bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Immune Features of the Systemic Inflammation Associated with Primary Hypercholesterolemia: Changes in Cytokine/Chemokine Profile, Increased Platelet and Leukocyte Activation
Authors: Collado Aida , Marques Patrice , Domingo Elena , Perello Eva , González-Navarro Herminia , Martinez-Hervás Sergio , Real José T. , Piqueras Laura , Ascaso Juan F. , Sanz Maria-Jesus
Published: December 2018

Primary hypercholesterolemia (PH) is associated with a low grade systemic inflammation that is likely the main driver of premature atherosclerosis. Accordingly, we characterized the immune cell behaviour in PH and its potential consequences. Whole blood from 22 PH patients and 21 age-matched controls was analysed by flow cytometry to determine the percentage of leukocyte immunophenotypes, activation, and platelet-leukocyte aggregates. Plasma markers were determined by Enzyme-Linked ImmunoSorbent Assay (ELISA). The adhesion of platelet-leukocyte aggregates to tumor necrosis factor-α (TNFα)-stimulated arterial endothelium was investigated using the dynamic model of the parallel-plate flow chamber. PH patients presented greater percentage of Mon 3 monocytes, Th2 and Th17 lymphocytes, activated platelets, and leukocytes than controls. The higher percentages of circulating platelet-neutrophil, monocyte and lymphocyte aggregates in patients caused increased platelet-leukocyte adhesion to dysfunctional arterial endothelium. Circulating CXCL8, CCL2, CX3CL1, and IL-6 levels positively correlated with key lipid features of PH, whereas negative correlations were found for IL-4 and IL-10. We provide the first evidence that increased platelet and leukocyte activation leads to elevated platelet-leukocyte aggregates in PH and augmented arterial leukocyte adhesiveness, a key event in atherogenesis. Accordingly, modulation of immune system behavior might be a powerful target in the control of further cardiovascular disease in PH.
Influence of Poly(Ethylene Glycol) End Groups on Poly(Ethylene Glycol)-Albumin System Properties as a Potential Degradable Tissue Scaffold
Authors: Overby Robyn J. , Feldman Dale S.
Published: December 2018

Chronic dermal lesions, such as pressure ulcers, are difficult to heal. Degradable tissue scaffold systems can be employed to serve as a provisional matrix for cellular ingrowth and facilitate regenerative healing during degradation. Degradable regenerative tissue scaffold matrices can be created by crosslinking albumin with functionalized poly(ethylene glycol) (PEG) polymers. The purpose of this study was to evaluate the stability of PEG-albumin scaffold systems formed using PEG polymers with three different functionalized end chemistries by quantifying in vitro system swellability to determine the most promising PEG crosslinking polymer for wound healing applications. Of the three polymers evaluated, PEG-succinimidyl glutarate (SG) exhibited consistent gelation and handling characteristics when used as the crosslinking agent with albumin. PEG-SG polymers were identified as an appropriate synthetic crosslinking moiety in a PEG-albumin scaffold system, and further in vitro and in vivo evaluation of this scaffold system is merited.
A Critical Review on Selected External Physical Cues and Modulation of Cell Behavior: Magnetic Nanoparticles, Non-thermal Plasma and Lasers
Authors: Smolková Barbora , Uzhytchak Mariia , Lynnyk Anna , Kubinová Šárka , Dejneka Alexandr , Lunov Oleg
Published: December 2018

Physics-based biomedical approaches have proved their importance for the advancement of medical sciences and especially in medical diagnostics and treatments. Thus, the expectations regarding development of novel promising physics-based technologies and tools are very high. This review describes the latest research advances in biomedical applications of external physical cues. We overview three distinct topics: using high-gradient magnetic fields in nanoparticle-mediated cell responses; non-thermal plasma as a novel bactericidal agent; highlights in understanding of cellular mechanisms of laser irradiation. Furthermore, we summarize the progress, challenges and opportunities in those directions. We also discuss some of the fundamental physical principles involved in the application of each cue. Considerable technological success has been achieved in those fields. However, for the successful clinical translation we have to understand the limitations of technologies. Importantly, we identify the misconceptions pervasive in the discussed fields.
Compressive Sensing Hyperspectral Imaging by Spectral Multiplexing with Liquid Crystal
Authors: Oiknine Yaniv , August Isaac , Farber Vladimir , Gedalin Daniel , Stern Adrian
Published: December 2018

Hyperspectral (HS) imaging involves the sensing of a scene’s spectral properties, which are often redundant in nature. The redundancy of the information motivates our quest to implement Compressive Sensing (CS) theory for HS imaging. This article provides a review of the Compressive Sensing Miniature Ultra-Spectral Imaging (CS-MUSI) camera, its evolution, and its different applications. The CS-MUSI camera was designed within the CS framework and uses a liquid crystal (LC) phase retarder in order to modulate the spectral domain. The outstanding advantage of the CS-MUSI camera is that the entire HS image is captured from an order of magnitude fewer measurements of the sensor array, compared to conventional HS imaging methods.
Opportunities and Challenges for Error Correction Scheme for Wireless Body Area Network—A Survey
Authors: Kadel Rajan , Islam Nahina , Ahmed Khandakar , Halder Sharly J.
Published: December 2018

