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A novel method combined with fabric embossing (embossing with fabric template) and thermal annealing is proposed to prepare multistage textured superhydrophobic polytetrafluoroethylene (PTFE) surface. Multistage (four-stage) textures of microscale Y-grooves (≈175 µm), F-grooves (≈10 µm), warts (≈3 µm), and nanoscale dendrites (≈380 nm) were obtained. The multistage textures endowed the PTFE surface with better superhydrophobicity, comparing with the two-stage textures with Y-grooves and F-grooves or the two-stage textures with warts and dendrites. Optimum superhydrophobicity is obtained at thermal annealing temperatures 345 °C and 360 °C.

Recovery of fluorine from wet-process phosphoric acid (WPA) to produce ammonium fluoride (NH4F) and sodium fluoride (NaF) provides an environmentally-friendly route to purify WPA and produce high value-added fluoride salt. The solubility data and the related electrolyte thermodynamics are essential for a rational separation design of pure NH4F from aqueous NaF solution by crystallization. In this contribution, the solubilities of NH4F in aqueous NaF solutions of different concentrations from dilute to saturated were systematically measured at 298.15 K using a dynamic synthesis method. Experimental results show that the presence of NaF in the solution could significantly decrease the solubility of NH4F due to the common-ion effect which was decreased by 72.4% when the molality of NaF was only around 0.015 mol/kg. The data can be used to determine the yield of NH4F and liquid composition in the vacuum evaporative crystallization of NH4F. The mean activity coefficients of NH4F at saturation were determined from the experimental solubility data and then correlated with the extended Debye-Hukel equation and the Pitzer model. With four adjustable parameters, both models are able to accurately calculate the experimental data over a wide range of salt concentrations. The average relative deviations between the experimental and calculated logarithm of mean activity coefficients of NH4F from the two models are 1.43% and 2.29%, respectively. The binary and ternary ionic parameters for the Pitzer model are found to be concentration dependent and the correlations of them as functions of ionic strength are proposed.

Post-earthquake damage in cementitious passive fire protection (PFP) systems is a serious fire safety hazard in steel frame structures, because it is unaccounted for at the design stage. This is of greatest concern after small to moderate earthquakes as modern structural components are designed to resist them with no damage. However, PFP systems are not currently subjected to any design regulations for seismic loading and therefore their performance cannot be quantified. Additionally, the inaccessibility of cementitious coatings hampers the evaluation of their remaining fire resistance capacity following earthquakes by means of visual inspections. This paper proposes an integrated multi-hazard framework using finite element analysis (FEA) for assessing the remaining fire resistance capacity of PFP protected steel frame structures subjected to moderate earthquakes. This multi-hazard framework is presented in the open source software environment OpenSEES, and provides structural engineers with a practical solution to access the fire safety concern associated with the PFP damage.

A new boron-dipyrromethene (BODIPY) fluorescent dye aimed at sensitively detecting hypochlorite anion (ClO−) has been designed, synthesized and characterized. The probe is comprised of a BODIPY fluorophore unit and a ClO− specific reactive group of amidoxime. The addition of hypochlorite results in a red-shift of absorption and emission spectra of the probe accompanied by a decrease of intensity and spectra changes (A500 and 1/I512) of the probe can achieve a good linearity to the concentration of ClO−. The fluorescence probe can react to ClO− rapidly (within 60 s) in a wide pH range (4–10) with high sensitivity (detection limit of 6.81 μM) and selectivity. The reaction mechanism has been proposed and confirmed by MS analysis, ClO− anion oxidizes amidoxime moiety to hydroxyl group and hydroxyl group is further oxidized to formyl group in the formation of a corresponding aldehyde compound. In addition, the probe has also been successfully applied to detect ClO− in tap water and river water samples by spiking a known amount of standard ClO−.

Cementitious coatings have been widely used as fire protection for steel structures, but they are vulnerable to structural deformations or vibrations, which may lead to reduction in their effectiveness and cause severe economic loss in the event of a fire. For buildings in practice, the problem can be critical because the coatings are assumed to be in good condition as they are usually hidden underneath architectural finishes, making it difficult and expensive to carry out routine inspection. To determine the actual fire resistance of a building after a moderate or severe loading event or a relatively long period of service, it is imperative to understand the performance of the coatings and to develop effective damage estimation methodologies. Loading conditions in a real buildings can be complex, however as there is inadequate previous work in this field, it is considered more important at this stage to determine the fundamental damage mechanisms in cementitious coatings on steel members subjected to axial loading, as investigated in this paper through experimental and numerical studies. At first, tests are carried out to obtain mechanical properties of the coating and the bond properties between the coating and the steel substrate. Then, a series of monotonic loading tests are conducted on axially loaded steel members to observe damage propagation in coating specimens. Subsequently, a cohesive zone finite element (CZFE) scheme is presented for modelling the damage with both interfacial and internal damage considered. The effectiveness of the proposed CZFE scheme is validated by comparison with different numerical approaches, interlaminar stress analysis and monotonic loading tests. From monotonic loading tests and CZFE numerical analyses, damage mechanisms in cementitious coatings on axially loaded steel members are clearly revealed. Under tensile loading, the damage begins with interfacial cracks at both ends, followed by transverse cracks within the coating resulting in its ultimate fracturing into segments. Under compressive loading, the damage also initiates at the ends with interfacial cracks and propagates towards the centre until the coating completely peels off. The findings from this research build a solid foundation for estimating the damage of cementitious coatings for trusses and large space structures, as most of the structural components in these structures are axially loaded. This work also provides an effective approach for further research on understanding damage mechanisms in cementitious coatings in steel frame structures under more realistic loading conditions.

