bluuebunny/crossref_metadata_2025 huggingface dataset:
Accurate Prediction of the Weld Bead Characteristic in Laser Keyhole Welding Based on the Stochastic Kriging Model
Authors: Ruan Xiongfeng , Zhou Qi , Shu Leshi , Hu Jiexiang , Cao Longchao
Published: June 2018

As an important index of weld quality, the weld bead geometry is closely related to the welding process parameters (WPP). Therefore, it is crucial to establish the relationships between the WPP and weld bead shape to serve as an indicator of the weld quality. However, it is difficult to predict the weld bead shape accurately due to uncertainty. In this paper, laser keyhole welding (LKW) experiments are conducted on 2205 stainless steel at sample points generated by the optimal Latin hypercube sampling (OLHS). Then the relationships between WPP and weld width (WW) are constructed using stochastic kriging model (SKM), considering the randomness of the welding process. To verify the effectiveness of the SKM, two validation approaches, the additional experiments validation and k-fold cross-validation, are used to compare the prediction performance of SKM and the traditional kriging model. SKM is superior to the kriging model at the whole five additional test points with smaller relative error. As to k-fold cross-validation, SKM provides a smaller root mean square error at four in five groups of the data. In addition, SKM can provide the variations of the entire weld bead shape. Overall, the SKM is very prominent in predicting the weld bead shape, considering fluctuations of WPP.
Microstructural and Fractographic Analysis of Plastically Deformed Al-Zn-Mg Alloy Subjected to Combined High-Cycle Bending-Torsion Fatigue
Authors: Kowalski Aleksander , Ozgowicz Wojciech , Jurczak Wojciech , Grajcar Adam , Boczkal Sonia , Kurek Andrzej
Published: June 2018

The present manuscript aims to determine the effect of various deformation levels during low-temperature thermo-mechanical treatment (LTTT) on the microstructure and fatigue strength of Zr-microalloyed Al-Zn-Mg alloy. The fatigue strength of the alloy was studied in high-cycle bending-torsion tests. The determination of the influence of plastic deformation level during LTTT on the microstructure was based on transmission electron microscopy (TEM) observations. The analysis of fracture after the fatigue tests was performed based on fractographic images using scanning electron microscopy (SEM). It was found that the major factor affecting the microstructure of the alloy, and determining the nature of fatigue fracture, is the strain level applied during LTTT.
Different Flotation Performance of Ultrafine Scheelite under Two Hydrodynamic Cavitation Modes
Authors: Zhou Weiguang , Ou Leming , Shi Qing , Feng Qiming , Chen Hao
Published: June 2018

In industrial practice, hydrodynamic cavitation (HC) is commonly triggered by jetting either reagent solution or pulp. Although both methods can enhance mineral flotation, are their roles the same? There are few research studies in the field, which severely limits our understanding on mineral flotation combined with HC. Therefore, in this study, the flotation of ultrafine scheelite with HC pretreatments of reagent solution and pulp (abbreviated to be HCPS and HCPP, respectively) was studied and compared through flotation tests, zeta potential analysis, microscope tests, and shear yield stress measurements. The results of flotation tests show that both HCPS and HCPP can enhance the final flotation performance, but in general, HCPP leads to greater improvements on the final flotation recovery. The presence of (hydrophobized) scheelite particles brings extra gas nuclei for the cavitation–flotation system, suggesting that more NBs may be produced in the case of HCPP compared with HCPS. These tiny bubbles remarkably reduce the size distribution of bubbles in the flotation system, thus increasing the particle–bubbles collision probability. Increase in particle aggregation may be another reason why flotation with HCPP results in a higher flotation recovery. The adherence of NBs on hydrophobized particles decreases the (absolute) surface charge of the solids, resulting in a smaller repulsive force among particles and more significant particle aggregation, which is confirmed by the microscope tests and shear yield stress measurements.
Multi-Stage Deformation of the Khangalas Ore Cluster (Verkhoyansk-Kolyma Folded Region, Northeast Russia): Ore-Controlling Reverse Thrust Faults and Post-Mineral Strike-Slip Faults
Authors: Fridovsky Valery Y. , Kudrin Maxim V. , Polufuntikova Lena I.
Published: June 2018

This study reports the results of the analysis of multi-stage deformation structures of the Khangalas gold ore cluster, northeast Russia. Four Late Mesozoic-Early Eocene deformation stages were identified. The first deformation event (D1) was characterized by the development of NW-striking tight to isoclinal folds of the first generation (F1) and interstratal detachment thrusts. Major folds, extensive thrusts, boudinage, cleavage, auriferous mineralized fault zones and quartz-vein gold mineralization were formed in the reverse and thrust fault stress field during the progressive deformation stage (D1), with NE-SW-oriented σ1. Post-ore deformation is widely manifested in the region. Structures D2 and D3 are coaxial. Sinistral strike-slip motions (D2 and D3) occurred along NW-trending faults under prevailing W-E compression. They were accompanied by the formation of NS- and NE-striking F2–3 folds with steep hinges and by bending of the earlier formed structures, among them ore-controlling ones. The last deformation event (D4) was represented by normal-dextral strike-slip faulting, refolding of rocks, pre-existing structures and ore bodies and by the development of folds with steep hinges. Key structural elements of varying age are described, the chronology of deformation events and mineralization reconstructed and their relation to geodynamic events in northeast Asia established.
Microbial Hydrolysis of Racemic β-Aryl-γ-ethylidene-γ-lactones and Antifeedant Activity of the Products against Alphitobius diaperinus Panzer
Authors: Skrobiszewski Andrzej , Gładkowski Witold , Mazur Marcelina , Szczepanik Maryla , Maciejewska Gabriela , Wawrzeńczyk Czesław
Published: June 2018