This paper offers a review of different types of Error Correction Scheme (ECS) used in communication systems in general, which is followed by a summary of the IEEE standard for Wireless Body Area Network (WBAN). The possible types of channels and network models for WBAN are presented that are crucial to the design and implementation of ECS. Following that, a literature review on the proposed ECSs for WBAN is conducted based on different aspects. One aspect of the review is to examine what type of parameters are considered during the research work. The second aspect of the review is to analyse how the reliability is measured and whether the research works consider the different types of reliability and delay requirement for different data types or not. The review indicates that the current literatures do not utilize the constraints that are faced by WBAN nodes during ECS design. Subsequently, we put forward future research challenges and opportunities on ECS design and the implementation for WBAN when considering computational complexity and the energy-constrained nature of nodes.
‘Un-Central’ Landscapes of NE-Africa and W-Asia—Landscape Archaeology as a Tool for Socio-Economic History in Arid Landscapes
Authors: Rieger Anna-Katharina
Published: December 2018

Arid regions in the Old World Dry Belt are assumed to be marginal regions, not only in ecological terms, but also economically and socially. Such views in geography, archaeology, and sociology are—despite the real limits of living in arid landscapes—partly influenced by derivates of Central Place Theory as developed for European medieval city-based economies. For other historical time periods and regions, this narrative inhibited socio-economic research with data-based and non-biased approaches. This paper aims, in two arid Graeco-Roman landscapes, to show how far approaches from landscape archaeology and social network analysis combined with the “small world phenomenon” can help to overcome a dichotomic view on core places and their areas, and understand settlement patterns and economic practices in a nuanced way. With Hauran in Southern Syria and Marmarica in NW-Egypt, I revise the concept of marginality, and look for qualitatively and spatially defined relationships between settlements, for both resource management and social organization. This ‘un-central’ perspective on arid landscapes provides insights on how arid regions functioned economically and socially due to a particular spatial concept and connection with their (scarce) resources, mainly water.
Local Effects in EHL Contacts with Oil-Impregnated Sintered Materials
Authors: Ebner Martin , Omasta Milan , Lohner Thomas , Šperka Petr , Krupka Ivan , Hartl Martin , Michaelis Klaus , Höhn Bernd-Robert , Stahl Karsten
Published: December 2018

Oil-impregnated open-pored sintered materials can be used to provide the intrinsic self-lubrication of tribological contacts. Although its general functionality was recently confirmed for highly-loaded contacts, detailed analyses on the local effects of surface porosity in tribological contacts are required in order to understand and improve its operating behavior. In this context, this study investigates the influence of different surface finishes at a twin-disk test rig, and the local effects of surface porosity in elastohydrodynamically lubricated (EHL) contacts at an optical tribometer, based on thin film colorimetric interferometry. The results show the detrimental influence of high surface porosity on the operating behavior. Local observations of the lubricant film in EHL contacts indicate the presence of “open” pores, resulting in local film breakdown, and “closed” pores, transporting the additional lubricant into the pressurized zone. An appropriate surface finish technique to manufacture a low permeable layer with an adequate mechanical strength is demanded.
Synthesis of Imine Congeners of Resveratrol and Evaluation of Their Anti-Platelet Activity
Authors: Bigdeli Mohammad , Sabbaghan Maryam , Esfahanizadeh Marjan , Kobarfard Farzad , Vitalini Sara , Iriti Marcello , Sharifi-Rad Javad
Published: December 2018

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a cardioprotective phytochemical occurring in many plant products. In this study, a new series of imine congeners of resveratrol has been synthesized in which the imine moiety replaced the double bond in the structure of resveratrol. In addition, the in vitro antiplatelet activity of these resveratrol derivatives has been evaluated against adenosine diphosphate (ADP), arachidonic acid (AA), and collagen as platelet aggregation inducers. In general, the synthesized compounds were active as antiplatelet agents, and, therefore, the imine functional group may be considered as an effective replacement for a double bond in resveratrol for developing new and promising antiplatelet drugs.
2′-Chloro-4-(1-methyl-1H-imidazol-2-yl)-2,4′-bipyridine
Authors: Zinad Dhafer , AL-Duhaidahaw Dunya , Al-Amiery Ahmed
Published: December 2018

The compound 2′-chloro-4-(1-methyl-1H-imidazol-2-yl)-2,4′-bipyridine was obtained with a good yield by the reaction of 2-chloro-4-(1-methyl-1H-imidazol-2-yl)pyridine with (2-chloropyridin-4-yl)boronic acid and structurally characterized by nuclear magnetic resonance (1H-NMR and 13C-NMR), thin-layer chromatography–mass spectrometry (TLC–MS), HPLC, gas chromatography–mass spectrometry (GC–MS), and elemental analysis. The functionalization of the pyridine was achieved by the palladium-catalyzed Suzuki–Miyaura carbon–carbon cross-coupling reaction that afforded the target compound.
Manganese Removal from Liquid Nickel by Hydrogen Plasma Arc Melting
Authors: Guo Xiliang , Yu Jianbo , Hou Yuan , Zhang Yujia , Wang Jiang , Li Xia , Liao Hanlin , Ren Zhongming
Published: December 2018

