bluuebunny/crossref_metadata_2025 huggingface dataset:
Brazilian version of the Care Transitions Measure: translation and validation
Authors: Acosta A.M. , Lima M.A.D.S. , Marques G.Q. , Levandovski P.F. , Weber L.A.F.
Published: October 2016

Aim

To translate, adapt and evaluate psychometric properties of the complete (15 items) and reduced (three items) versions of the Care Transitions Measure into Brazilian Portuguese.

Introduction

The Care Transitions Measure assesses the quality of care transitions, from the perspective of patients. As accomplishing effective transitions is a challenge to healthcare systems, the instrument provides an opportunity to assess care transitions and improve quality initiatives.

Methods

A three‐phased design was used for cross‐cultural adaptation, pre‐testing and evaluation of psychometric properties of the measurement in a Brazilian hospital. After forward translation, back translation and expert committee review, patients evaluated the instrument in a pre‐test. Psychometric testing included face and content validity, reliability, stability and factorial analysis.

Results

Cross‐cultural adaptation was completed successfully with a high clarity rate. Internal consistency was good in the 15‐item version and was moderate in the three‐item version. Test–retest reliability showed good stability of the two versions over time. The three‐item version had satisfactory criterion validity. Four factors were extracted for the 15‐item measure.

Limitations

Samples were restricted to a group of patients from one hospital in southern Brazil. Future studies should test the measurement's construct and predictive validity.

Conclusions

The translated version of the Care Transitions Measure has good face and content validity, reliability and stability. It has shown to be a valid measurement for evaluating the quality of care transitions in Brazil.

Implications for nursing and health policy

Results are beneficial for nurses, managers and policy makers for evaluating care transitions and support the need for changes in policies and practices.
Drought Priming at Vegetative Growth Stage Enhances Nitrogen‐Use Efficiency Under Post‐Anthesis Drought and Heat Stress in Wheat
Authors: Liu S. , Li X. , Larsen D. H. , Zhu X. , Song F. , Liu F.
Published: October 2016

To study the effects of early drought priming at 5th‐leaf stage on grain yield and nitrogen‐use efficiency in wheat (Triticum aestivum L.) under post‐anthesis drought and heat stress, wheat plants were first exposed to moderate drought stress (drought priming; that is, the leaf water potential reached ca. −0.9 MPa) at the 5th‐leaf stage for 11 days, and leaf water relations and gas exchange rates, grain yield and yield components, and agronomic nitrogen‐use efficiency (ANUE) of the primed and non‐primed plants under post‐anthesis drought and heat stress were investigated. Compared with the non‐primed plants, the drought‐primed plants possessed higher leaf water potential and chlorophyll content, and consequently a higher photosynthetic rate during post‐anthesis drought and heat stress. Drought priming also resulted in higher grain yield and ANUE in wheat under post‐anthesis drought and heat stress. Drought priming at vegetative stage improves carbon assimilation and ANUE under post‐anthesis drought and heat stress and their combination in wheat, which might be used as a field management tool to enhance stress tolerance of wheat crops to multiple abiotic stresses in a future drier and warmer climate.
A comparison of race‐related pain stereotypes held by White and Black individuals
Authors: Hollingshead Nicole A. , Meints Samantha M. , Miller Megan M. , Robinson Michael E. , Hirsh Adam T.
Published: October 2016

Pain judgments are the basis for pain management. The purpose of this study was to assess Black and White participants' race‐related pain stereotypes. Undergraduates (n = 551) rated the pain sensitivity and willingness to report pain for the typical Black person, White person, and themselves. Participants, regardless of race, rated the typical White person as being more pain sensitive and more willing to report pain than the typical Black person. White participants rated themselves as less sensitive and less willing to report pain than same‐race peers; however, Black participants rated themselves as more pain sensitive and more willing to report pain than same‐race peers. These findings highlight similarities and differences in racial stereotypic pain beliefs held by Black and White individuals.
Parent birds assess nest predation risk: influence of cavity condition and avian nest predator activity
Authors: Yoon Jongmin , Jung Jung‐Shim , Joo Eun‐Jin , Kim Byung‐Su , Park Shi‐Ryong
Published: October 2016