Hydrolysis of (±)-β-aryl-γ-ethylidene-γ-lactones by fungal strain Aspergillus ochraceus AM370 afforded (−)-(S)-γ-ethylidene-γ-lactones 2a–d and (+)-(R)-γ-ketoacids 3a–d. Enantiomeric purity of the unreacted lactones was strictly related to a size of an aryl substituent at C-4 of γ-lactone ring, with the highest ee (77%) obtained for the (−)-(S)-γ-ethylidene-γ-lactone possessing unsubstituted benzene ring (2a) and the lowest one (15%) determined for the (−)-(S)-γ-ethylidene-γ-lactone with bulky 1,3-benzodioxole system (2d). Lactones 2a–d, both racemic and enantiomerically enriched, as well as products of their hydrolysis showed varying degrees of feeding deterrent activity against lesser mealworm, Alphitobius diaperinus Panzer, which depended on the structure of the compound and the developmental stage of the lesser mealworm. In the case of adults, more active were γ-lactones 2a–d, compared with ketoacids 3a–d. Only in the case of lactone 2a was the effect of configuration of stereogenic center on the activity found. Particularly strong deterrents against this stage (T > 180) were racemic and (−)-(S)-γ-ethylidene-γ-lactone with p-methoxysubstituted phenyl ring (2c).
Commensal Microbiota Enhance Both Osteoclast and Osteoblast Activities
Authors: Uchida Yoko , Irie Koichiro , Fukuhara Daiki , Kataoka Kota , Hattori Takako , Ono Mitsuaki , Ekuni Daisuke , Kubota Satoshi , Morita Manabu
Published: June 2018

Recent studies suggest that the commensal microbiota affects not only host energy metabolism and development of immunity but also bone remodeling by positive regulation of osteoclast activity. However, the mechanism of regulation of bone cells by the commensal microbiota has not been elucidated. In this study, 8-week-old specific pathogen-free (SPF) and germ-free (GF) mice were compared in terms of alveolar bones and primary osteoblasts isolated from calvarias. Micro-CT analysis showed that SPF mice had larger body size associated with lower bone mineral density and bone volume fraction in alveolar bones compared with GF mice. Greater numbers of osteoclasts in alveolar bone and higher serum levels of tartrate-resistant acid phosphatase 5b were observed in SPF mice. Tissue extracts from SPF alveolar bone showed higher levels of cathepsin K, indicating higher osteoclast activity. SPF alveolar extracts also showed elevated levels of γ-carboxylated glutamic acid–osteocalcin as a marker of mature osteoblasts compared with GF mice. Polymerase chain reaction (PCR) array analysis of RNA directly isolated from alveolar bone showed that in SPF mice, expression of mRNA of osteocalcin, which also acts as an inhibitor of bone mineralization, was strongly enhanced compared with GF mice. Cultured calvarial osteoblasts from SPF mice showed reduced mineralization but significantly enhanced expression of mRNAs of osteocalcin, alkaline phosphatase, insulin-like growth factor-I/II, and decreased ratio of osteoprotegerin/receptor activator of nuclear factor-kappa B ligand compared with GF mice. Furthermore, PCR array analyses of transcription factors in cultured calvarial osteoblasts showed strongly upregulated expression of Forkhead box g1. In contrast, Gata-binding protein 3 was strongly downregulated in SPF osteoblasts. These results suggest that the commensal microbiota prevents excessive mineralization possibly by stimulating osteocalcin expression in osteoblasts, and enhances both osteoblast and osteoclast activity by regulating specific transcription factors.
Anthocyanins of Coloured Wheat Genotypes in Specific Response to SalStress
Authors: Mbarki Sonia , Sytar Oksana , Zivcak Marek , Abdelly Chedly , Cerda Artemio , Brestic Marian
Published: June 2018

The present study investigated the effect of salt stress on the development of adaptive responses and growth parameters of different coloured wheat genotypes. The different coloured wheat genotypes have revealed variation in the anthocyanin content, which may affect the development of adaptive responses under increasing salinity stress. In the early stage of treatment with salt at a lower NaCl concentration (100 mM), anthocyanins and proline accumulate, which shows rapid development of the stress reaction. A dose-dependent increase in flavonol content was observed for wheat genotypes with more intense purple-blue pigmentation after treatment with 150 mM and 200 mM NaCl. The content of Na+ and K+ obtained at different levels of salinity based on dry weight (DW) was more than 3 times greater than the control, with a significant increase of both ions under salt stress. Overall, our results demonstrated that coloured wheat genotypes with high anthocyanin content are able to maintain significantly higher dry matter production after salt stress treatment.
Antiproliferative and Antimicrobial Activities of Selected Bryophytes
Authors: Vollár Martin , Gyovai András , Szűcs Péter , Zupkó István , Marschall Marianna , Csupor-Löffler Boglárka , Bérdi Péter , Vecsernyés Anikó , Csorba Attila , Liktor-Busa Erika , Urbán Edit , Csupor Dezső
Published: June 2018