In this work, the removal of manganese from nickel melts by Ar and (10%, 20% and 40%) H2 plasma arc melting under various pressures (0.01–0.02, 0.04–0.05 and 0.09–0.1 MPa) was investigated experimentally. The results show that only a slight reduction in the manganese content is obtained by Ar plasma arc melting (PAM). By contrast, the manganese content of liquid nickel decreases noticeably upon the addition of hydrogen to plasma gas, and the rate of manganese removal increases with increasing hydrogen volume fraction. In addition, the reduction in the pressure enhances the efficiency of manganese removal from liquid nickel by hydrogen plasma arc melting (HPAM). The process of manganese removal by HPAM was found to obey a first-order rate law. From kinetic analysis, the rate of reduction in the manganese content increases proportionally to the 0.73–0.75th power of the hydrogen volume fraction in the plasma gas. However, the rate of the manganese content reduction increases proportionally to approximately 0.88th power of %H2 in the plasma gas for the initial manganese content of 0.89 mass%, which is slightly higher than that for the initial manganese concentration of 0.45 mass%. Thermodynamic analysis indicates that the volatilization of manganese benefits from negative pressure and the presence of active hydrogen atoms that act as the transfer media of the metal vapor in the gas boundary layer.
Evaluation of the Performance of Helmet Prototypes Fabricated from Acrylonitrile Butadiene Styrene Composites Filled with Natural Resource
Authors: Nikmatin Siti , Hermawan Bambang , Irmansyah Irmansyah , Indro Mohammad Nur , Kueh Ahmad Beng Hong , Syafiuddin Achmad
Published: December 2018

The performance of helmet prototypes fabricated from acrylonitrile butadiene styrene composites filled with oil palm empty fruit bunch fibers was evaluated. The fibers were produced using a milling procedure, while the composites were fabricated using a single-screw extrusion. The physical characteristics of the produced fibers, which are water content, size, and density, were investigated. In addition, the mechanical properties of the produced helmets, including shock absorption, yield stress, frequency, and head injury criterion (HIC), were examined. The impact strength of the produced helmets increases with the rise of filler content. In addition, the helmets were also able to withstand a considerable pressure such that the transmitted pressure was far under the maximum value acceptable by the human skull. The present work also found that HICs exhibited by the investigated helmet prototypes fulfill all the practical guidelines as permitted by the Indonesian government. In terms of novelty, such innovation can be considered the first invention in Indonesia since the endorsement of the use of motorcycle helmets.
Wear Performance Analysis of Ni–Al2O3 Nanocomposite Coatings under Nonconventional Lubrication
Authors: Bhutta Muhammad Usman , Khan Zulfiqar Ahmad , Garland Nigel
Published: December 2018

This article presents a wear study of Ni–Al2O3 nanocomposite coatings in comparison to uncoated steel contacts under reciprocating motion. A ball-on-flat type contact configuration has been used in this study in which a reciprocating flat steel sample has been used in a coated and uncoated state against a stationary steel ball under refrigerant lubrication. The next generation of environmentally friendly refrigerant HFE-7000 has been used itself as lubricant in this study without the influence of any external lubricant. The thermodynamic applications and performance of HFE-7000 is being studied worldwide, as it is replacing the previous generation of refrigerants. No work however has been previously performed to evaluate the wear performance of HFE-7000 using nanocomposite coatings. The wear scar developed on each of the flat and ball samples was studied using a Scanning Electron Microscope (SEM). The micrographs show that a combination of adhesive and abrasive wear occurs when using uncoated steel samples. Micro-delamination is observed in the case of Ni–Al2O3 nanocomposite coatings accompanied by adhesive and abrasive wear. Wear volume of the wear track was calculated using a White Light Interferometer. Energy-Dispersive X-ray Spectroscopic (EDS) analysis of the samples reveals fluorine and oxygen on the rubbing parts when tested using coated as well as uncoated samples. The formation of these fluorinated and oxygenated tribo-films helps to reduce wear and their formation is accelerated by increasing the refrigerant temperature. Ni–Al2O3 nanocomposite coatings show good wear performance at low and high loads in comparison to uncoated contacts. At intermediate loads the coated contacts resulted in increased wear, especially at low loads. This increase in wear is associated with the delamination of the coating and the slow formation of protective surface films under these testing conditions.
Effect of Modified Polyvinyl Alcohol Fibers on the Mechanical Behavior of Engineered Cementitious Composites
Authors: Sun Mian , Chen Youzhi , Zhu Jiaoqun , Sun Tao , Shui Zhonghe , Ling Gang , Zhong Haoxuan , Zheng Yourui
Published: December 2018

Polyvinyl alcohol (PVA) fiber was proposed to enhance the mechanical performance of engineered cementitious composite in this research. A mixture of engineered cementitious composite with better expected performance was made by adding 2% PVA fiber. Mechanics tests, including pressure resistance, fracture resistance, and ultimate tensile strength, were conducted. They reveal that the engineered cementitious composites not only exhibit good pressure resistance, but they also exhibit excellent fracture resistance and strain capability against tensile stress through mechanics tests, including pressure resistance, fracture resistance, and ultimate tensile resistance. To further improve the engineered composites’ ductility, attempts to modify the performance of the PVA fiber surface have been made by using a vinyl acetate (VAE) emulsion, a butadiene–styrene emulsion, and boric anhydride. Results indicated that the VAE emulsion achieved the best performance improvement. Its use in fiber pre-processing enables the formation of a layer of film with weak acidity, which restrains the hydration of adjacent gel materials, and reduces the strength of transitional areas of the fiber/composite interface, which restricts fiber slippage and pulls out as a result of its growth in age, and reduces hydration levels. Research illustrates that the performance-improvement processing that is studied not only improves the strain of the engineered cementitious composites, but can also reduce the attenuation of the strain against tensile stress.
Characteristics and Applications of Sugar Cane Bagasse Ash Waste in Cementitious Materials
Authors: Xu Qing , Ji Tao , Gao San-Ji , Yang Zhengxian , Wu Nengsen
Published: December 2018

