bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic iron overload causing haemochromatosis and hepatopathy in 21 horses and one donkey
Authors: Theelen M. J. P. , Beukers M. , Grinwis G. C. M. , Sloet van Oldruitenborgh‐Oosterbaan M. M.
Published: September 2018

Background

Iron toxicosis is rarely reported in horses and chronic excessive oral iron intake has not been reported to cause clinical symptoms in equids.

Objectives

This case series describes 21 genetically unrelated horses and one donkey with chronic iron overload causing haemochromatosis and hepatopathy.

Study design

Case series.

Methods

All equids showing clinical signs compatible with chronic liver disease presented to Utrecht University and diagnosed with iron overload and haemochromatosis based on histopathological evaluation of liver tissue and/or blood transferrin saturation levels of >80% and proof of excess dietary iron intake due to excess iron content in drinking water were included.

Results

This study included 22 equids. All tested animals (n = 19) had transferrin saturation >80% and 21 of 22 had increased gamma‐glutamyltransferase (γGT). Ultrasonography revealed rounded liver margins in five out of six horses and increased echogenicity in 4/6. Histological examination of liver tissue of 12 animals showed hepatitis, fibrosis and haemosiderin accumulation in macrophages and hepatocytes. Post‐mortem examination also revealed haemosiderin accumulation in other organs in all seven examined animals. High iron content in drinking water was identified as the source of iron overload in all cases. All animals were housed under the same conditions for a minimum of 9 years prior to diagnosis of haemochromatosis. Of 22 animals, 13 survived until 1 January 2018, ranging from 17 to 79 months post diagnosis.

Main limitations

Histology of liver tissue was not available for 10 of 22 cases.

Conclusions

Chronic iron overload can lead to haemochromatosis and hepatopathy in equids. Development of disease is slow and clinical signs are nonspecific. Long‐term excessive iron intake in equids should be avoided. If animals drink from natural water sources, it is important to test the water for iron content.

The Summary is available in Spanish ‐ see Supporting Information
Re‐casting experience and risk along rocky coasts: A relational analysis using qualitative GIS
Authors: Kamstra Peter , Cook Brian , Edensor Tim , Kennedy David M.
Published: September 2018

This study invites readers to experience risk on Australia’s hazardous rocky coasts with the rock fishing community. In the paper, we offer an understanding of risk that is relational, a process that emerges within human–environment interactions in a dynamic coastal space that is constantly changing. Exploring the in situ and ongoing sensory attunement of the fishers, we contend, expands upon the quantitative understandings that tend to be deployed by risk managers, offering an innovative approach to conceptualising risk. In identifying how fishers perceive and experience a rocky coastal location in Sydney, Australia, we track rock fishers’ movements using global positioning systems (GPS), undertake participant observation, and draw on video footage, semi‐structured interviews and participatory sketch maps. In doing so, fishers’ perceptions of socio‐environmental stimuli were spatially represented in a GIS, with sketch mapping being the proxy and/or the window into perception–environment relations that produce risk. We contend that the findings show that experienced fishers are more capable of anticipating and reacting to hazardous situations “safely” because they are more attuned to how changing coastal conditions affect risk. This study draws attention to the spatial and temporal phenomena that drive risk perceptions as well as the implications for future perception‐oriented research that adopt a relational understanding.
Laser Ablation In Situ Silicon Stable Isotope Analysis of Phytoliths
Authors: Frick Daniel A. , Schuessler Jan A. , Sommer Michael , von Blanckenburg Friedhelm
Published: September 2018

Silicon is a beneficial element for many plants and is deposited in plant tissue as amorphous bio‐opal called phytoliths. The biochemical processes of silicon uptake and precipitation induce isotope fractionation: the mass‐dependent shift in the relative abundances of the stable isotopes of silicon. At the bulk scale, δ30Si ratios span from −2 to +6‰. To further constrain these variations in situ, at the scale of individual phytolith fragments, we used femtosecond laser ablation multi‐collector inductively coupled plasma‐mass spectrometry (fsLA‐MC‐ICP‐MS). A variety of phytoliths from grasses, trees and ferns were prepared from plant tissue or extracted from soil. Good agreement between phytolith δ30Si ratios obtained by bulk solution MC‐ICP‐MS analysis and in situ isotope ratios from fsLA‐MC‐ICP‐MS validates the method. Bulk solution analyses result in at least twofold better precision for δ30Si (2s on reference materials ≤ 0.11‰) over that found for the means of in situ analyses (2s typically ≤ 0.24‰). We find that bushgrass, common reed and horsetail show large internal variations up to 2‰ in δ30Si, reflecting the various pathways of silicon from soil to deposition. Femtosecond laser ablation provides a means to identify the underlying processes involved in the formation of phytoliths using silicon isotope ratios.
A rational asymmetric hollow fiber membrane for oxygen permeation
Authors: Ren Chunlei , Gan Yun , Yang Chunyang , Lee Myongjin , Xue Xingjian
Published: September 2018

