bluuebunny/crossref_metadata_2025 huggingface dataset:
Preoviposition paternal care in a fully aquatic giant salamander: nest cleaning by a den master
Authors: Terry J. , Taguchi Y. , Dixon J. , Kuwabara K. , Takahashi M. K.
Published: September 2018

Parental care in salamanders is thought to be simple and typically limited to female egg attendance. No elaborate preoviposition parental care had been described from salamanders. Recent studies revealed complex care behaviours by male Japanese giant salamanders (Andrias japonicus), a fully aquatic, secretive species with external fertilization. These studies emphasize behavioural convergence in paternal care between some of the fish species and the giant salamanders. The fish examples further imply the possibility that males of A. japonicus provide preoviposition parental care in the form of nest cleaning and building. We tested this possibility and also predicted that cleaning effort by a male salamander, if exists, would increase as it approaches the spawning event. Prior to the breeding season, large males (i.e. den masters) of A. japonicus occupy and guard suitable burrows well‐hidden along the stream bank. In the falls of 2012, 2013 and 2015, we videotaped and examined a single den master's pre‐ and postoviposition behaviours at Asa Zoological Park in Hiroshima, Japan. The den master repeatedly exhibited vigorous movements of front and hind limbs in a paddling motion at the bottom of the nest every day for the three separate years. The cleaning effort by the den master lineally increased as the spawning event approached, after which the den master completely ceased cleaning. With the cleaning behaviour, the den master made the den filled with debris including leaves and twigs buried in the sand. The floating debris was subsequently removed by the water current flowing through the nest. Water mould infection is a major cause of offspring mortality of aquatic amphibians including A. japonicus. By reducing the amount of organic matter that provides food sources for water mould, the nest cleaning likely reduces the risk of water mould infection among the offspring, serving as an important preoviposition parental care.
Dietary energy density is associated with body mass index‐for‐age in Mexican adolescents
Authors: Arango‐Angarita Andrea , Shamah‐Levy Teresa , Rodríguez‐Ramírez Sonia
Published: September 2018

Dietary energy density (DED) has been widely considered a risk factor for weight gain. In adolescents, however, the evidence is inconclusive, and in Mexico, the ways in which DED is associated with overweight and obesity are unknown. Our study analysed the association of DED with overweight or obesity (OW‐O) in Mexican adolescents included in the National Health and Nutrition Survey 2012 (ENSANUT 2012). We analysed the data from a 7‐day Food Frequency Questionnaire administered to 2,203 Mexican adolescents aged 12–19 years. DED was calculated excluding all beverages. Plausible and implausible reporters were identified based on the relationship between the reported energy intake and the estimated energy requirement. The association of DED with body mass index (BMI)‐for‐age and OW‐O was analysed using multivariate statistical models restricted to plausible reporters. The combined prevalence of overweight and obesity was 35.4% in the complete sample and 27.8% in the sample of plausible reporters. Mean DED was 177 kcal/100 g, with higher DED in the north of the country. The proportion of plausible reporters was 38.5%. We found a positive association between high DED and the BMI‐for‐age z‐score (β = 0.347; 95% CI [0.101, 0.594]; P = 0.006), controlling for sociodemographic and dietary variables, but no significant association with OW‐O. It is necessary to consider the DED in the design and implementation of strategies to reduce energy density in the diets of young Mexicans.
Changes in growth, anaemia, and iron deficiency among children aged 6–23 months in two districts in Nepal that were part of the post‐pilot scale‐up of an integrated infant and young child feeding and micronutrient powder intervention
Authors: Locks Lindsey M. , Dahal Pradiumna , Pokharel Rajkumar , Joshi Nira , Paudyal Naveen , Whitehead Ralph D. , Chitekwe Stanley , Mei Zuguo , Lamichhane Bikash , Garg Aashima , Jefferds Maria Elena
Published: September 2018

There is limited research on integrated infant and young child feeding (IYCF) and micronutrient powders (MNPs) programmes operating at scale, despite widespread implementation. This study uses cross‐sectional baseline (n = 2,542) and endline (n = 2,578) surveys representative of children 6–23 months in two districts in Nepal that were part of a post‐pilot scale‐up of a IYCF–MNP programme. Multivariable log‐binomial regression models were used to estimate prevalence ratios (PRs) for stunting (length‐for‐age z‐score <−2), wasting (weight‐for‐length z‐score <−2), underweight (weight‐for‐age z‐score <−2), anaemia (altitude‐adjusted haemoglobin <110 μg/L), moderate or severe anaemia (altitude‐adjusted haemoglobin <100 g/L), iron deficiency (inflammation‐adjusted ferritin <12 μg/L), and iron deficiency anaemia (iron deficiency + anaemia [IDA]) at endline versus baseline and also to compare children in the endline survey based on frequency of mothers' interactions with female community health volunteers (FCHVs; >1× per month or monthly vs. <1× per month) and MNP coverage (1 or ≥2 distributions vs. none among children 12–23 months). Endline children were significantly less likely to be stunted than baseline children in both districts (multivariable‐adjusted PR [95% CI]: 0.77 [0.69, 0.85], P < 0.001 and 0.82 [0.75, 0.91], P < 0.001 in Kapilvastu and Achham, respectively); however, only Achham had significantly lower prevalences of underweight, moderate/severe anaemia, iron deficiency, and IDA at endline. At endline, 53.5% and 71.4% of children had tried MNP in Kapilvastu and Achham districts, respectively, consuming an average of 24 sachets from the last distribution. Frequent maternal–FCHV interactions were associated with a reduced risk of stunting and underweight at endline, whereas repeat MNP coverage was associated with reduced risk of anaemia and IDA. Future research using experimental designs should verify the potential of integrated IYCF–MNP programmes to improve children's nutritional status.
How bacterioplankton community can go with cascade damming in the highly regulated Lancang–Mekong River Basin
Authors: Wang Xun , Wang Chao , Wang Peifang , Chen Juan , Miao Lingzhan , Feng Tao , Yuan Qiusheng , Liu Sheng
Published: September 2018

