologies were identified and are outlined here, along with a discussion of history of AAL from a gerontological perspective and related theoretical considerations.
Dinuclear zinc(II) complex with tris(2-aminoethyl)amine ligand: synthesis, structure and properties
Authors: Kürkçüoğlu Güneş Süheyla , Yeşilel Okan Zafer , Şahin Onur , Sayın Elvan , Büyükgüngör Orhan
Published: March 2015

The dinuclear complex tris(2-aminoethyl)aminezinc(II)-μ-cyanothreecyanozincate(II) hemihydrate, [Zn(tren)Zn(μ-CN)(CN)3]·0.5H2O (1) (tren = tris(2-aminoethyl)amine), has been synthesized and characterized by spectral (FT-IR and Raman), elemental, thermal analysis (TG, DTG and DTA) as well as single crystal X-ray diffraction techniques. The asymmetric unit is composed of two Zn(II) ions, one tren ligand, four cyanide ligands and a half crystal water molecule which is situated at the special position. Zn1 ion exhibits tetrahedral coordination geometry with four carbon atoms of four cyanide ligands. Zn2 ion is five-coordinated by five nitrogen atoms from one tren and one cyanide ligands in a trigonal bipyramid coordination geometry. The cyanide nitrogen is in the axial position. Adjacent dinuclear units are connected by hydrogen bonding interactions to form three dimensional network. The decomposition reaction takes place in the temperature range 30–700 °C in the static air atmosphere.
Evaluation of Asphalt Overlay Permanent Deformation Based on Ground-Penetrating Radar Technology
Authors: Hong Feng , Chen Darhao
Published: March 2015

Permanent deformation in materials can lead to rutting on an asphalt pavement. Rutting poses potential hazard to vehicles running on the pavement because of hydroplaning during wet weather conditions. To mitigate or remedy rutting, it is of critical importance to identify the sources and causes of the permanent deformation. Traditional methods mainly rely on cutting a trench to approach this issue. Despite the accuracy, it is labor intensive and time consuming, not to mention having a destructive characteristic. To improve on these, this study discusses the feasibility of potential use of a non-destructive technology with ground-penetrating radar (GPR). GPR is used to estimate the permanent deformation in an asphalt overlay on top of an existing concrete pavement. The GPR antenna mounted on a moving vehicle could detect pavement layer thickness at a fast speed. It also provides full coverage on the pavement along the driving direction. The permanent deformation is estimated by comparing the layer thicknesses between the right wheel path and lane center. In particular, the results could reveal the permanent deformation involving the following three critical aspects: (1) in which layer(s) the permanent deformation occurs; (2) where the permanent deformation is located along the driving direction; and (3) how significant the permanent deformation is.
Analytical Evaluation of Ride Comfort on Asphalt Concrete Pavements
Authors: Wang Feng , Easa Said
Published: March 2015

Ride comfort is very important in the performance evaluation of highway concrete pavements. In this paper, three indices were integrated and used for the evaluation of ride comfort on asphalt concrete pavements: (1) weighted root mean square of the acceleration, (2) root mean square of the squared differences (a measure of heart rate variability), and (3) weighted value of subjective ride comfort. The study involved collection of comprehensive experimental data for 89 highway sections in China that included pavement roughness, ride speed, acceleration, dynamic friction, psychological and physiological data, pavement condition, and questionnaires. Indices and thresholds for acceleration, heart rate variability, and subjective evaluation of ride comfort were developed. In addition, quantitative relations between ride comfort and both pavement roughness and ride speed were established for two specific ranges of dynamic friction. Graphical relations among ride comfort, pavement roughness, and ride speed were established. These relations provide useful guidelines for ride comfort evaluation and highway maintenance management.
Evaluation of Thermomechanical Damage of a Slipper and Rail in a Rocket Sled System
Authors: Yeo Chang-Dong , Palazotto Anthony , Song Jingan , Buentello Rodolfo
Published: March 2015

During the rocket sled test, slippers and rail experience high-speed sliding contact causing critical damage on the surfaces. Because of the significant temperature rise on the contacting surfaces, its fracture mechanism relies on the temperature-dependent material properties. In this study, the thermomechanical damage of the slipper and the rail is systematically investigated through 3D finite-element analysis (FEA) model and simulations. The sliding velocity consisted of 20 m/s, 200 m/s, and 1500 m/s, whereas the vertical velocity (bouncing speed of the slippers) was assumed to be 1.1 m/s. The unique method of including the aerodynamic bounce by allowing the rail to move vertically is quite different from other models explored by collaborating authors. The process of material thermal softening by adiabatic and frictional heat generation is applied to the modeling. From the simulation results, it is found that the damage process and pattern of the slipper and the rail asperity is very dependent upon the sliding velocity and the slipper temperature. For the sliding velocity of 20 m/s, the damage rate of the slipper gradually increases with the elapsed contact time, where the slipper surface produces a plowing type of damage pattern (continuous scratch). However, when the sliding velocity increases beyond 200 m/s, the slipper surface starts showing a gouging type of damage pattern along with a chopping material removal in the rail asperity.
Static and Dynamic Strain Measurement at Ambient and Elevated Temperatures Using an Extrinsic Fabry–Perot Interferometer (EFPI) Optical Strain Sensor
Authors: Sebastian James , Boles William , Taylor James
Published: March 2015