As the traditional forging process has many problems such as low efficiency, high consumption of material and energy, large cylindrical shell rolling is introduced. Large cylindrical shell rolling is a typical rotary forming technology, and the upper and lower rolls have different radii and speeds. To quickly predict the three-dimensional stresses and eliminate fishtail defect, an improved strip layer method is developed, in which the asymmetry of the upper and lower rolls, non-uniform deformation and stress, as well as the asymmetrical spread on the end surface are considered. The deformation zone is divided into a certain number of layers and strips along the thickness and width, respectively. The transverse displacement model is constructed by polynomial function, in order to increase the computation speed greatly. From the metal plastic mechanics principle, the three-dimensional stress models are established. The genetic algorithm is used for optimization calculation in an industrial experiment example. The results show that the rolling pressure, the normal stresses, the upper and lower friction stress distributions are not similar with those of a general plate rolling. There are two relative maximum values in rolling pressure distribution. The upper and lower longitudinal friction stresses change direction nearby the upper and lower neutral points, respectively. The fishtail profile of spread on the end surface is predicted satisfactorily. The reduction could be helpful to eliminate fishtail defect. The large cylindrical shell rolling example illustrates the calculation results acquired rapidly are good agreements with the finite element simulation and experimental values of previous study. A highly effective and reliable three-dimensional simulation method is proposed for large cylindrical shell rolling and other asymmetrical rolling.

With the increase in mechanical strength, the yield to tensile strength ratio becomes more close to 1 and the elongation ratio appears a significant decrease, indicating a deterioration in the ductility and seismic behavior of high strength steel (HSS). For seismic design, understanding of the ductility and cyclic behavior in material level is important to guarantee the abilities of structural steel members to endure expected inelastic deformation under severe earthquake actions. This paper presents an experimental evaluation on the uniaxial cyclic behavior of Q460C steel through 6 cyclic loading tests. The specimens were cut and machined from both steel plates and flanges of hot-rolled H-shaped steel with the nominal yield strength of 460 MPa. For the purpose of comparing to normal strength steel, additional cyclic loading test was conducted on Q345B steel. Full hysteretic loops were achieved for HSS as well as normal strength steel. Based on the observations of the test results, a simple piece-wise model was developed for predicting the cyclic behavior of high strength steel, with considering the observed Bauschinger effect and cyclic strain hardening. To verify the accuracy of the proposed hysteretic model for HSS, quasi-static cyclic loading tests of Q460C steel beam-columns were simulated. The comparison between the experimental and predicted moment–curvature curves showed a good agreement, indicating a reasonable efficiency of the proposed trilinear kinematic hardening model in predicting the hysteretic behavior of HSS beam-columns.

This study presents the evaluation of seismic performance of high strength steel (HSS) beam-columns. Quasi-static experiments were carried out on four welded H-section and four box-section beam-column members fabricated from flame-cut Q460C HSS. The specimens were subjected to combined constant axial load and cyclic lateral load. The axial load was held at 30% of the yield strength of specimen during the loading history. The effects of width to thickness ratio and height to thickness ratio on the seismic behavior of HSS beam-columns were evaluated. It is found that component plate slenderness ratio has a significant effect on the deterioration behavior of beam-column under cyclic loading. According to the test results, welded Q460C HSS beam-columns with compact cross-sections show a good capacity of energy dissipation. No significant degradation was observed for the moment capacity of very compact cross-sections as class 1 under large inelastic rotation. The moderate compact cross-section belonging to class 2 shows a decrease in the moment capacity accompanied with the occurrence of local buckling when storey drift ratio is around 1/30. In addition to the obtained end moment–rotation hysteretic curves, the end moment–curvature hysteretic curves were developed to achieve more accurate descriptions of the cyclic performance of HSS specimens. Based on the generalization of experimental hysteretic curves, a trilinear hysteretic model was proposed in terms of the normalized moment–curvature relationship. This model was further compared with the experimental study to validate the accuracy in predicting the seismic behavior of HSS beam-column members.

Large cylindrical shell rolling is an advanced plastic-forming technique that has unequal speed and radius of both its upper and lower rolls. A theoretical model for a large cylindrical shell rolling that is based on the slab method is proposed, in which the non-uniform normal and shear stresses that act on the vertical sides are considered. A mixed friction model of combined Coulomb and sticking friction is used to present interface friction, to improve the accuracy of the proposed model. The rolling pressure, rolling force, and torque as well as friction stress can be rapidly and easily calculated through the proposed model at different rolling conditions. The predicted rolling force is consistent with the experimental result. The research results provide valuable guidelines for both the design and optimization of rolling product, process, and equipment.