One-hundred and sixty-eight aqueous and organic extracts of 42 selected bryophyte species were screened in vitro for antiproliferative activity on a panel of human gynecological cancer cell lines containing HeLa (cervix epithelial adenocarcinoma), A2780 (ovarian carcinoma), and T47D (invasive ductal breast carcinoma) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and for antibacterial activity on 11 strains using the disc-diffusion method. A total of 99 extracts derived from 41 species exerted ≥25% inhibition of proliferation of at least one of the cancer cell lines at 10 μg/mL. In the cases of Brachythecium rutabulum, Encalypta streptocarpa, Climacium dendroides, Neckera besseri, Pleurozium schreberi, and Pseudoleskeella nervosa, more than one extract was active in the antiproliferative assay, whereas the highest activity was observed in the case of Paraleucobryum longifolium. From the tested families, Brachytheciaceae and Amblystegiaceae provided the highest number of antiproliferative extracts. Only 19 samples of 15 taxa showed moderate antibacterial activity, including the most active Plagiomnium cuspidatum, being active on 8 tested strains. Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus were the most susceptible to the assayed species. This is the first report on the bioactivities of these 14 species.
Thermal Failure Analysis of Fiber-Reinforced Silica Aerogels under Liquid Nitrogen Thermal Shock
Authors: Du Ai , Liu Mingfang , Huang Shangming , Li Conghang , Zhou Bin
Published: June 2018

Aerogel materials are recognized as promising candidates for the thermal insulator and have achieved great successes for the aerospace applications. However, the harsh environment on the exoplanet, especially for the tremendous temperature difference, tends to affect the tenuous skeleton and performances of the aerogels. In this paper, an evaluation method was proposed to simulate the environment of exoplanet and study the influence on the fiber-reinforced silica aerogels with different supercritical point drying (SPD) technology. Thermal conductivity, mechanical property and the microstructure were characterized for understanding the thermal failure mechanism. It was found that structure and thermal property were significantly influenced by the adsorbed water in the aerogels under the thermal shocks. The thermal conductivity of CO2-SPD aerogel increased 35.5% after the first shock and kept in a high value, while that of the ethanol-SPD aerogel increased only 19.5% and kept in a relatively low value. Pore size distribution results showed that after the first shock the peak pore size of the CO2-SPD aerogel increased from 18 nm to 25 nm due to the shrinkage of the skeleton, while the peak pore size of the ethanol-SPD aerogel kept at ~9 nm probably induced by the spring-back effect. An 80 °C treatment under vacuum was demonstrated to be an effective way for retaining the good performance of ethanol-SPD aerogels under the thermal shock. The thermal conductivity increases of the ethanol-SPD aerogels after 5 shocks decreased from ~30 to ~0% via vacuum drying, while the increase of the CO2-SPD aerogels via the same treatments remains ~28%. The high-strain hardening and low-strain soften behaviors further demonstrated the skeleton shrinkage of the CO2-SPD aerogel.
Development and Evaluation of Surfactant Nanocapsules for Chemical Enhanced Oil Recovery (EOR) Applications
Authors: Cortés Farid B. , Lozano Mónica , Santamaria Oveimar , Betancur Marquez Stefania , Zapata Karol , Ospina Natalia , Franco Camilo A.
Published: June 2018

The primary objective of this study is the synthesis of nanocapsules (NC) that allow the reduction of the adsorption process of surfactant over the porous media in enhanced oil recovery processes. Nanocapsules were synthesized through the nanoprecipitation method by encapsulating commercial surfactants Span 20 and Petro 50, and using type II resins isolated from vacuum residue as a shell. The NC were characterized using dynamic light scattering, transmission electron microscopy, Fourier transform infrared, solvency tests, softening point measurements and entrapment efficiency. The obtained NC showed spherical geometry with sizes of 71 and 120 nm for encapsulated Span 20 (NCS20), and Petro 50 surfactant (NCP50), respectively. Also, the NCS20 is composed of 90% of surfactant and 10% of type II resins, while the NCP50 material is 94% of surfactant and 6% of the shell. Nanofluids of nanocapsules dispersed in deionized water were prepared for evaluating the nanofluid—sandstone interaction from adsorption phenomena using a batch-mode method, contact angle measurements, and FTIR analysis. The results showed that NC adsorption was null at the different conditions of temperatures evaluated of 25, 50, and 70 °C, and stirring velocities up to 10,000 rpm. IFT measurements showed a reduction from 18 to 1.62 and 0.15 mN/m for the nanofluids with 10 mg/L of NCS20, and NCP50 materials, respectively. Displacements tests were conducted using a 20 °API crude oil in a quarter five-spot pattern micromodel and showed an additional oil recovery of 23% in comparison with that of waterflooding, with fewer pore volumes injected than when using a dissolved surfactant.
Facile Preparation of Metal-Organic Framework (MIL-125)/Chitosan Beads for Adsorption of Pb(II) from Aqueous Solutions
Authors: Liang Xue-Xue , Wang Nan , Qu You-Le , Yang Li-Ye , Wang Yang-Guang , Ouyang Xiao-Kun
Published: June 2018