Sugar cane bagasse ash (SCBA) is an abundant byproduct of the sugar and ethanol industry. SCBA is generally used as a fertilizer or is disposed of in landfills, which has led to intensified environmental concerns. In recent years, SCBA research has mainly been focused on utilization in construction materials due to the abundance and pozzolanic characteristics of SCBA. In this paper, a comprehensive review of the state-of-the-art morphology, physical properties, chemical composition, and mineralogical composition of SCBA is presented. Studies indicate that SCBA is a potentially promising construction material. The applications of SCBA as a pozzolanic material, a new source for preparing alkali-activated binders, aggregates, and fillers in construction materials, are summarized. The impacts of SCBA on fresh and hardened concrete properties are highlighted, including the physical properties, mechanical strength, microstructure, and durability. Key factors that govern pozzolanic activity are discussed in detail, including calcination and recalcination temperatures, and durations, fineness, loss on ignition (LOI), and crystal silicon dioxide. Finally, further research on the optimal and broad utilization of SCBA in construction materials is recommended.
Performance Evaluation and Comparison between Direct and Chemical-Assisted Picosecond Laser Micro-Trepanning of Single Crystalline Silicon
Authors: Zhu Hao , Zhang Zhaoyang , Xu Kun , Xu Jinlei , Zhu Shuaijie , Wang Anbin , Qi Huan
Published: December 2018

The fabrication of micro-holes in silicon substrates that have a proper taper, higher depth-to-diameter ratio, and better surface quality has been attracting intense interest for a long time due to its importance in the semiconductor and MEMS (Micro-Electro-Mechanical System) industry. In this paper, an experimental investigation of the machining performance of the direct and chemical-assisted picosecond laser trepanning of single crystalline silicon is conducted, with a view to assess the two machining methods. The relevant parameters affecting the trepanning process are considered, employing the orthogonal experimental design scheme. It is found that the direct laser trepanning results are associated with evident thermal defects, while the chemical-assisted method is capable of machining micro-holes with negligible thermal damage. Range analysis is then carried out, and the effects of the processing parameters on the hole characteristics are amply discussed to obtain the recommended parameters. Finally, the material removal mechanisms that are involved in the two machining methods are adequately analyzed. For the chemical-assisted trepanning case, the enhanced material removal rate may be attributed to the serious mechanical effects caused by the liquid-confined plasma and cavitation bubbles, and the chemical etching effect provided by NaOH solution.
Plasmon-Induced Electrocatalysis with Multi-Component Nanostructures
Authors: Subramanian Palaniappan , Meziane Dalila , Wojcieszak Robert , Dumeignil Franck , Boukherroub Rabah , Szunerits Sabine
Published: December 2018

Noble metal nanostructures are exceptional light absorbing systems, in which electron–hole pairs can be formed and used as “hot” charge carriers for catalytic applications. The main goal of the emerging field of plasmon-induced catalysis is to design a novel way of finely tuning the activity and selectivity of heterogeneous catalysts. The designed strategies for the preparation of plasmonic nanomaterials for catalytic systems are highly crucial to achieve improvement in the performance of targeted catalytic reactions and processes. While there is a growing number of composite materials for photochemical processes-mediated by hot charge carriers, the reports on plasmon-enhanced electrochemical catalysis and their investigated reactions are still scarce. This review provides a brief overview of the current understanding of the charge flow within plasmon-enhanced electrochemically active nanostructures and their synthetic methods. It is intended to shed light on the recent progress achieved in the synthesis of multi-component nanostructures, in particular for the plasmon-mediated electrocatalysis of major fuel-forming and fuel cell reactions.
Structural Transformations of Hydrolysates Obtained from Ti-, Zr-, and Ti, Zr-Solutions Used for Clay Pillaring: Towards Understanding of the Mixed Pillars Nature
Authors: Bahranowski Krzysztof , Klimek Agnieszka , Gaweł Adam , Górniak Katarzyna , Michalik Alicja , Serwicka-Bahranowska Ewa
Published: December 2018

Structural characteristics of hydrolysates formed from the aqueous Ti-, Zr-, and Ti, Zr-pillaring solutions prepared from inorganic precursors (TiCl4 and ZrOCl2), was investigated and compared with that of precipitates obtained from the same solutions after a slight alkalization of pH to the values reported for the conditions of clay pillaring. The materials were recovered by lyophilization and subsequently subjected to calcination at 500, 800 and 1000 °C. Of special interest was the effect of pH on the possible formation of mixed Ti, Zr-oxide species. Powder X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope/energy dispersive spectrometer (SEM/EDS) analysis showed that even a relatively moderate alteration of pH in Ti-, Zr-, or Ti, Zr-precursor solutions caused substantial changes in the outcome of hydrolytic transformations, manifested by different phase and/or chemical composition of the resulting hydrolysates. Analysis of thermal evolution of hydrolysates showed that alkalization facilitated the transformation of anatase into rutile in materials obtained from Ti-pillaring solution, but retarded tetragonal to monoclinic zirconia conversion in samples derived from Zr-pillaring agent. The most striking effect was observed for the mixed Ti, Zr-pillaring solution, where an increase of pH enabled the formation of zirconium titanate as the only crystalline phase, rather than a multiphase mixture of anatase, monoclinic zirconia and zirconium titanate obtained from the more acidic precursor. The finding supports the model of mixed Ti-O-Zr network in props generated in Ti, Zr-pillared montmorillonites.
Highly Efficient Liquid-Phase Hydrogenation of Naringin Using a Recyclable Pd/C Catalyst
Authors: Zhao Jiamin , Yuan Ying , Meng Xiuhong , Duan Linhai , Zhou Rujin
Published: December 2018