The paper g describes a model meant for analysis of the wear geometry of plain woven fabric composites. The referred model consists of a mathematical description of plain woven fabric based on Peirce’s model coupled with a stratified method for the solution of the wear geometry. The evolutions of the wear area ratio of weft yarn, warp yarn and matrix resin on the worn surface are simulated by MatLab software in combination of warp and weft yarn diameters, warp and weft yarn-to-yarn distances, fabric structure phases (SPs). By comparing theoretical and experimental results from the PTFE/Kevlar fabric wear experiment, it can be concluded that the model can present a trend of the component area ratio variations along with the thickness of fabric, but has a inherently large error in quantitative analysis as an idealized model.

In order to eliminate the mixed crystals of the thick-walled heavy cylinder after rolling and improve the quench shortage of tank copious cooling, it is significant to analyze the cooling capacity of spray cooling and tank copious cooling. Models of heat transfer coefficient about spray cooling and copious cooling were established. The quenching process simulation was made based on the DEFORM software. The cooling rate models of center part about spray cooling and copious cooling were build. According to the CCT curves of heavy cylinder material and simulation results, which show that: (1) Using spray cooling can increase the cooling rate of center part to some extent and improve the mechanical properties. (2) The maximum capacity of spray cooling is 280mm, that is the microstructure of center part fully transfers to bainite, which is 50mm larger than copious cooling.

Compared to superhydrophobic surfaces, superamphiphobic surfaces possess more potential applications but are difficult to fabricate. Herein, to address this problem, we describe a simple method to fabricate a superamphiphobic surface based on a CNTs–SiO2 hybrid material. The CNTs–SiO2 hybrid material obtained by a sol–gel approach was sprayed onto glass slides to form coatings. After surface fluorination, the sprayed coating displayed superamphiphobicity toward water and a number of organic liquids, such as dodecane. It was found that the time of fluorination slightly influenced the surface wettability of the sprayed coating. We also investigated the role of CNTs and SiO2 on superamphiphobicity establishment separately, and such information allowed us to engineer surfaces with specific wettability.

Polyoxometalates K7[α-PW11O39]·14H2O (PW11) modified mesoporous silica (MCM-48) with cubic structure, was prepared by impregnation and calcination methods. The modified mesoporous silica sorbent (PW11/MCM-48) was studied as a potential adsorbent for U(VI) from aqueous solutions. MCM-48 and PW11/MCM-48 were confirmed by X-ray diffraction and nitrogen physisorption techniques. The results indicate the original keggin structure of PW11 and mesoporous structure of MCM-48 are maintained after supporting PW11 on mesoporous silica MCM-48. The effects of contact time, solid-to-liquid ratio (m/V), solution pH and ionic strength on U(VI) sorption behaviors of the pure and modified mesoporous silicas were also studied. Typical sorption isotherms such as Langmuir and Freundlich isotherms were determined for sorption process. The results suggest that the sorption of U(VI) on MCM-48 or PW11/MCM-48 are strongly dependent on pH values but independent of ionic strength. The sorption capacity of PW11/MCM-48 for U(VI) is about ten times more than that of MCM-48.

Two functionalized SBA-15 materials were prepared by a post-grafting method using phosphonate derivatives of diethylethylphosphonate (DEP) and ethylphosphonic acid (PA), which were used as adsorbents for removal of uranium(VI) from aqueous solution. These materials were characterized by FT-IR, NMR, TEM, nitrogen adsorption/desorption experiments, and elemental analysis. The effect on uranium(VI) sorption behaviors of the functionalized SBA-15 was studied. Typical sorption isotherms (Langmuir and Freundlich) were determined for the sorption process, and the maximum sorption capacity was calculated. The influence of organic functional groups on uranium(VI) sorption was also discussed. As a result, SBA-15-ethylphosphonic acid (SBA-15-PA) possessed not only a good sorption ability and a desirable selectivity for U(VI) over a range of competing metal ions but also an excellent reusability, which has potential application in separation of uranium(VI).

The establishment of current design curves for predicting the maximum strengths of centrally loaded columns was mostly based on the experimental and analytical studies of mild carbon steels. In order to study the overall buckling behavior of welded high strength steel (HSS) box-columns, an experimental study on the ultimate strength of welded box-columns with a nominal yield strength of 460 MPa under axial compression was conducted. This experiment program includes six welded box-columns with slenderness varying from 38 to 80. A nonlinear finite element model considering the actually measured geometric imperfections and residual stresses was developed and verified in order to perform an extensively parametric study. The effect of residual stresses on the ultimate bearing capacity and the sensitivity of yield strength to initial geometric imperfections were investigated and discussed. The purpose of the parametric study is to select an appropriate design curve for welded 460 MPa HSS box-columns. By comparing the theoretical curves with the design curves specified in Eurocode3 and GB 50017-2003, it is found that the currently adopted design curves underestimate the ultimate bearing capacity of the welded box-columns fabricated from 460 MPa HSS plates by 18.7% and 23.2% in average, respectively. The curves b in both Eurocode3 and GB 50017-2003 show a good agreement with the generated theoretic curve for the welded box-columns with the nominal yield strength of 460 MPa buckling about both principle axes.

