bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterizing Vascular Dysfunction in Genetically Modified Mice through the Hyperoxia Model
Authors: Monteiro Rodrigues Luis , Nazaré Silva Henrique , Ferreira Hugo , Gadeau Alain-Pierre
Published: May 2019

Modelling is essential for a better understanding of microcirculatory pathophysiology. In this study we tested our hyperoxia-mouse model with healthy and non-healthy mice. Animals (n = 41) were divided in groups—a control group, with 8 C57/BL6 non-transgenic male mice, a diabetic group (DB), with 8 C57BLKsJ-db/db obese diabetic mice and the corresponding internal controls of 8 age-matched C57BLKsJ-db/+ mice, and a cardiac hypertrophy group (CH), with 9 FVB/NJ cα-MHC-NHE-1 transgenic mice prone to develop cardiac failure and 8 age-matched internal controls. After anesthesia, perfusion data was collected by laser Doppler flowmetry (LDF) during rest (Phase 1), hyperoxia (Phase 2), and recovery (Phase 3) and compared. The LDF wavelet transform components analysis (WA) has shown that cardiorespiratory, myogenic, and endothelial components acted as main markers. In DB group, db/+ animals behave as the Control group, but WA already demonstrated significant differences for myogenic and endothelial components. Noteworthy was the increase of the sympathetic components in the db/db set, as in the cardiac overexpressing NHE1 transgenic animals, reported as a main component of these pathophysiological processes. Our model confirms that flow motion has a universal nature. The LDF component’s WA provides a deeper look into vascular pathophysiology reinforcing the model’s reproducibility, robustness, and discriminative capacities.
Improving Intrusion Detection Model Prediction by Threshold Adaptation
Authors: Al Tobi Amjad M. , Duncan Ishbel
Published: May 2019

Network traffic exhibits a high level of variability over short periods of time. This variability impacts negatively on the accuracy of anomaly-based network intrusion detection systems (IDS) that are built using predictive models in a batch learning setup. This work investigates how adapting the discriminating threshold of model predictions, specifically to the evaluated traffic, improves the detection rates of these intrusion detection models. Specifically, this research studied the adaptability features of three well known machine learning algorithms: C5.0, Random Forest and Support Vector Machine. Each algorithm’s ability to adapt their prediction thresholds was assessed and analysed under different scenarios that simulated real world settings using the prospective sampling approach. Multiple IDS datasets were used for the analysis, including a newly generated dataset (STA2018). This research demonstrated empirically the importance of threshold adaptation in improving the accuracy of detection models when training and evaluation traffic have different statistical properties. Tests were undertaken to analyse the effects of feature selection and data balancing on model accuracy when different significant features in traffic were used. The effects of threshold adaptation on improving accuracy were statistically analysed. Of the three compared algorithms, Random Forest was the most adaptable and had the highest detection rates.
P2P Botnet Detection Based on Nodes Correlation by the Mahalanobis Distance
Authors: Yang Zhixian , Wang Buhong
Published: May 2019

Botnets are a common and serious threat to the Internet. The search for the infected nodes of a P2P botnet is affected by the number of commonly connected nodes, with a lower detection accuracy rate for cases with fewer commonly connected nodes. However, this paper calculates the Mahalanobis distance—which can express correlations between data—between indirectly connected nodes through traffic with commonly connected nodes, and establishes a relationship evaluation model among nodes. An iterative algorithm is used to obtain the correlation coefficient between the nodes, and the threshold is set to detect P2P botnets. The experimental results show that this method can effectively detect P2P botnets with an accuracy of >85% when the correlation coefficient is high, even in cases with fewer commonly connected nodes.
Cross-Domain Text Sentiment Analysis Based on CNN_FT Method
Authors: Meng Jiana , Long Yingchun , Yu Yuhai , Zhao Dandan , Liu Shuang
Published: May 2019

Transfer learning is one of the popular methods for solving the problem that the models built on the source domain cannot be directly applied to the target domain in the cross-domain sentiment classification. This paper proposes a transfer learning method based on the multi-layer convolutional neural network (CNN). Interestingly, we construct a convolutional neural network model to extract features from the source domain and share the weights in the convolutional layer and the pooling layer between the source and target domain samples. Next, we fine-tune the weights in the last layer, named the fully connected layer, and transfer the models from the source domain to the target domain. Comparing with the classical transfer learning methods, the method proposed in this paper does not need to retrain the network for the target domain. The experimental evaluation of the cross-domain data set shows that the proposed method achieves a relatively good performance.
Benchmarking Image Processing Algorithms for Unmanned Aerial System-Assisted Crack Detection in Concrete Structures
Authors: Dorafshan Sattar , Thomas Robert J. , Maguire Marc
Published: May 2019