Skutch hypothesized that nest predators visually assess parental activities to locate a prey nest, whereas parents modify fitness‐related traits to reduce the probability of nest predation. We examined how cavity condition and parental activity interact with avian nest predators to shape the nest success of two coexisting parid species, marsh titsPoecile palustrisand oriental titsParus minor, breeding in nest‐boxes during the incubation period. Nest‐boxes were manipulated to create a prolonged risk of nest predation (entrance diameter 2.6 cm control vs 5.5 cm treatment) soon after clutch completion. To measure changes in parental behavior, we also simultaneously simulated a pulsed risk of nest predation, using sound playbacks of a coexisting control bird and an avian nest predator. We found that the parent tits merely responded the pulsed risk, presumably due to an environment with high avian nest predator encounters, compared to the prolonged risk. Instead, both species spent more time on vigilance at the nest, only under prolonged risk conditions. The activity of corvids near the nest‐box was higher in the marsh tit than that in oriental tits. This activity was also higher in the treatment nest box than that in the control nest‐box. Nest predation during the incubation period was higher in marsh tits than in oriental tits, presumably due to higher and more plastic vigilance in oriental tits, compared to marsh tits. Our results highlight that the differences in cavity condition and parental activities at the nests of two coexisting non‐excavators may contribute to differential nest predation by attracting avian nest predators.
Interisland gene flow among populations of the buff‐banded rail (Aves: Rallidae) and its implications for insular endemism in Oceania
Authors: Garcia‐R Juan C. , Joseph Leo , Adcock Greg , Reid Julian , Trewick Steven A.
Published: October 2016

Studies of fragmented habitat, such as island archipelagos, provide insights into the microevolutionary processes that drive early stages of diversification. Here, we examined genetic variation and gene flow among populations of the widespread buff‐banded rail Gallirallus philippensis in Oceania to understand the factors that promote speciation associated within this bird lineage. We analysed mtDNA Control Region sequences and six microsatellite loci from a total of 152 individuals of buff‐banded rail on islands and continental areas. We used a phylogeographic model‐testing approach and a structured spatial design ranging from within to among archipelagoes in the south Pacific. Buff‐banded rail populations in the Philippines archipelago and nearby Palau and Wallacea had high genetic diversity while those in geographically distant Australia showed lower variation. Other archipelagos sampled were found to have less genetic diversity and included haplotypes closely related to Wallacea (Bismarck, Vanuatu, New Caledonia) or Australia (New Zealand, Samoa, Fiji, Cocos Islands). Nucleotide diversity and allele frequency declined with degree of geographic isolation but haplotype diversity remained more even. However, both nucleotide and haplotype diversities were positively correlated with land area. Microsatellite data for a subset of locations showed moderate to high genetic differentiation and significant pairwise FST despite a relatively high migration rate. Our results are mostly consistent with a model of abrupt genetic changes due to founder events with multiple dispersals into Australia from Wallacea and Bismarck. Australia has probably been the source of birds for islands in the Pacific. This is shown by decreasing genetic diversity and growing genetic differentiation when distances separating populations increased from Australia. A history of range expansion and divergent natural selection may help explain the existence of numerous sympatric Gallirallus island endemics.
Genetic structure of West Greenland populations of lumpfish Cyclopterus lumpus
Authors: Garcia‐Mayoral E. , Olsen M. , Hedeholm R. , Post S. , Nielsen E. E. , Bekkevold D.
Published: October 2016

In this study, 11 microsatellite markers were used to determine the structure of West Greenlandic lumpfish Cyclopterus lumpus populations across six spawning locations spanning >1500 km and compared with neighbouring populations in Canada and Iceland. To evaluate whether data allow for identification of origin of C. lumpus in Greenlandic waters, genetic assignment analysis was performed for 86 C. lumpus sampled on a feeding migration. Significant structuring with isolation by distance was observed in the West Greenland samples and two major subpopulations, north and south, were suggested. Based on FST values, closer relationships were observed between Greenland and Canada, than Greenland and Iceland. Surprisingly, the North Greenland population showed more similarities with Canadian samples, than did the geographically closer south‐west Greenland population. Origin could be assigned for a high proportion of non‐spawning fish and demonstrated a marked east–west spatial separation of fish of Greenlandic and Icelandic genotypes.
Dynamics of Saxothuringian subduction channel/wedge constrained by phase‐equilibria modelling and micro‐fabric analysis
Authors: Collett S. , Štípská P. , Kusbach V. , Schulmann K. , Marciniak G.
Published: October 2016

Subduction and exhumation dynamics can be investigated through analysis of metamorphic and deformational evolution of associated high‐grade rocks. The Erzgebirge anticline, which forms at the boundary between the Saxothuringian and Teplá‐Barrandian domains of the Bohemian Massif, provides a useful study area for these processes owing to the occurrence of numerous meta‐basites preserving eclogite facies assemblages, and coesite and diamond bearing quartzofeldspathic lithologies indicating subduction to deep mantle depths. The prograde and retrograde evolution of meta‐basite from the Czech portion of the Erzgebirge anticline has been constrained through a combination of thermodynamic modelling and conventional thermobarometry. Garnet growth zoning indicates that the rocks underwent burial and heating to peak conditions of 2.6 GPa and at least 615 °C. Initial exhumation occurred with concurrent cooling and decompression resulting in the growth of amphibole and zoisite poikiloblasts overgrowing and including the eclogite facies assemblage. The development of clinopyroxene–plagioclase–amphibole symplectites after omphacite and Al‐rich rims on matrix amphibole indicate later heating at the base of the lower crust. Omphacite microstructures, in particular grain size analysis and lattice‐preferred orientations, indicate that the prograde evolution was characterized by a constrictional strain geometry transitioning into plane strain and oblate fabrics during exhumation. The initial constrictional strain pattern is interpreted as being controlled by competing slab pull and crustal buoyancy forces leading to necking of the subducting slab. The transition to plane strain and flattening geometries represents transfer of material from the subducting lithosphere into a subduction channel, break‐off of the dense slab and rebound of the buoyant crustal material.
Food‐Restriction Lowers the Acoustic Startle Response in both Male and Female Rats, and, in Combination with Acute Ghrelin Injection, Abolishes the Expression of Fear‐Potentiated Startle in Male Rats
Authors: Toufexis D. J. , Lipatova O. , Johnson A. C. , Abizaid A.
Published: October 2016