Advances in the testing of high temperature materials for aerospace structures and propulsion components requires a thorough characterization of mechanical behavior under combined thermal, mechanical, and acoustic loading. The ability to stably measure static strain in such materials is a historically difficult challenge, especially in applications where an extensometer cannot be used. Recent research in the Aerospace Systems Directorate of the Air Force Research Laboratory is establishing a capability for the reliable measurement of mechanical strain at temperatures up to 650°C (1200°F) on metals and above 870°C (1600°F) on ceramic composite materials. Sensor testing on both coupons and structural components has been demonstrated. Quasi-static strain measurement was achieved without the metallurgical drift or high thermal sensitivity of commercially available resistive strain gages. In addition to static measurements, dynamic strain measurement at moderate strain rates was also achieved, as was static strain measurement in the presence of high level broadband acoustic excitation.
The Privatization of Military Family Housing in Linda Vista, 1944–1956
Authors: Reft Ryan
Published: March 2015

From its creation as a military housing development to its ultimate transformation into private housing, Linda Vista, in San Diego, ran the ideological spectrum—ranging from a foil for alleged communism, to a repository for proto Right Wing conservatism—simultaneously revealing burgeoning sunbelt politics and the conflict between the housing needs of military families and the anti-public housing ethos of the city's political class. Though the Navy required such projects to house its service personnel and their dependents, the city and many residents sought to eliminate public housing. Linda Vista also demonstrates the intersection of military housing, race, and local politics. For the left, it served as a fortress of political support in the 1940s, but by the 1950s, Linda Vista came to be a Republican stronghold. Ultimately, Linda Vista's shift previewed the New Right conservatism that Sunbelt metropolises would promote in the latter half of the twentieth century.
Dienogest reduces HSD17β1 expression and activity in endometriosis
Authors: Mori Taisuke , Ito Fumitake , Matsushima Hiroshi , Takaoka Osamu , Koshiba Akemi , Tanaka Yukiko , Kusuki Izumi , Kitawaki Jo
Published: March 2015

Endometriosis is an estrogen-dependent disease. Abnormally biosynthesized estrogens in endometriotic tissues induce the growth of the lesion and worsen endometriosis-associated pelvic pain. Dienogest (DNG), a selective progesterone receptor agonist, is widely used to treat endometriosis and efficiently relieves the symptoms. However, its pharmacological action remains unknown. In this study, we elucidated the effect of DNG on enzymes involved in local estrogen metabolism in endometriosis. Surgically obtained specimens of 23 ovarian endometriomas (OE) and their homologous endometrium (EE), ten OE treated with DNG (OE w/D), and 19 normal endometria without endometriosis (NE) were analyzed. Spheroid cultures of stromal cells (SCs) were treated with DNG and progesterone. The expression of aromatase, 17β-hydroxysteroid dehydrogenase 1 (HSD17β1), HSD17β2, HSD17β7, HSD17β12, steroid sulfatase (STS), and estrogen sulfotransferase (EST) was evaluated by real-time quantitative PCR. The activity and protein level of HSD17β1 were measured with an enzyme assay using radiolabeled estrogens and immunohistochemistry respectively. OESCs showed increased expression of aromatase, HSD17β1, STS, and EST, along with decreased HSD17β2 expression, when compared with stromal cells from normal endometria without endometriosis (NESCs) (P<0.01) or stromal cells from homologous endometrium (EESCs) (P<0.01). In OESCs, DNG inhibited HSD17β1 expression and enzyme activity at 10−7 M (P<0.01). Results of immunohistochemical analysis displayed reduced HSD17β1 staining intensity in OE w/D (P<0.05). In conclusion, DNG exerts comprehensive inhibition of abnormal estrogen production through inhibition of aromatase and HSD17β1, contributing to a therapeutic effect of DNG on endometriosis.
Angiosperm diversity of the Great Indian Bustard Wildlife Sanctuary: a semi-arid grassland, Maharashtra, India
Authors: Janakiraman Jayanthi , Jalal Jeewan Singh
Published: March 2015