A highly efficient liquid-phase hydrogenation reaction using a recyclable palladium on carbon (Pd/C) catalyst has been used for the transformation of naringin to its corresponding dihydrochalcone. The effects of various solvents on the hydrogenation process were studied, with water being identified as the optimal solvent. The analysis also revealed that sodium hydroxide (NaOH) can accumulate on the surface of the Pd/C catalyst in alcoholic solvents, leading to its inactivation. The higher solubility of NaOH in water implies that it remains in solution and does not accumulate on the Pd/C catalyst surface, ensuring the catalytic activity and stability.
Effect of Scanning Routes on the Stress and Deformation of Overhang Structures Fabricated by SLM
Authors: Zhang Xiaochuan , Kang Jinwu , Rong Yiming , Wu Pengyue , Feng Tao
Published: December 2018

Selective laser melting (SLM) is a promising manufacturing method for the construction of complicated precision parts. However, deformation of the overhang during the fabrication process and post treatment is still a common problem. In this paper, the effect of the scanning route on the residual stress and deformation of fabricated AlSi10Mg overhang specimens by SLM was investigated. Different scanning routes for the overhang including longitudinal direction, transverse direction, and the alternation between these two scanning routes in consecutive layers were studied by experiments within this study. Numerical simulation was utilized to measure the stress of the specimens while deformation prediction was used for the different scanning routes. Both the experimental and simulated results showed that the scanning route had a substantial influence on the residual stress and deformation of the specimens. The longitudinal scanning resulted in significant upward bending deformation of the overhang as it was cut from the baseplate. However, there was less deformation for the overhangs fabricated by transverse and alternating scanning routes. A transverse scanning route is helpful for the reduction of residual stress in the longitudinal direction and the corresponding deformation.
Thermal Stability and Thermoelectric Properties of NaZnSb
Authors: Gvozdetskyi Volodymyr , Owens-Baird Bryan , Hong Sangki , Zaikina Julia V.
Published: December 2018

A layered Zintl antimonide NaZnSb (PbClF or Cu2Sb structure type; P4/nmm) was synthesized using the reactive sodium hydride NaH precursor. This method provides comprehensive compositional control and facilitates the fast preparation of high-purity samples in large quantities. NaZnSb is highly reactive to humidity/air and hydrolyzes to NaOH, ZnO, and Sb in aerobic conditions. On the other hand, NaZnSb is thermally stable up to 873 K in vacuum, as no structural changes were observed from high-temperature synchrotron powder X-ray diffraction data in the 300–873 K temperature range. The unit cell expansion upon heating is isotropic; however, interatomic distance elongation is not isotropic, consistent with the layered structure. Low- and high-temperature thermoelectric properties were measured on pellets densified by spark plasma sintering. The resistivity of NaZnSb ranges from 11 mΩ∙cm to 31 mΩ∙cm within the 2–676 K range, consistent with heavily doped semiconductor behavior, with a narrow band gap of 0.23 eV. NaZnSb has a large positive Seebeck coefficient (244 μV∙K−1 at 476 K), leading to the maximum of zT of 0.23 at 675 K. The measured thermoelectric properties are in good agreement with those predicted by theoretical calculations.
Fatigue Behavior of Concrete Beam with Prestressed Near-Surface Mounted CFRP Reinforcement According to the Strength and Developed Length
Authors: Park Hee Beom , Park Jong-Sup , Kang Jae-Yoon , Jung Woo-Tai
Published: December 2018

The prestressed near-surface mounted reinforcement (NSMR) using Fiber Reinforced Polymer (FRP) was developed to improve the load bearing capacity of ageing or degraded concrete structures. The NSMR using FRP was the subject of numerous studies of which a mere portion was dedicated to the long-term behavior under fatigue loading. Accordingly, the present study intends to examine the fatigue performance of the NSMR applying the anchoring system developed by Korea Institute of Construction and Building Technology (KICT). To that goal, fatigue test is performed on 6.4 m reinforced concrete beams fabricated with various concrete strengths and developed lengths of the Carbon Fiber Reinforced Polymer (CFRP) tendon. The test results reveal that the difference in the concrete strength and in the developed length of the CFRP tendon has insignificant effect on the strengthening performance. It is concluded that the accumulation of fatigue loading, the concrete strength and the developed length of the tendon will not affect significantly the strengthening performance given that sufficient strengthening is secured.
Tough and Elastic α-Tricalcium Phosphate Cement Composites with Degradable PEG-Based Cross-Linker
Authors: Rödel Michaela , Teßmar Jörg , Groll Jürgen , Gbureck Uwe
Published: December 2018

