bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of multiple spawning on female reproductive output and offspring quality in a freshwater caridean shrimp with direct development
Authors: Marciano Agustina , Tropea Carolina , López Greco Laura S.
Published: January 2018

The decline with age in components of fitness is variable among different taxa and includes changes in fertility and brood quality. In this study, we selected individuals of Neocaridina davidi, a freshwater shrimp with direct development, to analyze juvenile quality and female reproductive performance over successive spawnings, both of which are correlated with female age. Given the high costs of reproduction in species with direct development, we hypothesized that female reproductive performance and juvenile quality decrease in later spawns. Two experiments were performed. In Experiment 1, we evaluated the reproductive performance of females of N. davidi and the quality of juveniles (through a food restriction test) over the first six successive spawnings. In Experiment 2, we analyzed the lipid and protein contents in juveniles from the third, fourth, and fifth spawns, after feeding them daily or starving them for 8 d or 12 d after hatching. Female mortality was observed throughout Experiment 1, along with a decrease in the proportion of ovigerous females over successive spawns. However, the interval between spawnings and the number and size of newly hatched juveniles were similar among spawns. Moreover, females that spawned many times had a reproductive efficiency similar to those that spawned few times, as evidenced by a similar percentage of broods successfully hatched and a similar percentage of broods with more than 28 juveniles among all spawns. Overall, these results may indicate a partial effect of multiple spawning on female reproductive performance. Growth, survival, and biochemical composition of food‐restricted juveniles showed similar or even higher values in later spawns as compared to the first spawns. This is, to our knowledge, the first empirical demonstration in a decapod crustacean with direct development that, although the percentage of ovigerous females decreases over time, other reproductive variables and juvenile performance do not decline in successive spawnings, at least for the initial six consecutive spawns.
Cationic effect of charge compensation on the sulfide capacity of aluminosilicate slags
Authors: Choi Joon Sung , Park Youngjoo , Lee Sunghee , Min Dong Joon
Published: January 2018

The effect of CaO on the sulfide capacity of CaO‐Al2O3‐SiO2 slags was studied from the viewpoint of the ionic structure of alumina in slag. The aluminum coordination number was analyzed using 27Al 500‐MHz solid nuclear magnetic resonance spectroscopy and the results were compared with those of the sulfide capacity analysis. The sulfide capacity of slag, in the peralkaline region (), exhibited a linear relationship with respect to basicity () as excess free Ca2+ formed a 4‐coordinated aluminum unit structure ([IV]Al; ) and stabilized the sulfide ions (). However, sulfide capacity in the peraluminous region () exhibited a nonlinear relationship with respect to basicity () owing to the structure of higher‐coordinated aluminum units ([V]Al, [VI]Al; Al3+) and the relative lack of Ca2+. Therefore, the sulfide capacity of high Al2O3‐bearing slags strongly depended on the basicity () and stability of sulfide ions (), which depended on the competitive behavior of Ca2+ owing to the structural changes in Al2O3. The effect of the aluminum coordination number on the sulfide capacity was discussed in detail using an analysis of the slag structure and thermodynamics model.
Non‐isothermal crystallization kinetics of Al2O3‐YAG amorphous ceramic coating deposited via plasma spraying
Authors: Rong Jian , Yang Kai , Zhuang Yin , Zhong Xinghua , Zhao Huayu , Ni Jinxing , Tao Shunyan , Wang Liang , Ding Chuanxian
Published: January 2018

Crystallization kinetics of the newly developed Al2O3‐Y3Al5O12(YAG) amorphous ceramic coating fabricated by atmospheric plasma spraying (APS) were investigated via differential scanning calorimetry (DSC) under non‐isothermal conditions. The phase compositions and microstructure of the as‐sprayed coating were characterized by X‐ray diffraction (XRD) and Scanning electron microscopy (SEM). The glass transition temperatureTg, the onset temperature of crystallizationTcand the peak temperature of crystallizationTppresented heating rate dependence. The related kinetic parameters of activation energies (Eg,Ec,Ep) and Avrami exponents (n) were quantified using various methods including Kissinger, Augis–Bennett, Ozawa and Matusita–Sakka, etc., to understand the phase transition mechanism and crystallization process in depth. A series of parameters including devitrification interval ΔT, thermal stability (Tc,Ec), nucleation resistanceEc/RTgand fragility indexFwere quantified in order to evaluate the nucleation mechanism, crystallization behavior and thermal stability of Al2O3‐YAGamorphous ceramic coating. Excellent thermal stability was witnessed in the studied coating. Furthermore, theYAGcrystalline phases can be reasonably controlled and independently precipitated from the amorphous matrix via proper annealing.
The interactive effects of achievement goals and task complexity on enjoyment, mental focus, and effort
Authors: Donovan John J. , Hafsteinsson Leifur Geir , Lorenzet Steven J.
Published: January 2018