This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, and they have yet to be compared and evaluated on a dataset of concrete images taken by UAS. The authors created a generic image processing algorithm for crack detection, which included the major steps of filter design, edge detection, image enhancement, and segmentation, designed to uniformly compare different edge detectors. Edge detection was carried out by six filters in the spatial (Roberts, Prewitt, Sobel, and Laplacian of Gaussian) and frequency (Butterworth and Gaussian) domains. These algorithms were applied to fifty images each of defected and sound concrete. Performances of the six filters were compared in terms of accuracy, precision, minimum detectable crack width, computational time, and noise-to-signal ratio. In general, frequency domain techniques were slower than spatial domain methods because of the computational intensity of the Fourier and inverse Fourier transformations used to move between spatial and frequency domains. Frequency domain methods also produced noisier images than spatial domain methods. Crack detection in the spatial domain using the Laplacian of Gaussian filter proved to be the fastest, most accurate, and most precise method, and it resulted in the finest detectable crack width. The Laplacian of Gaussian filter in spatial domain is recommended for future applications of real-time crack detection using UAS.
Potential of MRI in Radiotherapy Mediated by Small Conjugates and Nanosystems
Authors: Putri Fauzia Retna , Denkova Antonia G. , Djanashvili Kristina
Published: May 2019

Radiation therapy has made tremendous progress in oncology over the last decades due to advances in engineering and physical sciences in combination with better biochemical, genetic and molecular understanding of this disease. Local delivery of optimal radiation dose to a tumor, while sparing healthy surrounding tissues, remains a great challenge, especially in the proximity of vital organs. Therefore, imaging plays a key role in tumor staging, accurate target volume delineation, assessment of individual radiation resistance and even personalized dose prescription. From this point of view, radiotherapy might be one of the few therapeutic modalities that relies entirely on high-resolution imaging. Magnetic resonance imaging (MRI) with its superior soft-tissue resolution is already used in radiotherapy treatment planning complementing conventional computed tomography (CT). Development of systems integrating MRI and linear accelerators opens possibilities for simultaneous imaging and therapy, which in turn, generates the need for imaging probes with therapeutic components. In this review, we discuss the role of MRI in both external and internal radiotherapy focusing on the most important examples of contrast agents with combined therapeutic potential.
Identification and Expression of Neurotrophin-6 in the Brain of Nothobranchius furzeri: One More Piece in Neurotrophin Research
Authors: Leggieri Adele , Attanasio Chiara , Palladino Antonio , Cellerino Alessandro , Lucini Carla , Paolucci Marina , Terzibasi Tozzini Eva , de Girolamo Paolo , D’Angelo Livia
Published: May 2019

Neurotrophins contribute to the complexity of vertebrate nervous system, being involved in cognition and memory. Abnormalities associated with neurotrophin synthesis may lead to neuropathies, neurodegenerative disorders and age-associated cognitive decline. The genome of teleost fishes contains homologs of some mammalian neurotrophins as well as a gene coding for an additional neurotrophin (NT-6). In this study, we characterized this specific neurotrophin in the short-lived fish Nothobranchius furzeri, a relatively new model for aging studies. Thus, we report herein for the first time the age-related expression of a neurotrophin in a non-mammalian vertebrate. Interestingly, we found comparable expression levels of NT-6 in the brain of both young and old animals. More in detail, we used a locked nucleic acid probe and a riboprobe to investigate the neuroanatomical distribution of NT-6 mRNA revealing a significant expression of the neurotrophin in neurons of the forebrain (olfactory bulbs, dorsal and ventral telencephalon, and several diencephalic nuclei), midbrain (optic tectum, longitudinal tori, and semicircular tori), and hindbrain (valvula and body of cerebellum, reticular formation and octavolateral area of medulla oblongata). By combining in situ hybridization and immunohistochemistry, we showed that NT-6 mRNA is synthesized in mature neurons. These results contribute to better understanding the evolutionary history of neurotrophins in vertebrates, and their role in the adult brain.
XPO1 Expression Is a Poor-Prognosis Marker in Pancreatic Adenocarcinoma
Authors: Birnbaum David Jérémie , Finetti Pascal , Birnbaum Daniel , Mamessier Emilie , Bertucci François
Published: May 2019

Pancreatic adenocarcinoma (PAC) is one of the most aggressive human cancers and new systemic therapies are urgently needed. Exportin-1 (XPO1), which is a member of the importin-β superfamily of karyopherins, is the major exporter of many tumor suppressor proteins that are involved in the progression of PAC. Promising pre-clinical data using XPO1 inhibitors have been reported in PAC, but very few data are available regarding XPO1 expression in clinical samples. Retrospectively, we analyzed XPO1 mRNA expression in 741 pancreatic samples, including 95 normal, 73 metastatic and 573 primary cancers samples, and searched for correlations with clinicopathological and molecular data, including overall survival. XPO1 expression was heterogeneous across the samples, higher in metastatic samples than in the primary tumors, and higher in primaries than in the normal samples. “XPO1-high” tumors were associated with positive pathological lymph node status and aggressive molecular subtypes. They were also associated with shorter overall survival in both uni- and multivariate analyses. Supervised analysis between the “XPO1-high” and “XPO1-low” tumors identified a robust 268-gene signature, whereby ontology analysis suggested increased XPO1 activity in the “XPO1-high” tumors. XPO1 expression refines the prognostication in PAC and higher expression exists in secondary versus primary tumors, which supports the development of XPO1 inhibitors in this so-lethal disease.
Feasibility and Effectiveness of Electrochemical Dermal Conductance Measurement for the Screening of Diabetic Neuropathy in Primary Care. Decoding Study (Dermal Electrochemical Conductance in Diabetic Neuropathy)
Authors: Cabré Juan , Mur Teresa , Costa Bernardo , Barrio Francisco , López-Moya Charo , Sagarra Ramon , García-Barco Montserrat , Vizcaíno Jesús , Bonaventura Immaculada , Ortiz Nicolau , Flores-Mateo Gemma , Solà-Morales Oriol ,   the Catalan Diabetes Prevention Research Group
Published: May 2019

