bluuebunny/crossref_metadata_2025 huggingface dataset:
16.16: Medium span steel‐concrete composite bridges: plate girders or box girders
Authors: Stroscio Riccardo
Published: September 2017

In today's environment and client's requirements, solutions for medium span road and rail bridges within the UK tend to result in an overlap between three types of steel‐concrete composite decks. From the ban and moratorium imposed on grouted post‐tensioned concrete bridges since the early 1990s, braced pairs of plate girders, twin plate girders with cross girders (ladder‐deck) as well as steel box sections have dominated the British construction market for spans varying between 30m and 70m.

Open box sections (bath tub) are sometimes preferred due to specific geometry requirements or even purely from aesthetic requirements. This paper reviews and compares the options based on the available design guidelines as well as the author's recent experience in delivering detail designs of each alternative arrangement.

The aim of this paper is to summarise the main driving factors leading to the choice of a specific arrangement. A discussion on geometrical considerations (skew, curve, span to depth slenderness ratios) as well as a comparison of estimated weight of steel per metre square of deck for each option are included. Each solution is presented from the detail design and fabrication point of views including the transport criteria, the erection consideration and the temporary stability stages. The aesthetic and the whole life cost aspects (such as durability, inspection and maintenance) are also considered in the comparison.
16.24: Load‐carrying capacity of steel girder damaged by collision
Authors: Yamaguchi Eiki , Tsuji Hiroyuki , Tanaka Yukito
Published: September 2017

It happens sometimes that a truck running on a highway collides with the main girder of a bridge over the highway. The influence of the damage due to collision on the mechanical behavior of the bridge has to be evaluated for the safety of traffic on the bridge. Yet it is not always an easy task, since the mechanical capacity of a deformed girder has not been studied much. One of the authors has been involved in the safety evaluation of a steel girder bridge damaged by collision. The bridge consisted of two steel main‐girders and one of them looked badly damaged: the web was deformed outwardly; some transverse stiffeners were buckled; some other stiffeners were separated from the web; and bolted connections between some lateral struts and the web were broken. Making use of the information on the actual damage, the collision load is estimated by the finite element analysis and the deformation of the main girder is reproduced. The load‐carrying capacities of the main girder without damage, the main girder damaged by collision, the main girder with larger damage are then studied. Based on the results, the influence of the collision damage on the load‐carrying capacity is discussed.
16.28: High speed railway bridge – Copenhagen and Ringsted – TP 30: The longest composite railway girder bridge in Denmark
Authors: Thomsen Kjeld , Petersen Christian Riis
Published: September 2017

ISC Consulting Engineers A/S as consulting engineers won the contract for the TP30 bridge in a turnkey competition.

The total length of the bridge is 512 m split with one expansion joint in the center of the bridge. The spans for the bridge vary between 36 and 21 m at the outer spans. The two sections of the bridge with at length of approximately 256 meter are anchored in the abutments. The bridge crosses the motorway near Vallensbæk in a very small angle and this cause for an innovative design solution for establishing the supports in a comprehensive way without disturbing the traffic.

The design is outstanding compared to earlier structures in Denmark for bridges as this is a composite box girder carrying the two rails which gives at total width of the bridge of 15 meters.

Full composite action is established by means of welded dowels on the top flanges of the box girder. It is the first time this type of structure is built in Denmark for a railway bridge carrying high speed trains with a max speed of 250 km/h.

The construction principle has been chosen in order to create as little disturbance to the motor roads as possible. Therefor the composite system was chosen and the steel bridge can be erected in full spans transported along the motor road and lifted into place with cranes.

After finishing the construction of the steel bridge a movable scaffolding system is arranged on top of the steel bridge and applied for casting of the concrete step by step in the spans starting in the center of the spans and on the way back above the abutments. In this way pre‐stressing can be omitted in the concrete deck as the two moments above the supports are minimized. The design started in spring 2014 the construction took place in 2015–2016.
17.02: Strengthening of oil platform with submerged cables: Strengthening of offshore oil production platform with prefabricated submerged cables
Authors: Lee Sørensen Paw , Sørensen Ove , Linneberg Poul
Published: September 2017

Cable stays were used to strengthen an offshore oil production platform that had suffered structural damage. Six cables were installed (nos. 169 parallel strands in each cable) in an x‐bracing configuration between the platform legs. The use of cable stays for cable supported bridges, roofs and buildings has been increasing over the last 40 to 50 years and the technology is still being optimized. One of the main durability issues is related to corrosion of the high strength steel wires caused by water ingress into the cables. Obviously, deliberately submerging such cable stays into seawater present a number of very complex challenges, both from a technical and an installation point of view. This paper focuses only on some of the technical aspects to solve these challenges and presents some of the many innovative solutions that were developed during the detailed design.
18.06: Preliminary transition piece design for an onshore wind turbine
Authors: Mohammadi Mohammad Reza Shah , Farhan Muhammad , Rebelo Carlos , Veljković Milan
Published: September 2017

Steel lattice structures are rather well established for very tall supporting structures for wind turbines. Recently, fully lattice towers and steel hybrid lattice/tubular towers are being investigated as a possible solution for taller onshore wind turbines for which convectional steel tubular towers are less competitive.