Several empirical studies have suggested that achievement goal researchers should put a greater emphasis on identifying factors that may moderate the effects of achievement goals on motivation and related outcomes. In line with this recommendation, the current study sought to examine how one task characteristics (task complexity) may moderate the impact of achievement goals on the motivational outcomes of task enjoyment, mental focus, and exerted effort. Consistent with both the theoretical foundations of achievement goals and the existing research literature, we hypothesized that achievement goals would interact with task complexity in their effects on motivation such that the positive effects of mastery goals would be stronger for complex tasks, the positive effects of performance‐approach goals would be stronger for simple tasks, and the negative effects of performance‐avoidance goals would be weaker for simple tasks. Data collected from 347 undergraduate students assigned to simple or complex task conditions when performing a puzzle‐based task supported these hypotheses. Under complex task conditions, the positive effects of mastery goals were amplified, whereas simple task conditions enhanced the positive effects of performance‐approach goals and minimized the negative impact of performance‐avoidance goals. Future directions for research on achievement goals are discussed, along with potential practical implications of the results of this study.
A literature review and hypothesis for the etiologies of cervical and root caries
Authors: Grippo John O. , Coleman Thomas A. , Messina Antonello Maria , Oh Daniel S.
Published: January 2018

The presence of endogenous acids from bacteria acting on a suitable substrate combined with sources of exogenous biocorrosives such as exogenous acids and proteolytic enzymes in areas of stress concentration are hypothesized to lead to the development and progression of cervical and root caries (RC). Quantifying the effects of each of the mechanisms (stress and biocorrosion) is a daunting task to investigate since so many factors are involved at various times in the etiology of noncarious cervical lesions (NCCLs), cervical caries (CC), and RC. Frictional action of the tongue has a cleansing effect and lingual serous saliva, which has a high flow rate buffering capacity from bicarbonates seem to account for the paucity of lingual NCCLs, cervical, and RC in these areas of teeth. Future studies are indicated to determine the effects of stress and biocorrosion and their factors in the etiology of CC and RC.

Clinical significance

This manuscript presents hypothetical and literary information that the combined effects of stress concentration and biocorrosion contribute to the formation as well as progression of cervical and root caries.
Effect of Temperature on Growth, Energy Budget, and Physiological Performance of Green, White, and Purple Color Morphs of Sea Cucumber, Apostichopus japonicus
Authors: Bai Yucen , Chen Yan , Pan Yang , Zhang Libin , Liu Shilin , Ru Xiaoshang , Xing Lili , Zhang Tao , Yang Hongsheng , Li Jing
Published: January 2018

As an intertidal species, Apostichopus japonicus is subject to diel and seasonal temperature fluctuations. Color variation is a distinct characteristic of A. japonicus, and a new color morph, purple A. japonicus, was recently found on the coast of Rushan, Weihai City. This study was conducted to compare the performance of green, white, and purple color morphs of A. japonicus at different water temperatures to help improving aquaculture technology and management. In this study, green, white, and purple color morphs of juvenile A. japonicus (1.5 ± 0.1 g) were cultured at 10, 14, 18, 22, and 26 C for 60 d, according to the suitable temperature range for sea cucumber growth. Temperature was shown to have a significant effect on growth, energy budget, and physiology of sea cucumbers (P < 0.05). Specific growth rates, feed conversion efficiencies, and the proportion of energy allocated to growth of all three color morphs were optimal at 18 C. Activities of the enzymes related with oxidative stress, immune response, and digestion were determined. Superoxide dismutase (SOD) and trypsin activities generally reached a maximum in all three color morphs at 18 C. The purple color morph of A. japonicus was higher in growth rate, food conversion efficiency, and proportion of energy allocated to growth than green and white color morphs at 18 and 22 C, consistent with its higher trypsin and SOD activity, indicating the mutual effect of growth and physiology. At 18, 22, and 26 C, the green color morph had the highest level of lysozyme activity and purple color morph had the lowest, indicating possible infection by external pathogens of green color morph, which might be caused by high temperature. These results suggested that the optimum temperature for culture of the three color morphs was approximately 18 C, the purple had a better adaption to high temperature, and the green and white color morphs may be more susceptible to thermal stress than the purple color morph.
Evaluating a Multidimensional Reading Comprehension Program and Reconsidering the Lowly Reputation of Tests of Near‐Transfer
Authors: Fuchs Douglas , Hendricks Emma , Walsh Meagan E. , Fuchs Lynn S. , Gilbert Jennifer K. , Zhang Tracy Wen , Patton Samuel , Davis‐Perkins Nicole , Kim Wooliya , Elleman Amy M. , Peng Peng
Published: January 2018