In this study, novel composite titanium-based metal-organic framework (MOF) beads were synthesized from titanium based metal organic framework MIL-125 and chitosan (CS) and used to remove Pb(II) from wastewater. The MIL-125-CS beads were prepared by combining the titanium-based MIL-125 MOF and chitosan using a template-free solvothermal approach under ambient conditions. The surface and elemental properties of these beads were analyzed using scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopies, as well as thermal gravimetric analysis. Moreover, a series of experiments designed to determine the influences of factors such as initial Pb(II) concentration, pH, reaction time and adsorption temperature was conducted. Notably, it was found that the adsorption of Pb(II) onto the MIL-125-CS beads reached equilibrium in 180 min to a level of 407.50 mg/g at ambient temperature. In addition, kinetic and equilibrium experiments provided data that were fit to the Langmuir isotherm model and pseudo-second-order kinetics. Furthermore, reusability tests showed that MIL-125-CS retained 85% of its Pb(II)-removal capacity after five reuse cycles. All in all, we believe that the developed MIL-125-CS beads are a promising adsorbent material for the remediation of environmental water polluted by heavy metal ions.
Structure-Activity Relationship of Cannabis Derived Compounds for the Treatment of Neuronal Activity-Related Diseases
Authors: Prandi Cristina , Blangetti Marco , Namdar Dvora , Koltai Hinanit
Published: June 2018

Cannabis sativa active compounds are extensively studied for their therapeutic effects, beyond the well-known psychotropic activity. C. Sativa is used to treat different medical indications, such as multiple sclerosis, spasticity, epilepsy, ulcerative colitis and pain. Simultaneously, basic research is discovering new constituents of cannabis-derived compounds and their receptors capable of neuroprotection and neuronal activity modulation. The function of the various phytochemicals in different therapeutic processes is not fully understood, but their significant role is starting to emerge and be appreciated. In this review, we will consider the structure-activity relationship (SAR) of cannabinoid compounds able to bind to cannabinoid receptors and act as therapeutic agents in neuronal diseases, e.g., Parkinson’s disease.
Properties, Preparation and Applications of Low Dimensional Transition Metal Dichalcogenides
Authors: Yang Lei , Xie Chenggen , Jin Juncheng , Ali Rai Nauman , Feng Chao , Liu Ping , Xiang Bin
Published: June 2018

Low-dimensional layered transition metal dichalcogenides (TMDs) have recently emerged as an important fundamental research material because of their unique structural, physical and chemical properties. These novel properties make these TMDs a suitable candidate in numerous potential applications. In this review, we briefly summarize the properties of low-dimensional TMDs, and then focus on the various methods used in their preparation. The use of TMDs in electronic devices, optoelectronic devices, electrocatalysts, biosystems, and hydrogen storage is also explored. The cutting-edge future development probabilities of these materials and numerous research challenges are also outlined in this review.
Cutting-Processed Single-Wall Carbon Nanotubes with Additional Edge Sites for Supercapacitor Electrodes
Authors: Kim Teayeop , Kim Mun Kyoung , Park Yunjeong , Kim Eunpa , Kim Jangho , Ryu Wonhyoung , Jeong Hyung Mo , Kim Kyunghoon
Published: June 2018

Carbon nanotubes are frequently selected for supercapacitors because of their major intrinsic properties of mechanical and chemical stability, in addition to their excellent electrical conductivity. However, electrodes using carbon nanotubes suffer from severe performance degradation by the phenomenon of re-stacking during fabrication, which hinders ion accessibility. In this study, short single-wall carbon nanotubes were further shortened by sonication-induced cutting to increase the proportion of edge sites. This longitudinally short structure preferentially exposes the active edge sites, leading to high capacitance during operation. Supercapacitors assembled using the shorter-cut nanotubes exhibit a 7-fold higher capacitance than those with pristine single-wall nanotubes while preserving other intrinsic properties of carbon nanotubes, including excellent cycle performance and rate capability. The unique structure suggests a design approach for achieving a high specific capacitance with those low-dimensional carbon materials that suffer from re-stacking during device fabrication.
The Influence of Nanomaterials on the Thermal Resistance of Cement-Based Composites—A Review
Authors: Sikora Pawel , Abd Elrahman Mohamed , Stephan Dietmar
Published: June 2018

Exposure to elevated temperatures has detrimental effects on the properties of cementitious composites, leading to irreversible changes, up to total failure. Various methods have been used to suppress the deterioration of concrete under elevated temperature conditions. Recently, nanomaterials have been introduced as admixtures, which decrease the thermal degradation of cement-based composites after exposure to high temperatures. This paper presents a comprehensive review of recent developments related to the effects of nanoparticles on the thermal resistance of cementitious composites. The review provides an updated report on the effects of temperature on the properties of cement-based composites, as well as a detailed analysis of the available literature regarding the inclusion of nanomaterials and their effects on the thermal degradation of cementitious composites. The data from the studies reviewed indicate that the inclusion of nanoparticles in composites protects from strength loss, as well as contributing to a decrease in disruptive cracking, after thermal exposure. From all the nanomaterials presented, nanosilica has been studied the most extensively. However, there are other nanomaterials, such as carbon nanotubes, graphene oxide, nanoclays, nanoalumina or nano-iron oxides, that can be used to produce heat-resistant cementitious composites. Based on the data available, it can be concluded that the effects of nanomaterials have not been fully explored and that further investigations are required, so as to successfully utilize them in the production of heat-resistant cementitious composites.
The Protective Role of Astaxanthin for UV-Induced Skin Deterioration in Healthy People—A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Ito Naoki , Seki Shinobu , Ueda Fumitaka
Published: June 2018