The steel hybrid towers require a transition piece to establish a connection between lattice and tubular parts. The transition piece is transferring the loads from the tubular segment at higher elevation to the lattice structure which is fixed to the foundation. It is critical component to design, because non‐standardized solution is necessary to resist cyclic loading in a cost‐effective solution. Well‐designed transition pieces with optimized resistance and feasible for manufacturing and execution on site is important for the market acceptance of a new type of onshore wind towers.

This research focuses on the investigation of the transition piece for an onshore wind turbine hybrid tower. The 5MW reference wind turbine and a hybrid lattice/tubular tower was simulated in the servo‐aeroelastic analysis tool (by ASHES software) from which the loads and dynamic response of the supporting structure was obtained. Cross‐section forces at the transition piece elevation were calculated and the connection with the lattice structure is designed.

The transition piece was designed by FEM considering ultimate limit load and fatigue load, using nonlinear analysis and hot spot method for life time prediction, respectively. Potential of using high strength steel S690 was investigated.
19.01: A study on the prediction of welding effects in steel box girders
Authors: Krausche Thomas , Launert Benjamin , Pasternak Hartmut
Published: September 2017

For standard sections including I‐girders and rectangular box girders, several approaches on geometrical and structural imperfections are given in the literature, which can be implemented in a numerical analysis. For complex sections, as found in many of today's lightweight roof structures, these assumptions are conservative due to the sections typically unique shape, which leads to increased thicknesses or additional stiffening of the plates. This, on the other hand, can significantly affect fabrication costs. This paper aims to provide an overview on the possibilities in the numerical prediction of weld residual stresses and weld‐induced deformations for these sections. The obtained values can be used in a subsequent numerical analysis to understand the structural behavior and optimize the design. A representative example on a section used in a steel compression ring is described and analyzed using the numerical welding simulation. A simplification of the originally transient weld procedure is used in order to reduce computation times to a practically reasonable level. In this context, the Abaqus Welding Interface (AWI) helps to automate working steps in conjunction with the definition of weld passes and their sequencing, which shall be shown in here. The applicability of this method is discussed showing also a need of further investigations in this field. This is especially with regard to result quality, which requires some experimental back‐up. Nonetheless, this method could already help to show up tendencies or to identify potential critical spots in the design.
21.05: Strength evaluation of steel beams prestressed with CFRP plates
Authors: Siwowska Paulina , Siwowski Tomasz
Published: September 2017

The use of CFRP (carbon fibre reinforced polymer) material for repair and strengthening of steel members has numerous benefits over the traditional methods of bolting or welding of steel plates. However, research on the application of CFRP composites to steel structures has still been limited. The RUT's research work was conducted to evaluate the strength of steel I‐beams prestressed with CFRP plates and to study the effect of strengthening. The evaluation of flexural behaviour of passively and actively CFRP strengthened beams was the main goal of this research. The strengthening material included CFRP plates with high strength and intermediate modulus of elasticity. The active plates were prestressed with three different levels including 40%, 50% and 60% of the ultimate tensile strength of the CFRP. An innovative anchorage system was applied to posttension CFRP plates against the beam itself. Flexural tests were carried out under 4‐point bending on several medium scale steel beams. The beams were loaded in a force‐control mode to track their full load response and to reach the ultimate load carrying capacity. A set of performance indicators was evaluated to analyse the behaviour and verify the strength of the tested beams. The performance indicators that have been established are all related to the response of the beams in terms of displacement and these are: ultimate‐to‐yield load ratio, displacement ductility ratio, effective elastic stiffness, strengthening effect on moment at yield as well as strengthening effect on ultimate moment. On the basis of the test results, the following conclusions are drawn: CFRP prestressed system was effective enough, strengthening steel beam with CFRP plates does not increase the stiffness while enhance the ductility of beam in the plastic range, level of prestressing has no considerable influence on beam performance and failure of prestressed beam is sudden attributable to either anchorage slippage or CFRP rapture. Finally, the effectiveness of strengthening and the influence of various parameters on this effectiveness was established.
21.07: Refurbishment of the historical Eiffel‐hall in Budapest
Authors: Pap Zsuzsa B. , Horváth László. , Kövesdi Balázs
Published: September 2017