We conducted a 14‐week experimental study of 2 versions of a relatively comprehensive RC intervention that involved 50 classroom teachers, 15 tutors, and 116 children drawn in equal proportions from grades 3 and 5 in 13 schools in a large urban school district. Students were randomly assigned in equal numbers to the two tutoring conditions and a control group. Results indicated that students in the two tutored groups tended to perform comparably on all tests and to outperform controls (more so in grade 5 than grade 3) on near‐transfer but not far‐transfer measures of RC. This differential pattern of program effects for near‐ versus far‐transfer measures raises questions about how tests of near‐transfer and far‐transfer are conventionally understood.
When Free Traders Become Protectionists: Constituent Advocacy at the International Trade Commission
Authors: Miler Kristina , Allee Todd
Published: January 2018

Although Members of Congress vote on few trade bills, they participate regularly in venues such as the International Trade Commission (ITC), where important trade policy decisions are made. We assert that once removed from the voting chambers of Congress, legislators are motivated overwhelmingly by the desire to advance constituents’ trade policy interests, even those that contradict the member’s established positions on trade. Utilizing an original dataset on legislator participation in antidumping cases, we find that both Democratic and Republican members advocate protection at the ITC when they have numerous firms and constituents in their district who benefit from trade restrictions, particularly when they receive sizeable financial contributions from them. Notably, self‐proclaimed free‐traders are just as likely to seek protection for their constituents as are trade opponents. Away from Capitol Hill, then, trade policymaking exhibits few partisan and ideological influences and serves as a means for members to expand political support.

[Correction added on 21 August 2018, after first online publication: Abstract was added to article]
Men's views and experiences of infant feeding: A qualitative systematic review
Authors: Earle Sarah , Hadley Robin
Published: January 2018

Although the advantages of breastfeeding are well documented, rates for breastfeeding often fall short of international and national targets. Increasing attention has been paid to the role of men in infant feeding, but a lot of the research about men has been elicited from women, rather than from men themselves. To explore these issues further, a systematic review of the qualitative research on infant feeding was carried out, focusing specifically on men's own views and experiences. Evidence was identified by searching electronic databases (CINAL, Cochrane, PubMed, and Scopus), manually searching citations, and by searching the grey literature. Studies were included in the review if they discussed men's views and experiences of infant feeding and if they reported primary qualitative data. Twenty research papers were included in the review, and each study was summarised and then analysed thematically to produce a synthesis. Five major analytical themes were identified: men's knowledge of infant feeding; men's perceptions of their role in infant feeding; positive views on breastfeeding; negative views on breastfeeding; and men's experiences of health promotion and support. The review concludes by highlighting that although men can play an important role in supporting women, they do not have a significant role in infant feeding decisions.
Effects of maternal anthropometrics on pregnancy outcomes in South Asian women: a systematic review
Authors: Slack E. , Rankin J. , Jones D. , Heslehurst N.
Published: January 2018

Aim

This systematic review investigates associations between maternal pre‐pregnancy/early‐pregnancy anthropometrics (e.g. weight and body fat), anthropometric change and pregnancy outcomes in South Asian and White women.

Methods

Twelve electronic literature databases, reference lists and citations of all included studies were searched. Observational studies published in the English language were included. Descriptive synthesis was used to summarize the evidence base.

Results

Twenty‐two studies met the inclusion criteria (403,609 births [351,856 White and 51,753 South Asian]). Nine were prospective cohort studies, nine were retrospective cohort studies and two were cross‐sectional studies. Results suggested that in South Asian women, maternal pre‐pregnancy/early‐pregnancy anthropometrics were associated with anthropometric change, birthweight, mode of delivery and gestational diabetes mellitus (GDM). Gestational anthropometric change was found to be associated with GDM. There was limited evidence to suggest that there may be associations between maternal pre‐anthropometrics/early anthropometrics and hypertensive disorders, stillbirth, congenital anomalies, post‐natal weight retention and post‐natal impaired glucose tolerance. The evidence suggested a combined effect of pre‐pregnancy/early‐pregnancy anthropometrics and gestational anthropometric change on both GDM and post‐natal weight retention.

Conclusion

The increased risk of adverse pregnancy outcomes in South Asian women should be considered in guidelines for weight management before and during pregnancy.
Immediate loading on fixed implant‐supported prosthesis with short implants: short‐term report of four cases
Authors: Moura L.B. , Paganelli O.E.B. , Gabrielli M.A.C. , Pereira Filho V.A.
Published: January 2018

Short implants are one of the best alternative treatments for atrophic mandibles due to low morbidity and good resolution. The use in posterior mandible is consolidated, however, in edentulous patients is rarely reported. The aim of this article is to present the use of short implants with fixed implant‐supported prosthesis and immediate loading in severely resorbed mandibles, in four patients. Four short implants were placed in the anterior mandible in each patient. The initial torque of all implants was higher than 45 N and the mean of resonance frequency analysis was 74.87. The fixed prosthesis was submitted to immediate loading. After 4 years of follow‐up there were two implant failures which were replaced by other short implants. All implants remain in function with no signs of perimplantitis or bone loss. The final resonance frequency analysis mean was 78.30 demonstrating adequate stability.
The optimal intestinal segment length for experimental size‐mismatched intestinal transplantation: Defining the maximum length with the lowest blood flow needs in a porcine model
Authors: Frongia Giovanni , Majlesara Ali , Saffari Arash , Emami Golnaz , Golriz Mohammad , Günther Patrick , Mehrabi Arianeb
Published: January 2018