The cation transport behavior of thermally treated reduced graphene oxide membranes (GOMs) is reported. The GOMs were reduced by heat treatment at 25, 80, and 120 &deg, C and then characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy to determine oxygen group content, C/O ratio, and layer spacing. The permeation rates of various cations with different sizes and charge numbers through these membranes were measured to understand the effect of the cations on transport behavior. The results indicated that the cation transport through the membranes depended on the layer spacing of the membrane and ion size and charge. Cations of the same valence permeating through the same GOM could be differentiated by their hydration radius, whereas the same type of cation passing through different GOMs could be determined by the spacing of the GOM layers. The cation valence strongly affected permeation behavior. The GOM that was prepared at 120 &deg, C exhibited a narrow layer spacing and high separation factors for Mg/Ca, Mg/Sr, K/Ca, and K/Fe. The cations moving through the membrane could insert into the membrane lamellas, which neutralized the negative charge of the membrane, enlarged the layer spacing of the GOMs, and affected cation permeation.

A strip layer method is presented for analyzing the three-dimensional deformations and stresses of large cylindrical shell rolling process. In this approach, the different radii and velocities of upper and lower rolls, the uneven distributions of deformations and stresses at the roll gap, are taken into account. The rolling deformation zone is divided into a number of strip and layer elements along the width and thickness directions, respectively. In order to reduce the optimization parameters and improve the computation efficiency, the exit lateral displacement distribution is expressed as polynomial function. Based on the fundamental principles of plasticity, the three-dimensional deformations and stresses of the deformation zone are formulated. The simulation results can be obtained quickly and easily. The fishtail spread is predicted satisfactorily on the free side, and the rolling pressure distribution is quite different from that of a conventional strip rolling. The predicted rolling force and average spread of the proposed method are in agreement with the experimental and FEM results.

The elctropulsing treatment (EPT) has been successfully applied to the processing of a low carbon Q235 steel strip. Comparing with the con- ventional heat treatment (CHT), a proper EPT is capable of achieving the similar or even better effect on the mechanical properties of the steel strip. It was found that the optimum combination of the EPT parameters are 180 V in voltage and 500 Hz in frequency (180 V – 500 Hz) leading to a combination of tensile strength-elongation of 371 MPa – 47,5 %. Optical microscopy analyses indicates that the EPT/180 V – 500 Hz for Q235 steel strip can accelerate the formation of the completely recrystallized microstructure in which the grain size become relatively finer and more uniform compared to the elongated one formed in the cold-rolled sample. Such phenomenon is consistent with the improvement of the mechanical performance of the Q235 steel sample under the EPT. However, the EPT with inadequate frequency can only result in partial recrystallization of the grains, while the one with an exceed frequency may lead to the apparent grain growth within the sample. Both cases can not produce satisfactory combination of strength and ductility for the steel samples.

When glass panels are subjected to blast loading, the flying shards may cause large amount of casualties and loss of properties. It is, therefore, essential to understand thoroughly the failure modes of common glass curtain wall systems subjected to blast loading. This paper describes the finite element analyses of failure modes of four-point-supported monolithic and laminated glass panels subjected to blast loading. The blast resistance performance of the two kinds of panels is evaluated. Then using the theory of pressure-impulse, the overpressure-impulse equation and diagram are presented, which provide practical blast-resistance assessment tools for four-point-supported monolithic glass panels.

In the present study, we evaluated the diagnosis and management modalities of caesarean scar pregnancy (CSP). Thirty patients diagnosed with CSP were retrospectively studied between February, 2010 and February, 2012. Twenty-five patients were offered prophylactic uterine artery embolization (UAE) and methotrexate (MTX) prior to uterine suction curettage. Five cases were referred from other hospitals where the initial management with uterine suction curettage had resulted in uncontrollable massive haemorrhage, 4 of the cases had UAE and one proceeded immediately to hysterectomy. In the 25 patients treated with prophylactic UAE and MTX, 12 had laparoscopy-guided curettage and 13 had ultrasound-guided curettage without complication. The results showed that the 25 patients with CSP, who received prophylactic UAE and MTX prior to uterine curettage, recovered without complications. Five patients referred from other hospitals, where uterine curettage was the primary procedure, had severe complications including uncontrolled vaginal bleeding and uterine rupture. Four of the five patients were treated successfully with emergency UAE and the remaining patient underwent emergency hysterectomy as ultrasound examination detected significant haemorrhage between the uterus and the bladder. Of the 25 patients who received prophylactic UAE combined with MTX, there were no reports of irregular menstruation or serious adverse effects. Notably, the decrease in serum human chorionic gonadotropin (HCG) levels 3 days post-surgery was greater with ultrasound-guided curettage (84.3±5.5%) than with laparoscopy-guided curettage (76.3±10.2%). In summary, the data suggested that prophylactic UAE with MTX followed by ultrasound-guided curettage is the most effective therapeutic approach in CSP.