The 130 years old Eiffel‐hall in Budapest is a single‐story historical steel building which function was a workshop for locomotives till 2009. The hall with a 95×235 m floor area is built up from 20 truss frames having 5 modules for each. In 2016 the change of the function of the hall was requested, and the workshop and rehearsal centrum of the Hungarian State Opera will be placed in the building. Therefore, the hall had to be checked if it satisfies the requirements of the present design codes containing fire and earthquake engineering and the requested safety level had to be proved. The structural system of the historical steel load‐bearing structure is very interesting and showed complex behaviour. Thus, the static and stability check and also the check against fire are made with the help of a finite element model developed in Ansys. To understand the behaviour of the structure GMNI analysis is performed on a more complex shell model. The current paper introduces the static check and reinforcement procedure of this historical building and points out some differences in the safety level and the design strategies nowadays and 130 years ago.
21.09: A study on repair method using TRS for fatigue cracks in orthotropic steel deck
Authors: Mizokami Yoshiaki , Kamata Masafumi , Kishi Yuki , Sakano Masahiro
Published: September 2017

For the purpose of reducing dead load, an orthotropic steel deck is used in many long span bridges. The Honshu‐Shikoku Bridges use orthotropic steel decks stiffened by closed section ribs (trough rib) as well. With the increase of the service years, fatigue cracks resulting from large vehicles have been observed. For the bead‐penetrating cracks that initiate at weld root and grow toward bead surface in trough‐deck weld, several repair methods have been studied. However, effective methods that are applicable from the underside of the deck are still under development. In this paper, development of plate‐splicing methods that are applicable from the underside of the deck using Thread Rolling Screw and other fasteners and results of the fatigue tests to confirm their performances are described
01.08: Bolted bearing connection with high strength steel and grade 12.9 bolt
Authors: Wang Yan‐Bo , Lyu Yi‐Fan , Li Guo‐Qiang
Published: September 2017

This paper presents an experimental program investigating the behavior of high strength steel connections consisting of one bolt in double shear. A total of 15 bolted connections fabricated from three grades of high strength steel with the nominal yield strengths of 550 MPa, 690 MPa and 890 MPa were tested. The effects of end distance and steel grade on the bolt bearing behavior were evaluated. The bearing resistances of the bolt on various high strength plates were determined and compared with respect to the tensile strength of the plates. The bolt hole elongation due to bolt bearing on high strength steel plate was measured and its implication on the plate bearing resistance was discussed. The test results were compared with Eurocode 3 and AISC 360‐10 predictions and it was found that Eurocode 3 could be used conservatively to predict the bolt bearing resistance on high strength steel with nominal yield strength up to 890 MPa whereas AISC 360‐10 method tends to overestimate the bearing resistance of the bolted connection. A regression analysis was performed based on the test data and those from the literature so that a more general method was proposed to predict the bolt bearing resistance on normal strength and high strength steel plate.
P11.01: A multi‐mode pushover analysis procedure to estimate seismic demands for steel moment‐resisting frames
Authors: Ferraioli Massimiliano , Lavino Angelo , Mandara Alberto
Published: September 2017

The main objective of the paper is the development and evaluation of a multi‐mode pushover procedure for the approximate analysis of the seismic response of steel moment‐resisting frames. A generalized force vector derived from modal combination simulates the instantaneous force distribution acting on the structure when the interstorey drift reaches its maximum value during the dynamic response to a seismic excitation. A set of generalized force vectors (each associated to maximum drift at one story) is applied separately to the structure until the corresponding target interstorey drift is attained. The envelope of results gives the maximum value of each response parameter. The proposed pushover procedure allows a simple implementation, reducing the computational effort compared with adaptive nonlinear static procedures and nonlinear response history analysis. Moreover, it does not suffer from the statistical combination of inelastic modal responses calculated separately. Its effectiveness and accuracy are verified through a comparative study involving regular steel moment resisting frames subjected to acceleration records.
01.10: Different approaches towards numerical modelling of bolt bearing
Authors: Jakše Bojan , Može Primož
Published: September 2017

Bolt bearing is characterized by large plastic deformations that occur mainly near the contact between bolts and plates and may possibly lead to fracture. Numerical modelling of such behaviour is not trivial. The paper focuses on the procedures for numerical analysis that allow numerical modelling of bolt bearing up to fracture. The commercially available software Abaqus software was used for this purpose, taking the advantages of built‐in material models and numerical procedures without introducing the user subroutines. The problem of bolt bearing is assessed using static stress analysis, explicit analysis and coupled Eulerian‐Lagrange analysis. The fracture model considered is based on stress modified fracture model and relies on the accumulating damage and on the reducing stiffness of finite elements to the point, where they offer no resistance and can be either removed from the model or are left with negligible stiffness. The required parameters (stress triaxiality, equivalent plastic strain to failure and displacement to failure) were determined from the experimental data.

