bluuebunny/crossref_metadata_2025 huggingface dataset:
Broadband electrical properties of clays and shales: Comparative investigations of remolded and preserved samples
Authors: Josh Matthew , Clennell Ben
Published: March 2015

The dielectric permittivity of mudrocks cannot be determined from the mixing ratios of the constituent minerals and brine and their individual dielectric response. The high-frequency dielectric permittivity is linked ([Formula: see text] correlation) to water content, but the relationship is complicated by mineral type and the hydration state. The cation exchange capacity (CEC) and specific surface area (SSA) determine the establishment of a polarizable electrical double layer and give rise to the long range diffusion of ions leading to Maxwell-Wagner polarization. This ultimately determines the dielectric response below 50 MHz. Procedures for SSA analysis based on sorption of 2-ethoxyethanol and CEC analysis based on methylene blue titration, were developed for investigating swelling clays. These were combined with a procedure for preparing remolded paste samples from pulverized rock and drill cuttings to form the basis of this investigation. In a case study of 123 drill cutting samples retrieved from an undisclosed well, dielectric analysis of the remolded samples exhibits [Formula: see text] correlation with SSA, [Formula: see text] correlation with CEC, and [Formula: see text] correlation with clay content. A pseudodielectric log of the remolded drill cuttings exhibited a weak correlation with downhole resistivity, gamma ray, and compressional slowness logs measured by a service company in the shaly sections of the well, but no correlation in the sandy section of the well. This attributed to better preservation of shaly cuttings due to finer microstructure and therefore less alteration during uphole transport and sample preparation.
Multidip tomography formulation for migration velocity analysis
Authors: Dafni Raanan , Reshef Moshe
Published: March 2015

We have developed a new approach for migration velocity analysis by ray-based reflection tomography, formulated according to more than a single dip direction. It is suggested to use a summation-free subsurface imaging system in the angle domain for generating multiparameter common image gathers through depth migration. Each gather associated with this system comprised dip-dependent opening-angle images contributed from the prestack data. Independent moveout information, coming from either a specular or nonspecular dip direction, was extracted inside these gathers to allow the entire scattered field to be involved in the velocity model optimization. By obeying the linear tomographic principle, a multidip tomography system was set to include imaging errors from specular and nonspecular directions. The updated velocity model was reconstructed by a least-squares inverse solution of the multidip tomographic equation system. Providing additional moveout from the migration’s dip, other than the specular one, was believed to be essential because the seismic data were misplaced in the image space while applying depth imaging by an erroneous velocity model. It might make the determination of a clear specular orientation, usually from the seismic image itself, misleading or ambiguous. The conversion of depth moveout into traveltime error along nonspecular rays was done according to an analytic mechanism, derived in the angle domain. The proposed analysis of migration errors by a multiple dip-angle orientation is demonstrated via the multidip tomography formulation by 2D synthetic and real data examples. It seems to be more efficient, as accurate and reliable as the conventional analysis, and to be better able to determine the ill-posed conditioning of the tomographic inversion.
Hummingbird flight stability and control in freestream turbulent winds
Authors: Ravi Sridhar , Crall James D. , McNeilly Lucas , Gagliardi Susan F. , Biewener Andrew A. , Combes Stacey A.
Published: March 2015

Airflow conditions close to the Earth's surface are often complex, posing challenges to flight stability and control for volant taxa. Relatively little is known about how well flying animals can contend with complex, adverse air flows, or about the flight-control mechanisms employed by animals to mitigate wind disturbances. Several recent studies have examined flight in the unsteady von Kármán vortex streets that form behind cylinders, generating flow disturbances that are predictable in space and time; these structures are relatively rare in nature, as they occur only the immediate, downstream vicinity of an object. In contrast, freestream turbulence is characterized by rapid, unpredictable flow disturbances across a wide range of spatial and temporal scales, and is nearly ubiquitous in natural habitats. Hummingbirds are ideal organisms for studying the influence of freestream turbulence on flight, as they forage in a variety of aerial conditions and are powerful flyers. We filmed ruby-throated hummingbirds (A. colubris) maintaining position at a feeder in laminar and strongly turbulent (intensity ∼15%) airflow environments within a wind tunnel, and compared their mean head, body, tail and wing kinematics, as well as variability in these parameters. Hummingbirds exhibited remarkably stable head position and orientation in both smooth and turbulent flow while maintaining position at the feeder. However, the hummingbird's body was less stable in turbulent flow and appeared to be most sensitive to disturbances along the mediolateral axis, displaying large lateral accelerations, translations, and rolling motions during flight. The hummingbirds mitigated these disturbances by increasing mean wing stroke amplitude and stroke plane angle, and by varying these parameters asymmetrically between the wings, and from one stroke to the next. They also actively varied the orientation and fan angle of the tail, maintaining a larger mean fan angle when flying in turbulent flow; this may improve their passive stability, but likely incurs an energetic cost due to increased drag. Overall, we observed many of the same kinematic changes noted previously for hummingbirds flying in a von Kármán vortex street, but we also observed kinematic changes associated with high force production, similar to those seen during load-lifting or high-speed flight. These findings suggest that flight may be particularly costly in fully mixed, freestream turbulence, the flow condition that hummingbirds are likely to encounter most frequently in natural habitats.
Predatory feeding behaviour in Pristionchus nematodes is dependent on a phenotypic plasticity and induced by serotonin
Authors: Wilecki Martin , Lightfoot James W. , Susoy Vladislav , Sommer Ralf J.
Published: March 2015