Rivers make vital contributions to the transport of water, sediment and nutrients from terrestrial to marine ecosystems. However, many large rivers worldwide are suffering from dam regulation. Increasing attention has been paid to bacterioplankton communities since they are highly responsive to river alterations and may influence biogeochemical processes. Here, a comprehensive study was conducted in the highly regulated Lancang–Mekong River Basin to address the question of how bacterioplankton communities respond to cascade damming. The results showed that dam constructions increased nutrient concentrations and threatened water quality in cascade reservoirs. Bacterioplankton cell abundance was reduced by damming, and α‐diversity was inhibited in cascade reservoirs. Fortunately, however, river ecosystems were resilient after the remarkable disturbance caused by damming. Moreover, bacterioplankton community composition was significantly altered by cascade dams, including a shift in the dominant phylum from r‐strategists to k‐strategists. Meanwhile, according to GeoChip analysis, the functional composition of bacterioplankton was less affected than taxonomic composition. In addition, geographic and environmental features both followed a distance–decay relationship with community and functional composition, but the local environment condition was the dominant driver in the Lancang River. Therefore, the impoundments of cascade dams had significant impacts on bacterioplankton communities and more attention should be paid to the potential ecological consequences of river regulation.
Lime powder regimen supplement alleviates urinary metabolic abnormalities in urolithiasis patients
Authors: Ungjaroenwathana Wattanachai , Chiramongkolsiri Thanida , Dissayabutra Thasinas , Boonla Chanchai , Prapunwattana Phisit , Tungsanga Kriang , Tosukhowong Piyaratana
Published: September 2018

Background

Urolithiasis has high recurrent rate after surgical removal within 3 years. Potassium citrate compound is used to prevent stone recurrence but it has intolerable gastrointestinal adverse effects. We conducted a phase 2 clinical study of lime power regimen (LPR), a limeade‐based supplement containing potassium and citrate for 6 months period of treatment, to evaluate its effects on biochemical and clinical aspects of recurrent urolithiasis.

Methods

Seventy‐four urolithiasis patients were randomly allocated to receive either LPR or placebo for 6 months in a double‐blinded manner. Plasma and 24 h urine samples were collected to measure urinary pH, mineral excretion and urinary total antioxidant status , plasma for creatinine and plasma protein carbonyl, and stone for elemental analysis at the initiation and end‐of‐treatment (6 month). Adverse effects were recorded.

Results

Administration of LPR significantly increased urinary pH, citrate and potassium excretion. Urinary levels of calcium and oxalate, and plasma protein carbonyl content were reduced, while urinary total antioxidant status was elevated by LPR treatment. Urinary supersaturation was decreased and urinary protein excretion was ameliorated in LPR‐treated patients. Gastrointestinal adverse effects were rarely observed. None of the participants developed stone recurrence for the duration of the trial.

Conclusion

Lime power regimen is a potential drug to correct urinary metabolic disorders associated with urolithiasis in high risk stone recurrent patients. A phase 3 clinical trial is underway to validate anti‐stone recurrence property of LPR in long‐term treatment.
Sera with anti‐enteric neuronal antibodies from patients with irritable bowel syndrome promote apoptosis in myenteric neurons of guinea pigs and human SH‐Sy5Y cells
Authors: Fan Wenjuan , Fei Guijun , Li Xiaoqing , Wang Xiyu , Hu Chaojun , Xin Haiwei , Sun Xiaohong , Li Yongzhe , Wood Jackie D , Fang Xiucai
Published: September 2018

Background

Sera anti‐enteric neuronal antibodies (AENA), neuronal inflammation, and degeneration in myenteric plexus in patients with irritable bowel syndrome (IBS) were reported. Effects of sera AENA in patients with IBS are unclear.

Methods

Patients with IBS met Rome III criteria were enrolled. Controls included healthy subjects (HS) and patients with slow transit functional constipation, inflammatory bowel disease, chronic intestinal pseudo‐obstruction, and autoimmune diseases. Indirect immunofluorescence was used to detect AENA. Anti‐enteric neuronal antibodies intensities were termed as “1” = weak fluorescence (mild positive); “2” = moderate fluorescence (moderate positive); “3” = very high fluorescence (intensive positive). Intensities of ≥1 were defined as positive and ≥2 were defined as obvious positive. Cultured myenteric neurons of small intestine from guinea pigs and human SH‐Sy5Y cells were incubated with fetal bovine serum (FBS), HS sera, or IBS sera with or without AENA. Indirect immunofluorescence with anti‐PGP9.5/DAPI/anti‐active caspase‐3 or TUNEL, Western blot, and flow cytometry were used to detect apoptosis.