The presence of residual stress in members can significantly compromise the stiffness and fatigue life of steel structural components. Researches in this area are well documented for structural members of mild carbon steels. Nevertheless, due to the difference of stress–strain relations and material properties under ambient and high temperatures, the residual stress distribution in a high strength steel member is physically different from those fabricated from mild carbon steel. It is imperative to study the residual stress distribution for structural members fabricated from high strength steel. In this paper, the residual stresses of three welded flame-cut H-section columns with a nominal yield strength of 460 MPa but different cross-section dimensions were investigated. Both sectioning and hole-drilling methods were used in the measurement and the obtained residual stresses were compared between the two methods. The magnitudes and distributions of the measured residual stresses are identical with those of carbon steel, however in relatively smaller residual stress ratios. Finally, based on the measurements, a simplified residual stress distribution for 460 MPa high strength steel members with welded flame-cut H-section is proposed.

2.25Cr1Mo0.25V alloy steel of making heavy cylinder for hydrogenation reactor was taken as research subject. The compression experiment was carried out on Gleeble-3500 thermal simulator under different conditions of deformation temperature, strain rate and deformation degree. The relationship between deformation resistance and deformation temperature, strain rate, deformation degree was analyzed. Two different types (dynamic recovery and dynamic recristallization) of deformation resistance model were established through multiple nonlinear regression method. The relative error of deformation resistance between the calculated value and the measured value was under 10% and the maximum error of the rolling force between the calculated value and the measured value was 9.7%, which showed that this deformation resistant model was accurate and met industry requirements.

High strength steel (HSS) columns have been located in the research scope of the introduction of multiple column curve to the design codes. However, the determination of current design curves for predicting the maximum strengths of centrally loaded columns was mostly based on the experimental and analytical studies of mild carbon steels. Due to some test data (e.g. residual stress distribution) of HSS columns were not available, the selection of the design curves for HSS columns was inevitably based on some assumptions which need the further confirmation of experiments. In this paper, an experimental study on the ultimate strength of welded H-section columns fabricated from flame-cut steel with the nominal yield strength of 460 MPa under axial compression was conducted. This experiment program include six welded H-section columns with varies slenderness form 40 to 80. The nominal thickness of flanges and webs are 21 mm and 11 mm. A nonlinear finite element model considering the actually measured geometric imperfections and residual stresses was established and used to perform an extensively parametric study. The purpose of the experimental and numerical studies is to find an appropriate design curve for welded 460 MPa HSS H-section columns. By comparing the theoretical curves with the design curves specified in Eurocode3 and GB 50017-2003, it is found that the currently adopted design curves can be extend to welded H-section columns fabricated from flame-cut 460 MPa HSS plates. But the curve c of Eurocode3 is very conservative when H-section columns are buckling about weak axis.

Rolling force is an important technological parameter in designing of the 3700mm cylindrical shell rolling mill. Due to the characteristics of double driving rolls and asynchronous rolling of 3700 mm cylindrical shell rolling mill, the force analysis of the deformation zone is complex. In this study, an analytic method was used to calculate the rolling force. The deformation zone was divided into the forward slip area, the backward slip area and the rub rolling area on the basis of metal flow velocity. The stress equilibrium equations of each area were built. Then the rolling force model of the 3700mm cylindrical shell rolling mill was built and solved, according to the boundary conditions. At the same time, in order to verify the validity of the analysis, the calculated values were compared with the measured in the spot. They have a good agreement, which indicates the calculation accuracy of the model could meet the industry requirements.

Much work on the investigation of the magnitude and distribution of residual stresses in mild carbon steel sections have been made previously. However, limited efforts have been put on residual stress measurements of high strength steel sections. The differences of stress–strain curves and high-temperature material properties between the high strength steel and mild carbon steel demands a necessary study of the residual stresses in high strength steel welded sections. In the present study, three box columns fabricated from Q460 steel plates of 11 mm in thickness with different details were used for the examination. Both sectioning and hole-drilling methods are adopted for the measurement. The measured residual stress distributions of three different box sections are presented, and the corresponding simplified residual stress pattern is proposed. By comparing with the residual stress patterns for mild carbon steel, it is found that the box section fabricated from HSS plates has the lower compressive residual stress ratio. The differences in the measurement by using sectioning and hole-drilling methods are also compared.

The mesoporous silicas (MCM-41 and MCM-48) are synthesized by hydrothermal method, which are characterized by XRD and BET techniques. The application of mesoporous silicas for the sorption of U(VI) from aqueous solution are studied by using batch technique under ambient condition. The effects of contact time, solid-to-liquid ratio (m/V), solution pH, ionic strength and temperature are determined, and the results indicate that the sorption of U(VI) to MCM-41 or MCM-48 are strongly dependent on pH values but independent of ionic strength. Compared with Langmuir model, the sorption isotherms can be simulated by Freundlich model well according to the high relative coefficients. The parameters for Langmuir and Freundlich sorption isotherms are calculated from the temperature at 298, 318 and 338 K, respectively, and the results suggest that the sorption of U(VI) on MCM-41 or MCM-48 is a spontaneous and exothermic process. In contrast to its sorption capacity for U(VI), MCM-48 is a suitable material for the preconcentration of U(VI) from large volumes of aqueous solutions.

Since recent advances of technology in material science and increasing demand for high strength steel, Q460 high strength steel has been applied to several landmark buildings and major projects. However, the application of high strength steel in seismic structures is limited by the relative worse ductility, which is usually decreasing with the increasing on yield strength. For this purpose, key issues of using high strength steels in seismic structures are discussed and two design methodologies are proposed. Recent research progress on application of high strength constructional steel achieved at Tongji University is introduced. Finally, future work related to the application of high strength steels are recommended.