Transplanted Intestinal Segments (IS) must match the perfusion capacities of the recipient. This can be challenging during a size‐mismatched SBTX. In this study, we defined the maximum IS length with lowest blood flow needs in a porcine model by evaluating the physiological perfusion rates of different IS lengths. Blood flow in the SMA, aorta segment four, and general circulatory parameters were monitored before and after sequential intestinal resection. IS lengths of 30 cm, 60 cm, 120 cm, and 300 cm (n = 8 each) were compared. The IS blood flow requirements increased with IS length (30 cm: 19.5 ± 3.4 mL/min; 60 cm: 16.9 ± 6.7 mL/min; 120 cm: 34.9 ± 8.5 mL/min; 300 cm: 62.9 ± 11.6 mL/min). Absolute IS blood flow (P = .004), percentage IS blood flow uptake from the SMA (P = .001), and percentage IS blood flow uptake from the aorta (P = .005) increased significantly between 60 cm and 120 cm. We concluded that 60 cm was the maximum IS length before blood flow demands significantly increased in a porcine model.
Protective Effect of BLED‐exposed Conditioned Media on Cell Injury
Authors: Oh Phil‐Sun , Kim Eun‐Mi , Kim Minjoo , Kim In Sun , Han Yeon‐Hee , Lim SeokTae , Sohn Myung‐Hee , Ko Myoung‐Hwan , Jeong Hwan‐Jeong
Published: January 2018

Previous studies have reported that 450 nm blue light emitting diode (BLED) induces apoptosis through a mitochondria‐mediated pathway in cancer cells and reduces the early stage tumor growth. This study was performed to determine the effects of BLED‐irradiated cell metabolites on cell injury. Our results showed that conditioned medium (CM) from cells irradiated with low‐dose BLED (LCM) inhibited apoptosis and increased cell survival. Cell protection‐related proteins were identified in cell metabolites of CM and LCM using 2‐DE and MALDI‐TOF analysis. Treatment with LCM inhibited apoptotic cell death and increased the live cell population. The cellular protective effect of LCM was associated with keratin and collagen type VI secretion from cells after low dose of BLED irradiation. Interestingly, expression of endoplasmic reticulum stress proteins was dose dependently increased after 4 h BLED irradiation. Only levels of BiP, CHOP and ERO1‐Lα were decreased significantly after 24 h incubation, indicating their anti‐apoptotic property in these cells. These results indicated that cell metabolites stimulated by low‐dose BLED irradiation have a cytoprotective effect on cell injury via increasing transient intracellular ER stress. Further studies remain to provide the molecular mechanisms of LCM for cytoprotective activity.
Biosensors: a potential tool for quality assurance and food safety pertaining to biogenic amines/volatile amines formation in aquaculture systems/products
Authors: Heerthana Veluthevar Ramanathan , Preetha Radhakrishnan
Published: January 2018

The present review focuses on the role of volatile amines as a quality indicator which affects the safety and acceptance parameters of the aquaculture products. The nurturing aquaculture requires good aquaculture practice to safeguard aquaculture environment. Particularly, poor water quality of aquaculture systems, changes in storage temperature after harvest and unhygienic handling practices enhance the growth of harmful microbes and thereby magnify the accumulation of biogenic amines (histamines, prolamines cadaverine, putrescine, spermidine, spermine, tyramine and tryptamine) and total volatile basic nitrogen (dimethylamine, trimethylamine and ammonia) content in the aquaculture products. Various conventional and advanced tools used to monitor the aquatic environment/aquaculture products are discussed in this review. Moreover, this review focuses on the biosensors used for determination of biogenic amines/volatile amines for assuring safety and quality of aquaculture products and aquaculture systems.
The paradox of decrease and dependent parts
Authors: Moran Alex
Published: January 2018

This paper is concerned with the paradox of decrease. Its aim is to defend the answer to this puzzle that was propounded by its originator, namely, the Stoic philosopher Chrysippus. The main trouble with this answer to the paradox is that it has the seemingly problematic implication that a material thing could perish due merely to extrinsic change. (For, intuitively, it is not possible for a mere extrinsic change to cause a material thing to cease to be.) It follows that in order to defend Chrysippus’ answer to the paradox, one has to explain how it could be that Theon is destroyed by the amputation without changing intrinsically. In this paper, I shall answer this challenge by appealing to the broadly Aristotelian idea that at least some of the proper parts of a material substance are ontologically dependent on that substance. I will also appeal to this idea in order to offer a new solution to the structurally similar paradox of increase. In this way, we will end up with a unified solution to two structurally similar paradoxes.
Lipoidal corneal degeneration in aged falcons
Authors: Moore Bret A. , Paul‐Murphy Joanne R. , Adamson Kathleen L. , Dubielzig Richard R. , Kern Thomas , Gonzales Ben J. , Wolff Peregrine , Murphy Christopher J.
Published: January 2018

Objective

To present a case series of idiopathic lipoidal corneal degeneration in falcons.