Behavioural innovation and morphological adaptation are intrinsically linked but their relationship is often poorly understood. In nematodes, a huge diversity of feeding morphologies and behaviours can be observed to meet their distinctive dietary and environmental demands. Pristionchus and their relatives show varied feeding activities consuming both bacteria and also predating other nematodes. In addition, Pristionchus nematodes display dimorphic mouth structures triggered by an irreversible developmental switch, which generates a narrower mouthed form with a single tooth and a wider mouthed form with an additional tooth. However, little is known about the specific predatory adaptations of these mouth forms nor the associated mechanisms and behaviours. Through a mechanistic analysis of predation behaviours, in particular in the model organism Pristionchus pacificus, we reveal multifaceted feeding modes characterised by dynamic rhythmic switching and tooth stimulation. This complex feeding mode switch is regulated by a previously uncharacterised role for the neurotransmitter serotonin, a process which appears conserved across several predatory nematode species. Furthermore, we investigated the effects of starvation, prey size and prey preference on P. pacificus predatory feeding kinetics revealing predation to be a fundamental component of the P. pacificus feeding repertoire thus providing an additional rich source of nutrition in addition to bacteria. Finally, we found that mouth form morphology also has a striking impact on predation suppressing predatory behaviour in the narrow mouthed form. Our results therefore hint at the regulatory networks involved in controlling predatory feeding and underscore P. pacificus as a model for understanding the evolution of complex behaviours.
Synchronized Self-assembly of a Fullerene Derivative Passing through a Programmable Microflow Field
Authors: Numata Munenori , Kozawa Tomohiro , Nakadozono Takuya , Sanada Yusuke , Sakurai Kazuo
Published: March 2015

To date, little attention has been paid to the positive control of the self-assemble process itself. Rapid activation and synchronous growth of PCBM, a kind of fullerene derivative, in a precisely controlled flow field led to the creation of various micrometer-sized sheet structures. Unlike the conventional vial mixing process, microflow always provides a reproducible chemical environment at the molecular level, overcoming the general difficulty in kinetically controlled self-assembly.
Effects of mutations on the molecular dynamics of oxygen escape from the dimeric hemoglobin of Scapharca inaequivalvis
Authors: Trujillo Kevin , Papagiannopoulos Tasso , Olsen Kenneth W.
Published: March 2015

Like many hemoglobins, the structure of the dimeric hemoglobin from the clamScapharca inaequivalvisis a “closed bottle” since there is no direct tunnel from the oxygen binding site on the heme to the solvent.  The proximal histidine faces the dimer interface, which consists of the E and F helicies.  This is significantly different from tetrameric vertebrate hemoglobins and brings the heme groups near the subunit interface. The subunit interface is also characterized by an immobile, hydrogen-bonded network of water molecules.  Although there is data which is consistent with the histidine gate pathway for ligand escape, these aspects of the structure would seem to make that pathway less likely. Locally enhanced sampling molecular dynamics are used here to suggest alternative pathways in the wild-type and six mutant proteins. In most cases the point mutations change the selection of exit routes observed in the simulations. Exit via the histidine gate is rarely seem although oxygen molecules do occasionally cross over the interface from one subunit to the other. The results suggest that changes in flexibility and, in some cases, creation of new cavities can explain the effects of the mutations on ligand exit paths.
The culture of scientific research
Authors: Joynson Catherine , Leyser Ottoline
Published: March 2015

In 2014, the UK-based Nuffield Council on Bioethics carried out a series of engagement activities, including an online survey to which 970 people responded, and 15 discussion events at universities around the UK to explore the culture of research in the UK and its effect on ethical conduct in science and the quality of research. The findings of the project were published in December 2014 and the main points are summarised here. We found that scientists are motivated in their work to find out more about the world and to benefit society, and that they believe collaboration, multidisciplinarity, openness and creativity are important for the production of high quality science. However, in some cases, our findings suggest, the culture of research in higher education institutions does not support or encourage these goals or activities. For example, high levels of competition and perceptions about how scientists are assessed for jobs and funding are reportedly contributing to a loss of creativity in science, less collaboration and poor research practices. The project led to suggestions for action for funding bodies, research institutions, publishers and editors, professional bodies and individual researchers.
Goal Setting and Monetary Incentives: When Large Stakes Are Not Enough
Authors: Corgnet Brice , Gómez-Miñambres Joaquín , Hernán-González Roberto
Published: March 2015