Food restriction has been reported to reduce anxiety‐like behaviour in male rats, whereas the effects of food restriction on anxiety in female rats are less clear. Ghrelin is a peptide hormone produced and secreted in the stomach that stimulates food intake and is considered to play a role in reward and emotional responses such as fear expression. Under food restriction, endogenous ghrelin levels increase. In the present study, we examined the effect of moderate food restriction (80% of ad libitum fed weight), with or without an acute application of a small dose of exogenous ghrelin intended to cause an immediate hunger response, on the expression of the acoustic startle reflex (ASR). This was carried out under basal conditions (baseline ASR to 90‐ and 95‐dB noise bursts), and in the presence of a light cue associated with a mild foot‐shock, as measured by fear‐potentiated startle, which compares the proportional change in ASR in the presence of the conditioned stimulus. The results obtained show that food‐restriction reduces basal ASR in both male and female rats, apart from any concomitant change in motor activity, suggesting that food‐restriction reduces anxiety levels in both sexes. In addition, the data show that food‐restriction reduces fear‐potentiated startle in male but not female rats. Acute ghrelin injection, prior to fear‐potentiated startle testing, eliminates the expression of fear‐potentiated startle in food‐restricted male rats alone, suggesting a role for ghrelin in the reduction of fear expression in food‐restricted male rats. These data imply that, although food‐restriction decreases anxiety in both sexes, learned fear responses remain intact after food‐restriction in female but not male rats.
An Answer to the Plant Variety Controversy in Chile
Authors: Prifti Viola
Published: October 2016

Chile has failed to ratify the 1991 International Convention for the Protection of New Varieties of Plants (UPOV) as stipulated in the free trade agreement (FTA) with the United States. Since Chile is amongst the US Priority Watch List countries, it is imperative for Chile to emanate a UPOV 1991‐compliant law. The ratification of UPOV 1991, however, has encountered strong resistance within the country and it is not yet clear when and how Chile will adopt UPOV 1991 provisions. Through an analysis of legal and economic aspects of the domestic plant variety law, this paper explains that Chile should make better use of UPOV flexibilities and gives recommendations in order to accommodate the interests of all stakeholders.
The “Grand Medium”: An Edwardsean Modification of Thomas Aquinas on the Beatific Vision
Authors: Boersma Hans
Published: October 2016

Jonathan Edwards's understanding of the beatific vision, which draws on Neoplatonist metaphysics, marks a modification of views that became dominant in the Western Church through the rise of Aristotelian anthropology as articulated in the theology of Thomas Aquinas. Edwards's account treats the resurrection of the body as significant, even indispensable for the deifying vision of God. It is also an account that regards Christ—the “grand medium” of the visio dei—as the consummate theophanic appearance of God. And it is, finally, an account that takes seriously the infinite progress of the vision of God, beginning in this life, continuing in the intermediate state, and on into the eternity of the resurrection.
Jackhammer esophagus: Observations on a European cohort
Authors: Herregods T. V. K. , Smout A. J. P. M. , Ooi J. L. S. , Sifrim D. , Bredenoord A. J.
Published: October 2016

Background

With the advent of high‐resolution manometry (HRM), a new diagnosis, jackhammer esophagus, was introduced. Little is known about this rare condition, and the relationship between symptoms and hypercontractility is not always straightforward. The aim of our study was to describe a large cohort of patients with jackhammer esophagus and to investigate whether manometric findings are associated with the presence of symptoms.

Methods

All patients from 06, 2014 until 12, 2015 seen at two tertiary centers with at least one hypercontractile swallow (distal contractile integral [DCI] >8000 mm Hg/s/cm) on HRM were analyzed. Patients with ≥20% premature swallows, or patients with another diagnosis explaining their symptoms were excluded.

Key Results

Of the 34 patients identified with jackhammer esophagus, most suffered from dysphagia (67.6%) and/or chest pain (47.1%). The symptom chest pain was not associated with any of the manometric findings, whereas dysphagia was associated with the DCI of the hypercontractile swallows and with intrabolus pressure. In addition, all patients who had an isolated DCI of the lower esophageal sphincter (LES) zone >2000 mm Hg/s/cm had dysphagia. The differences in HRM and clinical characteristics between subgroups based on the contraction type (single‐ or multi‐peaked) or based on meeting criteria of the Chicago Classification v3.0 and v2.0 were limited.