Skin is a major safeguard tissue in humans. Because biological barrier function is deteriorated by several kinds of stresses including exposure to ultra-violet (UV) rays, the protection and treatment of skin conditions by dietary supplements are important. We therefore evaluated the effects of dietary supplementation with an algal food-derived antioxidant, astaxanthin, on UV-induced skin deterioration. Twenty-three healthy Japanese participants were recruited to a 10-week double-blind placebo-controlled study. They were assigned to the astaxanthin group supplemented with a capsule containing 4 mg of astaxanthin or the placebo group. To assess the protective role of astaxanthin for UV-induced skin deterioration, we determined the minimal erythema dose (MED) and analyzed UV-induced changes of moisture and transepidermal water loss (TEWL) at baseline and after 9 weeks of supplementation. Subjective skin conditions were assessed by the visual analog scale. The astaxanthin group showed increased MED compared with placebo. In addition, the astaxanthin group had a reduced loss of skin moisture in the irradiated area compared with placebo. Subjective skin conditions for “improvement of rough skin” and “texture” in non-irradiated areas were significantly improved by astaxanthin. Astaxanthin seems protective against UV-induced skin deterioration and helps maintain healthy skin in healthy people.
Pharmaceutical Dispersion Techniques for Dissolution and Bioavailability Enhancement of Poorly Water-Soluble Drugs
Authors: Zhang Xingwang , Xing Huijie , Zhao Yue , Ma Zhiguo
Published: June 2018

Over the past decades, a large number of drugs as well as drug candidates with poor dissolution characteristics have been witnessed, which invokes great interest in enabling formulation of these active ingredients. Poorly water-soluble drugs, especially biopharmaceutical classification system (BCS) II ones, are preferably designed as oral dosage forms if the dissolution limit can be broken through. Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This article reviews the most commonly used dispersion techniques for pharmaceutical processing that can practically enhance the dissolution and bioavailability of poorly water-soluble drugs. Major interests focus on solid dispersion, lipid-based dispersion (nanoencapsulation), and liquisolid dispersion (drug solubilized in a non-volatile solvent and dispersed in suitable solid excipients for tableting or capsulizing), covering the formulation development, preparative technique and potential applications for oral drug delivery. Otherwise, some other techniques that can increase the dispersibility of a drug such as co-precipitation, concomitant crystallization and inclusion complexation are also discussed. Various dispersion techniques provide a productive platform for addressing the formulation challenge of poorly water-soluble drugs. Solid dispersion and liquisolid dispersion are most likely to be successful in developing oral dosage forms. Lipid-based dispersion represents a promising approach to surmounting the bioavailability of low-permeable drugs, though the technique needs to traverse the obstacle from liquid to solid transformation. Novel dispersion techniques are highly encouraged to develop for formulation of poorly water-soluble drugs.
Preparation of Graphene-Perfluoroalkoxy Composite and Thermal and Mechanical Properties
Authors: Zhang Wanlong , Zuo Haibin , Zhang Xinru , Wang Jingsong , Guo Longfei , Peng Xing
Published: June 2018

Perfluoroalkoxy (PFA) material exhibits perfect corrosion resistance under both acid or alkaline circumstances; thus, steel heat exchangers are being substituted by those made of PFA in high corrosion atmospheres. However, the low thermal conductivity of PFA degrades its heat transfer efficiency. Based on the extremely high heat conductivity of graphene, a novel grapheme-PFA composite was proposed to simultaneously meet the demands of heat transfer and corrosion resistance. Ultrasonic dispersion technology was used to disperse the aggregated graphene in the composite. Graphene–PFA composites with different graphene contents and using different dispersing solvents were prepared with a hot pressing method, and thermal conductivity, abrasion resistance, crystallization and pyrolysis properties were investigated. The thermal conductivity of PFA composites with graphene content of 20 wt % reached 5.017 W (m·k)−1, which is 21.88 times that of pure PFA. The relationship between the abrasion loss and the friction coefficient of the composites with different graphene contents was obtained. A thermogravimetric analyzer was used to investigate the crystallization and pyrolysis behavior of the composites; correspondingly, the temperature range that composites work in was determined. The heat conduction mechanism was analyzed through the thermal conductivity model of composite materials. The composite material is expected to play an important role in the development of high-performance thermal equipment.
Inland Water Atmospheric Correction Based on Turbidity Classification Using OLCI and SLSTR Synergistic Observations
Authors: Bi Shun , Li Yunmei , Wang Qiao , Lyu Heng , Liu Ge , Zheng Zhubin , Du Chenggong , Mu Meng , Xu Jie , Lei Shaohua , Miao Song
Published: June 2018