Key Results

Overall, 293 patients with IBS were enrolled (41.7 ± 11.5 years). AENA‐positive and obvious positive rates in IBS were higher than HS (76.8% vs 33%; 43.7% vs 7%; all P < 0.001). Myenteric neurons incubated with AENA moderate or intensive positive IBS sera showed higher rates of anti‐active caspase‐3 and TUNEL‐positive cells than HS or FBS (20% ± 7.3% and 35% ± 13.3% vs 4.3% ± 1.5% and 0.9% ± 0.4%, respectively; 6.2% ± 2.0% and 10.2% ± 4.6% vs 1.3% ± 1.9% and 0.5%±0.5%, respectively; all P < 0.05). Human SH‐Sy5Y cells incubated with AENA moderate or intensive positive IBS sera showed increased cleaved caspase‐3 and Bax expression and decreased Bcl‐2 expression. Flow cytometry showed apoptosis rates of these two groups were higher than that of AENA mild positive, negative, HS, and FBS (7.6%±0.8% and 10.7%±1.3% vs 5.0%±0.8%, 3.8%±0.3%, 3.4%±0.2% and, 2.8%±0.2%, P < 0.05).

Conclusions and Inferences

The AENA obvious positive rate in patients with IBS was higher than HS, and sera with higher levels of AENA promoted neuronal apoptosis. AENA‐mediated neuropathy might exist in a subset of patients with IBS.
Global prevalence and disease burden of vitamin D deficiency: a roadmap for action in low‐ and middle‐income countries
Authors: Roth Daniel E. , Abrams Steven A. , Aloia John , Bergeron Gilles , Bourassa Megan W. , Brown Kenneth H. , Calvo Mona S. , Cashman Kevin D. , Combs Gerald , De‐Regil Luz María , Jefferds Maria Elena , Jones Kerry S. , Kapner Hallie , Martineau Adrian R. , Neufeld Lynnette M. , Schleicher Rosemary L. , Thacher Tom D. , Whiting Susan J.
Published: September 2018

Vitamin D is an essential nutrient for bone health and may influence the risks of respiratory illness, adverse pregnancy outcomes, and chronic diseases of adulthood. Because many countries have a relatively low supply of foods rich in vitamin D and inadequate exposure to natural ultraviolet B (UVB) radiation from sunlight, an important proportion of the global population is at risk of vitamin D deficiency. There is general agreement that the minimum serum/plasma 25‐hydroxyvitamin D concentration (25(OH)D) that protects against vitamin D deficiency–related bone disease is approximately 30 nmol/L; therefore, this threshold is suitable to define vitamin D deficiency in population surveys. However, efforts to assess the vitamin D status of populations in low‐ and middle‐income countries have been hampered by limited availability of population‐representative 25(OH)D data, particularly among population subgroups most vulnerable to the skeletal and potential extraskeletal consequences of low vitamin D status, namely exclusively breastfed infants, children, adolescents, pregnant and lactating women, and the elderly. In the absence of 25(OH)D data, identification of communities that would benefit from public health interventions to improve vitamin D status may require proxy indicators of the population risk of vitamin D deficiency, such as the prevalence of rickets or metrics of usual UVB exposure. If a high prevalence of vitamin D deficiency is identified (>20% prevalence of 25(OH)D < 30 nmol/L) or the risk for vitamin D deficiency is determined to be high based on proxy indicators (e.g., prevalence of rickets >1%), food fortification and/or targeted vitamin D supplementation policies can be implemented to reduce the burden of vitamin D deficiency–related conditions in vulnerable populations.
Delivering remote monitoring data to patients with implantable cardioverter‐defibrillators: Does medium matter?
Authors: Mirro Michael , Daley Carly , Wagner Shauna , Rohani Ghahari Romisa , Drouin Michelle , Toscos Tammy
Published: September 2018

Background

This study presents findings on the impact of providing patients with their implantable device data on patients’ satisfaction, engagement, healthcare utilization, and provider's perceptions of this practice. Remote monitoring of implantable cardioverter defibrillators (ICDs) improves patient care through timely delivery of ICD data to the clinic. However, patients usually do not receive their ICD data. Providers are concerned that messaging patients with their device data could increase clinical workload.

Methods

To evaluate the impact of sharing ICD data summary through the patient portal, 128 patients were randomized into two groups. Group A and B received their data through the patient portal and postal mail, respectively. Data were collected through surveys and medical record reviews. Forty‐eight providers also completed a survey.

Results

At the end of the study, at least two‐thirds of patients were satisfied with the amount of information received through the electronic or paper ICD data summary. Additionally, providing patients with their device data did not increase ICD‐specific clinical workload (e.g., calls or messages to provider). While providers did not foresee the provision of ICD data to patients as decreasing or improving clinical workload, they did see potential value in it for patients.

Conclusions

Providing patients with their ICD data (through paper or electronic means) might have the potential to improve patient satisfaction and enhance shared‐decision making without adversely impacting clinical workload.
Development of simulation combining a physical heart model and three‐dimensional system for electrophysiology training
Authors: Rossi Luca , Penela Diego , Doni Lorenzo , Marazzi Raffaella , Napoli Velia , Napoli Leonardo , Vilotta Manola , Villani Giovanni Quinto , De Ponti Roberto
Published: September 2018

Background

A new three‐dimensional heart anatomical simulator (3D HAS) has been created combining a physical heart model with an electroanatomic mapping (EAM) system. The aim of this study is to describe the development and the validation process of this device.