Animals Studied

Five falcons including three peregrine falcons (Falco peregrinus), one prairie falcon (Falco mexicanus), and one red‐naped shaheen (Falco peregrinus babylonicus) were observed to develop slowly progressive corneal opacification that began at the temporal limbus and extended centripetally across the cornea over a period of years. Four of the birds were over 20 years old.

Procedures

All animals underwent complete ophthalmic examinations. A red‐naped shaheen underwent ocular imaging via spectral‐domain optical coherence tomography. Two peregrine falcons were euthanized due to declining health, and their eyes were examined histologically.

Results

The opacities were pale and granular, with frequent vascularization associated perilimbally. Diffuse neutral lipid was observed in stromal cells throughout the corneal stroma of both clear and opaque areas of the cornea, sparing only the acellular anterior limiting lamina. Clusters of cholesterol crystals surrounded by macrophages were present in the mid‐stroma. Fibrosis was evident in a subepithelial location, which separated the epithelium from the anterior limiting lamina. Ultrastructurally, diffuse vacuolization of the keratocytes was observed. No other ophthalmic or systemic abnormalities were noted.

Conclusions

Results suggest that lipid degeneration occurs rarely in captive falcons of advanced age. The underlying cause is unclear. Though unsubstantiated, possible contributing factors include dyslipoproteinemia, corneal trauma, diet, and age‐related alterations in corneal metabolism. The initiation of pathology at the temporal limbus, as well as slow progression, suggests that exposure contributes to the onset and progression of this unique keratopathy.
Characteristics of Thermal–Hydraulic and Heat Transfer in Liquid Windowless Target of Accelerator Driven Subcritical
Authors: Wang Feng , Wen Qiang , Qin Xue
Published: January 2018

In recent years, the morphological characteristics and stabilization methods of free interface in liquid windowless target become hot research topics in accelerator driven subcritical system (ADS). Based on the structure design of a certain windowless spallation target, computational fluid dynamics (CFD) software of CFX was used to simulate and analyze its free interface character. The method of k–ε turbulence, cavitation, and volume of fluid (VOF) model was used to study the flow characteristic of liquid Lead-Bismuth eutectic (LBE) alloy with cavitation phase change and to analyze the free interface morphology characteristics of coolant in the target area. It is concluded that the target region forms two stable free interfaces when fluid outlet pressure is in the range of 10–40 kPa and fluid entrance velocity is in the range of 0.5–1.2 m/s. The flow field near the free interface structure is complex. The vortex region appears, and the disorders in the vortex flow pattern lead to fluctuation of the free interface. After the study of stable free interface morphology establishing process, heat transfer characteristic of windowless target was further analyzed.
A
Numerical Analysis Method of Impurity Precipitation on Mesh Wire of Cold Trap in Fast Breeder
Reactor
Authors: Tamura Akinori , Takahashi Shiro , Nakata Hiroyuki , Takota Akio
Published: January 2018

A fast breeder reactor (FBR) is considered as the promising technology in terms of load reduction on the environment, because the FBR has capability to improve usage efficiency of uranium resources and can reduce high-level radioactive waste which needs to be managed for millions of years. A cold trap is one of the important components in the FBR to control the impurity concentration of the liquid sodium. For accurate evaluation of the cold trap performance, we have been proposing the three-dimensional (3D) numerical analysis method of the cold trap. In this method, the evaluation of the impurity precipitation phenomena on the surface of the mesh wire of the cold trap is the key. For this, the numerical analysis method which is based on the lattice kinetic scheme (LKS) has been proposed. In order to apply the LKS to the impurity precipitation simulation of the cold trap, two models (the low Reynolds number model and the impurity precipitation model) have been developed. In this paper, we focused on the validation of these models. To confirm the validity of the low Reynolds number model, the Chapman–Enskog analysis was applied to the low Reynolds number model. As a result, it has been theoretically confirmed that the low Reynolds number model can recover the correct macroscopic equations (incompressible Navier–Stokes equations) with small error. The low Reynolds number model was also validated by the numerical simulation of two-dimensional (2D) channel flow problem with the low Reynolds number conditions which correspond to the actual cold trap conditions. These results have confirmed that the error of the low Reynolds number model is ten times smaller than that of the original LKS. The validity of the impurity precipitation model was investigated by the comparison to the precipitation experiments. In this comparison, the mesh convergence study was also conducted. These results have confirmed that the proposed impurity precipitation model can simulate the impurity precipitation phenomena on the surface of the mesh wire. It has been also confirmed that the proposed impurity precipitation model can simulate the impurity precipitation phenomenon regardless of the cell size which were tested in this investigation.
The Tip Region of a Near-Surface Hydraulic Fracture
Authors: Wang Zhi-Qiao , Detournay Emmanuel
Published: January 2018