Conclusions & Inferences

The symptom dysphagia is accompanied with strong contractions of the LES, signs of a possible outflow obstruction, and a very high DCI. The presence of a multipeaked contraction seems to be of limited relevance, and caution is warranted in labeling patients with one hypercontractile swallow as normal.
Water transport and energy
Authors: Fricke Wieland
Published: October 2016

Water transport in plants occurs along various paths and is driven by gradients in its free energy. It is generally considered that the mode of transport, being either diffusion or bulk flow, is a passive process, although energy may be required to sustain the forces driving water flow. This review aims at putting water flow at the various organisational levels (cell, organ, plant) in the context of the energy that is required to maintain these flows. In addition, the question is addressed (1) whether water can be transported against a difference in its chemical free energy, ‘water potential’ (Ψ), through, directly or indirectly, active processes; and (2) whether the energy released when water is flowing down a gradient in its energy, for example during day‐time transpiration and cell expansive growth, is significant compared to the energy budget of plant and cell. The overall aim of review is not so much to provide a definite ‘Yes’ and ‘No’ to these questions, but rather to stimulate discussion and raise awareness that water transport in plants has its real, associated, energy costs and potential energy gains.
Coordination in a Single‐Supplier, Multi‐Retailer Distribution System: Supplier‐Facilitated Transshipments
Authors: Li Rong , Ryan Jennifer K. , Zeng Zhi
Published: October 2016

We consider supplier‐facilitated transshipments for achieving supply chain coordination in a single supplier, multi‐retailer distribution system with non‐cooperative retailers. The previous transshipment literature has focused on coordination through retailer‐negotiated transshipments and thus does not consider the supplier's decision‐making. In contrast, in this study, we assume the supplier is an active participant in the system and we seek to understand how the supplier can facilitate the implementation of coordinating transshipments. We study a two‐period model with wholesale orders at the start of the first period and preventive transshipments performed at the start of the second period. Inspired by a supplier‐facilitated transshipment scheme observed in practice, we assume the supplier implements transshipments through a bi‐directional adjustment contract. Under this contract, each retailer can either buy additional inventory from, or sell back excess inventory to, the supplier. We show that coordination can be achieved through carefully designed contracts with state‐dependent adjustment prices and a wholesale price menu. We demonstrate that the supplier's role in facilitating coordinating transshipments is critical. In addition, we use our understanding of the coordinating contract form to derive some simpler and easier‐to‐implement heuristic contracts. We use a numerical study to demonstrate the value, to the supplier, of using the coordinating adjustment and wholesale prices, and to evaluate the heuristics’ performance.
Impact of IT Capability on the Performance of Port Operation
Authors: Wang Ziping , Yao Dong‐Qing , Yue Xiaohang , Liu John J.
Published: October 2016

Based on the resource‐based view (RBV) and the transaction cost economics (TCE) theories, we study the impact of IT capability on the performance of port supply chain using an IT‐enabled transaction cost frontier model where the IT capability is modeled as a unique production input and as an endogenous transaction attribute as well. By examining the optimal levels of IT capability for different port systems from the viewpoint of production cost and transaction cost, we find theoretical evidence to explain why a port system with a horizontal competitive governance mode is less successful at integrating a port IT system in practice. Moreover, we find that the optimal IT capability of an individual port operator is lower than the IT capability in an integrated heterogeneous system. We further investigate how to improve IT capability to the desired system level through different forms of an incentive system that includes a subsidy offered by the port authority to coordinate the entire port system. The fixed subsidy is found to be the most cost‐effective and the easiest to implement. In addition, considering that information about effort cost for IT capability can be private under a market or hybrid governance mode, we study the performance of a direct revelation mechanism when revealing the port operator's private information and true cost to the port authority.
Modeling startle eyeblink electromyogram to assess fear learning
Authors: Khemka Saurabh , Tzovara Athina , Gerster Samuel , Quednow Boris B. , Bach Dominik R.
Published: October 2016

Pavlovian fear conditioning is widely used as a laboratory model of associative learning in human and nonhuman species. In this model, an organism is trained to predict an aversive unconditioned stimulus from initially neutral events (conditioned stimuli, CS). In humans, fear memory is typically measured via conditioned autonomic responses or fear‐potentiated startle. For the latter, various analysis approaches have been developed, but a systematic comparison of competing methodologies is lacking. Here, we investigate the suitability of a model‐based approach to startle eyeblink analysis for assessment of fear memory, and compare this to extant analysis strategies. First, we build a psychophysiological model (PsPM) on a generic startle response. Then, we optimize and validate this PsPM on three independent fear‐conditioning data sets. We demonstrate that our model can robustly distinguish aversive (CS+) from nonaversive stimuli (CS‐, i.e., has high predictive validity). Importantly, our model‐based approach captures fear‐potentiated startle during fear retention as well as fear acquisition. Our results establish a PsPM‐based approach to assessment of fear‐potentiated startle, and qualify previous peak‐scoring methods. Our proposed model represents a generic startle response and can potentially be used beyond fear conditioning, for example, to quantify affective startle modulation or prepulse inhibition of the acoustic startle response.
Parent–child negative emotion reciprocity and children's school success: An emotion‐attention process model
Authors: Moed Anat , Gershoff Elizabeth T. , Eisenberg Nancy , Hofer Claire , Losoya Sandra , Spinrad Tracy L. , Liew Jeffrey
Published: October 2016