Diabetes mellitus (DM) is the leading cause of polyneuropathy in the Western world. Diabetic neuropathy (DNP) is the most common complication of diabetes and is of great clinical significance mainly due to the pain and the possibility of ulceration in the lower limbs. Early detection of neuropathy is essential in the medical management of this complication. Early unmyelinated C-fiber dysfunction is one of the typical findings of diabetic neuropathy and the first clinical manifestation of dysfunction indicating sudomotor eccrine gland impairment. In order to assess newly developed technology for the measurement of dermal electrochemical conductance (DEC), we analyzed the feasibility and effectiveness of DEC (quantitative expression of sudomotor reflex) as a screening test of DNP in primary health care centers. The study included 197 people (with type 2 diabetes, prediabetes and normal tolerance) who underwent all the protocol tests and electromyography (EMG). On comparing DEC with EMG as the gold standard, the area under the receiver operating characteristic (ROC) curve (AUC, area under the curve) was 0.58 in the whole sample, AUC = 0.65 in the diabetes population and AUC = 0.72 in prediabetes, being irrelevant in subjects without glucose disturbances (AUC = 0.47). Conclusions: In usual clinical practice, DEC is feasible, with moderate sensitivity but high specificity. It is also easy to use and interpret and requires little training, thereby making it a good screening test in populations with diabetes and prediabetes. It may also be useful in screening general populations at risk of neuropathy.
Manufacture of Hybrid Natural/Synthetic Fiber Woven Textiles for Use in Technical Biocomposites with Maximum Biobased Content
Authors: Shamsuyeva Madina , Winkelmann Jana , Endres Hans-Josef
Published: May 2019

This feasibility study investigates the flexural properties of biocomposites containing woven flax textiles (plain, twill, satin) and woven twill patterned hybrid textiles containing flax-/glass or flax-/carbon mixture for lightweight applications. Synthetic fibers are integrated as weft and flax fibers are integrated as warp yarns using a double-rapier weaving machine with a Jacquard attachment. The corresponding biocomposites are manufactured via vacuum infusion process using a biobased epoxy resin as a matrix. The manufactured biocomposites are analyzed with regard to their density and flexural properties. The results show that the use of hybrid textiles offers a promising solution for the manufacture of biocomposites with a higher biobased content and significantly improved flexural properties. Furthermore, the introduction of high-performance synthetic fibers in textiles enables the manufacture of biocomposites with an isotropic mechanical performance.
Transverse Thermal Conductivity of Epoxy Carbon Fiber Prepreg Laminates with a Graphite Filled Matrix
Authors: Bard Simon , Demleitner Martin , Radtke Marius , Altstädt Volker
Published: May 2019

The thermal conductivity of carbon fiber reinforced polymers is crucial for new technologies and is used in cutting-edge technologies such as sensors, heated rollers and anti-icing of airplane wings. Researchers so far focused on coating conventional prepregs with thermally conductive materials to enhance the transversal conductivity. Another strategy is followed in this study: Thermally conductive matrices filled with graphite platelets were processed by a laboratory prepreg line. Laminates produced from this type of prepregs show an enhancement in thermal conductivity by 3.3 times with a 20 vol% filler content relative to the matrix, and a 55 vol% fiber volume content in the laminate. The research shows that the incorporation of conductive particles in the matrix is more effective for increasing the conductivity than previous methods.
Production and Characterization of Porous Polymeric Membranes of PLA/PCL Blends with the Addition of Hydroxyapatite
Authors: Moura Nayara Koba de , Siqueira Idália A. W. B. , Machado João Paulo de Barros , Kido Hueliton Wilian , Avanzi Ingrid Regina , Rennó Ana Claudia Muniz , Trichês Eliandra de Sousa , Passador Fabio Roberto
Published: May 2019