This paper investigates the tip region of a hydraulic fracture propagating near a free-surface via the related problem of the steady fluid-driven peeling of a thin elastic layer from a rigid substrate. The solution of this problem requires accounting for the existence of a fluid lag, as the pressure singularity that would otherwise exist at the crack tip is incompatible with the underlying linear beam theory governing the deflection of the thin layer. These considerations lead to the formulation of a nonlinear traveling wave problem with a free boundary, which is solved numerically. The scaled solution depends only on one number K, which has the meaning of a dimensionless toughness. The asymptotic viscosity- and toughness-dominated regimes, respectively, corresponding to small and large K, represent the end members of a family of solutions. It is shown that the far-field curvature can be interpreted as an apparent toughness, which is a universal function of K. In the viscosity regime, the apparent toughness does not depend on K, while in the toughness regime, it is equal to K. By noting that the apparent toughness represents an intermediate asymptote for the layer curvature under certain conditions, the obtention of time-dependent solutions for propagating near-surface hydraulic fractures can be greatly simplified. Indeed, any such solutions can be constructed by a matched asymptotics approach, with the outer solution corresponding to a uniformly pressurized fracture and the inner solution to the tip solution derived in this paper.
Taking Advantage of the Vastly Underused European Biogas Potential: Break-Even Conditions for a Fuel Cell and an Engine as Biogas Converters
Authors: Majerus Samuel , Lauinger Dirk , Van herle Jan
Published: January 2018

In this study, the European biogas market and its potential are analyzed. The four countries with the biggest biogas production and potential, namely Germany, Italy, France, and the UK, are studied in detail. Particular attention is paid to their agricultural characteristics (livestock population, average number of cattle per agricultural holding, number of farms), as well as their policy and market conditions (feed-in tariffs, average biogas investment costs). A financial model is built and used to compare the four countries, based on the net present value as the performance indicator. Solid oxide fuel cells (SOFCs) are considered as a more efficient alternative for valorizing agricultural-derived biogas, which, at the moment, is vastly done with cheaper conventional engines. After an analysis of the economic merits, target farm sizes are recommended for each country. It is shown that the low valorization of manure-derived biogas in Europe offers a big opportunity for the commercialization of SOFCs and for a push toward mass production. Considering the high installation costs, it is still primordial that policy-makers incentivize the installation of biogas plants throughout the EU.
Experimental Investigation of Inlet Distortion Effect on Performance of a Micro Gas Turbine
Authors: Naseri Alireza , Sammak Shervin , Boroomand Masoud , Alihosseini Alireza , Tousi Abolghasem M.
Published: January 2018

An experimental study has been carried out to determine how inlet total-pressure distortion affects the performance of a micro gas turbine. An inlet simulator is designed and developed to produce and measure distortion patterns at the inlet to the gas turbine. An air jet distortion generator (AJDG) is used to produce nonuniform flow patterns and total pressure probes are installed to measure steady-state total-pressure distribution at the inlet. A set of wind tunnel tests have been performed to confirm the fidelity of distortion generator and measuring devices. Tests are carried out with the gas turbine exposed to inlet flow with 60 deg, 120 deg, and 180 deg circumferential distortion patterns with different distortion intensities. The performance of the gas turbine has been measured and compared with that of clean inlet flow case. Results indicate that the gas turbine performance can be affected significantly facing with intense inlet distortions.
Reference Conditions and Substructuring Techniques in Flexible Multibody System Dynamics
Authors: O'Shea James J. , Jayakumar Paramsothy , Mechergui Dave , Shabana Ahmed A. , Wang Liang
Published: January 2018

The floating frame of reference (FFR) formulation is widely used in multibody system (MBS) simulations for the deformation analysis. Nonetheless, the use of elastic degrees-of-freedom (DOF) in the deformation analysis can increase significantly the problem dimension. For this reason, modal reduction techniques have been proposed in order to define a proper set of assumed body deformation modes. Crucial to the proper definition of these modes when the finite element (FE) FFR formulation is used is the concept of the reference conditions, which define the nature of the deformable body coordinate system. Substructuring techniques, such as the Craig–Bampton (CB) method, on the other hand, have been proposed for developing efficient models using an assembly of their lower order substructure models. In this study, the appropriateness and generality of using the CB method in MBS algorithms are discussed. It is shown that, when a set of reference conditions are not applied, the CB transformation leads to the free–free deformation modes. Because a square CB transformation is equivalent to a similarity transformation that does not alter the problem to be solved, the motivation of using the CB method in MBS codes to improve the solution is examined. This paper demonstrates that free–free deformation modes cannot be used in all applications, shedding light on the importance of the concept of the FE/FFR reference conditions. It is demonstrated numerically that a unique model resonance frequency is achieved using different modes associated with different reference conditions if the shapes are similar.
Subharmonic Bifurcations and Chaotic Dynamics for a Class of Ship Power System
Authors: Zhou Liangqiang , Chen Fangqi
Published: January 2018