Atmospheric correction is an essential prerequisite for obtaining accurate inland water color information. An inland water atmospheric correction algorithm, ACbTC (Atmospheric Correction based on Turbidity Classification), was proposed in this study by using OLCI (Ocean and Land Color Instrument) and SLSTR (Sea and Land Surface Temperature Radiometer) synergistic observations for the first time. This method includes two main steps: (1) water turbidity classification by the GRA index (GRAdient of the spectrum index); and (2) atmospheric correction by synergistic use of OLCI and SLSTR images. The algorithm was validated with 72 in situ sampling sites in Lake Erhai, Lake Hongze, and Lake Taihu, and compared with other atmospheric correction methods, i.e., C2RCC (Case 2 Regional Coast Colour processor), MUMM (Management Unit of the North Seas Mathematical Models), FLAASH (Fast Line-of-sight Atmospheric Analysis of Hypercubes), POLYMER (POLYnomial based algorithm applied to MERIS), and BPAC (Bright Pixel Atmospheric Correction). The results show that (1) the GRA index performed better than the proposed turbidity classification indices, i.e., the Diff (spectral difference index) and the Tind (turbid index), in inland lakes by using the reflectance peak at 1020 nm in clean water; (2) the synergistic use of OLCI and SLSTR performed feasibly for atmospheric correction, and the ACbTC algorithm achieved full-band average values of the mean absolute percentage error (MAPE) = 29.55%, mean relative percentage error (MRPE) = 13.98%, and the root mean square of error (RMSE) = 0.0039 sr−1, which were more reliable than C2RCC, MUMM, FLAASH, POLYMER, and BPAC; and (3) the synergistic use of the 17th band (865 nm) on OLCI and the 5th band (1613 nm) on SLSTR are suitable for clean inland lakes, while both the 5th band (1613 nm) and 6th band (2250 nm) on SLSTR are advisable for the turbidity.
Dual-Polarized L-Band SAR Imagery for Temporal Monitoring of Marine Oil Slick Concentration
Authors: Angelliaume Sébastien , Boisot Olivier , Guérin Charles-Antoine
Published: June 2018

SAR sensors are usually used in the offshore domain to detect marine oil slicks which allows the authorities to guide cleanup operations or prosecute polluters. As radar imagery can be used any time of day or year and in almost any weather conditions, the use and programming of such remote sensing data is usually favored over optical imagery. Nevertheless, images collected in the optical domain provide access to key information not accessible today by SAR instruments, such as the thickness or the amount of pollutant. To address this knowledge gap, a methodology based on the joint use of a scattering model (U-WCA) and remote sensing data collected by a low frequency (e.g., L-band) imaging radar over controlled release of mineral oil spill is reported in this paper. The proposed method allows estimation of the concentration of pollutant within an oil-in-water mixture as well as the temporal variation of this quantity due to weathering processes.
Mechanical Structural Design of a Piezoresistive Pressure Sensor for Low-Pressure Measurement: A Computational Analysis by Increases in the Sensor Sensitivity
Authors: Tran Anh Vang , Zhang Xianmin , Zhu Benliang
Published: June 2018

This paper proposes a novel micro-electromechanical system (MEMS) piezoresistive pressure sensor with a four-petal membrane combined with narrow beams and a center boss (PMNBCB) for low-pressure measurements. The stresses induced in the piezoresistors and deflection of the membrane were calculated using the finite element method (FEM). The functions of the relationship between the dimension variables and mechanical performance were determined based on the curve fitting method, which can provide an approach for geometry optimization of the sensor. In addition, the values in the equations were varied to determine the optimal dimensions for the proposed membrane. Then, to further improve the sensitivity of the sensor, a series of rectangular grooves was created at the position of the piezoresistors. The proposed diaphragm was compared to existing diaphragms, and a considerable increase in the sensitivity and a considerable decrease in nonlinearity error could be achieved by using the proposed sensor. The simulation results suggest that the sensor with the PMNBCB structure obtained a high sensitivity of 34.67 mV/kPa and a low nonlinearity error of 0.23% full-scale span (FSS) for the pressure range of 0–5 kPa. The proposed sensor structure is a suitable selection for MEMS piezoresistive pressure sensors.
Improved Visualization of Hydroacoustic Plumes Using the Split-Beam Aperture Coherence
Authors: Blomberg Ann E. A. , Weber Thomas C. , Austeng Andreas
Published: June 2018

Natural seepage of methane into the oceans is considerable, and plays a role in the global carbon cycle. Estimating the amount of this greenhouse gas entering the water column is important in order to understand their environmental impact. In addition, leakage from man-made structures such as gas pipelines may have environmental and economical consequences and should be promptly detected. Split beam echo sounders (SBES) detect hydroacoustic plumes due to the significant contrast in acoustic impedance between water and free gas. SBES are also powerful tools for plume characterization, with the ability to provide absolute acoustic measurements, estimate bubble trajectories, and capture the frequency dependent response of bubbles. However, under challenging conditions such as deep water and considerable background noise, it can be difficult to detect the presence of gas seepage from the acoustic imagery alone. The spatial coherence of the wavefield measured across the split beam sectors, quantified by the coherence factor (CF), is a computationally simple, easily available quantity which complements the acoustic imagery and may ease the ability to automatically or visually detect bubbles in the water column. We demonstrate the benefits of CF processing using SBES data from the Hudson Canyon, acquired using the Simrad EK80 SBES. We observe that hydroacoustic plumes appear more clearly defined and are easier to detect in the CF imagery than in the acoustic backscatter images.
A Robust Step Detection Algorithm and Walking Distance Estimation Based on Daily Wrist Activity Recognition Using a Smart Band
Authors: Trong Bui Duong , Nguyen Nhan Duc , Jeong Gu-Min
Published: June 2018