The aim of this paper is to test the effectiveness of wage-irrelevant goal-setting policies in a laboratory environment. In our design, managers can assign a goal to their workers by setting a certain level of performance on the work task. We establish our theoretical conjectures by developing a model in which assigned goals act as reference points to workers’ intrinsic motivation. Consistent with our model, we find that managers set goals that are challenging but attainable for a worker of average ability. Workers respond to these goals by increasing effort and performance and by decreasing on-the-job leisure activities with respect to the no-goal-setting baseline. Finally, we study the interaction between goal setting and monetary rewards and find, in line with our theoretical model, that goal setting is most effective when monetary incentives are strong. These results suggest that goal setting may produce intrinsic motivation and increase workers’ performance beyond what is achieved by using solely monetary incentives.

Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2014.2068 .

This paper was accepted by Uri Gneezy, behavioral economics.
‘I will make a difference’–training caregivers to improve the hearing of adults with learning disabilities
Authors: McShea Lynzee
Published: March 2015

People with learning disabilities are at a higher risk of hearing loss, but are less likely to have this diagnosed or managed. Although the reasons are varied, poor caregiver awareness is commonly mentioned. Training has often been suggested as a method to increase knowledge, although there are few studies in the literature, and it has been difficult to demonstrate change to practice as a result of training.

This project worked with caregivers collaboratively, to design and implement training to meet their needs and the needs of those they support. The result was an increase in knowledge and a transformation of knowledge to action. Although this meant some individuals were referred to secondary care, it also highlighted certain barriers in primary care that must now be investigated.
Shaping the future assistant/associate practitioner workforce: a Hampshire case study
Authors: Knight Anneyce , Parker Jan , Carmichael Helen , Esser Anita , Aspden Clare
Published: March 2015

This case study looks at the two-year, full-time-equivalent foundation degree (science) in health and social care (FdScH&SC), initially developed in partnership between University Hospital Southampton NHS Foundation Trust and Southampton Solent University, Hampshire, UK.

The aim of this collaborative initiative is to develop healthcare support workers to gain and apply the required knowledge, skills, values and behaviours to care for patients/families/other service users and relatives in complex clinical situations, within the emerging role descriptors of an assistant/associate practitioner (AP), often within a specialist/specified context.

Since the initial cohort of students began in January 2012, the foundation degree now has over 100 students/healthcare support workers (HCSWs) across the two years and is being delivered in partnership with an increasing number of NHS trusts.

This paper will discuss the innovative and unique features of this foundation degree in health and social care, including the collaborative model of its curriculum design, delivery and management.
Thermographic mapping of the abdomen in healthy subjects and patients after enterostoma
Authors: Siah C.J.R. , Childs C.
Published: March 2015

Objective:

Heat is a sign and symptom of surgical wound infection in wound assessment criteria but there is currently no diagnostic tool being used in clinical practice to assess the skin temperature of surgical wounds. Using thermal imaging, the objective of this study was to map the temperature of the healing surgical wound and to provide confirmatory data of: a) optimum IR imaging distance from skin temperature target field of view (FOV) b) body composition effects on abdominal skin surface temperature readings c) thermal mapping characteristics of infected versus non-infected wounds post stoma-closure.

Method:

The abdominal skin surface temperature of healthy, afebrile subjects was measured under controlled, ambient conditions in a small (240cm x 320cm) clinical room. Subject standing positions were 30cm, 60cm and 100cm from the IR camera. Abdominal skin surface temperature and thermal imaging maps were acquired in a population of surgical patients before and after closure of enterostoma.

Results:

Subjects (30) aged 19–52 (median=29) years were recruited. At a distance of 100cm, each of nine anatomical regions showed a decrease in mean temperature as BMI increased. Subjects with BMI >25 had lower mean abdominal temperatures. Statistically significant differences were observed for right hypochondrium (p=0.022), left lumbar region (p=0.009), right lumbar region (p=0.010) and the umbilical region (p=0.021). Half of patients (5/10) developed surgical wound infection.

Conclusion:

Within the operating distances investigated, no significant effect on abdominal temperature readings was observed. With increasing BMI, lower abdominal temperatures were noted. The thermal pattern of abdominal surgical wounds reveals some differences between the healing and infected wound. Healing wounds showed changes in the thermal ‘map’; an increase in temperature on the first post-operative day, and ‘warming’ over the subsequent five days. ‘Cold spots’ emerged on the thermogram of the surgical wounds which subsequently were shown to be infected. Within the setting of a clinical environment, distances up to 100cm did not significantly alter skin temperature readings within the FOV. There is a suggestion that body composition influences skin temperature. Infected surgical wounds appear ‘colder’ than healing wounds.