This paper mainly discusses the derivation and usage of simplified analysis model of circular concrete-filled steel tube specimen under lateral impact. At first, the robust software, LS-DYNA, is employed in this paper to simulate a test of circular concrete-filled steel tube (CFT) specimen under drop impact carried out by Li (2007). The numerical simulations results agree well with the experiment results and it shows good prediction of dynamic response of the CFT specimen under lateral impact could be achieved. Further analysis based on LS-DYNA model is then made to investigate the stain rate effect of the CFT column with fixed-simple supported ends. At last, a simplified analytic model is derived based on the combination of the tests results, the numerical simulation and theoretical analysis. The comparison between the maximum deflections at the mid-span obtained from the proposed simple analytical model and the numerical simulation shows that the proposed method gives good predictions of the maximum deflection of the CFT specimen under lateral impact.

The present work reports a novel and facile approach to fabricate stable superhydrophobic surfaces for universal applicability in practice. Poly(furfuryl alcohol)/copper composite coatings were prepared on substrates via a brush-painting method; after being immersed in a stearic acid solution, the superhydrophobic surfaces were obtained due to the formation of copper stearate on the substrates. These products were characterized by field-emission scanning electron microscopy, Fourier transform infrared spectrometry, X-ray powder diffraction and the X-ray photoelectron spectrum. Results demonstrate that the superhydrophobic surfaces formed originally on copper substrates can also be generated on other substrates without the copper element. Furthermore, this work will provide a simple and universal method to create large-scale superhydrophobic surfaces on various substrates.

Perimeter protection is an important physical protection approach for buildings and infrastructures, which is also regarded as the first line of protection. Vehicle borne improvised explosive devices (VBIED) have been recognized as a major design threat by many government agencies for years, since they have been so extensively used in past terrorist attacks against critical buildings and infrastructures. Preventing unauthorized vehicles from approaching a protected area with vehicle barriers installed in perimeter of the buildings and infrastructures would consequently reduce blast and debris threats. The history of test certification standard for vehicle barriers is briefly reviewed. The research achievements on anti-ram bollards, one type of vehicle barriers, in the fields of crash test, numerical simulation, and design theory are presented. The remaining problems and deficiencies of the research are pointed out and the corresponding proposals are put forward. Finally, some further research works on anti-ram bollards are proposed.

The heavy shell ring rolling process was taken as subject investigated. Because the size of shell ring is very large and the material of shell ring is special, in order to make the shell ring to be bitten smoothly and make the rolling process stable, the double drive rolls was proposed in the shell ring rolling mill. The thermal simulation test of heavy shell ring material was made on the Gleeble 3500 thermal simulation test machine. Based on FEM, the three dimensional thermal mechanical coupled model of shell ring rolling process was built in this paper. The influences of process parameters on the stress field, strain field and mechanical parameters were investigated. Simulation results show that, with the increase of feed velocity, the strain of shell ring increases, the forging penetration condition becomes good; With the increase of friction coefficient, the equivalent plastic strain of shell ring surface layers increases, the equivalent plastic strain of shell ring middle layers has little change. The conclusions are significant for designing equipments of shell ring rolling mill and developing new rolling schedule.

Two 60-day experiments were conducted to study the influence of photon flux density (PFD) and temperature on the attachment and development of Gloiopeltis tenax and Gloiopeltis furcata tetraspores. In the first experiment, tetraspores of the two Gloiopeltis species were incubated at five temperature ranges (8°C, 12°C, 16°C, 20°C, 24°C) under a constant PFD of 80 μmol photons m−2 s−1 with a photoperiod of 12:12. In a second experiment, tetraspores were incubated under five PFD gradients (30, 55, 80, 105, 130 μmol photons m−2 s−1) at a constant temperature of 16°C with a photoperiod of 12:12. Maximum density of attached tetraspores was observed at 16°C for both species. Maximum per cent of spore germinating into disc was recorded at 12–16°C for G. tenax and 8–12°C for G. furcata. Maximum per cent of discs producing erect axes for G. tenax and G. furcata were recorded at 24°C and 20°C, respectively. Light had no significant effect on tetraspore attachment and developing into disc, but it affected the growth, sprouting and survival of its discs. Under 30–55 μmol photons m−2 s−1, the discs of the two species of Gloiopeltis did not form thallus until the end of the experiment. Optimum PFD range for G. tenax discs was 80–105 μmol photons m−2 s−1, whilst it was 80–130 μmol photons m−2 s−1 for G. furcata. Results presented in this study are expected to assist the progress of artificial seeding of Gloiopeltis.