Dual setting cements composed of an in situ forming hydrogel and a reactive mineral phase combine high compressive strength of the cement with sufficient ductility and bending strength of the polymeric network. Previous studies were focused on the modification with non-degradable hydrogels based on 2-hydroxyethyl methacrylate (HEMA). Here, we describe the synthesis of suitable triblock degradable poly(ethylene glycol)-poly(lactide) (PEG-PLLA) cross-linker to improve the resorption capacity of such composites. A study with four different formulations was established. As reference, pure hydroxyapatite (HA) cements and composites with 40 wt% HEMA in the liquid cement phase were produced. Furthermore, HEMA was modified with 10 wt% of PEG-PLLA cross-linker or a test series containing only 25% cross-linker was chosen for composites with a fully degradable polymeric phase. Hence, we developed suitable systems with increased elasticity and 5–6 times higher toughness values in comparison to pure inorganic cement matrix. Furthermore, conversion rate from α-tricalcium phosphate (α-TCP) to HA was still about 90% for all composite formulations, whereas crystal size decreased. Based on this material development and advancement for a dual setting system, we managed to overcome the drawback of brittleness for pure calcium phosphate cements.
Mineralogical Analysis of Historical Mortars by FTIR
Authors: Jordán M. M. , Jordá J. , Pardo F. , Montero M. A.
Published: December 2018

A method for quantitative mineralogical analysis by ATR-FTIR [1] has been used first time for analysis of historical mortars. Mixtures of different minerals and gypsum were used in order to measure the minimum band intensity that must be considered for calculations and the detection limit. In this way, the molar absorptivity coefficient in the Lambert–Beer law and the components of a mixture in mol percentage can be calculated. The GAMS equation modeling environment and the NLP solver CONOPT (©ARKI Consulting and Development) were used to correlate the experimental data in the samples considered. The characterization of the vernacular mortars by FTIR analysis identifies the predominant minerals of the samples, and in conjunction with XRF and XRD, shows the exact composition of historical mortars, which will optimize the restoration and conservation of monuments, preserving our heritage.
Cause of Angular Distortion in Fusion Welding: Asymmetric Cross-Sectional Profile along Thickness
Authors: Xie Deqiao , Zhao Jianfeng , Liang Huixin , Liu Shuang , Tian Zongjun , Shen Lida , Wang Changjiang
Published: December 2018

Angular distortion is a common problem in fusion welding, especially when it comes to thick plates. Despite the fact that various processes and influencing factors have been discussed, the cause of the angular distortion has not been clearly revealed. In this research, the asymmetry of cross-sectional profile along thickness is considered of great importance to the angular distortion. A theoretical model concerning the melting-solidification process in fusion welding was established. An expression of the angular distortion was formulated and then validated by experiments of laser welding 316L stainless steel. The results show that the asymmetric cross-sectional profile is a major contributory factor towards the angular distortion mechanism. The asymmetry of cross-section profile along thickness causes the difference between two bending moments in the lower and upper parts of the joint. This is the difference that drives the angular distortion of the welded part. Besides, the asymmetry of cross-section profile is likely to be influenced by various processes and parameters, thereby changing the angular distortion.
Duality in Fuzzy Sets and Dual Arithmetics of Fuzzy Sets
Authors: Wu Hsien-Chung
Published: December 2018

The conventional concept of α-level sets of fuzzy sets will be treated as the upper α-level sets. In this paper, the concept of lower α-level sets of fuzzy sets will be introduced, which can also be regarded as a dual concept of upper α-level sets of fuzzy sets. We shall also introduce the concept of dual fuzzy sets. Under these settings, we can establish the so-called dual decomposition theorem. We shall also study the dual arithmetics of fuzzy sets in R and establish some interesting results based on the upper and lower α-level sets.
Strong Convergence Theorems of Viscosity Iterative Algorithms for Split Common Fixed Point Problems
Authors: Duan Peichao , Zheng Xubang , Zhao Jing
Published: December 2018

In this paper, we propose a viscosity approximation method to solve the split common fixed point problem and consider the bounded perturbation resilience of the proposed method in general Hilbert spaces. Under some mild conditions, we prove that our algorithms strongly converge to a solution of the split common fixed point problem, which is also the unique solution of the variational inequality problem. Finally, we show the convergence and effectiveness of the algorithms by two numerical examples.
Existence Results of a Coupled System of Caputo Fractional Hahn Difference Equations with Nonlocal Fractional Hahn Integral Boundary Value Conditions
Authors: Dumrongpokaphan Thongchai , Patanarapeelert Nichaphat , Sitthiwirattham Thanin
Published: December 2018

In this article, we propose a coupled system of Caputo fractional Hahn difference equations with nonlocal fractional Hahn integral boundary conditions. The existence and uniqueness result of solution for the problem is studied by using the Banach’s fixed point theorem. Furthermore, the existence of at least one solution is presented by using the Schauder fixed point theorem.
Diketopiperazine and Diphenylether Derivatives from Marine Algae-Derived Aspergillus versicolor OUCMDZ-2738 by Epigenetic Activation
Authors: Liu Wen , Wang Liping , Wang Bin , Xu Yanchao , Zhu Guoliang , Lan Mengmeng , Zhu Weiming , Sun Kunlai
Published: December 2018