Polymer membranes have been widely used in guided tissue regeneration (GTR) and guided bone regeneration (GBR). The literature recognizes that poly (lactic acid) (PLA)/poly (ε-caprolactone) (PCL) blends have better physicochemical properties and that a porous polymer surface facilitates cell adhesion and proliferation. In addition, hydroxyapatite (HAp) incorporated into the polymer matrix promotes osteoinduction properties and osteoconduction to the polymer-ceramic biocomposite. Therefore, polymer membranes of PLA/PCL blend with the addition of HAp could be an alternative to be used in GBR. HAp was obtained by precipitation using the mixture of solutions of tetrahydrate calcium nitrate and monobasic ammonium phosphate salts. The porous membranes of the PLA/PCL (80/20) blend with the addition of HAp were obtained by solvent casting with a controlled humidity method, with the dispersion of HAp in chloroform and subsequent solubilization with the components of the blend. The solution was poured into molds for solvent evaporation under a controlled humidity atmosphere. The membranes showed the formation of pores on their surface, together with dispersed HAp particles. The results showed an increase in the surface porosity and improved bioactivity properties with the addition of HAp. Moreover, in biological studies with cell culture, it was possible to observe that the membranes with HAp have no cytotoxic effect on MC3T3 cells. These results indicate a promising use of the new biomaterial for GBR.
Physical and Mechanical Properties of Binderless Particleboard Made from Steam-Pretreated Oil Palm Trunk Particles
Authors: Boon Jia Geng , Hashim Rokiah , Danish Mohammed , Nadhari Wan Noor Aidawati Wan
Published: May 2019

Formaldehyde emissions from conventional particleboards raise issues of health and safety. One of the potential solutions is binderless particleboards made without using synthetic adhesives. However, the physical and mechanical properties of untreated binderless particleboards are relatively poor compared to conventional particleboards. This research aims to reveal the potential of using steam pretreatment to improve binderless particleboard properties made from oil palm trunk. The oil palm trunk particles were treated with steam pretreatment for different durations of time (20, 40, 60 min). The chemical constituents of the treated and untreated particles were evaluated. The binderless particleboards were made from treated and untreated particles. In addition, panels using untreated oil palm trunk particles with 10% urea–formaldehyde resin were made and used as a comparison. The boards were evaluated according to European Standards. The results indicated that the hemicellulose and starch content gradually reduced with the progression of steam pretreatment. The physical and mechanical properties were improved by increasing steam pretreatment duration. The steam pretreatment was able to improve the properties of binderless particleboards made from oil palm trunk. However, the performance of steam-pretreated binderless particleboard in this study is not compatible with the particleboards made using 10% urea–formaldehyde.
Analysis of Sulfated Glycosaminoglycans in ECM Scaffolds for Tissue Engineering Applications: Modified Alcian Blue Method Development and Validation
Authors: Iimaa Tuyajargal , Ikegami Yasuhiro , Bual Ronald , Shirakigawa Nana , Ijima Hiroyuki
Published: May 2019

Accurate determination of the amount of glycosaminoglycans (GAGs) in a complex mixture of extracellular matrix (ECM) is important for tissue morphogenesis and homeostasis. The aim of the present study was to investigate an accurate, simple and sensitive alcian blue (AB) method for quantifying heparin in biological samples. A method for analyzing heparin was developed and parameters such as volume, precipitation time, solvent component, and solubility time were evaluated. The AB dye and heparin samples were allowed to react at 4 ℃ for 24 h. The heparin-AB complex was dissolved in 25 N NaOH and 2-Aminoethanol (1:24 v/v). The optical density of the solution was analyzed by UV-Vis spectrometry at 620 nm. The modified AB method was validated in accordance with U.S. Food and Drug Administration guidelines. The limit of detection was found to be 2.95 µg/mL. Intraday and interday precision ranged between 2.14–4.83% and 3.16–7.02% (n = 9), respectively. Overall recovery for three concentration levels varied between 97 ± 3.5%, confirming good accuracy. In addition, this study has discovered the interdisciplinary nature of protein detection using the AB method. The basis for this investigation was that the fibrous protein inhibits heparin-AB complex whereas globular protein does not. Further, we measured the content of sulfated GAGs (sGAGs; expressed as heparin equivalent) in the ECM of decellularized porcine liver. In conclusion, the AB method may be used for the quantitative analysis of heparin in ECM scaffolds for tissue engineering applications.
Sex Similarities and Differences in Intelligence in Children Aged Two to Eight: Analysis of SON-R 2–8 Scores
Authors: Buczyłowska Dorota , Ronniger Pola , Melzer Jessica , Petermann Franz
Published: May 2019

The aim of this study was to investigate sex similarities and differences in visuospatial and fluid abilities and IQ scores based on those abilities in children aged two to eight. Standardization data from the Snijders-Oomen Nonverbal Intelligence Test for Children aged 2–8 (SON-R 2–8) were used. A representative sample composed of 965 children from the Netherlands and 762 children from Germany was examined. Small but significant mean sex differences favoring girls were observed until age four. At ages six and seven, boys achieved similar cognitive development levels to girls regarding all abilities assessed and outperformed girls on the Mosaics subtest measuring visuospatial cognition. Boys also displayed higher variability rates in performance. The distribution of IQ scores, with the overrepresentation of girls scoring above mean and the overrepresentation of boys scoring below mean in early childhood, altered with age towards parity between the sexes. The results suggest that girls tend to mature earlier with respect to cognitive abilities. During the course of development, however, the differences between girls and boys may become negligible.
Could Social Farming Be a Strategy to Support Food Sovereignty in Europe?
Authors: Tulla Antoni F. , Vera Ana
Published: May 2019