Methods

We developed the 3D HAS combining a physical heart model with an EAM system. This simulator was then validated by 10 electrophysiologists, subdivided in two groups based on their experience in electrophysiology procedures. The performance of the experts was compared to the one of the novices in achieving three different tasks: fluoroless reconstruction of the right atrium, coronary sinus cannulation, and deployment of a linear ablation lesion in the cavotricuspid isthmus. For each operator, a score was calculated based on objective parameter for each task and for the overall performance.

Results

The 3D HAS was located in an environment that allowed use of the main features of the EAM system including contact force sensing. No technical issue was encountered during the validation process. The experts’ performance was significantly better than the one of the novices both overall (P = 0.009) and in each task (right atrium reconstruction, P = 0.016; coronary sinus cannulation, P = 0.008; ablation lesion, P = 0.03).

Conclusions

The 3D HAS is reliable and allows use of the main features of an EAM system in the right atrium. The ability to discriminate different levels of experience suggests that this simulator is enough realistic and could be useful for electrophysiology training.
Photocatalytic Performance of H6P2W18O62/TiO2 Nanocomposite Encapsulated into Beta Zeolite under UV Irradiation in the Degradation of Methyl Orange
Authors: Moosavifar Maryam , Bagheri Samira
Published: September 2018

In this work, neat and supported H6P2W18O62 into nanocage of β‐zeolite were synthesized. However, H6P2W18O62 into nanocage of β‐zeolite was synthesized via template synthesis method. In addition, TiO2 was supported on H6P2W18O62/β zeolite by impregnation method. The obtained materials were characterized by XRD, FT‐IR, UV‐Vis, FESEM and EDS techniques. Also, W and Ti contents of the catalyst were determined by ICP and EDS technique. The results reveal that the photocatalyst performance depends on catalyst loading, pH effect, and methyl orange concentration. Photocatalytic degradation of methyl orange follows a pseudo‐first order kinetic. The chemical oxygen demand (COD) experimental proved mineralization of methyl orange. Another reason for degradation and mineralization of methyl orange is the absence of hydrazine at the end of reaction which is one of the photodecolorization products. The plausible mechanism for photodegradation of MO was proposed.
Shouldering the Weight of the State: Religious Zionist Citizenship, National Responsibility, and Jewish Conversion in Israel
Authors: Kravel‐Tovi Michal
Published: September 2018

Based on ethnographic fieldwork conducted with Jewish conversion agents and activists in Israel between 2004 and 2007, this article argues that state‐run Jewish conversion provides a constructive institutional arena for religious Zionists to rework their active citizenship, in both the Israeli state and the religious Zionism movement. To the extent that Israel offers a compelling case for understanding how and why the politics of religious conversion intersect with the legal and bureaucratic dynamics of the modern nation‐state, it also allows us to unpack the identity work of those who take it upon themselves to embody the morals and ambitions of the Jewish state. I draw on anthropological writing on the state and citizenship to argue that, by working institutionally on behalf of the state and investing itself in a goal assumed to secure its future, the religious Zionist community attempts to reaffirm the idea of “national responsibility” —a discursive construct that underwrites its interdependent relationship with the Israeli state. Such a reaffirmation is of particular importance in light of the volatile struggles it has had with and within the state over Israel's political and religious policies.
Characterization ofc-,L- andϕk-optimal Designs for a Class of Non-Linear Multiple-Regression Models
Authors: Schmidt Dennis
Published: September 2018

Optimal designs for multiple-regression models are determined. We consider a general class of non-linear models including proportional hazards models with different censoring schemes, the Poisson and the negative binomial model. For these models we provide a complete characterization of c-optimal designs for all vectors c in the case of a single covariate. For multiple regression with an arbitrary number of covariates, c-optimal designs for certain vectors c are derived analytically. Using some general results on the structure of optimal designs for multiple regression, we determine L- and ϕk-optimal designs for models with an arbitrary number of covariates.
Origins and genesis of loess deposits in central Spain, as indicated by heavy mineral compositions and grain‐size variability
Authors: Wolf Daniel , Ryborz Karoline , Kolb Thomas , Calvo Zapata Ruben , Sanchez Vizcaino Jesús , Zöller Ludwig , Faust Dominik
Published: September 2018