The Great Indian Bustard Wildlife sanctuary is a semi-arid grassland ecosystem spread over an area of 1,222 km2 in the Solapur and Ahmednagar districts of Maharashtra, India. It is an abode of the critically endangered bird, the Great Indian Bustard. A total of 436 plants belonging to 259 genera and 67 families are reported in the present study from the sanctuary, including 22 endemic taxa. Grasses form one of the dominant components of the ecosystem and are represented by about 67 species. The sanctuary is facing severe habitat loss and degradation, posing a threat to its biodiversity. This paper provides a comprehensive documentation of the floristic diversity of the sanctuary. Threats and conservation measures are also discussed.
The testing of PCL: an open-source library for point cloud processing
Authors: Zygmunt Maria
Published: March 2015

In the era of the rapid development of the terrestrial laser scanning technology (TLS), that facilitates the acquisition of large data volumes in the form of three-dimensional point clouds, a need
arises to create modern solutions to enable effective and efficient data processing. This paper
presents the PCL (Point Cloud Library). This is an Open Source project that contains many of
the key algorithms for TLS data, designed for filtering, registration, estimation of function, surface reconstruction, modeling and segmentation, as well as structures for identifying and matching objects. The article discusses the structure of the project as well as its most useful modules
from the point of view of the TLS data processing. It describes the format used by the PCL data
storage. Also, a practical example is enclosed, as a basis for the discussion of consecutive steps of
working with the library, from recording input data in the correct format to visualization of the
effects of the used algorithm.
The location and conditions of the calligraphic parks in Matwijowce, Horodyszcze and Rybczyńce in Ukraina
Authors: Baster Przemysław
Published: March 2015

Calligraphic parks – it is a large group of realizations, unfortunately almost unknown in the
history of the landscape. Hundreds of them were designed on the turn of 19th century, but only
about one hundred still exist. They are recognized as the most subtle forms of the naturalistic
style. The characteristic shape of curved paths, streams and the lakeside – calling associations
with Polish calligraphic writing, recognized as a canon of beauty – was distinctive for this style.
Some of the parks were realized in the territory of the Ukraine. The description of their location
and status quo may contribute to their restoration and to better management of the surrounding
landscape.
The concept of ecologically sensitive residential development for areas at risk from natural disasters
Authors: Fedyczkowski Zbigniew Edward , Przystał Gabriela
Published: March 2015

Climate change has dramatically increased the frequency of natural disasters that destroy ever-larger areas inhabited by people. Thus, a complete change of spatial planning conception is
needed.
This paper aims to describe the technical capabilities of ArchitrAdom, an innovative construction and architectural project. The structure has been designed for use in areas at risk from
natural disasters: floods, hurricanes and earthquakes. It eliminates the drawbacks of traditional
residential developments, which is not disaster-resistant. This project allows for whole urban
organisms to be build.
The project’s focus is on elevating usable area above the surface of the flooded terrain and shaping the building; as to make it as resistant to wind force as possible. The other key aspect is the
integration of the structure by means of lines and bands which increases the buildings resilience.
The advantages of ArchitrAdom are:
• resistance to natural disasters and the effects of climate change,
• various adaptations: residential establishments, public utility buildings, public space, etc.,
• significant flexibility in forming groups of buildings: villages, housing estates, quarters, towns,
etc.,
• the highest respect for rules of sustainable and ecological design,
• an advantage in advanced prefabrication to minimizes costs.
A comparison of interpolation methods for flood zones adjacent to a stream
Authors: Grzelak Dominika , Kwinta Andrzej
Published: March 2015

Even small streams may cause severe flooding. The evaluation of the safety of people and objects
in the area of a watercourse is related to modelling of flood zones. The area of potential flood
zones is calculated on the basis of a Digital Terrain Model (DTM). This paper presents interpolation methods for creating DTMs based on land surveying data. The result of sample modelling
is compared with selected interpolation methods.
The study of methods for correcting global Digital Terrain Models using remote sensing data
Authors: Kolb Ihor , Lutcyschyn Marija , Panek Małgorzata
Published: March 2015

This work describes original methods of improving the quality of Digital Elevation Models
(DEM), obtained by means of satellite altimetry data. Shown are subsequent steps of geometric
correction of global raster DEM, such as SRTM, SRTM DLR and ASTER GDEM, which are
commonly available. According to the authors of this analysis, methods proposed here can be
used in geoinformation projects.
Determining the influence of the earthquake on the change(s) of objects using remote sensing data
Authors: Chetverikov Boris , Babiy Lyubov , Dorozhynskyy Oleksandr
Published: March 2015

Two methods of determining changes of objects (structures) using remote sensing data obtained
in different times are considered in this article. The comparison of the percentage of destroyed
buildings as a consequence of the earthquake in L’Aquila city (Italy) was implemented. For comparison two ways of data collection were used: obtaining data by the digitalization of objects
before and after the disaster (using MapInfo software) and by automatic image classification
using a special module Delta Cue (Erdas software).
Spatial management policies in the community of Tomice in the context of development directions of investment areas
Authors: Prus Barbara , Salata Tomasz
Published: March 2015