A typical oxygen permeation hollow fiber membrane fabricated by phase inversion‐based extrusion process demonstrates heterogeneous porous microstructures, in which the surface layer with relatively low porosity is used as a separation layer after sintering. It is usually not convenient to control the thickness of separation layer. And a high sintering temperature is needed to densify the separation layer, which in turn could destroy the desired porous microstructures in other portion. This paper studies a novel process to fabricate multilayer asymmetric hollow fiber membrane with a rational design using 67 vol. % Gd0.2Ce0.8O2−δ−33 vol. % La0.6Sr0.4Co0.2Fe0.8O3−δ (GDC‐LSCF) as a model material system. The phase inversion‐based extrusion process in open literature is employed to fabricate a hollow fiber substrate featuring radially well‐aligned microchannels open at the inner surface. Built upon the hollow fiber substrate, a thin dense separation layer and porous surface catalyst layer at shell side are then fabricated through dip‐coating and sintering process alternatively. The oxygen permeation flux of the fabricated hollow fiber membrane reaches 2.68 mL/cm2/min at 900°C under Ar/air gradient, the highest performance of the membranes with GDC‐LSCF material system in open literature. The innovative fabrication process is able to readily control the thickness of functional layers while decreasing sintering temperatures.
Effect of alumina fiber content on pore structure and properties of porous ceramics
Authors: Lang Ying , Zhao Lin , Dai Xin , Wang Chang‐An
Published: September 2018

Porous Al2O3 ceramics with different contents of alumina fibers were prepared by gel‐casting process. The effects of Al2O3 fiber content on pore size distribution, porosity, compressive strength, and load‐displacement behavior of the ceramic materials were investigated. Initial results showed that with the increase of Al2O3 fiber content, the pore size and porosity of the material is increased, and the compressive strength is decreased. However, upon increasing the fiber content from 50 wt% to 67 wt%, the performance of the samples changed greatly. The compressive strength of the material increased, while the porosity remained unchanged, the pore size increased greatly, and the shape of the load displacement curve changed. It showed that when the fiber content increased from 50 wt% to 67 wt%, the loading body in the fiber‐reinforced porous ceramics changed from particles to fibers.
The effect of ZrO2 alloying on the microstructures and thermal properties of DyTaO4 for high‐temperature application
Authors: Wu Peng , Hu Mingyu , Chen Lin , Wu Fushuo , Chong Xiaoyu , Feng Jing
Published: September 2018

High fracture toughness of 8 YSZ (8 wt% yttria‐stabilized zirconia) is linked to its ferroelastic toughening mechanism. In this work, the similar ferroelastic domain is detected in monoclinic Dy1−xTa1−xZr2xO4 ceramics, which derives from the ferroelastic transformation between the high‐temperature tetragonal (t) and low‐temperature monoclinic (m) phase. The lowest thermal conductivity of Dy1−xTa1−xZr2xO4 ceramics is reduced by 30% compared with 8 YSZ, and the largest thermal expansion coefficients (TECs) is up to 11 × 10−6 K−1 at 1200°C, which is comparable to that of 8 YSZ. Notably, the systematic investigations containing phase, microstructure, thermophysical properties of Dy1−xTa1−xZr2xO4 ceramics will provide guidance for its high‐temperature application, especially as thermal barrier coatings.
ZnO‐based single crystal‐polycrystal structures for piezotronic applications
Authors: Keil Peter , Gehringer Maximilian , Frömling Till , Novak Nikola , Rödel Jürgen
Published: September 2018

Electrostatic potential barriers at doped ZnO‐ZnO interfaces can be modified by stress‐induced polarization charges. This concept was enhanced by preparing ZnO‐based single crystal‐polycrystal‐single crystal structures by diffusion bonding. Increasing time for epitaxial solid‐state transformation results in structures with a decreasing thickness of residual polycrystalline material in between two well‐oriented single crystals. Microstructural and electrical analysis quantifies the influence of high‐temperature treatment during epitaxial growth on the stress sensitivity of the prepared structures. The orientation of the single crystals is defined to maximize the interaction between stress‐induced polarization charges and the potential barriers at doped ZnO‐ZnO interfaces. With decreasing thickness of residual polycrystalline material, the percentage of grain boundaries with favorably aligned polarization vectors is increased resulting in a higher stress sensitivity. This effect is compensated by an adverse effect of the high‐temperature treatment on the initial potential barrier height. Hence, a maximum in stress sensitivity can be observed for intermediate times of epitaxial growth. The prepared structures close the gap between the varistor piezotronics based on bulk ceramics with random orientation of the polarization vector and the bicrystal piezotronics with perfect orientation of the polarization vector, demonstrating the capability of microstructural engineering for varistor‐based piezotronic devices.
Struggling with Meaningfulness when Context Shifts: Volunteer Work in a German Refugee Shelter
Authors: Florian Mona , Costas Jana , Kärreman Dan
Published: September 2018

This article draws on an ethnographic study of volunteer work in a German refugee shelter to explore how individual experiences of meaningfulness are intertwined with shifting discursive and organisational contexts. At the beginning of the so‐called refugee crisis, societal discourses portrayed this volunteer work as extraordinarily meaningful – a state we capture through the metaphor of ‘overflow’. This ‘overflow’ mobilised volunteers and was an important point of reference for framing their work experiences as meaningful. Later, shifting discursive and organisational contexts challenged their framings. Instead of letting go, however, the ‘overflow’ triggered volunteers to reframe their experience in dysfunctional ways in order to sustain their sense of meaningfulness. This paper reveals how shifting societal discourses feed into individual experiences of meaningfulness, shows how individuals may respond to such shifts in problematic ways and theorises the nature of such shifts in drawing on Swidler’s notion of settling contexts.
Demographic factors in the choice of coronal restoration after root canal treatment in the Swedish adult population
Authors: Olsson Sara R. , Pigg Maria , Isberg Per‐Erik ,   EndoReCo, Fransson Helena
Published: September 2018

Background

After root canal treatment, a choice is made between different coronal restorations which in the long run could affect the survival of the tooth.