Declaration of interest:

The authors have no conflict or interest. The work was supported by a grant from the SingHealth Foundation.
Comparative study of two antimicrobial dressings in infected leg ulcers: a pilot study
Authors: Mosti G. , Magliaro A. , Mattaliano V. , Picerni P. , Angelotti N.
Published: March 2015

Objective:

The aim of the study was to compare the efficacy of a microorganism-binding (MB) dressing with a silver-containing hydrofiber (SCH) dressing in controlling the bacterial loads of heavily colonised or locally infected chronic venous leg ulcers, before surgical management with homologous skin grafts.

Method:

A randomised comparative single centre study recruited patients presenting with hard-to-heal critically colonised or locally infected leg ulcers, who could be treated with skin grafting. Inclusion criteria included; ulcers of vascular aetiology, over 18 years old, a wound duration ≥6 months and ankle brachial index (ABPI) >0.6. Patients were randomly assigned to treatment with SCH dressings (Aquacel Ag) or MB dressing (Cutimed Sorbact). Dressings were changed daily over a four-day observation period, after which they were taken for a skin grafting procedure. Swab samples from ulcer beds were taken in order to quantify the bacterial load at inclusion (D0) and at the end of the observation period day 4 (D4). No antibiotics were administered before or during the evaluation period.

Results:

Both groups (n=20 SCH, n=20 MB) were similar in gender, age, pathophysiology (both had 15 patients with venous leg ulcers and 5 with arterial leg ulcers), ulcer surface, ulcer duration, treatment-related pain and initial bacterial load. Analysing bacterial load variation showed a significant reduction of bacterial burden at D4 in both groups. In the SCH group, we found an average bacterial load reduction of 41.6%, with an average reduction of 73.1% in the MB group (p< 0.00001). No serious adverse events were reported.

Conclusion:

Our evaluation confirmed that MB and SCH dressings are effective in reducing the bacterial burden in critically colonised or locally infected chronic leg ulcers, without inducing adverse events, with MB dressings significantly more effective.

Declaration of interest:

There were no external sources of funding for this study. The authors have no conflicts of interest to declare.
Comparison of lipidocolloid and chlorhexidine-impregnated tulle gras dressings following microscopically controlled surgery
Authors: Hessam S. , Georgas D. , Sand M. , Kassa T. , Bruns N. , Bechara F.G.
Published: March 2015

Objective:

Modified microscopically controlled surgery (MCS) is a staged and margin-controlled excision; after MCS, the selection of an appropriate initial wound dressing plays an important role in wound healing. A wide range of dressings is available for temporary wound coverage; however, data comparing different types of wound dressings after MCS are lacking. The aim of this study was to compare two commonly used and commercially available types of wound dressings.

Method:

We assessed pain levels, wound adherence, bleeding upon dressing removal and signs of infection, with chlorhexidine-impregnated tulle gras and a lipidocolloid dressing used for primary wound dressing following MCS.

Results:

A total of 42 patients were included. Adherence of the dressing to the wound (p<0.001) and bleeding after removal (p=0.001) were significantly higher in the chlorhexidine-impregnated tulle gras dressing group. Pain during removal of wound dressing had a higher visual analogue scale score (1.9 ± 2.2) in the chlorhexidine-impregnated tulle gras dressing group compared to 0.7 ± 1.0 in the lipidocolloid dressing group (p=0.022).

Conclusion:

The results indicate that the lipidocolloid dressing, when compared with the chlorhexidine-impregnated tulle gras dressing, offers a significant benefit during removal in terms of less pain, less wound adherence and less wound bleeding.

Declaration of interest:

The authors have no conflict of interest to declare.
Safety and efficacy of active Leptospermum honey in neonatal and paediatric wound debridement
Authors: Amaya R.
Published: March 2015

Objective:

Safety is a critically important factor in the selection of products used in neonatal and paediatric wound care. Given the lack of standardisation of neonatal and paediatric wound care protocols, the goal of this study was to present data on the safety and efficacy of active Leptospermum honey (ALH) in this patient population.

Method:

A multicentre, retrospective chart review was conducted at eight inpatient facilities and one outpatient clinic between October 2011 and March 2014. The number of applications of ALH, adverse events, and the success of debridement and wound healing were recorded.

Results:

Data were collected on 115 neonatal and paediatric patients, with 121 wounds requiring debridement, treated with ALH. Patients were treated for an average of 18.7 days. ALH was well tolerated, with two (1.7%) patients reporting adverse events involving a transient stinging sensation on application, which did not prohibit additional applications of ALH. Successful debridement was achieved in 86.0% (104 wounds), and 77.7% (94 wounds) were successfully closed using nonsurgical intervention. Outcomes in neonates were similar to the overall paediatric population, with 86.1% (31/36) wounds successfully debrided with no adverse events. In a subset of six patients with available pre- and post-treatment data, no clinically meaningful changes in white blood cell counts or glucose levels were associated with the initiation of treatment with ALH.

Conclusion:

The results of this study support ALH as a safe and effective treatment option in this group of patients.