Subharmonic bifurcations and chaotic dynamics are investigated both analytically and numerically for a class of ship power system. Chaos arising from heteroclinic intersections is studied with the Melnikov method. The critical curves separating the chaotic and nonchaotic regions are obtained. The chaotic feature on the system parameters is discussed in detail. It is shown that there exist chaotic bands for this system. The conditions for subharmonic bifurcations with O type or R type are also obtained. It is proved that the system can be chaotically excited through finite subharmonic bifurcations with O type, and it also can be chaotically excited through infinite subharmonic bifurcations with R type. Some new dynamical phenomena are presented. Numerical simulations are given, which verify the analytical results.
Gun Barrel Refurbishing Using a Shrink-Fitted Autofrettaged Liner
Authors: Perry J. , Perl M.
Published: January 2018

During the firing of guns, the barrel undergoes two major damaging processes: wear of its inner surface and internal cracking. Barrel's are condemned based on either the increase of their internal diameter due to wear or the severity of their internal cracking. The cost of replacing such a damaged gun barrel runs in the tenth of thousands of U.S.$. Therefore, cost effective methods are sought for restoring such gun barrels. In the present analysis, a new method is proposed for refurbishing vintage gun barrels by machining their inner damaged layer and replacing it by an intact, autofrettaged, shrink-fit liner that will restore the barrel to its original performance. The design of the shrink-fitted liner is based on two design principles. First, the von-Mises residual stress distribution through the thickness of the barrel at each of its cross sections along the inserted liner should be at least equal in magnitude to von Mises stress, which prevailed in the original barrel. Second, once the maximum pressure is applied to the compound barrel, the von-Mises stresses at the inner surfaces of the liner machined barrel should be equal to their respective yield stresses. The preliminary results demonstrate the ability of this process to mend such barrels and bringing them back to their initial safe maximum pressure (SMP) and their intact conditions, rather than condemn them. Furthermore, from the authors' experience, based on a preliminary rough estimate, such an alternative seems to be cost effective.
Influence of incident angle of sputtered atom on the size and shape of granule in granular films using CoFeAlSi alloy
Authors: Fujiwara Yuji , Ishii Ryosuke , Shimizu Toshifumi , Jimbo Mutsuko
Published: January 2018

Granular films were prepared using Co2FeAl0.5Si0.5 alloy in two different target-substrate configurations in order to investigate the influence of the incident angle of the sputtered atoms on the granule size and the tunnel magnetoresistance (MR) effect. The samples prepared with the incident angle perpendicular to the substrates showed typical tunnel-type MR loops reflecting the superparamagnetic behavior of granules. On the other hand, in the samples prepared with glancing angle incidence, the MR loops measured by applying the magnetic field parallel to the film plane tended to saturate at relatively low fields compared to the case wherein the applied magnetic field was perpendicular to the film plane. These results indicate that the granules deposited by the glancing incident angle of the sputtered atoms have large diameter and exhibit an oblate spheroidlike shape.
Prediction of flow induced sound generated by cross flow past finite length circular cylinders
Authors: Karthik K. , Vengadesan S. , Bhattacharyya S. K.
Published: January 2018

The paper presents aeroacoustic results for the flow around finite-length circular cylinders at Reynolds number 84 770 for various length-to-diameter (L/D) ratios (= 3, 9, 20, 25, 30, and 35). The incompressible Navier-Stokes equations are solved using the large eddy simulation model of turbulence followed by acoustic predictions in the far field using Ffwocs Williams and Hawkings method. The comparisons of numerical and anechoic wind tunnel measurements show good agreement in terms of the aerodynamic forces and acoustic parameters such as tonal frequency, tonal sound pressure level, and overall sound pressure level. The cylinder L/D ratio was observed to be a significant parameter that controls vortex shedding and consequently the flow induced sound generation.
Combining degradations: The effect of background noise on intelligibility of disordered speech
Authors: Yoho Sarah E. , Borrie Stephanie A.
Published: January 2018

The effect of background noise on intelligibility of disordered speech was assessed. Speech-shaped noise was mixed with neurologically healthy (control) and disordered (dysarthric) speech at a series of signal-to-noise ratios. In addition, bandpass filtered control and dysarthric speech conditions were assessed to determine the effect of noise on both naturally and artificially degraded speech. While significant effects of both the amount of noise and the type of speech were revealed, no interaction between the two factors was observed, in either the broadband or filtered testing conditions. Thus, it appears that there is no multiplicative effect of the presence of background noise on intelligibility of disordered speech relative to control speech. That is, the decrease in intelligibility due to increasing levels of noise is similar for both types of speech, and both types of testing conditions, and the function for dysarthric speech is simply shifted downward due to the inherent source degradations of the speech itself. Last, large-scale online crowdsourcing via Amazon Mechanical Turk was utilized to collect data for the current study. Findings and implications for this data and data collection approach are discussed.
Genetic Analysis of Serum-Derived Defective Hepatitis C Virus Genomes Revealed Novel Viral
cis
Elements for Virus Replication and Assembly
Authors: Li Qingchao , Tong Yimin , Xu Yongfen , Niu Junqi , Zhong Jin
Published: January 2018