Objective

To compare demographic characteristics between individuals choosing an indirect coronal restoration (crown, inlay/onlay) and individuals choosing other restorations after completion of a root filling.

Methods

The cohort consisted of all root‐filled upper first molars that were reported to the tax‐funded Swedish Social Insurance Agency (SSIA) during 2009. After registration of the root filling, any subsequent coronal restorations within 2 years were identified. The crown group consisted of individuals registered with an indirect coronal restoration and the restoration group was the remaining individuals with a direct coronal restoration or lacking registration. Demographic data (gender, disposable income, age, educational level, civil status and country of birth) were received from Statistics Sweden or the SSIA. Statistical analyses included chi‐square test, t test and logistic regression analysis. P < 0.05 was considered statistically significant.

Results

An indirect coronal restoration was received by 7806 individuals (21.9%), and 27 886 individuals (78.1%) received a direct restoration. All demographic variables except gender differed significantly between groups. Logistic regression analysis found significant associations for all demographic variables and the registration of an indirect restoration except for country of birth and gender.

Conclusions

The identified demographic differences between individuals choosing to restore their newly root‐filled teeth with an indirect restoration compared to those receiving other restorations may indicate that the tax‐funded Swedish dental insurance fails to provide dental care on equal terms for Swedish citizens.
Laudato Si’: Integral Ecology and Preferential Option for the Poor
Authors: Martins Alexandre A.
Published: September 2018

This essay examines Pope Francis’s encyclical Laudato si’ from a Latin American perspective and its reception in this part of the world, especially in Brazil. It focuses on two aspects of Laudato si’: its dialogical approach, and the connection it makes between ecological issues and poverty. These two aspects allow us to understand Francis’s proposal of integral ecology and how the preferential option for the poor becomes central to his perspective. In addition, this essay explains how Latin American theology and pastoral experience are present in Pope Francis’s thought.
The Mysterious Silence of Mother Earth in Laudato Si'
Authors: Jenkins Willis
Published: September 2018

Laudato si' attempts simultaneously to disrupt prevailing global environmental discourse and to reorient central concepts in Catholic moral tradition by requalifying the meaning of dominion and by ecologically expanding human dignity. The image of Earth crying out to humans from within a kinship relation plays a central role in both arguments. However, the political consequences of those shifts remain vague because the “voice” of Earth remains silent in crucial loci of the encyclical's argument.
The Destiny of Creation: Theological Ethical Reflections on Laudato Si'
Authors: Schweiker William
Published: September 2018

In this essay, I ask what the precise relation is between Laudato si's theology and its claims about our individual and corporate responsibility for the environment and the plight of the poor. To do so, I first clarify the relationship between the theological claims and its account of moral norms, situating the text within the history of western ethical theory. I then turn to reconstruct the submerged theology of the encyclical, focusing on Pope Francis's accounts of the techno‐economic paradigm and the possibility of an “integral ecology” paradigm. I end by assessing the text in terms of the coherence and plausibility of its argument as an ethical and theological statement.
Reframing the Catholic Understanding of Just War: Two Contrasting Approaches in the Interwar Period
Authors: Reichberg Gregory M.
Published: September 2018

During the inter war period, European Catholic authors exhibited two different approaches to the question of just war. One approach was articulated at the “Fribourg Conventus,” a 1931 meeting of French, Swiss, and German theologians, whose subsequent declaration (Conventus de bello, published in 1932) called for a reformulation of Catholic teaching based on the premise that the traditional just‐war doctrine had been superseded by developments in international law. A competing approach was articulated by the Dutch Jesuit Robert Regout, who maintained that the just‐war doctrine could contribute to the formation of international law by providing a much‐needed normative foundation for the use of armed force by individual states in redress of their violated rights. After presenting these two approaches and explaining how they differ, this essay shows how the outlook of theConventusde bellois reflected in subsequent papal statements on armed force—to the detriment of the traditional terminology of just war.
Oh God, that's an ugly looking fish – negotiating sociocultural distance in transnational families through culinary othering
Authors: Wilczek‐Watson Marta
Published: September 2018