A few different bolted connections with different types of failure are analysed with full failure model and the results are compared with experiments. The advantage of Eulerian meshing is considered, where excessive plastic deformations lead to contact problems. Coupled Eulerian‐Lagrange analysis with model parts expected to have large deformations were modelled with Eulerian approach and the rest with more conventional Lagrange approach. Diverse material models, element options, time step and their impact on numerical simulation were compared and optimized for speed and accuracy.
01.19: Cyclic behaviour of friction materials for FREEDAM connections
Authors: Cavallaro Giovanni Ferrante , Francavilla Antonella Bianca , Latour Massimo , Piluso Vincenzo , Rizzano Gianvittorio
Published: September 2017

A FREE from DAMage friction connection is a connection where at the level of the lower beam flange is realized a friction damper by means of angles and plates pre‐stressed with high strength bolts. In these connections, the bending moment transferred to the column through the connection can be easily calibrated controlling the friction coefficient of the material employed to realize the friction damper and the value of the preload applied by means of high strength bolts. Therefore, in order to guarantee a correct behaviour of the friction connection both under Serviceability and Ultimate limit states (SLS, ULS), it is necessary to know with a sufficient level of accuracy the value of the static and dynamic friction coefficients and the value of the bolts' preloading.

The aim of this paper is to provide a characterization of the friction coefficient of some materials appropriate for the application in the FREEDAM connections. To this scope, the results of an experimental programme consisting of 51 specimens, developed following the guidelines provided by EN 1090‐2 and EN 15129 (anti‐seismic devices), are presented. The experimental work is mainly devoted to the evaluation of the response of three different materials, applied as a coating on steel plates by means of thermal spray, investigating the influence of the bolt preloading level and of the washer's typology on their response. In particular, the possible influence of the pressure applied to the analysed interfaces is considered carrying out tests at variable values of the pre‐loading (between 40% and 100% of the standard pre‐loading value), and the influence of the washers' configuration is evaluated performing tests with flat washers and different configurations of series and parallel of Belleville disc springs. The influence of the washer's typology is considered in order to assess the effectiveness of the Belleville disc springs in the reduction of the bolts' loosening during a cyclic test.

The main results of the experimental activity are represented in terms of static and kinetic friction coefficients evaluating also the bolt's force degradation, the development of heat during the test and the degradation of the effective damping. Some of the tests are realized with the aim to determine the random variability of the friction coefficient of the analysed interfaces and to provide values of the friction coefficient to be used in design for ULS and SLS.
01.20: Preloading of stainless steel bolting assemblies
Authors: Stranghöner Natalie , Jungbluth Dominik , Afzali Nariman
Published: September 2017

In modern steel constructions, the use of stainless steel becomes more important, especially in corrosive environments. But: the use of stainless steel bolting assemblies is restricted to non preloaded assemblies by EN 1090‐2 due to several reasons. Stainless steel tends to creep and relaxation which might result in severe preload losses in bolting assemblies. In addition, the susceptibility of stainless steel to galling respectively cold welding causes problems in bolting assemblies because of undefined coefficients of friction. Herewith, qualification procedures are necessary for every possible application scenario. Within the European RFCS‐research project “Execution and reliability of slip resistant connections for steel structures using CS and SS” (SIROCO), stainless steel components and stainless steel bolting assemblies made of austenitic, super duplex, duplex and lean duplex materials have been investigated in tightening tests according to EN ISO 16047 and EN 14399‐2. Furthermore, relaxations tests of bolted connections with bolts according to EN ISO 4014 and EN ISO 4017 have been carried out. The presented paper intends to provide an initial insight into the behaviour of stainless steel bolts based on first results achieved from SIROCO. Regarding the tightening tests, in a first step the evaluation was chosen similar to EN 14399‐2 which specifies essential properties and characteristics of carbon steel bolting assemblies for preloading which should be fulfilled for tightening. The objective of the investigations will be to define a secure preload level and a corresponding tightening procedure for preloaded stainless steel bolting assemblies. The tightening tests are compared with results of the well‐known carbon steel preloading systems HR according to EN 14399‐3 and HV according to EN 14399‐4. Within this contribution, the so far achieved results of the tightening and relaxation tests will be summarized and discussed. For now, the susceptibility to galling and the tendency to creep and relaxation can be confirmed even though galling can be significantly reduced by the use of suitable lubricants which could be determined by experimental testing. Furthermore, secure preload levels could be defined depending on the stainless steel grade and strength class.
00.01: Future challenges and developments in the design of steel structures – an Australian perspective
Authors: Rasmussen Kim J.R. , Zhang Hao
Published: September 2017