A chemical-epigenetic method was used to enhance the chemodiversity of a marine algicolous fungus. Apart from thirteen known compounds, (+)-brevianamide R ((+)-3), (‒)-brevianamide R ((‒)-3), (+)-brevianamide Q ((+)-4), (‒)-brevianamide Q ((‒)-4), brevianamide V ((+)-5), brevianamide W ((‒)-5), brevianamide K (6), diorcinol B (7), diorcinol C (8), diorcinol E (9), diorcinol J (10), diorcinol (11), 4-methoxycarbonyldiorcinol (12), two new compounds, (+)- and (‒)-brevianamide X ((+)- and (‒)- 2)), as well as a new naturally occurring one, 3-[6-(2-methylpropyl)-2-oxo-1H-pyrazin-3-yl]propanamide (1), were isolated from chemical-epigenetic cultures of Aspergillus versicolor OUCMDZ-2738 with 10 µM vorinostat (SAHA). Compared to cultures in the same medium without SAHA, compounds 1–4, 8, 9, 11, and 12 were solely observed under SAHA condition. The structures of these compounds were elucidated based on spectroscopic analysis, specific rotation analysis, ECD, and X-ray crystallographic analysis. (±)-3, (±)-4, and (±)-5 were further resolved into the corresponding optically pure enantiomers and their absolute configurations were determined for the first time. Compounds 11 and 12 showed selective antibacterial against Pseudomonas aeruginosa with a minimum inhibitory concentration (MIC) of 17.4 and 13.9 μM, respectively. Compound 10 exhibited better α-glucosidase inhibitory activity than the assay control acarbose with IC50 values of 117.3 and 255.3 μM, respectively.
Medicinal Cannabis—Potential Drug Interactions
Authors: Alsherbiny Muhammad A. , Li Chun Guang
Published: December 2018

The endocannabinoids system (ECS) has garnered considerable interest as a potential therapeutic target in various carcinomas and cancer-related conditions alongside neurodegenerative diseases. Cannabinoids are implemented in several physiological processes such as appetite stimulation, energy balance, pain modulation and the control of chemotherapy-induced nausea and vomiting (CINV). However, pharmacokinetics and pharmacodynamics interactions could be perceived in drug combinations, so in this short review we tried to shed light on the potential drug interactions of medicinal cannabis. Hitherto, few data have been provided to the healthcare practitioners about the drug–drug interactions of cannabinoids with other prescription medications. In general, cannabinoids are usually well tolerated, but bidirectional effects may be expected with concomitant administered agents via affected membrane transporters (Glycoprotein p, breast cancer resistance proteins, and multidrug resistance proteins) and metabolizing enzymes (Cytochrome P450 and UDP-glucuronosyltransferases). Caution should be undertaken to closely monitor the responses of cannabis users with certain drugs to guard their safety, especially for the elderly and people with chronic diseases or kidney and liver conditions.
Enhancing the Reduction of High-Aluminum Iron Ore by Synergistic Reducing with High-Manganese Iron Ore
Authors: Zhou Xianlin , Luo Yanhong , Chen Tiejun , Zhu Deqing
Published: December 2018

How to utilize low grade complex iron resources is an issue that has attracted much attention due to the continuous and huge consumption of iron ores in China. High-aluminum iron ore is a refractory resource and is difficult to upgrade by separating iron and alumina. An innovative technology involving synergistic reducing and synergistic smelting a high-aluminum iron ore containing 41.92% Fetotal, 13.74% Al2O3, and 13.96% SiO2 with a high-manganese iron ore assaying 9.24% Mntotal is proposed. The synergistic reduction process is presented and its enhancing mechanism is discussed. The results show that the generation of hercynite (FeAl2O4) and fayalite (Fe2SiO4) leads to a low metallization degree of 66.49% of the high-aluminum iron ore. Over 90% of the metallization degree is obtained by synergistic reducing with 60% of the high-manganese iron ore. The mechanism of synergistic reduction can be described as follows: MnO from the high-manganese ore chemically combines with Fe2SiO4 and FeAl2O4 to generate Mn2SiO4, MnAl2O4 and FeO, resulting in higher activity of FeO, which can be reduced to Fe in a CO atmosphere. The main products of the synergistic reduction process consist of Fe, Mn2SiO4, and MnAl2O4.
Revealing the Early Forming Behaviors of a Carbon-Fiber-Reinforced Aluminum Foam through Synchrotron X-ray
Authors: Sun Xi , Huang Peng , Wang Zhaoke , Fang Dongyu , Zeng Qianjin , Zu Guoyin
Published: December 2018

The effect of copper-coated carbon fiber (Cf) on the foaming behavior of aluminum foam prepared by the powder metallurgy (PM) method, was studied, by using the synchrotron radiation technique. The corresponding stabilizing mechanism of the Cf was discussed and analyzed, by a comparison of the dynamic foaming process of the samples, prepared using pure Al, and that with an additional Cf, under the same heating regime. It was found that the Cf, acting as an “artificial defect” in the matrix, effectively guided the cell’s nucleation process. It not only improved the dispersion of the cell nucleation—which led to a more dispersed distribution of internal stress in the early nucleation stage—but also effectively eliminated the influence of the internal differences caused by the preparation method, which led to a more uniform distribution of cells, during the nucleation and growth stage. Thus, the cell evolution stability was greatly improved when the matrix was still in the solid phase.
Annotating Nontargeted LC-HRMS/MS Data with Two Complementary Tandem Mass Spectral Libraries
Authors: Oberacher Herbert , Reinstadler Vera , Kreidl Marco , Stravs Michael A. , Hollender Juliane , Schymanski Emma L.
Published: December 2018