This paper presents a qualitative discourse analysis of food‐related interactions in four U.K.‐based Polish–British families. The data include the families’ video‐recorded celebratory meals and audio‐recorded interviews. The analysis explores how food talk projects ‘stance’ (Du Bois ) – that is, how it indexes the speakers’ positioning towards their sociocultural field, thus shaping their identities. The data reveal that, as the speakers negotiate their stances in the culinary context, they recurrently ‘other’ their interlocutors’ foodscapes – represent them as different, abnormal and/or inferior. This othering could be interpreted as distancing from other speakers. However, the analysis shows that by humorously highlighting differences between their culinaro‐celebratory repertoires, the family members also reaffirm their sharedness. The speakers’ discursive collaboration during their difference talk demonstrates how othering can be unifying in these transnational families, the potential of which is understudied in face‐to‐face interactions and in the context of food.
Melatonin protects embryonic development and maintains sleep/wake behaviors from the deleterious effects of fluorene‐9‐bisphenol in zebrafish (Danio rerio)
Authors: Mi Ping , Zhang Qiu‐Ping , Li Shi‐Bao , Liu Xing‐Yu , Zhang Shu‐Hui , Li Meng , Chen Dong‐Yan , Zhao Xin , Feng Dao‐Fu , Feng Xi‐Zeng
Published: September 2018

Environmental endocrine chemicals have various adverse effects on the development of vertebrates. Fluorene‐9‐bisphenol (BHPF), a substitute of bisphenol A (BPA), is widely used in commercial production. The effects of BHPF on development and behavior are unclear. Melatonin plays a protective role under many unfavorable conditions. In this study, we investigated the effects of BHPF on the development and behaviors of zebrafish and whether melatonin reverses effects induced by BHPF. Zebrafish embryos were exposed to 0.1, 10, or 1000 nmol/L BHPF with or without 1 μmol/L melatonin from 2 hours postfertilization to 6 days postfertilization. The results showed that 0.1 and 10 nmol/L BHPF had little effect on development. High‐dose BHPF (1000 nmol/L) delayed the development, increased mortality and surface tension of embryonic chorions, caused aberrant expression of the key genes (ntl, shh, krox20, pax2, cmlc2) in early development detected by in situ hybridization, and damaged the CaP motor neurons, which were associated with locomotion ability detected by immunofluorescence. Melatonin addition reversed or weakened these adverse effects of BHPF on development, and melatonin alone increased surface tension as the effects of high‐dose BHPF. However, all groups of BHPF exposure triggered insomnia‐like behaviors, with increased waking activity and decreased rest behaviors. BHPF acted on the hypocretin (hcrt) system and upregulated the expression of sleep/wake regulators such as hcrt, hcrt receptor (hcrtr), arylalkylamine N‐acetyltransferase‐2 (aanat2). Melatonin recovered the alternation of sleep/wake behaviors induced by BHPF and restored abnormal gene expression to normal levels. This study showed that high‐dose BHPF had adverse effects on early development and induced behavioral alternations. However, melatonin prevented BHPF‐induced aberrant development and sleep/wake behaviors.
t(6;9)(MYB‐NFIB) in head and neck adenoid cystic carcinoma: A systematic review with meta‐analysis
Authors: de Almeida‐Pinto Yasmin Dias , Costa Sara Ferreira dos Santos , de Andrade Bruno Augusto Benevenuto , Altemani Albina , Vargas Pablo Agustin , Abreu Lucas Guimarães , Fonseca Felipe Paiva
Published: September 2018

The presence of a translocation involving MYB and NFIB genes have been described in adenoid cystic carcinoma (AdCC) from different anatomical regions. However, the exact frequency of this genetic event and its prognostic impact for patient survival remain obscure. The aim of this study was to carry out a systematic review to address the prevalence and the prognostic potential of t(6;9)(MYB‐NFIB) in head and neck AdCC. Quantitative analysis was done to determine the prevalence of the translocation. A total of 1,107 articles were initially retrieved with 36 remaining for data extraction. The prevalence of t(6;9)(MYB‐NFIB) varied significantly (16%–100%), especially due to methodological heterogeneity among studies. A total of 11 studies attempted to determine the prognostic importance of the translocation, but no study found any significant association with survival rates; only three studies observed a significant association with age, sex, tumour location and the presence of recurrences and metastases. The prevalence of t(6;9)(MYB‐NFIB) in head and neck AdCC varies according to the laboratorial methods used, and the best evidence available demonstrates that t(6;9)(MYB‐NFIB) does not seem to be a prognostic determinant.
Prediction of Acute Postoperative Pain from Assessment of Pain Associated With Venous Cannulation
Authors: Persson Anna K. M. , Åkeson Jonas
Published: September 2018

Background

It has previously been reported that venous cannulation‐induced pain (VCP) can be used to predict acute postoperative pain after laparoscopic cholecystectomy. Patients rating VCP at ≥2.0 VAS units had 3.4 times higher risk for moderate or severe pain. The purpose of this study was to evaluate if VCP scores of ≥2.0 VAS units are associated with higher risk for acute postoperative pain after various common surgical procedures.

Methods

In a prospective clinical observational study, 600 male and female 18‐ to 80‐year‐old patients scheduled for elective surgery were included. The primary outcome measure was the difference in maximum postoperative pain intensity between low responders (VCP < 2.0) and high responders (VCP ≥ 2.0) to VCP. Secondary outcome measures were the difference in proportion of patients with moderate or severe postoperative pain between low and high responders, and potential influence of age, gender, and preoperative habitual pain.