The formation of loess deposits strongly depends on the availability of deflatable dust‐sized material. Identification of source areas and mechanisms of dust production is essential for an appropriate characterization of related palaeoenvironmental conditions. So far, little research has been done on loess deposits in the Mediterranean region and information about mechanisms of dust production is very rare. In this context, it is not clear from where the loess deposits from the upper Tagus Basin in central Spain originated. The main objective of this study was to find out whether these loess deposits were formed primarily by mountain processes and fluvial comminution, or whether they have their origin in the weathering of Tertiary marls in the centre of the Madrid Basin. A further concern was to link the determined source areas with loess formation mechanisms and concomitant environmental contexts. Following a comprehensive approach using heavy minerals and grain‐size data, together with information on stratigraphic features and geomorphic positions, different local loess sources could be identified. This study shows that during the last 35 kyr a major proportion of the Tagus loess deposits was deflated from river floodplains, while the mountain region of the Iberian Range was identified as a significant source of respective floodplain sediments. Based on heavy mineral compositions and dating results, it was found that during Heinrich Stadial 3, sediment supply from the Iberian Range strongly increased, suggesting an environmental shift from initially warmer towards colder temperatures in late Marine Isotope Stage 3. Furthermore, it was found that grain‐size patterns clearly indicate maximum wind strengths during Heinrich Stadial 3, followed by Heinrich Stadial 2 and Heinrich Stadial 1. These results demonstrate that the formation of dust‐sized particles in this part of the Mediterranean operated similar to many other places in temperate and continental regions, and that weathering processes linked to hot and dry environments were only of minor importance.
Just the Place is Different: Comparisons of Place and Settlement Practices of some Hong Kong Migrants in Sydney
Authors: Mar Phillip
Published: September 2018

Interviews with HK migrants in Sydney yield a diverse array of perceptions about their sense of space and position. These 'spatial stories' (following de Certeau) can be read as different ways of inhabiting the everyday, as narratives which may cut across the 'proper' spatial order. All the senses are brought into play in accounts of densities and absences in people's everyday world. Banal discourses about 'here' and 'there' provide migrant subjects with a means to evaluate their social and spatial trajectories by comparing the 'feel' of very different places and scales. I also point to the limits of such strategies, and the kind of memories which lie outside of discursive exchanges.
The novel HLA‐DRB3*02:02:11 allele identified in an Italian individual
Authors: Battarra Mariarosa , Locatelli Franco , Galluccio Tiziana , Guagnano Annalisa , Andreani Marco
Published: September 2018

HLA‐DRB3*02:02:11 differs from HLA‐DRB3*02:02:01:01 by a single synonymous substitution in exon 3’.
Detection of an HLA‐B*58 variant, HLA‐B*58:19, by sequence‐based typing in a Taiwanese individual
Authors: Yang K. L. , Lin Py Y.
Published: September 2018

One nucleotide substitution at codon 152 of HLA‐B*58:01:01:01 results in a novel allele, HLA‐B*58:19.
Microbiota in anaerobic digestion of sewage sludge with and without co‐substrates
Authors: Walter Andreas , Probst Maraike , Franke‐Whittle Ingrid H. , Ebner Christian , Podmirseg Sabine Marie , Etemadi‐Shalamzari Mohammad , Hupfauf Sebastian , Insam Heribert
Published: September 2018

In this study, seven full‐scale anaerobic digesters, with or without co‐substrate regime, were analysed by physicochemical and molecular biological methods. A combination of robust community fingerprinting and Illumina MiSeq sequencing revealed a core bacterial community dominated by Chloroflexi, Firmicutes, Bacteroidetes and Proteobacteria, with variations in the profiles because of differences in the co‐substrate feeding regime. Despite these differences, physicochemical properties revealed a stable performance of all reactors, indicating a resilient bacterial microbiota in all full‐scale reactors. A rich bacterial core community ensured reactor functionality, whilst feeding regime and reactor type impacted the overall and the core bacterial diversity. Within the Archaea, Methanosaeta dominated in all reactors. Results indicated no relationship between archaeal community structure and the type of co‐substrate digested. Methanogens rely on the metabolic end products of bacterial activity and are thus less dependent on differences in the initial co‐substrate regime.
Meeting Management Skills of District Directors of National Education According to Perceptions of School Managers
Authors: Çalışkan Abdulkadir , Özdemir Ali
Published: September 2018

The purpose of this research is the examination of meeting management skills of District Directors of National Education according to the perception of school managers. Scanning model, as one of the Quantitative methods, was used in the research. The research universe is the managers of schools in districts of Maltepe, Sultanbeyli, Kartal and Pendik. 309 school managers formed the sample of the research which was determined by a random sampling method. According to the education level of school managers, in their perception of meeting management skills of District Directors of National Education, no significant difference was found in sub-dimensions of participant management, time management, and management of meeting room facilities, management of meeting agenda, and management of minutes of meeting. However, a significant difference was found in the sub-dimension of meeting management skills and in total scale. Managers with a B.A degree evaluated more positively the District Directors of National Education than managers with a graduate degree. According to the duties of the school managers, there was a significant difference in the sub-dimension of participant management among the arithmetic averages (mean) of the groups in the meeting management skills of the District Director of National Education. While there was a significant difference in total scale and in skills of meeting management and time management regarding school managers’ perception of meeting management skills of the District Director of National Education according to the age of school managers, there was no difference in other sub-dimensions.
Optimal Design of Three-Dimensional Heat Flow Structures for Power Electronics Applications
Authors: Dede Ercan M. , Liu Yanghe , Joshi Shailesh N. , Zhou Feng , Lohan Danny J. , Shin Jong-Won
Published: September 2018