Tandem mass spectral databases are indispensable for fast and reliable compound identification in nontargeted analysis with liquid chromatography–high resolution tandem mass spectrometry (LC-HRMS/MS), which is applied to a wide range of scientific fields. While many articles now review and compare spectral libraries, in this manuscript we investigate two high-quality and specialized collections from our respective institutes, recorded on different instruments (quadrupole time-of-flight or QqTOF vs. Orbitrap). The optimal range of collision energies for spectral comparison was evaluated using 233 overlapping compounds between the two libraries, revealing that spectra in the range of CE 20–50 eV on the QqTOF and 30–60 nominal collision energy units on the Orbitrap provided optimal matching results for these libraries. Applications to complex samples from the respective institutes revealed that the libraries, combined with a simple data mining approach to retrieve all spectra with precursor and fragment information, could confirm many validated target identifications and yield several new Level 2a (spectral match) identifications. While the results presented are not surprising in many ways, this article adds new results to the debate on the comparability of Orbitrap and QqTOF data and the application of spectral libraries to yield rapid and high-confidence tentative identifications in complex human and environmental samples.
Process Variability—Technological Challenge and Design Issue for Nanoscale Devices
Authors: Lorenz Jürgen , Bär Eberhard , Barraud Sylvain , Brown Andrew R. , Evanschitzky Peter , Klüpfel Fabian , Wang Liping
Published: December 2018

Current advanced transistor architectures, such as FinFETs and (stacked) nanowires and nanosheets, employ truly three-dimensional architectures. Already for aggressively scaled bulk transistors, both statistical and systematic process variations have critically influenced device and circuit performance. Three-dimensional device architectures make the control and optimization of the device geometries even more important, both in view of the nominal electrical performance to be achieved and its variations. In turn, it is essential to accurately simulate the device geometry and its impact on the device properties, including the effect caused by non-idealized processes which are subject to various kinds of systematic variations induced by process equipment. In this paper, the hierarchical simulation system developed in the SUPERAID7 project to study the impact of variations from equipment to circuit level is presented. The software system consists of a combination of existing commercial and newly developed tools. As the paper focuses on technological challenges, especially issues resulting from the structuring processes needed to generate the three-dimensional device architectures are discussed. The feasibility of a full simulation of the impact of relevant systematic and stochastic variations on advanced devices and circuits is demonstrated.
Total Porosity Measured for Shale Gas Reservoir Samples: A Case from the Lower Silurian Longmaxi Formation in Southeast Chongqing, China
Authors: Chen Fangwen , Lu Shuangfang , Ding Xue , Zhao Hongqin , Ju Yiwen
Published: December 2018

Measuring total porosity in shale gas reservoir samples remains a challenge because of the fine-grained texture, low porosity, ultra-low permeability, and high content of organic matter (OM) and clay mineral. The composition content porosimetry method, which is a new method for the evaluation of the porosity of shale samples, was used in this study to measure the total porosity of shale gas reservoir samples from the Lower Silurian Longmaxi Formation in Southeast Chongqing, China, based on the bulk and grain density values. The results from the composition content porosimetry method were compared with those of the Gas Research Institute method. The results showed that the composition content porosimetry porosity values of shale gas reservoir samples range between 2.05% and 5.87% with an average value of 4.04%. The composition content porosimetry porosity generally increases with increasing OM and clay content, and decreases with increasing quartz and feldspar content. The composition content porosimetry results are similar to the gas research institute results, and the differences between the two methods range from 0.05% to 1.52% with an average value of 0.85%.
Sulfur Isotope Ratios from VMS Deposits in the Penokean Volcanic Belt, Great Lakes Region, USA: Constraints on the Source of Sulfur in a Paleoproterozoic Intra-Arc Rift
Authors: Moleski Nicholas , Boxleiter Anthony , Thakurta Joyashish
Published: December 2018

The Paleoproterozoic (~1.8 Ga) Penokean Volcanic Belt (PVB) in the Great Lakes Region of North America hosts several polymetallic volcanogenic massive sulfide (VMS) deposits. These deposits were formed by back-arc extensional volcanism during the accretion of island-arc terranes along the southern margin of the Archean Superior Craton. This study reports δ34S values obtained from sulfide minerals collected from eight VMS deposits in the PVB: Back Forty, Bend, Eisenbrey, Flambeau, Horseshoe, Lynne, Reef, and Schoolhouse. The average δ34S values from most of these deposits lie within the mantle-range between −2 and 2‰, relative to Vienna Canyon Diablo Troilite (V-CDT). Average δ34S values from Back Forty and Lynne deposits are slightly higher, at 2.5 and 2.4‰, respectively. No systematic variation in δ34S was observed based on factors such as the kind of sulfide mineral, ore-texture, type of host rock, or the nature of host-rock alteration. The narrow observed range from the PVB offers a clear indication that sulfur in the mineralizing fluid, originated predominantly from a magmatic source. If there was a significant contribution of sulfur from seawater, the δ34S of seawater sulfur must also have been close to the mantle range. Slightly higher values from Back Forty and Lynne indicate minor involvement of oxidized sulfur at shallow water levels, possibly derived from the continental margin.
Directional Oxidation of Pyrite in Acid Solution
Authors: Feng Jiling , Tian Hua , Huang Yaling , Ding Zhiying , Yin Zhoulan
Published: December 2018

This study aimed to investigate the oxidation mechanism of pyrite crystallographic direction by cutting pyrite samples to expose their (100), (110), and (111) planes. Differences in the oxidation rates of pyrite planes in acid solution were determined. The morphological changes of pyrite were evaluated by scanning electron microscopy and hyperdepth-3D microscopy. The oxidation products of pyrite were examined by Raman spectroscopy and X-ray photoelectron spectroscopy. Results showed that the aqueous oxidation of pyrite produced Fe(OH)3, Fe2O3, Fe2(SO4)3, and S8 on the surface. Moreover, the morphologies of corrosion patterns differed from one crystal plane to another: square, rectangular, and triangular etch pits were found on the (100), (110), and (111) planes, respectively. The corrosion patterns reflected the symmetrical arrangement of the crystallographic planes in the lattice on which they formed.