Results

Patients scoring VCP ≥2.0 VAS units reported higher acute postoperative pain intensity levels than those scoring VCP <2.0 VAS units (median 3.0 [interquartile range 0.0 to 5.0] vs. 0.2 [interquartile range 0.0 to 4.0], P = 0.001), and also had 1.7 times higher risk for moderate or severe postoperative pain (P = 0.005). Moderate or severe postoperative pain was reported by 38% of patients with VCP scores of ≥2.0 VAS units and by 26% with VCP scores of <2.0 VAS units (P = 0.005).

Conclusion

Scoring of VCP intensity before surgery, requiring no specific equipment or training, is useful to predict individual risks for moderate or severe postoperative pain, regardless of patient age or gender, in a setting involving different kinds of surgery.
An Internet‐Based Survey to Assess Clinicians’ Knowledge and Attitudes Towards Opioid‐Induced Hypogonadism
Authors: Hochberg Uri , Ojeda Antonio , Brill Silviu , Perez Jordi
Published: September 2018

Background

Long‐term opioid therapy for chronic pain management requires regularly assessing and documenting benefits and side effects. Opioid‐induced sex hormone disturbances are a complication that needs to be assessed routinely and perhaps not only when suspected. There is abundant literature about its prevalence, clinical consequences, and treatment, yet routine hormone screening and appropriate treatment are seldom performed in pain clinics. Ignorance, skepticism, and/or indifference are possible reasons explaining why opioid‐induced hypogonadism (OIH) remains underdiagnosed among chronic pain patients.

Methods

This was an Internet‐based survey reaching out to pain clinicians to assess their knowledge and attitudes regarding OIH.

Results

A total of 135 responses were received, representing a 23.7% response rate. Analysis of responses showed that 47% of responders were somewhat familiar with this complication, but their knowledge about the prevalence and the time to develop varied. Screening for OIH is ordered based on suspicion of its presence (50%), but not routinely (38%). Lack of knowledge was the most frequent reason adduced for not screening for OIH. Sex‐related symptoms and signs are the most relevant reasons leading to suspicion and screening of OIH. Upon laboratory confirmation, most responders refer their patients to endocrinology (82%) for further management since most (60%) believe that testosterone replacement would improve their patients’ health.

Conclusions

Knowledge and attitudes towards OIH varied among this population of pain clinicians invited to participate in the research. Lack of knowledge and incertitude seem to impact the attitudes towards screening and treating OIH. Better medical training at undergraduate and postgraduate levels as well as continuous medical education may contribute to raising awareness about this complication and providing early treatment.
Prospective Cohort Analysis of DRG Stimulation for Failed Back Surgery Syndrome Pain Following Lumbar Discectomy
Authors: Kallewaard Jan Willem , Nijhuis Harold , Huygen Frank , Wille Frank , Zuidema Xander , van de Minkelis Johan , Raza Adil
Published: September 2018

Introduction

Surgical lumbar discectomy is a commonly performed routine spinal procedure that is usually undertaken to alleviate lumbar radicular symptoms caused by a herniated intervertebral disc. Surgical lumbar discectomy can also lead to chronic postsurgical leg and/or back pain (failed back surgery syndrome [FBSS]), a condition that can be refractory to conventional medical management. Early clinical results on the use of dorsal root ganglion (DRG) stimulation for FBSS have supported the use of this treatment alternative.

Methods

A multicenter, single‐arm, observational cohort study enrolled patients who had chronic pain following surgical lumbar discectomy, had failed conservative treatments, and reported pain intensity of at least 6 out of 10 in the primary region of pain. Data were collected on pain, quality of life, disability, and mood at baseline and through 12 months.

Results

Thirteen patients underwent a trial of DRG stimulation; 11 (84.6%; 95% confidence interval = 57.8% to 95.7%) had good outcomes and underwent permanent device placement. Pain was reduced from a score of 8.64 (±0.92) at baseline to 2.40 (±2.38; n = 9) after 12 months of treatment, a 72.05% average reduction (P < 0.001). Similar improvements were observed across the secondary clinical measures, and safety data were in line with published rates.

Discussion

These results suggest that DRG stimulation induces pain relief in subjects diagnosed with FBSS. These reductions in pain were also associated with improvements in quality of life and disability. Additional prospective studies are warranted to further investigate this potential application of DRG stimulation, as well as to optimize patient selection, lead placement, and programming strategies.
Relational geographies of human trafficking: Inequality, manoeuvring and im/mobility across space and time
Authors: Blazek Matej , Esson James , Smith Darren P.
Published: September 2018

This paper demonstrates why and how a fuller geographical perspective extends contemporary scholarship on human trafficking within and beyond the discipline. We employ a relational approach and draw on in‐depth qualitative research with trafficked persons and a range of stakeholders in Slovakia and the United Kingdom (UK), to depict how the processes underpinning human trafficking are non‐linear and operate instantaneously at multiple intersecting scales and temporalities and through diverse mobilities. The analysis problematises the discrete and homogeneous notion of space coupled with a linear conceptualisation of time and, more specifically, the normative portrayals of recruitment, transit and exploitation as distinct and sequential phases of human trafficking. Instead, the individuated experiences of trafficked persons are examined in relational geographies of inequality, manoeuvring and mobilities. Such a conceptual shift ensures that efforts to understand and combat human trafficking address its effects as well as the wider social relations and structural conditions that facilitate exploitation. We conclude the paper by outlining how a relational‐geographic perspective has the potential to foster new forms of dialogue and inquiry within and beyond the discipline.
First On-Sun Tests of a Centrifugal Particle Receiver System
Authors: Ebert Miriam , Amsbeck Lars , Buck Reiner , Rheinländer Jens , Schlögl-Knothe Bärbel , Schmitz Stefan , Sibum Marcel , Stadler Hannes , Uhlig Ralf
Published: October 2018