The paper provides an overview of recent advances towards developing the Direct Design Method (DDM) and its implementation in design standards. The DDM allows design by advanced structural analysis (GMNIA) requiring no recourse to a design standard for checking member or cross‐sectional strength. As the capability of structural analysis programs increasingly incorporate both geometric and material nonlinear effects, and as standard desktop computers have become sufficiently powerful to run GMNIA analysis, the DDM is poised to become the future method of design. The paper outlines the system reliability framework that underpins the DDM and the calibration of the Method for 2D and 3D hot‐rolled structural frames as well cold‐formed structural frames featuring cross‐sectional instability. The system reliability implications of the DDM and load and resistance factor design (LRFD) are discussed. The paper also discusses the philosophy of teaching steel structural design and argues this is most rationally and efficiently undertaken using the DDM. Lastly, the paper comments on ongoing and future developments on the DDM including the implementation of the method in design practice.
02.07: A numerical approach to the rotational stiffness of stake welds
Authors: Nilsson Peter , Al‐Emrani Mohammad , Atashipour Seyed Rasoul
Published: September 2017

Stake welds of two parallel plates enable the production of several different types of all‐steel sandwich panels. One example is laser‐welded corrugated core all‐steel sandwich panels. The normal stresses close to the welds and in the welds of corrugated core steel sandwich panels with dual weld lines through subjected to shear has been shown to be affected by the rotational stiffness of the weld region. This paper presents an approximate closed‐form solution for the weld region rotational stiffness as a function of the geometric properties. The solution is based on linear and non‐linear regression analysis using the results of 4000 finite element analyses (FEA). All FEA are executed with linear constitutive relations. The presented solution is shown to have a high accuracy within the investigated range. The study ranges over plate thicknesses between 4 and 16mm, gap between the plates between 0.1 and 1.0mm and weld widths from 1 to 4mm. It was shown that the maximum possible error of 7% between the closed‐form solution and FEA within the investigated range has a negligible effect on the transverse shear stiffness of corrugated core steel sandwich panels.
03.01: Bonded steel joints under cyclic loading: Study on structural behaviour und fatigue
Authors: Ciupack Yvonne , Ledecký Lukáš , Pasternak Hartmut , Fischer Vitali , Stammen Elisabeth , Dilger Klaus
Published: September 2017

Bonding technology can be seen as an alternative to classical bonding methods in steel construction, because fundamental problems such as residual stresses can be prevented. Yet, doubts remain concerning this innovative bonding technology, due to a lack of knowledge regarding the durability. This is the focus of an ongoing experimental study, which addresses the prediction of the service life of adhesive bonded façade connections, concentrating on the connection of a trapezoidal façade profile. This innovative connection provides mechanical and aesthetic benefits. But in comparison to classical steel bonding, the performance of adhesive bonds must be regarded as time and environment dependent. Because the studied façade connection is mainly stressed by temperature and wind loads, the first aim is to derive a representative experimental process based on actual measured environmental data. Cyclic small sized and model component experiments allow a comprehensive consideration of the effects mentioned. Three different adhesive systems are examined, which are well suited for cyclic loading. The results of the experiments form the foundation for developing design rules for adhesive steel bonds in façade construction. Particular focus lies on the low cycle fatigue domain, which has not been examined for adhesive bonds before. By means of the described method, the aim is to enhance the integration of adhesive bonding in steel construction, strengthen the confidence of engineers regarding the novel adhesive technology and further increase the innovation ability of construction engineering.
03.02: Structural assessment of a column splice with opened slotted holes: Finger Connection
Authors: Andrade Pedro , Lagerqvist Ove , Simões Rui , Veljkovic Milan
Published: September 2017

This paper introduces a novel joint based on a friction connection designed for column‐splices. The joint was developed within the scope of modular construction to improve the fast assembly of prefabricated frames and to accommodate eventual misalignments. Gaps at the connection are considered on the joint horizontal and vertical axis to accommodate misalignments whether they are rotations and/or displacements and so to allow for the easy fit of the columns. The efficiency of the joint resistance based on different connection gaps subjected to uniform compression is assessed.
03.13: Experimental study on cyclic plastic behaviour of steel joint components
Authors: Budaházy Viktor , Dunai László
Published: September 2017

Civil engineering structures are subjected to enormous cyclic forces during a seismic event. Designing structures with dissipative zones provides an efficient solution to withstand these seismic forces. The zones, which dissipate energy through plastification, can be designated parts of the structural skeleton, or special, sacrificable elements that built into the structure. An economical way to increase the dissipative capacity of a structure is to utilize the cyclic plasticity of the connections. The local ductility of these structural connections is sensitive to their arrangement and requires a careful design.