Research has demonstrated that emotions expressed in parent–child relationships are associated with children's school success. Yet the types of emotional expressions, and the mechanisms by which emotional expressions are linked with children's success in school, are unclear. In the present article, we focused on negative emotion reciprocity in parent–child interactions. Using structural equation modeling of data from 138 parent to child dyads [children's mean age at Time 1 (T1) was 13.44 years, SD = 1.16], we tested children's negative emotionality (CNE) at T1 and low attention focusing (LAF) at Time 2 (T2) as sequential mediators in the relation between parent and child negative emotion reciprocity at T1 and children's grade point average (GPA) and inhibitory control at T2. Our findings supported an emotion‐attention process model: parent–child negative emotion reciprocity at T1 predicted CNE at T1, which predicted children's LAF at T2, which was, in turn, related to low inhibitory control at T2. Findings regarding children's GPA were less conclusive but did suggest an overall association of negative reciprocity and the two mediators with children's GPA. Our findings are discussed in terms of emotion regulation processes in children from negatively reciprocating dyads, and the effects of these processes on children's ability to obtain and use skills needed for success in school.
Does the desire to conform to peers moderate links between popularity and indirect victimization in early adolescence?
Authors: Closson Leanna M. , Hart Nicole C. , Hogg Leslie D.
Published: October 2016

This study of 426 Canadian early adolescents (Mage = 12.52; 53% girls) investigated whether associations between popularity and indirect victimization (i.e., reputational victimization, exclusion) varied as a function of gender and the desire to conform to characteristics and competencies that are valued within the peer group (i.e., peer conformity goals). Regression analyses revealed popularity was uniquely and positively associated with reputational victimization, but was not significantly related to exclusion after accounting for the effects of meanness and likeability. The associations between popularity and indirect victimization were moderated by peer conformity goals and gender. The results indicated that popular girls with high peer conformity goals experienced more reputational victimization and exclusion than popular girls with low peer conformity goals. However, popular boys with high peer conformity goals experienced less exclusion than popular boys with low peer conformity goals. The findings suggest that peer conformity goals carry with them some risks for popular girls, but may serve a protective function for popular boys.
Targeting Social Assistance: Dibao and Institutional Alienation in Rural China
Authors: Li Mianguan , Walker Robert
Published: October 2016

China's Dibao (Minimal Living Security System) is the world's biggest cash social assistance system serving 52 million people. However, Dibao is less effective at alleviating poverty in rural areas than should it be. The analytic concepts of targeting and institutional alienation (the mismatch between stated goals and true functioning) are applied in a village case‐study to understand why. It appears that Dibao reaches some people considered self‐evidently to be needy, but funds are diverted for purposes of rural governance and social control (reward, punishment and deterrence) and personal gain. Although culturally framed, the concepts and findings potentially have relevance to the global South and North.
Overexpression of MsDREB6.2 results in cytokinin‐deficient developmental phenotypes and enhances drought tolerance in transgenic apple plants
Authors: Liao Xiong , Guo Xiao , Wang Qi , Wang Yantao , Zhao Di , Yao Liping , Wang Shuang , Liu Guojie , Li Tianhong
Published: October 2016

Dehydration‐responsive element binding factors (DREBs) play important roles in plant growth, development, and stress signaling pathways in model plants. However, little is known about the function of DREBs in apple (Malus × domestica), a widely cultivated crop that is frequently threatened by drought. We isolated a DREB gene from Malus sieversii (Ledeb.) Roem., MsDREB6.2, and investigated its functions using overexpression analysis and chimeric repressor gene‐silencing technology (CRES‐T). We identified possible target genes of the protein encoded by MsDREB6.2 using electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP). Overexpression of MsDREB6.2 increased the expression of a key cytokinin (CK) catabolism gene, MdCKX4a, which led to a significant reduction in endogenous CK levels, and caused a decrease in shoot:root ratio in transgenic apple plants. Overexpression of MsDREB6.2 resulted in a decrease in stomatal aperture and density and an increase in root hydraulic conductance (L0), and thereby enhanced drought tolerance in transgenic plants. Furthermore, manipulating the level of MsDREB6.2 expression altered the expression of two aquaporin (AQP) genes. The effect of the two AQP genes on L0 was further characterized using the AQP inhibitor HgCl2. Based on these observations, we conclude that MsDREB6.2 enhances drought tolerance and that its function may be due, at least in part, to its influence on stomatal opening, root growth, and AQP expression. These results may have applications in apple rootstock breeding programs aimed at developing drought‐resistant apple varieties.
Landscapes of extended ruralisation: postcolonial suburbs in Dar es Salaam, Tanzania
Authors: Mercer Claire
Published: October 2016