Food sovereignty (FS) aims to obtain value-added products in proximity agriculture (PA) in order to achieve food security in a country. Social farming (SF) can help to develop this PA as well as favoring integration of people at risk of social exclusion (RSE). The methodology includes a review of the literature, a survey of 161 SF projects in Catalonia, and ten selected in-depth interviews. “Social Return on Investment” (SROI) methodology is also applied to assess the efficiency of the projects analyzed. The results show the economic, social, and environmental viability of the majority of the SF projects which, also favored by FS and PA, allows the development of innovative experiences and sustainable forms of governance. SF has been carried out in different ways in European countries, although with the common aims of benefitting people at RSE, and using the natural environment and PA through projects basically promoted by Third Sector entities. Management of these projects is in the hands of foundations and non-profit companies making top-down decisions, and in cooperatives and associations, where decision-making is bottom-up. It can be concluded that the promotion of SF can favor PA, and therefore, FS in Europe.
Preparation and Characterization of Gradient Compressed Porous Metal for High-Efficiency and Thin-Thickness Acoustic Absorber
Authors: Yang Xiaocui , Shen Xinmin , Bai Panfeng , He Xiaohui , Zhang Xiaonan , Li Zhizhong , Chen Liang , Yin Qin
Published: May 2019

Increasing absorption efficiency and decreasing total thickness of the acoustic absorber is favorable to promote its practical application. Four compressed porous metals with compression ratios of 0%, 30%, 60%, and 90% were prepared to assemble the four-layer gradient compressed porous metals, which aimed to develop the acoustic absorber with high-efficiency and thin thickness. Through deriving structural parameters of thickness, porosity, and static flow resistivity for the compressed porous metals, theoretical models of sound absorption coefficients of the gradient compressed porous metals were constructed through transfer matrix method according to the Johnson–Champoux–Allard model. Sound absorption coefficients of four-layer gradient compressed porous metals with the different permutations were theoretically analyzed and experimentally measured, and the optimal average sound absorption coefficient of 60.33% in 100–6000 Hz was obtained with the total thickness of 11 mm. Sound absorption coefficients of the optimal gradient compressed porous metal were further compared with those of the simple superposed compressed porous metal, which proved that the former could obtain higher absorption efficiency with thinner thickness and fewer materials. These phenomena were explored by morphology characterizations. The developed high-efficiency and thin-thickness acoustic absorber of gradient compressed porous metal can be applied in acoustic environmental detection and industrial noise reduction.
Study of the Structural and Magnetic Properties of Co-Substituted Ba2Mg2Fe12O22 Hexaferrites Synthesized by Sonochemical Co-Precipitation
Authors: Koutzarova Tatyana , Kolev Svetoslav , Krezhov Kiril , Georgieva Borislava , Kovacheva Daniela , Ghelev Chavdar , Vertruyen Benedicte , Boschini Frederic , Mahmoud Abdelfattah , Tran Lan Maria , Zaleski Andrzej
Published: May 2019

Ba2Mg0.4Co1.6Fe12O22 was prepared in powder form by sonochemical co-precipitation and examined by X-ray diffraction, Mössbauer spectroscopy and magnetization measurements. Careful XRD data analyses revealed the Y-type hexaferrite structure as an almost pure phase with a very small amount of CoFe2O4 as an impurity phase (about 1.4%). No substantial changes were observed in the unit cell parameters of Ba2Mg0.4Co1.6Fe12O22 in comparison with the unsubstituted compound. The Mössbauer parameters for Ba2Mg0.4Co1.6Fe12O22 were close to those previously found (within the limits of uncertainty) for undoped Ba2Mg2Fe12O22. Isomer shifts (0.27–0.38 mm/s) typical for high-spin Fe3+ in various environments were evaluated and no ferrous Fe2+ form was observed. However, despite the indicated lack of changes in the iron oxidation state, the cationic substitution resulted in a significant increase in the magnetization and in a modification of the thermomagnetic curves. The magnetization values at 50 kOe were 34.5 emu/g at 4.2 K and 30.5 emu/g at 300 K. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves were measured in magnetic fields of 50 Oe, 100 Oe, 500 Oe and 1000 Oe, and revealed the presence of two magnetic phase transitions. Both transitions are shifted to higher temperatures compared to the undoped compound, while the ferrimagnetic arrangement at room temperature is transformed to a helical spin order at about 195 K, which is considered to be a prerequisite for the material to exhibit multiferroic properties.
Numerical Study on Concrete Pumping Behavior via Local Flow Simulation with Discrete Element Method
Authors: Zhan Yijian , Gong Jian , Huang Yulin , Shi Chong , Zuo Zibo , Chen Yiqun
Published: May 2019

The use of self-consolidating concrete and advanced pumping system enables efficient construction of super high-rise buildings; however, risks such as clogging or even bursting of pipeline still exist. To better understand the fresh concrete pumping mechanisms in detail, the discrete element method is employed in this paper for the numerical simulation of local pumping problems. By modeling the coarse aggregates as rigid clumps and appropriately defining the contact models, the concrete flow in representative pipeline units is well revealed. Important factors related to the pipe geometry, aggregate geometry and pumping condition were considered during a series of parametric studies. Based on the simulation results, their impact on the local pumping performance is summarized. The present work demonstrates that the discrete element simulation offers a useful way to evaluate the influence of various parameters on the pumpability of fresh concrete.
Plasmonics with Metallic Nanowires
Authors: Niedziółka-Jönsson Joanna , Mackowski Sebastian
Published: May 2019