The fundaments for sustainable development are constitute by spatial management policies expressed in the study of conditions and directions of spatial management as well as in the local
spatial management plan. Polish agricultural lands are more often reclassified as non-agricultural areas. For example, this is confirmed by statistical data from the Polish Central Statistical
Office. Also, there is an increasing number of non-agricultural and non-forest areas in spatial
management studies. Ensuring access to technical infrastructure is an important argument in
favour for development of investment areas. This article analyses, land zoning patterns in the
community of Tomice, with particular consideration to investment areas. This paper also takes
a close look at local spatial management policies and discusses the location of investment areas
in the context of their access to utilities network.
The article applies geoprocessing methods, including geometric and spatial analysis of selected
basic evaluation fields.
Platinum-Induced Neurotoxicity and Preventive Strategies: Past, Present, and Future
Authors: Avan Abolfazl , Postma Tjeerd J. , Ceresa Cecilia , Avan Amir , Cavaletti Guido , Giovannetti Elisa , Peters Godefridus J.
Published: March 2015

Neurotoxicity is a burdensome side effect of platinum-based chemotherapy that prevents administration of the full efficacious dosage and often leads to treatment withdrawal. Peripheral sensory neurotoxicity varies from paresthesia in fingers to ataxic gait, which might be transient or irreversible. Because the number of patients being treated with these neurotoxic agents is still increasing, the need for understanding the pathogenesis of this dramatic side effect is critical. Platinum derivatives, such as cisplatin and carboplatin, harm mainly peripheral nerves and dorsal root ganglia neurons, possibly because of progressive DNA-adduct accumulation and inhibition of DNA repair pathways (e.g., extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase/stress-activated protein kinase, and p38 mitogen-activated protein kinass), which finally mediate apoptosis. Oxaliplatin, with a completely different pharmacokinetic profile, may also alter calcium-sensitive voltage-gated sodium channel kinetics through a calcium ion immobilization by oxalate residue as a calcium chelator and cause acute neurotoxicity. Polymorphisms in several genes, such as voltage-gated sodium channel genes or genes affecting the activity of pivotal metal transporters (e.g., organic cation transporters, organic cation/carnitine transporters, and some metal transporters, such as the copper transporters, and multidrug resistance-associated proteins), can also influence drug neurotoxicity and treatment response. However, most pharmacogenetics studies need to be elucidated by robust evidence. There are supportive reports about the effectiveness of several neuroprotective agents (e.g., vitamin E, glutathione, amifostine, xaliproden, and venlafaxine), but dose adjustment and/or drug withdrawal seem to be the most frequently used methods in the management of platinum-induced peripheral neurotoxicity. To develop alternative options in the treatment of platinum-induced neuropathy, studies on in vitro models and appropriate trials planning should be integrated into the future design of neuroprotective strategies to find the best patient-oriented solution.
Parental effects enhance risk tolerance and performance in offspring
Authors: Donelan Sarah C. , Trussell Geoffrey C.
Published: March 2015

Predation risk can strongly influence community dynamics through its effects on prey foraging decisions that often involve habitat shifts (i.e., from risky to refuge habitats). Although the within‐generation effects of risk on prey are well appreciated, the effects of parental experience with risk on offspring decision‐making and growth are poorly understood. The capacity of parents to prepare their offspring for potential risk exposure may be adaptive when the likelihood of eventual risk exposure is high and be instrumental in shaping how offspring allocate their foraging effort and habitat use. Using a simple rocky intertidal food chain, we examined the influence of parental exposure to predator risk cues on the behavior, foraging, and tissue maintenance of offspring exposed to the presence and absence of risk. We found that offspring of risk‐experienced parents were bolder. When confronted with risk, these offspring spent more time out of refuge habitat, foraged more, and maintained more tissue than offspring of risk‐free parents. Thus, parental experience with risk was most important when offspring were exposed to risk. These results suggest that the effects of parental experience with predation risk on offspring traits strongly shape the transmission of risk effects in ecological communities.
Impacts of weather on long‐term patterns of plant richness and diversity vary with location and management
Authors: Jonas Jayne L. , Buhl Deborah A. , Symstad Amy J.
Published: March 2015