Declaration of interest:

This study was supported by a grant from Derma Sciences (Princeton, NJ USA). Dr Amaya is a paid speaker for Derma Sciences.
Going Public: How Stock Market Listing Changes Firm Innovation Behavior
Authors: Wies Simone , Moorman Christine
Published: March 2015

Although going public allows firms access to more financial capital that can fuel innovation, it also exposes them to a set of myopic incentives and disclosure requirements that constrain innovation. This tension is expected to produce a unique pattern of innovation strategies among firms going public, causing such firms to increase their innovation levels but reduce their innovation riskiness. Specifically, the authors predict that after going public, firms innovate at higher levels and introduce higher levels of variety with each innovation; however, these innovations are less risky, characterized by fewer breakthrough innovations and fewer innovations in new-to-the-firm categories. The authors compare 40,000 product introductions in the period 1980–2011 from a sample of consumer packaged goods firms that went public with a benchmark sample of firms that remained private, and the results support their predictions. Utilizing tests to resolve questions about endogeneity, including self-selection, reverse causality, and competing explanations, the authors demonstrate that initial public offering selection and dynamics do not drive this going-public effect. The authors also uncover a set of industry factors that mitigate the drop in breakthrough innovation by offering product-market incentives that counterbalance the documented effect of stock market incentives.
Mystische Reimverse mit Kommentar
Authors: Gottschall Dagmar
Published: March 2015

The paper presents mystical rhyme verses preserved on page 153a–b of the manuscript Einsiedeln, Stiftsbibliothek, Cod. 278 from the 14th century. The verses, which have never been discussed before, follow the preceding mystical poem ›Ein meister der seit vns das wesen blos‹ in terms of content. However, they are separated from the poem by two aphorisms in prose attributed to a master. In the following paper the newly found rhyme verses are edited and interpreted in the context of the poem ›Ein meister der seit vns das wesen blos‹ and the two aphorisms of the master.
A method for stereoscopic strain analysis of the right ventricle by digital image correlation during coronary bypass surgery: short communication
Authors: Mirow Nikolas , Hokka Mikko , Nagel Horst , Irqsusi Marc , Moosdorf Rainer G. , Kuokkala Veli-Tapani , Vogt Sebastian
Published: March 2015

Perioperative cardiosurgical management of volume therapy remains one of the challenging tasks in cases of patients with severe heart disease. Early detection of congestive cardiac failure prevents subsequent low output and worse outcome. An effective method for controlling extracorporeal circulation is created by developing a non-invasive intraoperative method for right ventricular strain analysis through digital image contrast correlation.
Elevations of inflammatory markers PTX3 and sST2 after resuscitation from cardiac arrest are associated with multiple organ dysfunction syndrome and early death
Authors: Ristagno Giuseppe , Varpula Tero , Masson Serge , Greco Marta , Bottazzi Barbara , Milani Valentina , Aleksova Aneta , Sinagra Gianfranco , Assandri Roberto , Tiainen Marjaana , Vaahersalo Jukka , Kurola Jouni , Barlera Simona , Montanelli Alessandro , Latini Roberto , Pettilä Ville , Bendel Stepani , Skrifvars Markus B. , for the FINNRESUSCI Study Group
Published: March 2015

A systemic inflammatory response is observed after cardiopulmonary resuscitation. We investigated two novel inflammatory markers, pentraxin 3 (PTX3) and soluble suppression of tumorigenicity 2 (sST2), in comparison with the classic high-sensitivity C-reactive protein (hsCRP), for prediction of early multiple organ dysfunction syndrome (MODS), early death, and long-term outcome after out-of-hospital cardiac arrest.

PTX3, sST2, and hsCRP were assayed at ICU admission and 48 h later in 278 patients. MODS was defined as the 24 h non-neurological Sequential Organ Failure Assessment (SOFA) score ≥12. Intensive care unit (ICU) death and 12-month Cerebral Performance Category (CPC) were evaluated.

In total, 82% of patients survived to ICU discharge and 48% had favorable neurological outcome at 1 year (CPC 1 or 2). At ICU admission, median plasma levels of hsCRP (2.8 mg/L) were normal, while levels of PTX3 (19.1 ng/mL) and sST2 (117 ng/mL) were markedly elevated. PTX3 and sST2 were higher in patients who developed MODS (p<0.0001). Admission levels of PTX3 and sST2 were also higher in patients who died in ICU and in those with an unfavorable 12-month neurological outcome (p<0.01). Admission levels of PTX3 and sST2 were independently associated with subsequent MODS [OR: 1.717 (1.221–2.414) and 1.340, (1.001–1.792), respectively] and with ICU death [OR: 1.536 (1.078–2.187) and 1.452 (1.064–1.981), respectively]. At 48 h, only sST2 and hsCRP were independently associated with ICU death.