The large number of available connection types prohibits any comprehensive treatment of dissipate zones on the connection level; however, it is feasible to make generalizable observations on the component level, which can support engineers to design connections with sufficient plastic capacity.

As part of an ongoing research program, an extended cyclic experimental campaign is completed on 51 specimens, related to three important joint components: (i) T‐butt weld and T‐fillet weld; (ii) single and double‐sided lap joints; (iii) bolted T‐stub. These components are subjected to monotonic and cyclic loading by increasing and constant load amplitudes. In the T‐butt weld and T‐fillet weld tests the effect of the load direction and throat thickness are analysed. The lap joint and bolted T‐stub experiments are focused on the effect of cyclic plasticity and cyclic degradation types of failure modes. The low‐cyclic fatigue response of the investigated components are evaluated, and the critical mechanisms, which influence the energy dissipation, are identified. Based on the experimental study design recommendations can be developed which can be used to increase the local ductility of the investigated joints.
Direct numerical simulation of turbulent flow over wide‐rib rectangular grooves
Authors: Huang Chonghai , Wang Qinghui , Wei Jinjia , Yu Bo
Published: September 2017

The turbulent flow over the wide‐rib rectangular grooves, the motions and variations of near‐wall streamwise vortices with time, and the interaction between microgroove and near‐wall streamwise vortices were investigated by direct numerical simulation method (DNS). The distributions of radius, density, and swirling strength of streamwise vortex were also studied quantitatively by using swirling‐strength criterion. It was found that the distribution of vortex radius in smooth channels can approximately be divided into three parts. The vortex radii are smaller in grooved channels than in smooth channels and almost the same when y+ > 40 for all grooved cases. Moreover, a simple prediction method was proposed to estimate the optimal height and spacing of drag‐reducing microgrooves for different fluids, and they were about 10 and 17 wall units for water, respectively. Furthermore, using the same frictional velocity uτ to normalize the shear stress is more suitable for the quantitative comparison and analysis of different longitudinal microgrooves. The drag‐reducing mechanism of longitudinal microgrooves could be considered as the competition results between the “restriction or blockage effect” of microgroove on the near‐wall vortices (causing a drag‐reducing effect) and the “tip effect” of microgrooves caused by the scouring of higher speed fluid near the groove tip (causing a drag‐increasing effect). A large number of small streamwise secondary vortices with small swirling strength within the groove valley, which are induced by microgrooves, may be the essential reason of drag reduction by microgrooves.
Calcium Coordination Solids for pH‐Triggered Release of Olsalazine
Authors: Levine Dana J. , Gonzalez Miguel I. , Legendre Christina M. , Runčevski Tomče , Oktawiec Julia , Colwell Kristen A. , Long Jeffrey R.
Published: September 2017

Calcium coordination solids were synthesized and evaluated for delivery of olsalazine (H4olz), an anti‐inflammatory compound used for treatment of ulcerative colitis. The materials include one‐dimensional Ca(H2olz)⋅4 H2O chains, two‐dimensional Ca(H2olz)⋅2 H2O sheets, and a three‐dimensional metal‐organic framework Ca(H2olz)⋅2DMF (DMF=N,N‐dimethylformamide). The framework undergoes structural changes in response to solvent, forming a dense Ca(H2olz) phase when exposed to aqueous HCl. The compounds Ca(H2olz)⋅x H2O (x=0, 2, 4) were each pressed into pellets and exposed to simulated gastrointestinal fluids to mimic the passage of a pill from the acidic stomach to the pH‐neutral intestines. All three calcium materials exhibited a delayed release of olsalazine relative to Na2(H2olz), the commercial formulation, illustrating how formulation of a drug within an extended coordination solid can serve to tune its solubility and performance.
Outcomes in adolescents and young adults with Hodgkin lymphoma treated on US cooperative group protocols: An adult intergroup (E2496) and Children's Oncology Group (COG AHOD0031) comparative analysis
Authors: Henderson Tara O. , Parsons Susan K. , Wroblewski Kristen E. , Chen Lu , Hong Fangxin , Smith Sonali M. , McNeer Jennifer L. , Advani Ranjana H. , Gascoyne Randy D. , Constine Louis S. , Horning Sandra , Bartlett Nancy L. , Shah Bijal , Connors Joseph M. , Leonard John I. , Kahl Brad S. , Kelly Kara M. , Schwartz Cindy L. , Li Hongli , Friedberg Jonathan W. , Friedman Debra L. , Gordon Leo I. , Evens Andrew M.
Published: September 2017

BACKGROUND

There is no clear consensus between pediatric and adult providers about the treatment of adolescents and young adults (AYAs) with Hodgkin lymphoma (HL).