African cities are becoming increasingly suburban, yet we know little about suburban spaces, how they are historically produced and by whom. This paper argues that African suburbs can be usefully understood as postcolonial suburbs. The postcolonial suburb de‐centres the Anglo‐American suburban model and pays attention to the historical co‐constitution of suburban space across colony and metropole. It draws attention to the colonial and post‐colonial policies on land and housing that make suburban development possible, but also attends to the everyday ways in which suburban spaces are built through the efforts of self‐builders and their house‐building projects. Using the case of Dar es Salaam, Tanzania, the paper shows how these low‐density residential spaces towards the edge of the city are being shaped by the new middle classes with their appetite for large houses and private cars. But these are not copies of suburban forms from elsewhere. Architecturally they are dominated by bungalows and villas, but these buildings are self‐built rather than part of large planned housing schemes. Socially the suburbs are dominated by the middle classes, but these middle classes are oriented towards the countryside rather than towards the city. Drawing on interviews with suburban residents in Dar es Salaam, I show how self‐build housing projects straddle the suburban and the rural in terms of economic investments, land security and social relations. The paper concludes by arguing that the colonial and postcolonial making of the suburbs produces landscapes of ruralisation.
Novel Catalytic Systems for Waste Tires Pyrolysis: Optimization of Gas Fraction
Authors: Kordoghli Sana , Paraschiv Maria , Tazerout Mohand , Khiari Besma , Zagrouba Fethi
Published: October 2016

In this paper, catalyzed pyrolysis of scrap tires was studied in order to identify the influence of catalysts on gas composition during the main thermal range of the decomposition process. The aim is related to gas fraction optimization in terms of yield, composition, and distribution during the pyrolysis process. This is an original work using for the first time powder catalysts (MgO, Al2O3, CaCO3, and zeolite ZSM-5) uniformly distributed on a single layer of oyster shells (OSs) particles. The catalyst/tires mass ratio was kept for all the tests at 1/30. Depending on used catalyst, pyrolysis products yields ranged from 39 to 42 wt.% for char, from 26 to 38 wt.% for oils, and from 16 to 30 wt.% for gas. Compared to the thermal pyrolysis, it was found that the liquid yield increases in the presence of MgO/OS, while the use of Al2O3/OS decreases it significantly. The gas yield grows in the presence of Al2O3/OS ranging from 24.6 wt.% (thermal pyrolysis) to 30.6 wt.%. On the other hand, ZSM-5/OS and CaCO3/OS did not bring significant changes in products yield, but there are considerable influences on the evolution of gas composition during the tires decomposition. Also, two important advantages of using these new catalytic systems are identified. These relate to the formation of gaseous species throughout the waste decomposition, thus harmonizing the calorific value for the entire thermal range, and the disappearance of heavy molecules in liquid fractions, simplifying or canceling further upgrading processes.
Effect of Ice and Blade Interaction Models on Compressor Stability
Authors: Saxena Swati , Woo George T. K. , Singh Rajkeshar , Breeze-Stringfellow Andrew , Nakano Tsuguji , Szucs Peter
Published: October 2016

As air traffic continues to increase in the subtropical areas where high moisture laden air is present at subfreezing conditions, engine icing probability increases. It has been shown that compressor stages rematch under icing conditions—front stages are choked, while rear stages throttle due to ice melting and evaporation. Such an analysis uses various empirical models to represent ice-breakup and water-splash processes as ice/water particles interact with rotors/stators. This paper presents a compressor stall sensitivity analysis around different splash models. The effect of droplet splash at both rotor and stator blades, blade solidity effect, and trailing edge shed effect is modeled. A representative ten-stage high-speed compressor section operating near design point (100% Nc) is used for the study. Results show that the temperature drop at high-pressure compressor (HPC) exit and the overall compressor operability are functions of evaporating stages, and droplet–blade interaction models influence them. A comprehensive compressor stability envelope has been evaluated for different models. It is observed that the droplet–blade interaction behavior influences overall compressor stability and the stall-margin predictions can vary by as much as 25% with different models. Therefore, there is a need for better calibration and continual improvement of empirical models to capture compressor interstage dynamics and stage rematching accurately under ice/water ingestion.
Industrial Gas Turbine Health and Performance Assessment With Field Data
Authors: Roumeliotis I. , Aretakis N. , Alexiou A.
Published: October 2016