The purpose of this review is to introduce and present the concept of metallic nanowires as building-blocks of plasmonically active structures. In addition to concise description of both the basic physical properties associated with the electron oscillations as well as energy propagation in metallic nanostructures, and methods of fabrication of metallic nanowires, we will demonstrate several key ideas that involve interactions between plasmon excitations and electronic states in surrounding molecules or other emitters. Particular emphasis will be placed on the effects that involve not only plasmonic enhancement or quenching of fluorescence, but also propagation of energy on lengths that exceed the wavelength of light.
Structure–Property Relationships in Shape Memory Metallic Glass Composites
Authors: Şopu Daniel , Yuan Xudong , Moitzi Franco , Stoica Mihai , Eckert Jürgen
Published: May 2019

Metallic glass composites with shape memory crystals show enhanced plasticity and work-hardening capability. We investigate the influence of various critical structural aspects such as, the density of crystalline precipitates, their distribution and size, and the structural features and intrinsic properties of the phase on the deformation behavior of metallic amorphous Cu 64 Zr 36 composites with B2 CuZr inclusions using molecular dynamics simulations. We find that a low density of small B2 inclusions with spacing smaller than the critical shear band length controls the formation and distribution of plastic zones in the composite and hinders the formation of critical shear bands. When the free path for shearing allows the formation of mature shear bands a high volume fraction of large B2 precipitates is necessary to stabilize the shear flow and avoid runaway instability. Additionally, we also investigate the deformation mechanism of composites with pure copper crystals for comparison, in order to understand the superior mechanical properties of metallic glass composites with shape memory crystals in more detail. The complex and competing mechanisms of deformation occurring in shape memory metallic glass composites allow this class of materials to sustain large tensile deformation, even though only a low-volume fraction of crystalline inclusions is present.
Anisotropy of Graphene Nanoflake Diamond Interface Frictional Properties
Authors: Zhang Ji , Osloub Ehsan , Siddiqui Fatima , Zhang Weixiang , Ragab Tarek , Basaran Cemal
Published: May 2019

Using molecular dynamics (MD) simulations, the frictional properties of the interface between graphene nanoflake and single crystalline diamond substrate have been investigated. The equilibrium distance between the graphene nanoflake and the diamond substrate has been evaluated at different temperatures. This study considered the effects of temperature and relative sliding angle between graphene and diamond. The equilibrium distance between graphene and the diamond substrate was between 3.34 Å at 0 K and 3.42 Å at 600 K, and it was close to the interlayer distance of graphite which was 3.35 Å. The friction force between graphene nanoflakes and the diamond substrate exhibited periodic stick-slip motion which is similar to the friction force within a graphene–Au interface. The friction coefficient of the graphene–single crystalline diamond interface was between 0.0042 and 0.0244, depending on the sliding direction and the temperature. Generally, the friction coefficient was lowest when a graphene flake was sliding along its armchair direction and the highest when it was sliding along its zigzag direction. The friction coefficient increased by up to 20% when the temperature rose from 300 K to 600 K, hence a contribution from temperature cannot be neglected. The findings in this study validate the super-lubricity between graphene and diamond and will shed light on understanding the mechanical behavior of graphene nanodevices when using single crystalline diamond as the substrate.
Mechanical Characterization of Different Aluminium Foams at High Strain Rates
Authors: Amaro Ana M. , Neto Maria A. , Cirne José S. , Reis Paulo N.B.
Published: May 2019

Samples having nominal compositions of AlSi12 and Al6082-T4 were prepared using a lost wax casting process, with nominal relative densities of 20%, 40%, and 60%, as well as arrangements of a uniform cell structure (US) or a dual-size cell (DS). For comparison, samples of aluminium foam-filled tubes having the same nominal composition were also prepared with the same technique, with nominal relative densities of 20% and similar arrangements (US and DS). Impact tests at different velocities were performed using a split Hopkinson pressure bar (SHPB). It is possible to conclude that Al6082-T4 foams have better performance, in both configurations, than the AlSi12 ones. Considering a uniform cell structure and a density of 20%, the absorbed energy by the Al6082-T4 foams was around 25% higher than the value observed for the AlSi12 ones. In terms of arrangement, the US structure presents absorbed energy around 57% lower than the DS ones, while the AlSi12 foams with a relative density of 20% were compared. Finally, the absorbed energy growths from 2.8 × 105 to 5.2 × 105 J/m3, when the density increased from 20% to 60%. However, when these foams were involved with a tube, the performances increased substantially.
Design for Disassembly (DfD) and Augmented Reality (AR): Case Study Applied to a Gearbox
Authors: Frizziero Leonardo , Liverani Alfredo , Caligiana Gianni , Donnici Giampiero , Chinaglia Luca
Published: May 2019