Better understanding the influence of precipitation and temperature on plant assemblages is needed to predict the effects of climate change. Many studies have examined the relationship between plant productivity and weather (primarily precipitation), but few have directly assessed the relationship between plant richness or diversity and weather despite their increased use as metrics of ecosystem condition. We focus on the grasslands of central North America, which are characterized by high temporal climatic variability. Over the next 100 years, these grasslands are predicted to experience further increased variability in growing season precipitation, as well as increased temperatures, due to global climate change. We assess the portion of interannual variability of richness and diversity explained by weather, how relationships between these metrics and weather vary among plant assemblages, and which aspects of weather best explain temporal variability. We used an information‐theoretic approach to assess relationships between long‐term plant richness and diversity patterns and a priori weather covariates using six data sets from four grasslands. Weather explained up to 49% and 63% of interannual variability in total plant species richness and diversity, respectively. However, richness and diversity responses to specific weather variables varied both among sites and among experimental treatments within sites. In general, we found many instances in which temperature was of equal or greater importance as precipitation, as well as evidence of the importance of lagged effects and precipitation or temperature variability. Although precipitation has been shown to be a key driver of productivity in grasslands, our results indicate that increasing temperatures alone, without substantial changes in precipitation patterns, could have measurable effects on Great Plains grassland plant assemblages and biodiversity metrics. Our results also suggest that richness and diversity will respond in unique ways to changing climate and management can affect these responses; additional research and monitoring will be essential for further understanding of these complex relationships.
Linking spatial patterns of leaf litterfall and soil nutrients in a tropical forest: a neighborhood approach
Authors: Uriarte María , Turner Benjamin L. , Thompson Jill , Zimmerman Jess K.
Published: March 2015

Leaf litter represents an important link between tree community composition, forest productivity and biomass, and ecosystem processes. In forests, the spatial distribution of trees and species‐specific differences in leaf litter production and quality are likely to cause spatial heterogeneity in nutrient returns to the forest floor and, therefore, in the redistribution of soil nutrients. Using mapped trees and leaf litter data for 12 tree species in a subtropical forest with a well‐documented history of land use, we: (1) parameterized spatially explicit models of leaf litter biomass and nutrient deposition; (2) assessed variation in leaf litter inputs across forest areas with different land use legacies; and (3) determined the degree to which the quantity and quality of leaf litter inputs and soil physical characteristics are associated with spatial heterogeneity in soil nutrient ratios (C:N and N:P). The models captured the effects of tree size and location on spatial variation in leaf litterfall (R2 = 0.31–0.79). For all 12 focal species, most of the leaf litter fell less than 5 m away from the source trees, generating fine‐scale spatial heterogeneity in leaf litter inputs. Secondary forest species, which dominate areas in earlier successional stages, had lower leaf litter C:N ratios and produced less litter biomass than old‐growth specialists. In contrast, P content and N:P ratios did not vary consistently among successional groups. Interspecific variation in leaf litter quality translated into differences in the quantity and quality (C:N) of total leaf litter biomass inputs and among areas with different land use histories. Spatial variation in leaf litter C:N inputs was the major factor associated with heterogeneity in soil C:N ratios relative to soil physical characteristics. In contrast, spatial variation soil N:P was more strongly associated with spatial variation in topography than heterogeneity in leaf litter inputs. The modeling approach presented here can be used to generate prediction surfaces for leaf litter deposition and quality onto the forest floor, a useful tool for understanding soil–vegetation feedbacks. A better understanding of the role of leaf litter inputs from secondary vegetation in restoring soil nutrient stocks will also assist in managing expanding secondary forests in tropical regions.
Were Aqueous Ripples on Mars Formed by Flowing Brines?
Authors: Lamb Michael P. , Grotzinger John P. , Southard John B. , Tosca Nicholas J.
Published: March 2015

The discovery in 2004 by Mars exploration rover Opportunity of sedimentary rocks with centimeter-scale trough cross-bedding is one of the compelling lines of evidence for flowing water on the Martian surface. The rocks contain a significant evaporite component mixed with weathered mafic silicates, suggesting that the aqueous fluid in contact with the sediments must have been of very high ionic strength because dissolution features are not observed. Recent thermodynamic modeling indicates that these brines could have had higher densities (by up to a factor of 1.3) and significantly higher viscosities (by up to a factor of 40) than pure water. Because fluid density and viscosity can significantly affect sediment transport mechanics, herein we analyze whether ripples could have been stable bed forms under flowing Martian brines. To this end, we compiled bed form stability diagrams with an emphasis on those studies that have considered high-viscosity fluids. For the case of viscous Martian brines, we find that ripples are stable under modest Shields numbers and low particle Reynolds numbers. These conditions translate into sediment sizes ranging from sand to gravel, and they are substantially coarser than sediment sizes for equivalent ripple-forming flows in freshwater. It is likely that ripples might also form in silt sizes under viscous brines, but these conditions (i.e., particle Reynolds numbers < 0.1) have not yet been explored in flume experiments, motivating future work. Using flow-resistance equations and assuming steady uniform flow, we calculate that Marian brines must have had flow depths ranging from 0.01 to 1 m and flow velocities of 0.01 to 1 m/s, and been driven by gravity on slopes of 10−4 to 10−2 in order to generate the bed stresses necessary to produce ripples. These conditions seem reasonable given the interdune environment that has been proposed for the Burns formation. In addition to the potential for ripples in much coarser sediments, ripples formed by viscous brines also might be larger in height and wavelength than their freshwater counterparts by as much as a factor of 12. Thus, large (>10 cm heights) and fine-grained (<1 mm particle diameter) cross strata would be compelling physical evidence for flowing brines in the Martian past, provided that independent evidence could be provided for a subaqueous (i.e., not eolian) origin of the cross-stratification. Smaller centimeter-scale ripples can also be formed by brines due to flow-depth limitations or lower-viscosity fluids, and therefore the physical sedimentological evidence in support of brines versus freshwater flows may be ambiguous in these cases.
Potential Recognition of Accretionary Lapilli in Distal Impact Deposits on Mars
Authors: Fralick Philip , Grotzinger John , Edgar Lauren
Published: March 2015