One direct absorption receiver concept currently investigated at the DLR is the Centrifugal Particle Receiver (CentRec®). Successful tests and promising results of this receiver design have been achieved in a Proof-of-Concept scale with 7.5 kW thermal power and 900°C particle temperature in 2014. Based on these results the prototype has been scaled up to 2.5 MW thermal power for a future pilot plant. Lab tests have been carried out with infrared heaters. In a next step the prototype has been prepared to be tested on-sun in a test setup in the Juelich Solar Tower, Germany. The tests aim to demonstrate high temperature operation and to evaluate the performance of the system.

The test setup consists of a centrifugal receiver integrated into the tower and a closed loop particle transport system. The transport system includes an air cooling system to cool down the particles at the receiver outlet, cold particle storage, belt bucket elevator, hopper and particle metering system. While the 2.5 MWth receiver prototype has been developed in a former project, the further infrastructure for the on-sun tests needed to be designed, manufactured and installed. The system is equipped with measurement instrumentation, data acquisition system and control software. Manufacturing of all main components has been completed. Installation of the test setup started in November 2016 and finished in June 2017. Cold and hot commissioning have been carried out from July 2017 until September 2017. On-sun tests started in September 2017. Receiver tests up to 775°C/1,430°F receiver outlet temperature and more than 900°C/1,650°F particle temperature in the receiver have already been achieved. Tests up to 900°C particle outlet temperature are planned at different load levels and will be conducted until summer 2018.

This paper describes the test setup for a centrifugal particle receiver system, presenting design, installation and commissioning of the system. It presents test results of first on-sun tests and gives an outlook on further steps regarding solar tests planned for 2018.
Performance and Emissions of a CRDI Passenger Van Using CME-Diesel Blends
Authors: Quiros Edwin N. , Aguila Rupert Karlo D. , Hernandez Manuel V. , Reyes Joseph Gerard T. , Mercado Jose Gabriel E.
Published: October 2018

In a move to reduce dependence on imported fossil fuels, develop and utilize indigenous renewable and sustainably-sourced clean energy sources, the Philippines enacted the Biofuels Act of 2006 (or Republic Act 9367) that mandated blending of biodiesel with commercially sold diesel fuels which presently is at 2% coconut methyl ester (CME) by volume. Deliberations are underway to shift to 5% by volume so that data on the effects on performance and emissions of percentage blends are necessary. This study presents fuel consumption and emissions measurements of an in-use passenger van with a common-rail direct injection (CRDI) powertrain fueled with 2, 5, 10, & 20 percent CME-diesel blends by volume (designated as B2, B5, B10, & B20 respectively) driven on the Japanese 10–15 Mode drive cycle. Results indicate B2-B20 had only a marginal effect on heating values, fuel blend density, and maximum power. Relative to neat diesel, the blends showed a 1–5% lower specific fuel consumption (SFC) with B5 lowest. Mileage was 1–5% higher with the blends with B5 highest. CO decreased with increasing blend. THC emissions of B1-B20 were roughly half that of diesel. NOx from the CME blends was marginally lower than diesel. The CO and THC trends agreed with published literature and usually ascribed to overall lean mixtures and increased amount of oxygenated fuel at higher CME blends. The NOx results need further investigation as it seemed to contradict other studies. Based on these results, B5 yielded the best combination of fuel economy and emissions improvement over neat diesel and B2 without performance loss.
Addressing Economic and Energy Poverty Through Locally Available Biomass Resources: Investigation of Issues Concerning India and South Africa
Authors: Enweremadu Christopher , Baruah Debendra , Mahapatra Sadhan , Patowary Dipam , Sarma Gunajit , Kataki Sampriti
Published: October 2018

The cyclic effect of energy poverty and economic poverty has been conclusively evidenced primarily from the experiences of developing World. In the developing countries, struggle to meet the basic energy needs impacts the life of the poorer section in terms of cost of health, education and quality. However, considering the adequate biomass resources and sustainable technologies for conversion of surplus biomass into useful form of energy; integration of the surplus resources with appropriate technology offers opportunities to address both energy and economic poverty. In this study, feasibility of some proven options of bioenergy based energy technologies and enterprises are investigated to understand their prospects to address energy and economic hardship considering a case study from India and analyzed its replicability in South Africa. Resources inventories, avenues of additional income generation and long term impact of selected bioenergy enterprise options (biogas and producer gas and improved stove) are investigated in the context of both the countries. Organic fertilizer (vermicompost), mushroom and community based agro-industries are some of the prospective entrepreneurial activities which can be supported by the bioenergy options. Considering the abundance and characteristics, feasibility of converting surplus biomass resources (crop residue, manure, food waste) into required energy along with revenue earning avenues is indicated by the study. However, there are social and managerial issues which required to be addressed besides provisions for financial incentives to realize the benefits of such integrated systems.
Parametric Experiments of Water Transport Characteristic in Nafion® Membrane
Authors: Son Jaemin , Yu Sangseok
Published: October 2018

In a PEMFC (Proton electrolyte membrane fuel cell), water transport mechanism inside the membrane is very important in performance and durability of whole fuel cell stack. Diffusion of water through the membrane is governed by humidity conditions of outer layers and the humidity conditions of gases depend on temperature, pressure and operating pressures. Since those parameters are varied non-linearly, it is necessary to investigate water transport mechanism by concentration difference between both sides of membrane.