Design optimization of a three-dimensional (3D) heat flow structure for power electronics gate drive circuit thermal management is described. Optimization methods are described in the creation of several structural concepts targeted toward simultaneous temperature reduction of multiple gate drive integrated circuit (IC) devices. Each heat flow path concept is intended for seamless integration based on power electronics packaging space constraints, while maintaining required electrical isolation. The design synthesis and fabrication of a select concept prototype is presented along with the development of an experimental test bench for thermal performance characterization. Experimental results indicate a significant 45 ∘C maximum temperature reduction for the gate drive IC devices in a laboratory environment, which translates to an estimated 41 °C maximum temperature reduction under high temperature (∼100 °C) ambient conditions. The technical approach and design strategy are applicable to future wide band-gap (WBG) electronics packaging applications, where enhanced 3D thermal routing is expected to be critical to maximizing volumetric power density.
Experimental Investigation of Heat Transfer in Cavities of Steam Turbine Casings Under Generic Test Rig Conditions
Authors: Spura David , Eschmann Gunter , Uffrecht Wieland , Gampe Uwe
Published: September 2018

This paper presents the first experimental results of the systematic investigation of forced convection heat transfer in scaled generic models of steam turbine casing side spaces with varied geometric dimensions under fully turbulent air flow. Data were obtained by two redundant low-heat measuring methods. The results from the steady-state inverse method are in good agreement with the data from the local overtemperature method, which was applied via a novel miniaturized heat transfer coefficient (HTC) sensor concept. All experiments were conducted at the new side space test rig “SiSTeR” at TU Dresden. The dependencies of the HTC distributions on the axial widths of the cavity and its inlet and on the eccentricity between them were investigated for Reynolds numbers from Re=40,000 to 115,000 in the annular main flow passage. The measured HTC distributions showed a maximum at the stagnation point where the induced jet impinges on the wall surface, and decreasing values toward the cavity corners. Local values scaled roughly with the main flow Reynolds number. The HTC distributions thereby differed considerably depending on the dimensions and the form of the cavity, ranging from symmetric T-shape to asymmetric L-shape, with upstream or downstream shifted sidewalls.
Theoretical Analysis on the Constitution of Calorific Values of Biomass Fuels
Authors: Yao Fengqi , Wang Haihui
Published: September 2018

The present work explored the constitution of the calorific values of biomass fuels and the mechanism by which basic chemical compositions affect the fuel calorific data. For the first time, an energy conversion model was developed for the functional groups stored in biomass fuels by combustion. Validation of the model was performed by testing with various types of substances. By analyzing the effect of mass increase of individual chemical species on the amount of heat released by a fuel, it was confirmed that for ligno-cellulosic fuels, the species containing C–H, C–C and C=C bonds positively affect the fuel calorific values, whereas the species containing O–H, C–N, C–O, and C=O bonds have negative role in the increase of the fuel calorific values. A ratio parameter was then developed to quantitatively evaluate the potential of individual chemical bonds to contribute to the calorific values of biomass fuels, which well explained the existing techniques for treating biomass as fuels. The outcomes of this work serve as a theoretical basis for improving the efficiency in energy utilization of biomass fuels.
Integrating Topic, Sentiment, and Syntax for Modeling Online Reviews: A Topic Model Approach
Authors: Tang Min , Jin Jian , Liu Ying , Li Chunping , Zhang Weiwen
Published: September 2018

Analyzing product online reviews has drawn much interest in the academic field. In this research, a new probabilistic topic model, called tag sentiment aspect models (TSA), is proposed on the basis of Latent Dirichlet allocation (LDA), which aims to reveal latent aspects and corresponding sentiment in a review simultaneously. Unlike other topic models which consider words in online reviews only, syntax tags are taken as visual information and, in this research, as a kind of widely used syntax information, part-of-speech (POS) tags are first reckoned. Specifically, POS tags are integrated into three versions of implementation in consideration of the fact that words with different POS tags might be utilized to express consumers' opinions. Also, the proposed TSA is one unsupervised approach and only a small number of positive and negative words are required to confine different priors for training. Finally, two big datasets regarding digital SLR and laptop are utilized to evaluate the performance of the proposed model in terms of sentiment classification and aspect extraction. Comparative experiments show that the new model can not only achieve promising results on sentiment classification but also leverage the performance on aspect extraction.
The Complete Set of One-Degree-of-Freedom Planetary Gear Trains With Up to Nine Links
Authors: Yang Wenjian , Ding Huafeng
Published: September 2018

The structural synthesis of planetary gear trains (PGTs) is helpful for innovating transmission systems in machinery. A great deal of research has been devoted to the synthesis of one-degree-of-freedom (1-DOF) PGTs over the past half century. However, most synthesis methods are limited to PGTs with no more than eight links. Moreover, the synthesis results are not consistent with each other. Until now, the inconsistency of synthesis results is still unresolved and exact synthesis results remain elusive. This paper presents a systematic and fully automatic method based on parent graphs to synthesize 1-DOF PGTs. The complete database of rotation graphs (r-graphs) and displacement graphs (d-graphs) of 1-DOF PGTs with up to nine links is established for the first time. All possible reasons for the contradictory synthesis results in the literature are analyzed and the controversy in the existing synthesis results which has lasted for nearly half a century is completely resolved. The exact results of the 6-, 7-, and 8-link r-graphs are confirmed to be 27, 152, and 1070, respectively. The exact results of the 6-, 7-, and 8-link d-graphs are confirmed to be 81, 647, and 6360, respectively. Additionally, the new results of 8654 r-graphs and 71,837 d-graphs of 9-link PGTs are provided for the first time.
Model Discrepancy Quantification in Simulation-Based Design of Dynamical Systems
Authors: Hu Zhen , Hu Chao , Mourelatos Zissimos P. , Mahadevan Sankaran
Published: September 2018