Defective viral genomes (DVGs) of hepatitis C virus (HCV) exist, but their biological significances have not been thoroughly investigated. Here, we analyzed HCV DVGs circulating in patient sera that possess deletions in the structural protein-encoding region. About 30% of 41 HCV clinical isolates possess DVGs that originated from the full-length genome in the same patients. No correlation between DVGs, viremia, and alanine aminotransferase (ALT) levels was found. Sequencing analysis of DVGs revealed the existence of deletion hot spots, with upstream sites in E1 and downstream sites in E2 and NS2. Interestingly, the coding sequences for the core protein and the C-terminal protease domain of NS2 were always intact in DVGs despite the fact that both proteins are dispensable for HCV genome replication. Mechanistic studies showed that transmembrane segment 3 (TMS3) of NS2, located immediately upstream of its protease domain, was required for the cleavage of NS2-NS3 and the replication of DVGs. Moreover, we identified a highly conserved secondary structure (SL750) within the core domain 2-coding region that is critical for HCV genome packaging. In summary, our analysis of serum-derived HCV DVGs revealed novel viral
cis
elements that play important roles in virus replication and assembly.

IMPORTANCE
HCV DVGs have been identified
in vivo
and
in vitro
, but their biogenesis and physiological significances remain elusive. In addition, a conventional packaging signal has not yet been identified on the HCV RNA genome, and mechanisms underlying the specificity in the encapsidation of the HCV genome into infectious particles remain to be uncovered. Here, we identified new viral
cis
elements critical for the HCV life cycle by determining genetic constraints that define the boundary of serum-derived HCV DVGs. We found that transmembrane segment 3 of NS2, located immediately upstream of its protease domain, was required for the cleavage of NS2-NS3 and the replication of DVGs. We identified a highly conserved secondary structure (SL750) within the core-coding region that is critical for HCV genome packaging. In summary, our analysis of serum-derived HCV DVGs revealed previously unexpected novel
cis
elements critical for HCV replication and morphogenesis.
P12 Factors affecting intravenous fluid bolus administration in paediatrics
Authors: Grace Allport , Stephen Playfor
Published: January 2018

Aim

Bolus administration of 0.9% sodium chloride solution has been associated with hyperchloraemia, acidosis, acute kidney injury and increased mortality. Such adverse effects are believed to be less likely with balanced electrolyte solutions, such as Plasma- Lyte 148 or Hartmann’s solution. Despite existing evidence, 0.9% sodium chloride solution remains a popular choice for intravenous fluid boluses in paediatrics. This project aims to establish current practice of fluid bolus administration in paediatric patients, and to collect testimony from prescribers to help understand why decisions to prescribe specific fluids were made.

Method

Paediatric patients in critical care areas (PICU and PHDU), the Emergency Department (PED) and in general ward areas who had been administered intravenous fluid boluses were identified using a pragmatic data collection technique and the dose, type of fluid, indication and patient’s weight were recorded. Where possible, the prescriber was identified and asked to be interviewed. Prescribers were asked what factors had affected their decision to prescribe the type and dose of fluid administered.

Results

More than 30 individual episodes of intravenous fluid bolus administration were identified. Most fluid boluses were administered in PICU and PHDU, where balanced electrolyte solutions, specifically Plasma-Lyte 148, were the most popular choice. On general paediatric wards and in PED, 0.9% sodium chloride solution remained the most commonly administered fluid bolus solution. While some prescribers were able to give confident explanations of the factors involved in fluid selection, others referred to clinical guidelines. Individual prescribers described how their prescribing practice would vary according to the clinical setting; with senior clinicians and nursing staff being less accepting of balanced electrolyte solutions in general ward areas. Significant lack of knowledge of intravenous fluid physiology was demonstrated by some prescribers.

Conclusion

Our findings demonstrate an increase in the administration of balanced electrolyte solutions, such as Plasma-Lyte 148, as fluid boluses; this is in keeping with other international surveys of fluid administration.1,2 Similarly, we have also found significant differences in fluid bolus administration practice across different clinical areas as demonstrated by Jonsson and Perner in 2017.

We have demonstrated the importance of on-going multi-disciplinary educational efforts in continuing the evolution of intravenous fluid bolus administration practice to reflect current best practice.

References

Hammond NE, Taylor C, Finfer S, et al. Patterns of intravenous fluid resuscitation use in adult intensive care patients between 2007 and 2014: An international cross-sectional study. PLoS One2017;12:e0176292.

Jonsson AB, Perner A. Changes from 2012 to 2015 in intravenous fluid solutions issued to hospital departments. Acta Anaesthesiol Scand2017;61:532–538.