METHODS

Failure‐free survival (FFS) and overall survival (OS) were compared between 114 patients ages 17 to 21 years with HL who were treated on the Eastern Cooperative Oncology Group‐American College of Radiology Imaging Network Intergroup adult E2496 study and 391 similarly patients ages 17 to 21 years with HL who were treated on the pediatric Children's Oncology Group (COG) AHOD0031 study.

RESULTS

Comparing AYAs from the COG and E2496 studies, there were no significant differences in extralymphatic disease, anemia, or hypoalbuminemia. More AYAs in the E2496 trial had stage III and IV disease (63% vs 29%; P < .001) and B symptoms (63% vs 27%; P < .001), and fewer had bulk disease (33% vs 77%; P < .001). More AYAs on the COG trial received radiotherapy (76% vs 66%; P = .03), although in smaller doses. E2496 AYA The 5‐year FFS and OS rates were 68% and 89%, respectively in the E2496 AYAs and 81% and 97%, respectively, in the COG AYAs, indicating a statistically superior compared in the COG AYAs (P = .001). In stratified multivariable analyses, E2496 AYAs had worse FFS than COG AYAs in all strata except patients who had stage I and II HL without anemia. Propensity score analysis (based on stage, anemia, and bulk disease) confirmed inferior FFS for E2496 AYAs compared with COG AYAs (P = .004). On the E2496 study, FFS was significantly divergent across age groups (P = .005), with inferior outcomes for those ages 17 to 21 years versus 22‐44 years. There was no difference across age on the COG study.

CONCLUSIONS

Younger AYA patients with HL appear to have better outcomes when treated on a pediatric trial than patients of similar age on an adult trial. Prospective studies examining these differences are warranted. Cancer 2018;124:136‐44. © 2017 American Cancer Society.
Finding Homologs in Amino Acid Sequences Using Network BLAST Searches
Authors: Ladunga Istvan
Published: September 2017

BLAST, the Basic Local Alignment Search Tool, is used more frequently than any other biosequence database search program. We show how to run searches on the Web, and demonstrate how to increase performance by fine‐tuning arguments for a specific research project. We offer guidance for interpreting results, statistical significance and biological relevance issues, and suggest complementary analyses. This unit covers both protein‐to‐protein (blastp) searches and translated searches (blastx, tblastn, tfastx). blastx conceptually translates the query sequence and tblastn translates all nucleotide sequences in a database, while tblastx translates both the query and the database sequences into amino acid sequences. © 2017 by John Wiley & Sons, Inc.
Effect of Silyl Ether‐functinoalized Dimethoxydimethylsilane on Electrochemical Performance of a Ni‐rich NCM Cathode
Authors: Jang Seol Heui , Yim Taeeun
Published: September 2017

Dimethoxydimethylsilane (DODSi) is used as an interface stabilizing additive through a selective HF scavenging reaction for layered Ni‐rich oxide cathodes. Ex situ NMR analyses demonstrated that DODSi effectively removes HF from the electrolyte based on the matched chemical reactivity of Si with F− and O with H+. The cells employing DODSi exhibit higher specific capacity with retention than those cycled with a DODSi‐free electrolyte even under in situ HF generating conditions. Scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and inductively coupled plasma‐mass spectroscopy (ICP‐MS) analyses indicate that DODSi effectively protects the Ni‐rich oxide cathodes against HF corrosion, resulting in improved surface stability of Ni‐rich cathodes.
Fluid model of H‐form of the positive column in DC oxygen glow discharge
Authors: Laca Marek , Morávek Matěj Jan , Schmiedt Lukáš , Hrachová Věra , Kaňka Adolf
Published: September 2017