The paper presents a thorough analysis of the historical data and results acquired over a period of two years through an on-line real-time monitoring system installed at a combined heat and power (CHP) plant. For gas turbine health and performance assessment, a gas path analysis tool based on the adaptive modeling method is integrated into the system. An engine adapted model built through a semi-automated method is part of a procedure which includes a steam/water cycle simulation module and an economic module used for power plant performance and economic assessment. The adaptive modeling diagnostic method allowed for accurate health assessment during base and part load operation identifying and quantifying compressor recoverable deterioration and the root cause of an engine performance shift. Next, the performance and economic assessment procedure was applied for quantifying the economic benefit accrued by implementing daily on-line washing and for evaluating the financial gains if the off-line washings time intervals are optimized based on actual engine performance deterioration rates. The results demonstrate that this approach allows continuous health and performance monitoring at full and part load operation enhancing decision making capabilities and adding to the information that can be acquired through traditional analysis methods based on heat balance and base load correction curves.
Local Ice Loads on the Sakhalin-II Project Structures: Probability Analysis and Comparison by Existing Design Codes
Authors: Sabodash Olga A.
Published: October 2016

In the study the probabilistic modeling of local ice loads and pressures on wide structure has been carried out. Probabilistic analysis has traditionally been focused on distribution of their maximum values. The “Molikpaq” (PA-A) ice-class platform for “Sakhalin-II” project is considered as an example. The input parameters were modelled by Monte-Carlo method taking into account of full-scale data in the Piltun-Astokhskoe field during 1989÷2002 ice seasons. A comparative analysis of local ice loads and pressures on wide structure has been made on the basis of the Russian and international design codes, standards and recommendations. The obtained local pressure values were compared with public available data collected on the “Molikpaq” (PA-A) platform.

Some preliminary results and discussions are presented. Recommendations on the local ice loads and pressures for engineering design of structures on the Sakhalin offshore have been done.
Potential of Solar Enhanced Oil Recovery in the Major Heavy Oil Areas of China
Authors: Frasquet Miguel , Silva Manuel
Published: October 2016

Solar steam generation for enhanced oil recovery has a significant potential at regions where, in addition to heavy oil reservoirs, solar resource is abundant. China ranks amongst the countries with greater heavy oil reserves. In addition, Western regions of China have a solar resource equivalent to that of places in which solar energy is being developed in a commercial scale. This paper addresses the technical feasibility of using concentrating solar collectors to produce the steam required in the recovery of heavy oil through thermal methods. Three locations have been selected for this study. In each location, three different reservoir injectivity scenarios have been taken into account: No injectivity limitation (as upper bound), partial limitation and full limitation (meaning that the injection rate cannot be greater than the design value for constant rate). In the first scenario, the surface model uses parabolic through collectors and direct steam generation. When injectivity is restricted, thermal storage becomes necessary in order to be able to inject the same amount of heat into the reservoir within the limits of the reservoir’s injectivity. Therefore, molten salts tower system with sensible storage is proposed as technology for the second scenario. In the third scenario, also parabolic through collectors are used but in this case, the solar system is coupled with conventional Once-Through Steam Generators (OTSGs) in a hybrid scheme (this approach represents the current state of the art).
Hydrodynamic Loads on a Submerged Floating Tube Bridge Induced by a Passing Ship or Two Ships in Maneuver in Calm Water
Authors: Xiang Xu , Eidem Mathias Egeland , Sekse Jorunn Hillestad , Minoretti Arianna
Published: October 2016

The European highway E39 ferry-free Project led by the Norwegian Public Roads Administration (Statens vegvesen, NPRA) is in its full momentum on solving the technological challenges to cross the deep (up to 1350 m) and wide (up to around 6 km) Norwegian fjords. Different types of crossing solutions have been explored up to now. The current paper is related to the submerged floating tube bridge (SFTB) solution. But the model itself can be applied to any other structure that may experience loads induced by a passing vessel. The method of Xiang and Faltinsen (2010) for evaluating the calm water interacting loads between two vessels up to the point of collision has been extended to include an SFTB. Equations of loads are extended to include also the vertical load and pitch moment on the body in question. The vertical load induced on the SFTB is investigated for the purpose of identifying the significance of this effect on the design. The investigation includes this effect under different maneuver scenarios of the passing vessels: a single ship passing, two ships advancing in side-by-side positions, encountering or overtaking maneuvers. In addition, parametric studies on the submergence of floating tube bridge, and vessel speeds are studied to get more understanding of this effect. A simple exercise shows that it is worth of further investigation on ship-induced surface waves effects on the structures in vicinity of the ship path. Finally, the evaluated loads are compared with other types of loads from the analysis results of the on-going NPRA SFTB design.
Seamless Linepipe Response Under Small and Full Scale Reeling Simulation
Authors: Marines-Garcia Israel , Aldana-Díaz Jorge A. , Darcis Philippe P. , Quintanilla Hector M.
Published: October 2016

Offshore pipelines projects, installed by reel-laying operations, are gaining momentum due to the increasing worldwide capacity of Reel Lay Vessels. It is well known that reel-laying installation causes repeated plastic straining (cyclic deformation) and, as a consequence, cyclic strain and ageing test is usually required for qualifying line pipe materials for such installation method. This qualification is typically named reeling simulation.