Human activity recognition and pedestrian dead reckoning are an interesting field because of their importance utilities in daily life healthcare. Currently, these fields are facing many challenges, one of which is the lack of a robust algorithm with high performance. This paper proposes a new method to implement a robust step detection and adaptive distance estimation algorithm based on the classification of five daily wrist activities during walking at various speeds using a smart band. The key idea is that the non-parametric adaptive distance estimator is performed after two activity classifiers and a robust step detector. In this study, two classifiers perform two phases of recognizing five wrist activities during walking. Then, a robust step detection algorithm, which is integrated with an adaptive threshold, peak and valley correction algorithm, is applied to the classified activities to detect the walking steps. In addition, the misclassification activities are fed back to the previous layer. Finally, three adaptive distance estimators, which are based on a non-parametric model of the average walking speed, calculate the length of each strike. The experimental results show that the average classification accuracy is about 99%, and the accuracy of the step detection is 98.7%. The error of the estimated distance is 2.2–4.2% depending on the type of wrist activities.
DNA-Based Sensor for the Detection of an Organophosphorus Pesticide: Profenofos
Authors: Selvolini Giulia , Băjan Ioana , Hosu Oana , Cristea Cecilia , Săndulescu Robert , Marrazza Giovanna
Published: June 2018

In this work, we propose an electrochemical DNA aptasensor for the detection of profenofos, an organophosphorus pesticide, based on a competitive format and disposable graphite screen-printed electrodes (GSPEs). A thiol-tethered DNA capture probe, which results to be complementary to the chosen aptamer sequence, was immobilised on gold nanoparticles/polyaniline composite film-modified electrodes (AuNPs/PANI/GSPE). Different profenofos solutions containing a fixed amount of the biotinylated DNA aptamer were dropped onto the realized aptasensors. The hybridisation reaction was measured using a streptavidin-alkaline phosphatase enzyme conjugate, which catalyses the hydrolysis of 1-naphthyl -phosphate. The 1-naphtol enzymatic product was detected by means of differential pulse voltammetry (DPV). The aptasensor showed itself to work as a signal off sensor, according to the competitive format used. A dose response curve was obtained between 0.10 μM and 10 μM with a detection limit of 0.27 μM.
Enhancing Sustainability Transparency in Local Governments—An Empirical Research in Europe
Authors: Navarro-Galera Andrés , Alcaraz-Quiles Francisco José , Ortiz-Rodriguez David
Published: June 2018

In the current socioeconomic context, the question of local government sustainability transparency is of great interest to policymakers, managers, citizens and other stakeholders, and yet one to which previous research has devoted little specific attention. At the same time, the Internet has become an instrument of good governance worldwide and government entities in Europe have strived to promote e-government to improve transparency towards citizens. The aim of this study was to identify factors that can help politicians and managers improve practices of sustainability information disclosed by European local governments. To do so, an empirical study was conducted of 91 municipalities in nine countries, comparing three main administrative cultures. Our analysis of the study results highlights various demographic, socioeconomic, financial and legal factors that may be useful to policymakers and managers in promoting the online provision of sustainability information in Anglo-Saxon, Nordic and Southern European countries.
Assessing Mismatches in the Provision of Urban Ecosystem Services to Support Spatial Planning: A Case Study on Recreation and Food Supply in Havana, Cuba
Authors: Orta Ortiz Maria Susana , Geneletti Davide
Published: June 2018

Integrating information about how ecosystem services (ES) are provided and benefited from in spatial planning is essential to enhance quality of life in urban areas. This study aims to assess mismatches in the provision of urban ES. Specifically, it compares the amount of services that urban dwellers currently benefit from with the capacity of green spaces to provide service and the ES demand, in order to assess two mismatches: “unsustainable flow” and “unsatisfied demand”, respectively. We focus on two ES, recreation and food supply, and conduct an empirical study in two adjacent municipalities of the city of Havana, Cuba. The methodological approach includes: the identification of services providing and demanding areas; and the quantification of mismatches by carrying out a spatial comparison between critical capacity and flow, and demand and flow. Results show that urban green spaces may be potentially exposed to overcrowding. Concerning food supply, a mismatch between demand and flow emerged in both of the municipalities. The assessment can support planners in addressing the sustainable use of green spaces and the equitable distribution of ES benefits. However, its applicability requires a deep understanding of local specificities, including demand levels, accessibility to ES, and sustainability thresholds.
Creating Smart Energy Cities for Sustainability through Project Implementation: A Case Study of Bolzano, Italy
Authors: Hunter Garfield Wayne , Vettorato Daniele , Sagoe Gideon
Published: June 2018