Discrete-time state-space models have been extensively used in simulation-based design of dynamical systems. These prediction models may not accurately represent the true physics of a dynamical system due to potentially flawed understanding of the system, missing physics, and/or numerical approximations. To improve the validity of these models at new design locations, this paper proposes a novel dynamic model discrepancy quantification (DMDQ) framework. Time-instantaneous prediction models are constructed for the model discrepancies of “hidden” state variables, and are used to correct the discrete-time prediction models at each time-step. For discrete-time models, the hidden state variables and their discrepancies are coupled over two adjacent time steps. Also, the state variables cannot be directly measured. These factors complicate the construction of the model discrepancy prediction models. The proposed DMDQ framework overcomes these challenges by proposing two discrepancy modeling approaches: an estimation-modeling approach and a modeling-estimation approach. The former first estimates the model discrepancy and then builds a nonparametric prediction model of the model discrepancy; the latter builds a parametric prediction model of the model discrepancy first and then estimates the parameters of the prediction model. A subsampling method is developed to reduce the computational effort in building the two types of prediction models. A mathematical example and an electrical circuit dynamical system demonstrate the effectiveness of the proposed DMDQ framework and highlight the advantages and disadvantages of the proposed approaches.
Effective
Thermal Conductivity of Stainless Steel Fiber Sintered Felt With Honeycombed
Channels
Authors: Wan Zhenping , Wang Xiaowu , Zou Shuiping , Deng Jun
Published: September 2018

A novel stainless steel fiber sintered felt (SSFSF) with honeycombed channels (SSFSFHC) is a promising support for catalytic combustion of the volatile organic compounds (VOCs). The SSFSFHC consists of stainless steel fiber, three-dimensionally reticulated porous structures, and interconnected honeycombed channels. The equivalent thermal conductivity (ETC) of the SSFSFHC is tested. It is found that the ETC of the SSFSFHC increases with the hot side temperature increasing but decreases with the porosity increasing and channel occupied area ratio increasing. The ETC of the SSFSFHC changes little with channel diameter increasing. The heat transfer model of the SSFSFHC is considered as parallel/series combinations of relevant thermal resistances. In order to estimate the ETC of the SSFSFHC, the correlation of the ETC of the SSFSF is derived. The expressions of the axial temperature under different porosities are deduced when eliminating the radial heat transfer between the channel section and the SSFSF section. The relationships of the transferred heats and the corresponding resistances along the radial direction are obtained by assuming that the radial heat transfer can be simplified as a serial of heat resistances located between the channels and the SSFSF.
Melting Heat Transfer in Squeezed Nanofluid Flow Through Darcy Forchheimer Medium
Authors: Farooq M. , Ahmad S. , Javed M. , Anjum Aisha
Published: September 2018

In this attempt, melting heat transfer characteristic of unsteady squeezed nanofluid flows in non-Darcy porous medium is interrogated. The nanofluid model incorporates Brownian diffusion and thermophoresis to characterize the heat and mass transport in the presence of thermal and solutal stratification. Similarity solutions are implemented to acquire nonlinear system of ordinary differential equations which are then evaluated using Homotopic technique. Flow behavior of involved physical parameters is examined and explanations are stated through graphs. We determine and analyze skin friction coefficient, Nusselt and Sherwood numbers through graphs. It is evident that larger melting parameter results in decrement in temperature field, while horizontal velocity enhances for higher melting parameter. Moreover, temperature and concentration fields are dominant for higher Brownian diffusion parameter.
The Second Law Analysis of Thermodynamics for the Plate–Fin Surface Performance in a Cross Flow Heat Exchanger
Authors: Khalaji Mansour Nasiri , Kotcioglu Isak , Caliskan Sinan , Cansiz Ahmet
Published: September 2018

In this paper, a particular heat exchanger is designed and analyzed by using second law of thermodynamics. The heat exchanger operates with the cross flow forced convection having cylindrical, square, and hexagonal pin fins (tubular router) placed in the rectangular duct. The pin fins are installed periodically at the top and bottom plates of the duct perpendicular to the flow direction, structured in-line, and staggered sheet layouts. The entropy generation in the flow domain of the channels is calculated to demonstrate the rate of irreversibilities. To obtain the efficiencies, irreversibility, thermal performance factor, and entropy generation number (EGN), the heat exchanger is operated at different temperatures and flow rates by using hot and cold fluids. Optimization of the design parameters and winglet geometry associated with the performance are determined by entropy generation minimization. The variation of the EGN with Reynolds number for various tubular routers is presented. The Reynolds number is determined according to the experimental plan and the performance is analyzed with the method of effectiveness—number of transfer unit (NTU). Based on particular designs, it was determined that the increment in fluid velocity enhances the heat transfer rate, which in turn decreases the heat transfer irreversibility.
Model Predictive Motion Cueing Algorithm for an Overdetermined Stewart Platform
Authors: Miunske Tobias , Pradipta Justin , Sawodny Oliver
Published: September 2018