Higher plasma levels of PTX3 and sST2, but not of hsCRP, at ICU admission were associated with higher risk of MODS and early death.
Active Noise Control Experiments using Sound Energy Flu
Authors: Krause Uli
Published: March 2015

This paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.
A Novel Anti-Stealth Technique Based on Stratospheric Balloon-Borne Radar in Heterogeneous Environments
Authors: Barbary Mohamed , Zong Peng
Published: March 2015

Radar cross section (RCS) of a stealth target model like F-117A can be improved by multichannel stratospheric balloon-borne bistatic radar at higher aspect angle. The potential problem is that the stealth target may produce range walk in clutter heterogeneous environments, thus it is difficult to determine the range ambiguity under quadratic range cell migration (QRCM). In this paper, a novel detection technique known as hybrid modified fractional-radon Fourier transform (MFrRFT) and knowledge-aided space–time adaptive processes (KA-STAP) is proposed to impact this kind of problem simultaneously. KA-STAP is applied to suppress the non-homogeneous clutter in the received data, and MFrRFT is used to eliminate the QRCM along with the second-order keystone transform (SOKT), so as to estimate the range ambiguity and compensate the stealth target’s range walk. The hybrid MFrRFT/KA-STAP scheme is simple and applicable to the small RCS of fast stealth target with a long-time coherent integration. Finally, to achieve high accuracy of locating stealth target, a non-parametric detection technique based on Legendre orthogonal polynomials is applied to reconstruct the probability density function (pdf) of real RCS data predicted by physical optics (PO) approximation method.
Experimental Tests with Rice Straw on a Conical Square-Based Spouted Bed Reactor
Authors: Moliner Cristina , Curti Massimo , Bosio Barbara , Arato Elisabetta , Rovero Giorgio
Published: March 2015

A spouting bed reactor using rice straw as feedstock for further gasification purposes was studied in the present work. Experimental fluid dynamic tests were carried out in a conical square-based spouted bed reactor using a mixture of straw and silica, the latter acting as inert material. The influence of the initial bed of particles and the presence of coarse particles in the mixture on the pressure drop and minimum spouting velocity were evaluated. As a result, lower values of pressure drop along the bed were found compared to conventional fluidisation processes. Higher initial bed heights and higher percentage of straw in the mixture resulted in higher values of pressure drop and minimum spouting velocity. A new correlation for a cross section spouted bed reactor was proposed for the prediction of the minimum spouting velocity.
All-Fiber Linearly Polarized Wavelength-Selectable Yb3+-Doped Double-Clad Fiber Laser Yielding Green Second Harmonics
Authors: Huang Q. J. , Feng D. J. , Ji W.
Published: March 2015

An all-fiber linearly polarized Yb
The Last Decade of Digital Preservation: A Personal View from Australia
Authors: Harvey Ross
Published: March 2015

In 2003 an international survey described digital preservation in Australia in these words: “For a country with a relatively small population, Australia has a relatively large number of leading-edge online projects across all sectors.” Is this still the case in 2014? This paper gives a personal view of the current state of digital preservation in Australia and examines what we have learned since 2003 to answer this question; it then notes what we still need to learn about digital preservation-in particular, the activities of the National Library of Australia and of the key roles that research and collaboration play in digital preservation are noted.
Bond-Fatigue Behavior of Bonded Concrete Overlay
Authors: Kim Young Kyu , Lee Seung Woo
Published: March 2015

Bonded concrete overlays have a structural advantage over unbonded concrete overlays when the overlay and the existing pavement layer behave as a monolithic layer. Therefore, it is important to ensure suitable bond strength between the two layers. Many studies have specified the bond-strength criteria for the construction of bonded concrete overlays based on a monotonic load as pull off test. However, cyclic stress at the interface of bonded concrete overlay layer occurs by the repetition of traffic loading and environmental loading caused by daily temperature changes. In this study, a strategic test procedure is developed to investigate potential bond failures caused by cyclic loading, and a bond-fatigue equation for a bonded concrete overlay was suggested. The test results indicate that early distress in bonded concrete overlay may arise because of a bond failure if the bond stress at the interface exceeds 90 % of the bond strength.
Investigation of the Impact of Increasing Design Loads of a Conventional Structural Silicone Joint Using Finite Element Analysis and Hyperelastic Material Properties
Authors: Kimberlain Jon , Knowles John A.
Published: March 2015

Design methodology for structural silicone glazed curtain wall assembly has been well established for many decades with proven performance of building projects around the globe. At its core, the design methodology is based on the individual performance of the materials, and the assembly is designed using physical and geometric principles to perform within an expected load and deflection which usually are confirmed via experiential confirmation via mock-up assemblies. Structural silicone performance and allowable design stress is based on physical relationships of stress due to the strain of a proto-typical joint. There has been recent interest in exploring increased or modified design stress of sealants based on similar methodology. However, the challenge in the methodology is that silicone materials behave as hyperelastic elastomers which indicate that the relationship of stress versus strain is not linear and the materials behave with different moduli depending on the location of the allowable stress on the stress–strain curve. Using finite element models, the paper presents a comparative analysis of a structural silicone joint designed via the conventional hand calculation at different design loads. The analysis illustrates the higher potential stress peaks developed within the sealant during loading versus the expected stress from the conventional method of calculation. Frame deflection and glass thickness were also factored to understand the variables’ impact to the distribution of stresses in the sealant joint compared to the original stress predicted from conventional methods of design. Methods to calibrate the actual material model used in the finite element software for hyperelastic materials are also presented. Physical assemblies were tested to compare the results of the software model, which also includes a modified test procedure to better understand the durability of the materials due to cyclical testing.
Aqueous Alteration in Martian Meteorites
Authors: Velbel Michael A.
Published: March 2015