Reeling simulations can be made via full or small scale. In practice, full scale qualification lead time and full scale reeling simulation machines availability could be a constraint, thus, small scale reeling simulation is usually the best alternative. However, the similitude of small scale versus full scale simulations could be questioned. On this basis, an extensive study was carried-out considering tensile, toughness and sour testing, in order to evaluate the material response after reeling simulation, in order to clarify if the line pipe material will behave similarly regardless the straining method (small scale or full scale).

Different small scale samples configuration for straining were tested, depending on the posterior mechanical or sour test, and two different full scale reeling simulation machines were used for plain pipes straining.

Five seamless plain pipes, X65 line pipe were used for this study, with 3 (three) different outer diameters of 10.75″, 11.67″ & 16″ (273 mm, 296 mm & 406 mm). The current paper will present the main mechanical results of these materials after strain and ageing condition, comparing full and small scale straining methods.
Experimental Investigation of Friction and Hydraulics in Circular and Non-Circular Wellbores With Oil Based Drilling Fluids
Authors: Taghipour Ali , Lund Bjørnar , Ytrehus Jan David
Published: October 2016

Borehole hydraulics, hole cleaning and mechanical friction are important factors for well planning and drilling operations. Many studies aim to exploit and optimize the effect of different operational parameters. The effect of wellbore geometry on hole cleaning and mechanical friction has so far not received much attention. This paper presents results from experimental laboratory tests where hydraulics, hole cleaning and mechanical friction have been investigated for circular and non-circular wellbore geometries with a relevant oil-based field drilling fluid (OBM). The non-circular wellbore geometry was made by adding spiral grooves to the wellbore walls in order to investigate the effects on cuttings transport and mechanical friction. The study contributes to describe the function and ability of deliberately induced non-circular geometry in wellbores as means to achieve a more efficient drilling and well construction. Improving hole cleaning will improve drilling efficiency in general, and will in particular enable longer reach for ERD wells. Reduced mechanical friction may improve the drilling process and many operations during the completion phase.

The laboratory experiments were performed in an advanced flow loop setup reproducing field-relevant flow conditions. The flow loop consists of a 10 m long 4″ inner diameter borehole made of concrete. A free whirling rotational string with 2″ diameter provides a realistic down hole annular geometry. A field-relevant oil based drilling fluid (OBM) was circulated through the test section at different flow rates. To represent the effect of rate of penetration, synthetic drilling cuttings (quartz sand particles) were injected at different rates through the annulus in the horizontal test section. The test results show that borehole hydraulics and cutting transport properties are significantly improved in the non-circular wellbore relative to the circular wellbore. The effect of the mechanical friction is more complex, yet significantly different for the two geometries.
Effect of Near Wall Turbulence on the Particle Removal From Bed Deposits in Horizontal Wells
Authors: Bizhani Majid , Kuru Ergun , Ghaemi Sina
Published: October 2016

Although solids entrainment and deposition mechanisms have been studied extensively over the years, our understanding of fluids-particle interactions near bed interface is still limited. Progress toward such understanding has been relatively slow because of the difficulties inherent simultaneous measurement of local solids transport and adjacent near-bed fluid flow. With the introduction of non-intrusive measurement techniques such as Particle Image Velocimetry (PIV), it is now possible to determine the instantaneous velocity field and observe particle deposition/resuspension simultaneously under non-uniform flow conditions.

An experimental program was conducted to investigate different aspects of turbulent flow of water over the cuttings bed deposited in horizontal annuli. A large-scale horizontal flow loop consisting of 9 m long high quality optic glass pipes (95 mm ID of outer pipe and 38 mm OD of inner pipe) equipped with state of the art PIV system has been used for the experiments. Turbulent flow over cuttings bed experiments were conducted at superficial Reynolds numbers of 9300 and 10800. Natural irregular shaped quartz sands with 3 different mean sieve sizes of 260, 350 and 600 micron were used as solid particles.

The proposed work was accomplished through several tasks: i-) conduct experiments to measure the instantaneous local velocity profile during turbulent flow in the horizontal concentric annuli and examine the effect of stationary cutting bed on the local velocity profile, Reynolds stress and turbulence intensity; ii-) investigate the impact of particle size on the near-wall turbulent activities.

Results have indicated that existence of a cuttings bed on the lower side of the wellbore dramatically alters the near wall velocity profile comparing to the case with no cuttings bed. Presence of cuttings bed causes the maximum velocity to shift toward the inner pipe.

Presence of stationary cutting bed causes a reduction in Reynolds stress, axial and radial turbulence intensity, which in turn, would adversely affect the hole cleaning. Larger cuttings slightly enhanced turbulent stress and radial intensities. However, the increase in these entities as a result of increasing cutting size was far less than the decrease in them as a consequence of presence of stationary cutting bed. Axial turbulence intensity was the same in the core flow away from the cuttings bed for flow with and without a cuttings bed. However, the peak of axial intensities is shown to be less for flow near the cuttings bed.