To make motion perception more realistic, a current-implemented classical washout motion cueing algorithm (CWMCA) is extended to a model predictive motion cueing algorithm (MPMCA) for a seven-cylinder pneumatically actuated Stewart platform. Through this enhancement, not only are potential predictive signals taken into account, but also comprehensive information and data sets relating to the mechanical limitations of the simulator platform. The significantly increased information content enables the calculation of far more specific targeted requirements for the platform. First, the platform kinematics are derived and its physical platform constraints are examined. Furthermore, the CWMCA is extended and transformed into a state space-based motion cueing algorithm for the purpose of setting up a linear quadratic MPMCA. Finally, the MPMCA is simulated and evaluated with respect to its degree of realism.
Effects of a Diverging Cup on Swirl Number, Flow Pattern, and Topology of Premixed Flames
Authors: Degenève A. , Jourdaine P. , Mirat C. , Caudal J. , Vicquelin R. , Schuller T.
Published: September 2018

Impact of the diverging cup angle of a swirling injector on the flow pattern and stabilization of technically premixed flames is investigated both theoretically and experimentally with the help of OH* chemiluminescence, OH laser-induced fluorescence and particle image velocimetry (PIV) measurements. Recirculation enhancement with a lower position of the internal recirculation zone (IRZ) and a flame leading edge protruding further upstream in the swirled flow are observed as the injector nozzle cup angle is increased. A theoretical analysis is carried out to examine whether this could be explained by changes of the swirl level as the diffuser cup angle is varied. It is shown that pressure effects need in this case to be taken into account in the swirl number definition and expressions for changes of the swirl level through a diffuser are derived. It is demonstrated that changes of the swirl level including or not the pressure contribution to the axial momentum flux are not at the origin of the changes observed of the flow and flame patterns in the experiments. The swirl number without the pressure term, designated as pressure-less swirl, is then determined experimentally with laser Doppler velocimetry (LDV) measurements at the injector outlet for a set of diffusers with increasing quarl angles under nonreacting conditions and the values found corroborate the predictions. It is finally shown that the decline of axial velocity and the rise of adverse axial pressure gradient, both due to the cross section area change through the diffuser cup, are the dominant effects that control the leading edge position of the IRZ of the swirled flow. This is used to develop a model for the displacement of the recirculation bubble as the quarl angle varies that shows very good agreement with experiments.
Hermetically Sealed Squeeze Film Damper for Operation in Oil-Free Environments
Authors: Ertas Bugra , Delgado Adolfo
Published: September 2018

The following work advances a new concept for a hermetically sealed squeeze film damper (HSFD), which does not require an open-flow lubrication system. The hermetically sealed concept utilizes a submersed plunger within a contained fluidic cavity filled with incompressible fluid and carefully controlled end plate clearances to generate high levels of viscous damping. Although the application space for a hermetic damper can be envisioned to be quite broad, the context here will target the use of this device as a rotordynamic bearing support damper in flexibly mounted gas bearing systems. The effort focused on identifying the stiffness and damping behavior of the damper while varying test parameters such as excitation frequency, vibration amplitude, and end plate clearance. To gain further insight to the damper behavior, key dynamic pressure measurements in the damper land were used for identifying the onset conditions for squeeze film cavitation. The HSFD performance is compared to existing gas bearing support dampers and a conventional open-flow squeeze film dampers (SFD) used in turbomachinery. The damper concept yields high viscous damping coefficients an order of magnitude larger than existing oil-free gas bearing supports dampers and shows comparable damping levels to current state of the art open-flow SFD. The force coefficients were shown to contribute frequency-dependent stiffness and damping coefficients while exhibiting amplitude independent behavior within operating regimes without cavitation. Finally, using experimentally based force density calculations, the data revealed threshold cavitation velocities, approximated for the three end seal clearance cases. To complement the experimental work, a Reynolds-based fluid flow model was developed and is compared to the HSFD damping and stiffness results.
Interactions of bioactive molecules with thin dendritic glycopolymer layers
Authors: Bittrich Eva , Mele Flavia , Janke Andreas , Simon Frank , Eichhorn Klaus-Jochen , Voit Brigitte , Appelhans Dietmar
Published: September 2018

The authors report on highly swellable, stable layers of spherical dendritic glycopolymers, composed of hyperbranched poly(ethylene imine) (PEI) as core and two different maltose shells (A = dense shell and B = open shell). These glycopolymers are cross-linked and attached with poly(ethylene-alt-maleic anhydride) (PEMA) or citric acid on SiOx substrates. The swelling and adsorption of biomolecules were analyzed by spectroscopic ellipsometry and quartz crystal microbalance with dissipation. The swelling degree and complexation with the drug molecule adenosine triphosphate (ATP) were found to be up to 10 times higher for dendritic glycopolymer layers cross-linked with PEMA than for layers cross-linked with citric acid. ATP complexation by electrostatic interaction with the PEI cores was confirmed by x-ray photoelectron spectroscopy analysis. Complexation led to partial collapsing, stiffening, and increase of polymer layer viscosity of the PEMA cross-linked layers. From modeling of ellipsometric data, it was deduced that ATP complexation preferably takes place at the polymer layer-solution interface. The size effect of the adsorbates was investigated by comparing ATP complexation with the adsorption of larger vitamin B12 and human serum albumin (HSA) protein. PEI-Mal A cross-linked with PEMA was found to be resistant toward B12 and HSA adsorption due to the diffusion barrier of the polymer layer. Thus, the authors present potentially biocompatible polymer surfaces for drug loading and their surface supported release.