Globally, cities are experiencing an unprecedented socio-economic, demographic, and environmental transition that brings with it negative environmental externalities, such as climate change and environmental degradation. Smart energy city (SEC) has emerged as the latest urban development strategy in European countries. It can vastly accelerate cities’ decarbonisation efforts, which can have several co-benefits. Capitalising on advances in information and communication technologies (ICT), various SEC projects have been initiated and seek to integrate ICT into the urban system. Although there are a significant number of SEC demonstration projects, there has been a scant examination of the performance and overall effect of these projects in addressing core sustainability endogenous principles. This research provides an in-depth analysis of the components of the SEC projects, highlighting the strengths and shortcomings. By highlighting the “Smart INitiative of cities Fully cOmmitted to iNvest In Advanced large-scale energy solutions” (SINFONIA) project in Bolzano, we aimed to determine the extent to which the current practical processes are achieved in reality. Our methodology entailed a structured literature review of the different components of SEC projects, followed by a content analysis based on the 5W1H (why, what, who, how, where, and when) conceptual framework. The data collection methods adopted included a review of specific open-access sources and project deliverables of each of the selected SEC projects, personal observation of the case study city, and interviews with SEC project experts. We analysed the SEC projects components against fundamental sustainability principles of integration, implementation, equity (intra-generational, procedural, and inter-generational), and scalability and replicability to assess their potential for creating sustainable urban settlements. The study found that the critical components of SEC projects are strategically aligned with sustainability dimensions. However, although ICT integration in urban planning and development provides the core determinants of the components, stakeholder engagement and dynamic business models are critical for successful implementation. Furthermore, through scalability and replicability of SEC projects, diversification of sustainability principles can be actualised throughout the entire city and in other geographical regions to ensure long-term intra-generational and inter-generational equity.
A Study on Needs for Automotive Interiors Based on Lifestyle Characteristics of Taiwanese Female Office Workers
Authors: Tu Jui-Che , Yang Chun , Hung Yu-Ting
Published: June 2018

With the transformation of social patterns, the proportion of female office workers has increased and women have seen a huge increase in purchasing power in the consumer market due to economic independence. From the perspective of the automotive industry, whose main customers were male customers, nowadays, it has changed to designing smaller models, which are more suitable for women to drive. When it comes to a car, men are more focused on horsepower and speed, while women pay more attention to its storage, safety, and easy operation. For female office workers, a car is not only a transportation tool for commutes, but also an assistant that can accompany them shopping and travelling. Therefore, if automotive interiors can meet the usage needs of females, meaning practicality and safety, they can make female drivers feel intimate and comfortable. In order to understand the real needs of female office workers for automotive interiors, in the first phase, this paper adopted case interviews to determine female car-purchasing trends in best-selling automobile manufacturers, as well as their opinions on needs for automotive interiors, which were used as the basis for the questionnaire design. In the second phase, the questionnaire method was used to discuss the life characteristics and needs of female office workers for automotive interiors, and the statistical software SPSS was employed to analyze the differences in needs for automotive interiors among female office workers of different types; and finally, a design principle suitable for this consumer group was concluded. Regarding the results of this paper, automotive interiors are divided into five factors, which are functional storage, spatial aesthetics, digital devices, comfortable feeling, and safety and cleanness. Female office workers are divided into the three groups: (1) The discerning and intellectual pleasure seekers; (2) The regular and easy-going-life seekers; and (3) The modern information seekers. The results show that there are differences in the needs for automotive interiors among female office workers of different types. To be specific, group 1, the discerning and intellectual pleasure seekers, who are engaged in the medical and electronics industries, pay the most attention to safety, cleanliness, and digital device needs. Group 2, the regular and easy-going-life seekers, who are engaged in public education, the financial industry, and traditional industries, pay most attention to the needs of comfortable feeling. Group 3, the modern information seekers, who are engaged in service and design industries, pay most attention to the needs of functional storage, spatial aesthetics, digital devices, safety, and cleanliness.
Evolution of the Spatiotemporal Pattern of Urban Industrial Land Use Efficiency in China
Authors: Zhao Xiaofeng , Zhang Lin , Huang Xianjin , Zhao Yuntai , Zhang Yunpeng
Published: June 2018

Along with the globally increasing concern for environmental sustainability, improving urban industrial land use efficiency (UILUE) is critically important for China’s development trajectory. However, the existent studies on UILUE in China are mainly conducted at the provincial level, which significantly undermines their value for tailoring practical policy formulations for lower-level governments. To fill this gap, this paper aims to investigate the spatial and temporal pattern of UILUE in China at the prefectural level, examining the underpinning influential factors for the period 2000–2014. Employing the means of spatial autocorrelation and regression, it is found that UILUE in China has improved significantly over the past decade in general but is also accompanied by significant spatial variations. UILUE is positively related to the agglomeration of industries, labour, capital, and technology, in which technology has fundamental effects upon the other factors. It is suggested to policy makers that government policy interventions should be placed predominantly upon technology regulation, i.e., setting admittance criterion for foreign direct investment (FDI), and industrial investment. For future studies, consistent efforts ought to be exerted to examine UILUE at and even under the prefectural level to achieve better understanding among academics and policy practitioners.