In this study, water contents of Nafion® membrane is measured in terms of relative humidity, temperatures, and operating pressure. Water diffusion is also measured at different pressures in both sides. Test chamber is designed to fix membrane in the middle of chamber and the membrane separates chambers in two spaces. Parametric study is conducted to measure the water contents of membranes in terms of temperatures 30°C, 50°C, 70°C, 90°C and 0 to 100% relative humidity. When the water diffusivity is calculated by measured data, the water concentrations in both sides are determined by harmonic averages of inlet and exit water humidity. Additionally, water flux is also investigated in terms of both sides humidity, operating pressure and temperatures. As a result, the water diffusion coefficient was explained by the operating temperature and the relative humidity and operating pressures.
Brazings for Metal-Ceramic Joining in Sodium Thermal Electrochemical Converter (Na-TEC) Devices
Authors: Gunawan Andrey , Ha Jong Min , England Diane M. , Limia Alexander , Kottke Peter A. , Fedorov Andrei G. , Lee Seung Woo , Yee Shannon K.
Published: October 2018

Sodium thermal electrochemical converters (Na-TECs) offer a high efficiency advancement for converting thermal energy into electrical energy without moving parts. Since the cell operates using a Na pressure difference between the high temperature evaporator and the lower temperature condenser, a hermetic seal capable of maintaining that pressure difference is essential. This study looked at brazing of the ceramic electrolyte used in these cells, which is a β”-alumina solid-electrolyte referred to as BASE. Since a literature search found no papers pertaining to brazing of BASE, knowledge from ceramic to metal brazing called widegap brazing was used. Specifically, the widegap brazing of α-alumina to nickel-based alloys. Initial brazing trials used a traditional inert atmospheric brazing technique with an Ar-H2 gas mixture. However, the very low pO2 atmosphere resulted in the destruction of the BASE layers due to the diffusion of carbon to the outer surface of the electrolyte during brazing. A new and radically different brazing technique called air brazing was then attempted. This brazing technique proved successful using the brazing alloy Ag-8CuO. Both Ag and Cu are not deleteriously affected by Na corrosion; thus, Ag-8CuO were a good choice for the braze alloy. Leak tests were performed on these cells to establish their hermeticity. This cell structure and brazing technique proved to be successful. Air brazing is an exciting joining operation for these types of cells.
Estimating the Agricultural Environmental Burden As Part of a Holistic Life Cycle Assessment of Food
Authors: Dai T. , Fleischer A. S. , Wemhoff A. P. , Lee R.
Published: October 2018

A precise calculation of the environmental burden of food products is a prerequisite for creating food eco-labeling as a strategy for environmental impact mitigation. Life cycle assessment (LCA) is widely used for this purpose, and proxy data is traditionally used due to the shortage of data. Uncertainties are introduced in this process since food products contain a variety of origins. In this study, data from the United States Department of Agriculture (USDA) is used to examine the temporal and geographic variability of the global warming potential (GWP) of seven kinds of field crops. Artificial neural network (ANN) models are then used to predict the GWP of these products at both product and category levels based on temporal and spatial variables such as soil properties, climate, latitude and elevation. The results show that temporally, a monotonic GWP trend was found in corn, soybean and winter wheat. The average geographic variability is more than 27% and is larger than temporal variability. ANN was proven to be a good prediction tool at the product level, with a coefficient of correlation (CC) of at least 0.78 in the simplest model and higher CCs when the number of neurons increases. Predictions with ANN at the category level shows that the selected variables cannot fully encompass all temporal and geographical variability.
Erosion Wear and Performance Simulation of Centrifugal Pump for Solid-Liquid Flow
Authors: Lai Fen , Zhu Xiangyuan , Xu Xun , Li Guojun
Published: October 2018

Erosion wear caused by solid particles is recognized as one of the major concerns for centrifugal pumps. In this paper, a two-way coupled Eulerian-Lagrangian approach is employed to solve the solid-liquid flow in the centrifugal pump. The erosion model developed in the Erosion/Corrosion Research Center (E/CRC), combined with the Grant and Tabakoff particle-wall rebound model, are employed to predict particles behaviors and erosion wear. Three-dimensional transient calculation of the centrifugal pump for solid-liquid flow is carried out to research the performance and erosion wear of centrifugal pump. The influence of concentrations and diameters of solid particles are also investigated. The results show that the existence of solid particles decreases the static pressure and the velocity of liquid. The frequency of impingement and rebound will increase with the increase of the concentrations of solid particles. The middle of the hub and the trailing edge of blades pressure side are the most serious erosion regions.
Simulation of Dissolution Front Propagation During Acid Injection Into Porous Media: A CFD Approach
Authors: Abdelfatah Elsayed , Pournik Maysam , Craig David
Published: October 2018