This study presents a framework for dynamic analysis of a coupled system of high-speed maglev train and curved viaduct. A series of trajectory coordinates are used to define the motion of maglev vehicles moving over a horizontally curved track, the stiffness and damping matrices of the equations can be thus reduced into those of the straight track. The curved viaduct system is modeled in the global coordinate system using the finite element method, in which the inner and outer rails in the different horizontal planes are duly included. The electromagnet force-air gap model is adopted for the maglev vehicle via its electromagnets and rails on the viaduct, by appropriate transformation of coordinates. By applying the proposed framework to the Shanghai maglev line, curved path-induced dynamic responses and characteristics of the vehicle are explored, which agree well with the measurement ones. The dynamic responses of the curved viaduct are also examined in the vertical, lateral and rotational directions by comparison with the straight viaduct. Moreover, the effect of various curve radii and cant deficiencies on the coupled system are investigated. The results show that for a maglev vehicle moving with an initial equilibrium state, its lateral and rotational response are mainly excited by track roughness. In addition to the track radius, cant deficiencies significantly affect the operational safety of the viaduct.

Finite element simulations are increasingly used in structural analysis and design, especially in cases where complex structural and loading conditions are involved. Due to considerable progresses in computer technology as well as nonlinear finite-element analysis techniques in past years, it has become possible to pursue an accurate analysis of the complex blast-induced structural effects by means of numerical simulations. This paper aims to develop a better understanding of the behavior of steel-concrete composite beams (SCCB) under localized blast loading through a numerical parametric study. A finite element model is set up to simulate the blast-resistant features of SCCB using the transient dynamic analysis software LS-DYNA. It is demonstrated that there are three dominant failure modes for SCCB subjected to localized blast loading. The effect of loading position on the behavior of SCCB is also investigated. Finally, a simplified model is proposed for assessing the overall response of SCCB subjected to localized blast loading.

In order to analyze the behavior of steel columns in a fire with partial damage to their fire protection, two simple models are presented. One of the models based on the differential equation of equilibrium may be used to predict the ultimate load bearing capacity of steel columns hinged at two ends and the other may be employed to predict the critical temperature of axially restrained steel columns. The imperfections including initial flexure of steel columns and load eccentricity are taken into account in the models. The edge fiber yielding at the mid-span of a column is taken as the failure criteria for the fire-resistance of the column. A numerical application is carried out to demonstrate the effect of the damage to fire protection on the ultimate load bearing capacity and critical temperature of steel columns in a fire. The results show that the load bearing capacity is reduced at a given temperature with increasing damaged length of fire protection. The axially restrained stiffness and load ratio have a significant influence on the critical temperature of steel columns. By employing the computer models, the approach proposed in the paper has been validated and good agreement has been found.

An explosive blast mitigation alternative has increased the safety of structures by using “catcher” systems. These systems “catch” or repel the failure of the window or in-fill wall protecting life and property from ballistic shards or fragments. They can be designed to be standalone in new construction and structural retrofits or used to augment structural hardening techniques. Cables, fabrics, and thin gauge sheet steel are examples of catcher systems used in the past. A new and evolving category of catcher systems are based on polymeric materials that can be used for both wall and window upgrades. These products are a proven blast mitigation concept and K&C Protective Technologies Pte Ltd (KCPT) together with Sherwin-Williams(SW) use KCPT’s blast engineering capacity and SW’s material engineering principles to create engineered systems for even greater in-use performance.

Performance based engineering (PBE) is increasingly recognised as the gold standard for ensuring structural safety under extreme loading conditions such as a post-flashover fire. While no universally agreed methodology exists for implementing PBE for various kinds of extreme loadings in general, there are three clearly defined stages for doing so in order to design or assess structural resistance under fire loading. The fire loading is characterised in the first stage, which may range from simple prescribed time-temperature relationships if standard fires are adopted, which is against the spirit of PBE, to an expensive computational fluid dynamics simulation, which in most cases would constitute overkill. A number of options are available and gradually being developed that lie between these two extremes. A realistic characterisation of the load should in general allow the possibility of non-uniform heat fluxes to structural surfaces, which makes the second stage of determining structural temperatures very tedious. Furthermore, the computational models used in the third stage of determining nonlinear structural response are usually very different from the models used in the second stage thereby requiring significant manual intervention by the analyst. In the author’s view this, bar the need for further research on realistic fire scenarios, is the greatest obstacle in carrying out PBE for structural fire resistance design. This paper presents a simulation tool developed within the open source software framework OpenSees with the aim of integrating all the stages of the analysis discussed earlier in order to make PBE feasible even for design offices with modest resources in terms of trained analysts and computing hardware.

This paper describes the first case of using hanging plastic tray for three-dimensional collection of the spat in the hatchery production of antique mactra. Different numbers of clusters (72, 90, 108) of plastic trays loaded with fine sand were hung in three tanks for three-dimensional collection of antique mactra, while the other two tanks without hanging plastic trays were controls. There was a higher survival rate in the tanks with hanging plastic trays than the controls and there was significantly increasing the survival rate of the spat as the numbers of clusters of plastic trays increased. At the end of the experiment, in the tank with most numbers of clusters of hanging plastic trays the survival spats was almost 2.6 times of that in the controls. In the early stage of the experiment there was significantly faster growth of the spat in the tank with hanging plastic trays than the controls. However, at the end of the experiment, there was significantly shorter shell length of the spat in the tank with most numbers of clusters of hanging plastic trays, and there was no significant difference in the shell length of the spat among the others tank.