Many of the minerals observed or inferred to occur in the sediments and sedimentary rocks of Mars, from a variety of Mars-mission spacecraft data, also occur in Martian meteorites. Even Martian meteorites recovered after some exposure to terrestrial weathering can preserve preterrestrial evaporite minerals and useful information about aqueous alteration on Mars, but the textures and textural contexts of such minerals must be examined carefully to distinguish preterrestrial evaporite minerals from occurrences of similar minerals redistributed or formed by terrestrial processes. Textural analysis using terrestrial microscopy provides strong and compelling evidence for preterrestrial aqueous alteration products in a number of Martian meteorites. Occurrences of corroded primary rock-forming minerals and alteration products in meteorites from Mars cover a range of ages of mineral–water interaction, from ca. 3.9 Ga (approximately mid-Noachian), through one or more episodes after ca. 1.3 Ga (approximately mid–late Amazonian), through the last half billion years (late Amazonian alteration in young shergottites), to quite recent. These occurrences record broadly similar aqueous corrosion processes and formation of soluble weathering products over a broad range of times in the paleoenvironmental history of the surface of Mars.

Many of the same minerals (smectite-group clay minerals, Ca-sulfates, Mg-sulfates, and the K-Fe–sulfate jarosite) have been identified both in the Martian meteorites and from remote sensing of the Martian surface. This suggests that both kinds of samples—Martian meteorites and Mars’ surface rocks, regolith, and soils—were altered under broadly similar conditions. Temporarily and locally occurring but likely stagnant aqueous solutions reacted quickly with basaltic/mafic/ultramafic minerals at low water–rock ratios. Solutes released by primary mineral weathering precipitated locally on Mars as cation-rich clays and evaporite minerals, rather than being leached away, as on Earth.

The main secondary host minerals for Fe differ between Martian meteorites and Mars’ surface materials. In Martian meteorites, sideritic–ankeritic carbonate is the predominant secondary host mineral for Fe, whereas in Mars’ surface materials, ferric oxides and ferric sulfates are the predominant secondary host minerals for Fe. Differences in the initial compositions of the altering solutions are implied, with carbonate/bicarbonate dominating in the solutions that altered Martian meteorites, and sulfate dominating the solutions that altered most Mars’surface materials. During impact on and ejection from Mars, Martian meteorites may have been exhumed from depths sufficient to have isolated them from large quantities of Mars’surface solutions. Pre-ejection weathering of the basaltic rocks occurred in grain-boundary fracture microenvironments at high pH values in aqueous solutions buffered by reactions with basalt minerals.
Duststones on Mars
Authors: Bridges Nathan T. , Muhs Daniel R.
Published: March 2015

Dust is an abundant material on Mars, and there is strong evidence that it is a contributor to the rock record as “duststone,” analogous in many ways to loess on Earth. Although a common suite of dust formation mechanisms has operated on the two planets, fundamental differences in environments and geologic histories have resulted in vastly different weighting functions, causing distinct depositional styles and erosional mechanisms. On Earth, dust is derived predominantly from glacial grinding and, in nonglacial environments, by other processes, such as volcanism, eolian abrasion, and fluvial comminution. Hydrological and biological processes convert dust accumulations to loess deposits. Active hydrology also acts to clean dust from the atmosphere and convert loess into soil or erode it entirely. On Mars, glacial production of dust has been minor, with most fine particles probably produced from ancient volcanic, impact, and fluvial processes. Dust is deposited under arid conditions in which aggregate growth and cementation are the stabilizing agents. Thick accumulations result in duststone.
Focusing the Search for Biosignatures on Mars
Authors: Oehler Dorothy Z. , Allen Carlton C.
Published: March 2015

The search for martian biosignatures can be enhanced by focusing exploration on locations most likely to contain organic-rich shales. Such shales both concentrate and preserve organic matter and are major repositories of organic geochemical biomarkers in sediments of all ages on Earth. Moreover, it has been suggested that for Mars, accumulations of organic matter may be the most easily detected and least ambiguous of possible biosignatures (Summons et al. 2010). Since current surface conditions on Mars are unfavorable for preservation of organic matter, focusing exploration on locations predicted to contain ancient organic-rich shales would offer one of the best chances of detecting evidence of life—if it ever evolved on the planet.