Acid is often injected into porous media to dissolve rock material and enhance flow capability of the rock. Most simulation studies on the propagation of the dissolution front are based on constant injection rate (CIR). Therefore, the objective of this work is to develop numerical model to study acid dissolution front under constant injection pressure (CIP) and also incorporate the effect of fluid temperature on acid–rock interaction. Commercial computational Fluid Dynamics (CFD) software (ANSYS Fluent) is used to solve three-dimensional acid-rock interaction model in cylindrical coordinates. In this work, correlated porosity and permeability distributions are generated. Effect of heat transfer between the injected fluid and the formation on fluid properties and surface reaction rate are accounted for in the model. The study confirmed that all types of acid dissolution patterns exist during constant injection pressure. CIP technique requires lower acid volume to achieve breakthrough in the conical and branched dissolution regimes, than that is required for CIR technique. In dominant wormhole pattern, both techniques require nearly the same acid volume to breakthrough. Thermal interaction between the injected fluid and the formation leads to change of surface reaction rate and physical properties of the fluid, such as viscosity, density, and diffusivity. Injection of cold fluid into heated formation leads to a higher wormhole density as found from experimental studies due to retardation of surface reaction rate. The model developed in this work accurately captures different dissolution patterns. The model shows that the acid volume required for wormhole breakthrough depends on the inlet conditions (CIR or CIP) and the thermal interaction between the injected fluid and formation. This modeling study attempts to answer the critical questions pertaining to the effect of temperature and injection conditions on acid-rock interaction.
Exergetic and Exergoeconomic Analyses of a Parabolic Trough Solar Power Generation System
Authors: Wang Anming , Liu Ming , Han Xiaoqu , Liu Jiping
Published: October 2018

As concentrating solar power technologies moves to maturity progressively, large-scale solar thermal power plants have gained increasing attention. The exergetic and exergoeconomic analyses allow indicating energy degradation of the component quantitatively and establishing the monetary value to all material and energy flows. Therefore, they have strong theoretical implications to the system optimization. A thermodynamic simulation model of a 50 MW parabolic trough solar power generation system and the related exergetic and exergoeconomic analyses were presented in this paper. The results of exergetic analysis showed that the component of the lowest exergy efficiency was solar field, and the efficiency only had approximate 22%. Moreover, the exergy efficiencies of thermal energy storage and power block were about 81% and 58% respectively. According to the exergoeconomic analysis, the exergoeconomic cost of electricity and output thermal energy of solar field and thermal energy storage varied respectively in the ranges of 0.1277–0.1322 $/kWh, 0.0427–0.0503 $/kWh, and 0.0977–0.1074 $/kWh when thermal energy storage capacity ranged from 4 hours to 12 hours.
Time and Spatial Modeling of Wear Mechanisms in Nuclear Steam Turbine Blades Using Dynamic Bayesian Networks
Authors: Quintanar-Gago David A. , Nelson Pamela F. , Díaz-Sánchez Ángeles
Published: October 2018

This paper describes a quantitative methodology to estimate the probability of blade failure modes resulting from typical wear mechanisms in nuclear turbines, which can be used to optimize maintenance. The approach used to model time and spatial dependence of wear mechanisms that affect blades involves the coupling of a Static Bayesian Network to a Dynamic Bayesian Network. This prototype model has been designed to use conditional and time dependent Weibull-like failure rates that can be computed from reliability data bases (failure times and modes, associated causes, row and blade part that failed) to quantify Markov matrixes contained within dynamic nodes.

The model can be used to make inferences such as the most probable causes of failure in a row and blade part, and visualize the probability as a function of time. It can be also used to determine the riskier location given evidence such as failure mode or the wear mechanisms involved. Also, maintenance tasks acting over time dependent failure functions have been implemented to exemplify the effect of perfect and three kinds of imperfect actions and how they affect the mechanisms and failure mode evolution, given the conditional dependences among them.
Experimental Investigation of Heat Transfer and Friction Factor Characteristics Using Helical Surface Ring Turbulators in an Annulli of Double Pipe Heat Exchanger
Authors: Yadav Saurabh , Paulraj Maheandera Prabu , Sahu Santosh K.
Published: October 2018

Augmentation in heat transfer is very useful for various engineering and scientific applications due to the call for energy and cost saving. The heat transfer and pressure drop characteristics in annuli of double pipe heat exchanger using helical and plain surface ring turbulators are studied through experimental investigation. The effect of helical surface ring turbulators and plain surface ring turbulators are studied for varied range of pitch ratio (4.0–6.4), Reynolds Number (3,000–10,500) and two different diameter ratios (0.475 and 0.54). Water (hot fluid) flows in the inner tube and air (cold fluid) flows through the annulus. The tests are conducted for air with uniform wall temperature condition. The heat exchanger with least pitch and least diameter ratio is found to exhibit the highest Nusselt number and pressure drop. Results indicate that maximum enhancement is obtained for smallest diameter ratio 0.475 and pitch ratio 4.0 at lowest Reynolds Number. Also, thermal performance factor is always greater than unity for the DPHE using helical surface turbulators. Correlations have been developed for enhancement in Nusselt number and friction factor; show the good agreement with experimental test data within test range.