Today’s market drives companies to change, adapt, and compete. Many consumers are increasingly looking at price, without sacrificing quality. In order to be attractive to the customer, companies must be able to offer the required quality at the lowest possible price. The life cycle of many products has been shortened compared to the past because now technologies are evolving faster. For these reasons, it is important that companies reevaluate all the operations that are carried out within them, to optimize them and eventually adopt new technologies if they offer interesting opportunities. In this discussion, we first study the design for disassembly, a technique that can bring several advantages during the life cycle of a component, offering the possibility of reducing time and cost of disassembling a product, and better reuse of the different materials of which it is composed. Subsequently, augmented reality is discussed, and how this technology is exploited in the world, especially in the industrial sector. During the work, we discuss a case study, with the gearbox being the object of analysis. This allows us to apply the theoretical concepts illustrated in a concrete way, allowing for a better understanding of the topics.
A Comparative Study of Open-Source and Licensed CAD Software to Support Garment Development Learning
Authors: Papachristou Evridiki , Kyratsis Panagiotis , Bilalis Nikolaos
Published: May 2019

Most universities have included computer-aided design (CAD) pattern making systems education and training in their clothing technology courses in recent years, so as to respond to the actual needs of the fashion world for high-skilled fashion designers and clothing engineers. With the rapid rise in the use of open source software (OSS) in all types of applications, it is important to know if the existing OSS CAD software for garment prototyping development can successfully support the learning process. The present study compares two commercial licensed CAD systems for pattern design (Polypattern and Create) to an open source software, Seamly2D, and to Wild Ginger’s Caveo V6 programme, which runs within an OSS. In total, two licensed and two OSS systems have been evaluated in their weights in accomplishing the garment development of ten different pattern designs. The results obtained for the evaluation of a set of OS and licensed CAD systems are presented and critically discussed.
Prešić Type Nonself Operators and Related Best Proximity Results
Authors: Ali Muhammad Usman , Farheen Misbah , Kamran Tayyab , Maniu Georgeta
Published: May 2019

The purpose of this article is to discuss the existence of best proximity points for Pre s ˇ i c ´ -type nonself operators, say T : A k → B . We also give several examples to support our results. As a consequence of our results, we have provided some interesting formulations of Pre s ˇ i c ´ fixed point results.
Enhancing Elephant Herding Optimization with Novel Individual Updating Strategies for Large-Scale Optimization Problems
Authors: Li Jiang , Guo Lihong , Li Yan , Liu Chang
Published: May 2019

Inspired by the behavior of elephants in nature, elephant herd optimization (EHO) was proposed recently for global optimization. Like most other metaheuristic algorithms, EHO does not use the previous individuals in the later updating process. If the useful information in the previous individuals were fully exploited and used in the later optimization process, the quality of solutions may be improved significantly. In this paper, we propose several new updating strategies for EHO, in which one, two, or three individuals are selected from the previous iterations, and their useful information is incorporated into the updating process. Accordingly, the final individual at this iteration is generated according to the elephant generated by the basic EHO, and the selected previous elephants through a weighted sum. The weights are determined by a random number and the fitness of the elephant individuals at the previous iteration. We incorporated each of the six individual updating strategies individually into the basic EHO, creating six improved variants of EHO. We benchmarked these proposed methods using sixteen test functions. Our experimental results demonstrated that the proposed improved methods significantly outperformed the basic EHO.
Food Allergies: Current and Future Treatments
Authors: Licari Amelia , Manti Sara , Marseglia Alessia , Brambilla Ilaria , Votto Martina , Castagnoli Riccardo , Leonardi Salvatore , Marseglia Gian Luigi
Published: May 2019

Food allergies are an increasingly public health problem, affecting up to 10% of children and causing a significant burden on affected patients, resulting in dietary restrictions, fear of accidental ingestion and related risk of severe reactions, as well as a reduced quality of life. Currently, there is no specific cure for a food allergy, so the only available management is limited to strict dietary avoidance, education on prompt recognition of symptoms, and emergency treatment of adverse reactions. Several allergen specific- and nonspecific-therapies, aiming to acquire a persistent food tolerance, are under investigation as potential treatments; however, to date, only immunotherapy has been identified as the most promising therapeutic approach for food allergy treatment. The aim of this review is to provide an updated overview on changes in the treatment landscape for food allergies.
Structures, Properties, and Performances—Relationships of Polymeric Membranes for Pervaporative Desalination
Authors: Singha Nayan , Karmakar Mrinmoy , Chattopadhyay Pijush , Roy Sagar , Deb Mousumi , Mondal Himarati , Mahapatra Manas , Dutta Arnab , Mitra Madhushree , Roy Joy
Published: May 2019