Our understanding of the significance and abundance of sedimentary strata on Mars has increased considerably during the last decade. The highly cratered surface of Mars leads to the prediction that impact ejecta deposits, possibly containing accretionary lapilli, should be part of the sediment record. While no impact-induced base surge deposits have been confirmed on Mars, it is likely that they will one day be discovered, and it is important to establish criteria for their recognition in the rock record. The recognition of ejecta deposits containing accretionary lapilli on Mars requires reliable facies models developed from known impact-generated strata on Earth. Sections through ejecta layers formed by the 1850 Ma Sudbury impact event provide data to begin development of such models. These deposits are laterally variable but generally show a vertical decrease in lithic clast size and, where present, an upward fining in accretionary lapilli. In thicker deposits, the accretionary lapilli–bearing portion of sections generally progresses upward from decimeter-scale beds of clast-supported lapilli interlayered with centimeter-scale sandstone beds, to parallel and undulatory laminated lapilli, and sandstones. These are overlain by lapilli stringers and isolated lapilli in parallel-laminated to cross-stratified sandstone. Both grain size and sedimentary structures indicate a succession deposited by an impact-generated base surge during decelerating flow. Thinner deposits of ejecta, possibly laid down on topographic highs, are commonly massive with reverse and normal grading. We compare the accretionary lapilli–bearing strata in the Sudbury ejecta deposits to proposed impact-generated base surge deposits in the Burns formation at Meridian Planum, Mars. Units comprising the Burns formation do not have the internal organization of spherule-bearing layers exhibited by the Sudbury ejecta deposits. Comparison with Sudbury ejecta layers and theoretical considerations indicate that the spherules developed in the Burns formation do not represent grains deposited by a base surge and are most likely diagenetic in origin. However, impact ejecta layers should be present in the sedimentary successions on Mars, and comparison with similar strata on Earth may lead to their eventual identification.
Activated Reamer at-Bit System Reduces Rathole to 3 ft in RSS Hole-Enlargement Applications
Authors: Tilley Jim , Evans John , Ravndal Svein
Published: March 2015

Operators frequently use hole enlargement techniques to address drilling challenges, such as pore pressure and fracture gradient windows, ECD reduction, swelling and reactive formations, and tight casing tolerances, and to increase production. Typically, concentric underreamers are run above the logging-while-drilling (LWD) tool to enlarge the hole during drilling operations while providing optimum LWD log quality. Rotary steerable systems (RSS) are normally required in this application to provide full steerability with continuous rotation. The position of the underreamer in the bottomhole assembly (BHA) leaves a long rathole section that is not enlarged. In some cases, this pilot hole must be opened on a dedicated opening run, incurring additional rig time and expense, while the additional formation exposure time can result in deteriorating hole conditions. Long rathole sections can present problems with running casing to total depth (TD), as well as problems of breaking down the formation while cementing.

A large international oil company in Norway required a solution that enabled underreaming while drilling and that could provide rathole reduction to less than 20 ft to ensure a good casing seat while eliminating the dedicated run to enlarge the rathole. A new system was developed for this application that enabled underreaming while drilling reducing the rathole to 3 ft for hole sizes from 8 ½” to above 20”. The system includes a conventional or wired underreamer that can be run above the LWD tool or above the RSS, and an at-bit underreamer that can be run below the RSS. The at-bit reamer can be opened by hydraulic or ball-assisted activation. At TD, the at-bit reamer is activated to enlarge the rathole between the upper underreamer and the bottom of the hole, thereby reducing the rathole to 3 ft.

The RSS BHA with the at-bit reamer was designed and optimized using BHA modeling software. A balanced BHA design is critical with underreaming operations to minimize drilling dysfunctions. Stabilizer position and fulcrum-point loading were optimized to ensure good directional performance of the RSS while underreaming.

A total of nine runs have been performed to date in hole sizes ranging from 12¼×13½ in. to 17½×20 in. Directional work has also been performed, showing good directional control with this system. In the 17½×20-in. sections, a total of 7,569 ft was drilled and reamed in five runs. In the 12¼×13½-in. sections, four runs were drilled/reamed for a total of 19,743 ft.