Orbital data can be used to evaluate regional sediment sources and sinks on Mars, and, based on that, facies can be predicted and locations identified that are most likely to contain organic-rich sediments. An example is presented from Acidalia Planitia, in the martian lowlands, where this approach led to the conclusion that facies in southern Acidalia were likely to be dominated by fine-grained, muddy sediments. That conclusion added weight to the hypothesis that mounds in Acidalia are martian versions of mud volcanoes as well as the suggestion that organic materials, if present, would have been deposited in the same area as the mounds. This allowed speculation that potential mud volcano clasts in Acidalia could include preserved, organic biosignatures and, thus, that the mounds in Acidalia constitute an untested class of exploration target for Mars.

Facies prediction using orbital data is particularly applicable to planetary exploration where ground truth is most often lacking but orbital data sets are increasingly available. This approach is well suited to the search for potential geochemical biomarkers in organic-rich shales. The approach additionally could be applied to exploration for other categories of biosignatures (such as stromatolites or morphologically preserved microfossils) and to more general planetary objectives, such as the search for hydrothermal sediments, carbonates, or any particular type of geologic deposit.
Stratigraphic Architecture of Bedrock Reference Section, Victoria Crater, Meridiani Planum, Mars
Authors: Edgar Lauren A. , Grotzinger John P. , Hayes Alex G. , Rubin David M. , Squyres Steve W. , Bell James F. , Herkenhoff Ken E.
Published: March 2015

The Mars Exploration Rover Opportunity has investigated bedrock outcrops exposed in several craters at Meridiani Planum, Mars, in an effort to better understand the role of surface processes in its geologic history. Opportunity has recently completed its observations of Victoria crater, which is 750 m in diameter and exposes cliffs up to ∼15 m high. The plains surrounding Victoria crater are ∼10 m higher in elevation than those surrounding the previously explored Endurance crater, indicating that the Victoria crater exposes a stratigraphically higher section than does the Endurance crater; however, Victoria strata overlap in elevation with the rocks exposed at the Erebus crater. Victoria crater has a well-developed geomorphic pattern of promontories and embayments that define the crater wall and that reveal thick bedsets (3–7 m) of large-scale cross-bedding, interpreted as fossil eolian dunes. Opportunity was able to drive into the crater at Duck Bay, located on the western margin of Victoria crater. Data from the Microscopic Imager and Panoramic Camera reveal details about the structures, textures, and depositional and diagenetic events that influenced the Victoria bedrock. A lithostratigraphic subdivision of bedrock units was enabled by the presence of a light-toned band that lines much of the upper rim of the crater. In ascending order, three stratigraphic units are named Lyell, Smith, and Steno; Smith is the light-toned band. In the Reference Section exposed along the ingress path at Duck Bay, Smith is interpreted to represent a zone of diagenetic recrystallization; however, its upper contact also coincides with a primary erosional surface. Elsewhere in the crater the diagenetic band crosscuts the physical stratigraphy. Correlation with strata present at nearby promontory Cape Verde indicates that there is an erosional surface at the base of the cliff face that corresponds to the erosional contact below Steno. The erosional contact at the base of Cape Verde lies at a lower elevation, but within the same plane as the contact below Steno, which indicates that the material above the erosional contact was built on significant depositional paleotopography. The eolian dune forms exposed in Duck Bay and Cape Verde, combined with the geometry of the erosional surface, indicate that these outcrops may be part of a larger-scale draa architecture. This insight is possible only as a result of the larger-scale exposures at Victoria crater, which significantly exceed the more limited exposures at the Erebus, Endurance, and Eagle craters.
Fit-For-Purpose Acoustic Cement Evaluation Using Logging While Drilling in Deepwater
Authors: Fuller George Allen , Gupta Nadish , Blyth Matthew , Aparicio Alfredo
Published: March 2015

Cement evaluation is a critical part of a cementing operation. Recent industry events and the continuous tightening of regulations for cement placement have elevated the importance of cement evaluation to heights greater than ever. The initial verification of a primary cement job is performed using the pressure trend obtained while pumping, because the pressure increases as the cement rises in the annulus. The actual pressure trend can then be compared with the expected pressure to infer the actual cement height in the annulus; however, this methodology can only predict but not confirm the top of cement (TOC). In deepwater, the regulatory agencies may require physical evaluation of TOC in specific strings of the well that can require running cement bond log (CBL) tools for those strings. This would use the critical path time for every CBL run. In addition, this regulatory agency requirement can also be technically challenging because cement bond evaluation for casing as large as 18-in. that is placed in a 22-in. open hole is the upper threshold limit for conventional wireline conveyed CBL tools. Many operators are now runing logging-while-drilling (LWD) sonic tools for open hole compressional data. Using the same sonic tools, logging can be performed through the casing strings on the same run and the results can be analyzed to confirm the TOC. The data presented here seems to show that the results agreed well with the predicted TOC from the pumping data. The use of this tool for cement evaluation was further validated against CBL evaluation that was performed on deeper strings in example deepwater exploration wells. The paper will elaborate on how the integration of this technology can provide precise TOC evaluation and save the operators considerable rig time per section.