For the fulfilment of increasing global demand and associated challenges related to the supply of clean-and-safe water, PV has been considered as one of the most attractive and promising areas in desalinating salty-water of varied salinities. In pervaporative desalination, the sustainability, endurance, and structural features of membrane, along with operating parameters, play the dominant roles and impart paramount impact in governing the overall PV efficiency. Indeed, polymeric- and organic-membranes suffer from several drawbacks, including inferior structural stability and durability, whereas the fabrication of purely inorganic membranes is complicated and costly. Therefore, recent development on the high-performance and cost-friendly PV membrane is mostly concentrated on synthesizing composite- and NCP-membranes possessing the advantages of both organic- and inorganic-membranes. This review reflects the insights into the physicochemical properties and fabrication approaches of different classes of PV membranes, especially composite- and NCP-membranes. The mass transport mechanisms interrelated to the specialized structural features have been discussed. Additionally, the performance potential and application prospects of these membranes in a wide spectrum of desalination and wastewater treatment have been elaborated. Finally, the challenges and future perspectives have been identified in developing and scaling up different high-performance membranes suitable for broader commercial applications.
Strength and Fracture Toughness of Hardox-400 Steel
Authors: Dzioba Ihor , Pała Robert
Published: May 2019

This paper presents results of strength and fracture toughness properties of low-carbon high-strength Hardox-400 steel. Experimental tests were carried out for specimens of different thickness at wide temperature range from −100 to 20 °C. The dependences of the characteristic of material strength and fracture toughness on temperature based on experimental data are shown. Numerical calculation of the stress and strain distributions in area before crack tip using the finite element method (FEM) was done. Based on results of numerical calculation and observation of the fracture surfaces by scanning electron microscope (SEM), the critical local stress level at which brittle fracture takes place was assessed. Consideration of the levels of stress and strain in the analysis of the metal state at the tip of the crack allowed to justify the occurrence of the brittle-to-ductile fracture mechanism. On the basis of the results of stretch zone width measurements and stress components, the values of fracture toughness at the moment of crack initiation were calculated.
Effect of Elastic Module Degradation Measurement in Different Sizes of the Nonlinear Isotropic–Kinematic Yield Surface on Springback Prediction
Authors: Baara Wisam Ali Basher , Baharudin B. T. Hang Tuah b. , Anuar Mohd Khairol , Ismail Mohd Idris Shah b.
Published: May 2019

Commercial finite element software that uses default hardening model simulation is not able to predict the final shape of sheet metal that changes its dimensions after removing the punch due to residual stress (strain recovery or springback). We aimed to develop a constitutive hardening model to more accurately simulate this final shape. The strain recovery or balancing of residual stress can be determined using the isotropic hardening of the original elastic modulus and the hardening combined with varying degrees of elastic modulus degradation and the size of the yield surfaces. The Chord model was modified with one-yield surfaces. The model was combined with nonlinear isotropic–kinematic hardening models and implemented in Abaqus user-defined material subroutine for constitutive model (UMAT). The Numisheet 2011 benchmark for springback prediction for DP780 high-strength steel sheet was selected to verify the new model, the Chord model, the Quasi Plastic-Elastic (QPE) model, and the default hardening model using Abaqus software. The simulation of U-draw bending from the Numisheet 2011 benchmark was useful for comparing the proposed model with experimental measurements. The results from the simulation of the model showed that the new model more accurately predicts springback than the other models.
Identification of Relationships between Heat Treatment and Fatigue Crack Growth of αβ Titanium Alloys
Authors: Renon Vincent , Henaff Gilbert , Larignon Céline , Perusin Simon , Villechaise Patrick
Published: May 2019

This study deals with the influence of microstructure on the fatigue crack growth resistance of αβ titanium alloys: Ti-6Al-4V ELI (Extra Low Interstitial) that may compete with the conventional Ti-6Al-4V alloy in the manufacture of high performance aircraft. Six different microstructures have been considered: the as-received bimodal microstructures and five distinct fully lamellar microstructures. The characteristic parameters of these microstructures were determined and crack growth tests were performed with crack closure measurements in order to evaluate the shielding effect induced by closure. A comparison of crack growth rates, fracture surfaces, and crack path was carried out for the different microstructures. The results outline a transition between two propagation regimes from a microstructure-sensitive to microstructure-insensitive propagation.
Numerical Analysis of a New Nonlinear Twist Extrusion Process
Authors: Yalçinkaya Tuncay , Şimşek Ülke , Miyamoto Hiroyuki , Yuasa Motohiro
Published: May 2019

Severe plastic deformation (SPD) can produce ultrafine grained (UFG) and nanocrystalline (NC) materials by imposing intense plastic strain. One of the many options for inducing large plastic strains is to pass the material through a torsional/twist extrusion. The high-strength materials fabricated by SPD has no limit in dimension, and they can even be applied to load-carrying structural materials. Even though the method is quite successful, the industrial transfer has been limited so far because of low production efficiency and high cost. To remedy such difficulties, a new torsional extrusion process called nonlinear twist extrusion (NLTE) is introduced in this study, which has been designed based on two principles; (1) linear arrangement of the production line and (2) effective die geometry resulting in higher and more homogeneous plastic strain evolution which would give better grain refinement. The initial computational study of the designed geometry for the new extrusion process is addressed in the current study. The obtained results are discussed in detail with respect to conventional extrusion process, which is referred to as linear twist extrusion (LTE). The method is expected to offer a great potential for industrial use.