The development of this technology has added new capability to the industry in the optimization of hole enlargement applications. The benefit is realized in a reduced number of days required to drill the well and in reduced total well cost. In addition, getting casing into the hole sooner reduces risk and can help to reduce operational nonproductive time (NPT).
Elastic Pipe Control and Compensation for Managed Pressure Drilling Under Sea Wave Heave Conditions
Authors: Samuel Robello , Lovorn Randy
Published: March 2015

Managed pressure drilling (MPD) was developed as a group of technologies to more precisely control the annular pressure profile for which accuracy of the estimation of the bottomhole pressure is important. Particularly, under severe wave heaves in deepwater environments, the estimation based on static state pipe movement models can result in underestimation/overestimation of bottomhole pressures. The purpose of this study is to investigate the dynamic axial response of the drillstring with friction to applied heaving velocity, with particular interest to the effect at the bottomhole pressure.

The paper presents an efficient and accurate method for solving the dynamic axial drillstring with friction and it allows it to be applied to heave velocity at surface. The model that couples the pipe motion solves the full balance of mass and balance of momentum for pipe and annulus flow, considering the compressibility of the fluids, the elasticity of the system, and the dynamic motions of pipes and fluids. Also considered are surge pressures related to fluid column length below the moving pipe, compressibility of the formation, and axial elasticity of the moving string. Fluid properties are adjusted to reflect the effects of pressure and temperature on the fluids. The modeling takes into account the pipe elasticity under different combinations of heave and pipe velocities. Furthermore, the real-time torque and drag models are calibrated to actual hole conditions in real-time using survey, temperature, pressure, and downhole tool data to calculate friction factors in a wellbore.

It has been observed that different conditions exist, some resulting in velocity reversal, thus causing surge or swab pressures. It has also been observed that heave amplitude has significant influence on bottomhole pressure. The different conditions observed for periodic or time function of displacements include: Surface pipe velocity attributed to wave heave is in phase with the bottom movement of the string.Surface velocity of the pipe is out of phase with the bottom velocity of the pipe.Wave velocity and surface pipe velocity can be out of sync, and the bottom pipe velocity can be in phase with the surface velocity.Wave velocity and surface pipe velocity can be out of sync, and the bottom pipe velocity can be out of phase with the surface velocity.

The results of these calculations can be coupled to a real-time hydraulics model to determine a setpoint pressure for the MPD choke system.
Historical Advances in Drill Pipe Internal Coating Systems and the Performance of Liquid versus Powder Applied Coating Systems
Authors: Lauer Robert S.
Published: March 2015

As one scans the market today, it is noted that the vast majority of drill pipe is internally coated with a polymeric coating system. One also notes that completion pipe, landing strings, etc are increasingly utilizing internal coating technology to provide corrosion, hydraulic and scale mitigating benefits. Transitioning from simple drilling operations in the 1950’s to the ability to withstand drilling, fracing, cementing, gravel packing, acidizing, and mechanical intervention at high temperatures and pressures. There has been a transition in technology from those very early coating systems to the newest technology available today. Several milestones define the technological advances in internal coating capabilities.

Initial versions of these drilling coating systems utilized a liquid applied epoxy phenolic coating systems. As the industry developed, there became a need for a powder version of the traditional drill pipe coating systems. From there, the market showed a need for a more abrasion resistant system to handle not only drilling applications, but also completion operations. A third era was ushered in with this new abrasion resistant technology, but transitioned back from a powder application to a liquid application due to the market experienced performance benefits of a liquid applied material. We now stand in a new era of coating technology in the drilling and completion market. While still focusing on a liquid applied material, the traditional epoxy phenolic is being left behind. This new coating utilizes a high temperature, multi-functional epoxy resin as its backbone. This system also deviates from the norm in that specialized additives are used to improve characteristics such as coating toughness and flexibility. Historically, the use of additives would reduce the final glass transition of the coating system, reducing its overall performance in a given environment. These new additive systems in conjunction with this multi-functional epoxy allow for them to be used in concert without reducing the glass transition temperature. This new system increases the chemical resistance over traditional liquid applied systems, doubles the flexibility over other industry available systems, exhibits greater performance at temperature over traditional coating systems, and now possesses the most abrasion resistance available in the market.
Defining Design and Optimization Method: Dynamic Simulation Model Produces Integrated BHA Solutions for Efficient Wellbore Delivery
Authors: Chen Wei , Shen Yuelin , Harmer Richard , Rawlins Sheldon , Dong Yani , Chen Rongbing
Published: March 2015

In difficult drilling environments, a critical aspect for success is BHA design optimization in the pre-job phase. In previous operations, modeling and run simulations have proven valuable at helping operators improve drilling efficiency (reduce NPT; increase footage/day), produce high-quality log data and properly position the wellbore to increase contact with the reservoir. To further improve modeling accuracy/reliability, a dynamic modeling system was used for BHA analysis. The FEA (finite element analysis)-based system enables engineers to leverage the team's combined expertise and full suite of drilling tools to optimize a BHA for a specific application.