The Di Wang Building is one of the tallest composite buildings in the world, located in downtown Shenzhen City of China about 2 km from the Hong Kong border. On 16 September 1999, Typhoon York – that is the strongest typhoon since 1983 and the typhoon of longest duration on record – attacked Hong Kong and Shenzhen. The wind and structural monitoring system installed in the Di Wang Building timely recorded wind and structural response data. The newly emerged Hilbert–Huang transform (HHT) method in conjunction with the random decrement technique (RDT) is applied to the measured data in this paper to identify dynamic characteristics of the building. A series of natural frequencies and modal damping ratios of the building under different wind speeds in different directions are identified and compared with those from the fast Fourier transform (FFT)-based method. The variations of natural frequency, total modal damping ratio and net structural modal damping ratio with wind speed and vibration amplitude are also investigated. The results show that the natural frequencies identified by the HHT method are almost the same as those obtained by the FFT-based method. The first two modal damping ratios given by the HHT method are, however, lower than those by the FFT-based method, which may indicate that the FFT-based method overestimates the modal damping ratios. Both the total and the net structural modal damping ratios increase with increasing wind speed and vibration amplitude but the situation is reversed for the natural frequency. Copyright © 2003 John Wiley & Sons, Ltd.

Three different functional SBA-15 were prepared by a post-grafting method using three iminodiacetic acid derivatives of ethylenediaminetriacetic acid (ED3A), diethylenetriaminetetraacetic acid (DT4A), and 1,2-cyclohexylenedinitrilotriacetic acid (CyD3A), which were used as adsorbents for removal of uranium(VI) from aqueous solution. These materials were characterized by FT-IR, NMR, TEM, nitrogen adsorption/desorption experiments, and elemental analysis. The effect of pH, ionic strength, contact time, solid–liquid ratio, initial metal ion concentration, temperature, and coexisting ions on uranium(VI) sorption behaviors of the functionalized SBA-15 was studied. Typical sorption isotherms (Langmuir and Freundlich) were determined for the sorption process, and the maximum sorption capacity was calculated. The influence of functional groups on uranium(VI) sorption was also discussed. As a result, compared with other current U(VI) sorbents (granite, kaolin, attapulgite), SBA-15-1,2-cyclohexylenedinitrilotriacetic acid (SBA-15-CyD3A) possessed good selective sorption properties, which had potential application in separation of uranium(VI).

Cementitious coatings are widely used as fire protection for steel structures but they are vulnerable to damage from structural deformations. In this paper, damage mechanisms in cementitious coatings on steel members in bending are investigated. A series of monotonically loaded beam tests are conducted to observe the occurrence of cracks and their propagation leading to final failure. The experiments are then simulated using a cohesive zone finite-element scheme, capable of modelling interfacial damage between the coating and steel substrate as well as internal coating damage. The results of the experimental and numerical studies clearly reveal the distinct damage mechanisms of cementitious coatings on both tension and compression sides of structural steel members in bending. Findings from this study provide the foundation for developing practical methods to determine the condition of cementitious coatings on steel structures after a short-duration extreme loading event (earthquake, blast, windstorms), where there is minimal external damage to the building fabric or long-duration cumulative damage from moderate levels of repeated non-monotonic loading. It is very unlikely in either of these cases that the integrity of cementitious fire protective coatings has been investigated in current practice.

Post-earthquake fire is an important issue for buildings in seismic zone, especially for the steel buildings. To evaluate fire resistance of steel buildings after earthquake, one should consider the seismic induced damage to the fire protection of steel member, in addition to the consideration of steel structure′s fire resistance after earthquake. Cementitious Coatings have been widely used as fire protection for steel structures, but they are vulnerable to structural deformations, which may reduce their effectiveness. To evaluate the damage of fireproof coatings, firstly a series of monotonic loading experiments have been conducted on fireproof material coated steel members when in compression, or in tension, or in bending. Damage initiation and propagation for different loading cases were observed and investigated. Then, a cohesive zone finite element (CZFE) scheme is presented for modeling coating′s damage with both interfacial and internal damage considered. The effectiveness of the proposed CZFE scheme is validated by comparison with different numerical approaches, interlaminar stress analysis and monotonic loading tests. From monotonic loading tests and CZFE numerical analyses, damage mechanisms of cementitious coatings on steel members are clearly revealed. Under tensile loading, the damage begins with interfacial cracks at both ends, followed by transverse cracks within the coating and resulting in its ultimate fracturing into segments. Under compressive loading, the damage also initiates at the ends with interfacial cracks and propagates towards the center until the coating completely peels off. Under bending loading, on tension side, the damage mechanism is similar to the case of tensile loading but severer fracture occurs due to the effect of curvature. On compression side, the initiation of damage is similar to the case of compressive loading but the failure mode is different, where shear fracture occurs at the ends because of the effect of curvature. It is found that increasing the thickness causes earlier occurrence of cracking and failure and may change the damage mode.

Slender structures such as tall buildings and chimneys can be modeled as cantilevers with bending and shear deformation. A flexibility approach for damage identification of cantilever-type structures by utilizing the data of dynamic modes is proposed in this paper. An important advantage of the approach is that it only requires a small number of modes, so that it is convenient for practical application. The effectiveness of the approach is verified by numerical and experimental examples.