Four criteria are used to evaluate BHA performance during simulations: stability; robustness/reliability; measurement quality; steerability. Simulations are run to determine each configuration's potential for axial, lateral/torsional vibration and identify the root cause and dominant mode. To ensure maximum BHA robustness, the loading on BHA components is mapped/rated allowing refinements to increase BHA service life and reduce the potential for costly NPT. Simulations are run to observe the potential for MWD/LWD tool deformation and sag angle to determine the adverse effect sensor motion could have on measurement quality. To mitigate steerability issues, build/walk tendencies are simulated to determine how the BHA will respond to steering command from RSS/PDM.

A wide-range of factors can be considered in this procedure. Various cutting structures and steering tools are analyzed and modified as required. The type and location of BHA components are also modeled and re-positioned for optimization purposes. Various drilling scenarios and operating parameters are fed into the system including RPM/WOB, sliding/rotating time, back-reaming and rotating off bottom. Formation characteristics including rock types, friction factor, heterogeneity/homogeneity, degree/amount of interbedding can all be varied to investigate the BHA's corresponding directional implications and vibrational response.

All potential BHA designs are evaluated under a set of pre-defined drilling scenarios. A comparative analysis is performed to investigate BHA responses against each specific criterion to identify the optimum BHA configuration. Operating conditions are analyzed for each BHA and an optimal parameter window of minimized BHA shock and vibration is generated with a range of RPM/WOB recommendations. The authors will present several conclusive case studies that document the method's effectiveness and cost reducing capabilities.
MPC-Based Feedback Delay Compensation Scheme for Directional Drilling Attitude Control
Authors: Bayliss Martin , Bogath Chris , Whidborne James
Published: March 2015

For practical engineering reasons, the attitude control of directional drilling tools is subject to significant temporal feedback delays, which reduce the performance and stability of these algorithms. This paper details the modification of an existing attitude tracking algorithm to use a model predictive control (MPC) scheme incorporating a state-space plant model augmented with pure delays on the state variables. Provided with an estimate of the temporal feedback delay and other plant model parameters, the MPC scheme is able to mitigate for the effects of the feedback delay. Additionally, feedback loops designed by pole placement are added to the core MPC scheme to identify disturbances to the plant, which cannot be measured directly on line. The paper details the algorithm and gives results from a transient simulation-based on the stated scheme.
Drilling Systems Automation Roadmap - The Means to Accelerate Adoption
Authors: de Wardt John P , Macpherson John D , Zamora Mario , Dow Blaine , Hbaieb Slim , Macmillan Robin A , Laing Moray L , DiFiore Amanda M , Inabinett Calvin E , Anderson Mark W
Published: March 2015

The Drilling Systems Automation Roadmap (DSA-R) initiative is a cross-industry effort launched in June 2013 to help accelerate the adoption of advancements in drilling systems automation for both onshore and offshore wells. When completed, this technology roadmap will provide the drilling industry with a well-defined guide on the expected development and adoption of drilling systems automation technology in the near and long terms. The focus on needs, vision, scope, and boundaries will enable development of solutions to implement Drilling Systems Automation (DSA) in a manner that effectively improves performance, reduces well costs, removes people from high-risk operations, and promotes general drilling safety, among other key goals. To enhance consensus, the DSA-R initiative decided to affiliate with the SPE, IADC and the Association for Unmanned Vehicle Systems International (AUVSI).

This technology roadmap uses the well-known template developed by Sandia National Laboratories to provide a mechanism to forecast how DSA developments can progress, and to provide a framework to coordinate among disparate players. The process also will enable players outside of the oil and gas industry to envision how to participate and contribute to the implementation and advancement of DSA.

From the onset, the roadmap was segmented into eight key challenges, each individually defined in terms of functional description, performance targets, current status, problem statement, and development to meet the vision. The eight challenges are (1) Systems Architecture, (2) Communications, (3) Instrumentation and Measurement Systems, (4) Drilling Machines and Equipment, (5) Control Systems, (6) Simulation Systems and Modeling, (7) Human Systems Integration, and (8) Certification and Standards. Interdisciplinary challenge teams formed by subject-matter experts from both inside and outside the oil and gas industry are developing the maps for the challenges. The interdependencies and related interfaces among the challenges are being coordinated through the committee to ensure consistency of approach and timelines.

The purpose of this paper is to describe the launch of the DSA technology roadmap initiative, the processes being applied and key details on the status of each of the challenges. All roadmaps are invariably long-term projects, but the sharing of information at this critical stage is important to encourage wide industry involvement and participation to accelerate the implementation of automation in drilling.