In our contribution, the positive column of oxygen DC glow discharge is investigated using methods of computational physics at medium pressures (200–687 Pa) and discharge currents from 20 to 40 mA. Under mentioned conditions, the attributes of the DC oxygen discharge are particular, what is based on the existence of two forms: H‐form and T‐form. One‐dimensional fluid model of the stable H‐form has been developed. Not only radial profiles of various species in cylindrical tube but also the reaction among them and their interaction with the walls are taken into account. The model is built on the continuous description of concentration of species and drift‐diffusion approximation of the particle flux. The results of the simulation are in good agreement with experimental ones.
Ants as ecological indicators of rainforest restoration: Community convergence and the development of an Ant Forest Indicator Index in the Australian wet tropics
Authors: Lawes Michael J. , Moore Anthony M. , Andersen Alan N. , Preece Noel D. , Franklin Donald C.
Published: September 2017

Ecosystem restoration can help reverse biodiversity loss, but whether faunal communities of forests undergoing restoration converge with those of primary forest over time remains contentious. There is a need to develop faunal indicators of restoration success that more comprehensively reflect changes in biodiversity and ecosystem function. Ants are an ecologically dominant faunal group and are widely advocated as ecological indicators. We examine ant species and functional group responses on a chronosequence of rainforest restoration in northern Australia, and develop a novel method for selecting and using indicator species. Four sampling techniques were used to survey ants at 48 sites, from grassland, through various ages (1–24 years) of restoration plantings, to mature forest. From principal components analysis of seven vegetation metrics, we derived a Forest Development Index (FDI) of vegetation change along the chronosequence. A novel Ant Forest Indicator Index (AFII), based on the occurrences of ten key indicator species associated with either grassland or mature forest, was used to assess ant community change with forest restoration. Grasslands and mature forests supported compositionally distinct ant communities at both species and functional levels. The AFII was strongly correlated with forest development (FDI). At forest restoration sites older than 5–10 years that had a relatively closed canopy, ant communities converged on those of mature rainforest, indicating a promising restoration trajectory for fauna as well as plants. Our findings reinforce the utility of ants as ecological indicators and emphasize the importance of restoration methods that achieve rapid closed‐canopy conditions. The novel AFII assessed restoration status from diverse and patchily distributed species, closely tracking ant community succession using comprehensive species‐level data. It has wide applicability for assessing forest restoration in a way that is relatively independent of sampling methodology and intensity, and without a need for new comparative data from reference sites.
Multiscale variation in drought controlled historical forest fire activity in the boreal forests of eastern Fennoscandia
Authors: Aakala Tuomas , Pasanen Leena , Helama Samuli , Vakkari Ville , Drobyshev Igor , Seppä Heikki , Kuuluvainen Timo , Stivrins Normunds , Wallenius Tuomo , Vasander Harri , Holmström Lasse
Published: September 2017

Forest fires are a key disturbance in boreal forests, and characteristics of fire regimes are among the most important factors explaining the variation in forest structure and species composition. The occurrence of fire is connected with climate, but earlier, mostly local‐scale studies in the northern European boreal forests have provided little insight into fire–climate relationship before the modern fire suppression period. Here, we compiled annually resolved fire history, temperature, and precipitation reconstructions from eastern Fennoscandia from the mid‐16th century to the end of the 19th century, a period of strong human influence on fires. We used synchrony of fires over the network of 25 fire history reconstructions as a measure of climatic forcing on fires. We examined the relationship between fire occurrence and climate (summer temperature, precipitation, and a drought index summarizing the influence of variability in temperature and precipitation) across temporal scales, using a scale space multiresolution correlation approach and Bayesian inference that accounts for the annually varying uncertainties in climate reconstructions. At the annual scale, fires were synchronized during summers with low precipitation, and most clearly during drought summers. A scale‐derivative analysis revealed that fire synchrony and climate varied at similar, roughly decadal scales. Climatic variables and fire synchrony showed varying correlation strength and credibility, depending on the climate variable and the time period. In particular, precipitation emerged as a credible determinant of fire synchrony also at these time scales, despite the large uncertainties in precipitation reconstruction. The findings explain why fire occurrence can be high during cold periods (such as from the mid‐17th to early‐18th century), and stresses the notion that future fire frequency will likely depend to a greater extent on changes in precipitation than temperature alone. We showed, for the first time, the importance of climate as a decadal‐scale driver of forest fires in the European boreal forests, discernible even during a period of strong human influence on fire occurrence. The fire regime responded both to anomalously dry summers, but also to decadal‐scale climate changes, demonstrating how climatic variability has shaped the disturbance regimes in the northern European boreal forests over various time scales.
NLRP3 inflammasome driven liver injury and fibrosis: Roles of IL‐17 and TNF in mice
Authors: Wree Alexander , McGeough Matthew D. , Inzaugarat Maria Eugenia , Eguchi Akiko , Schuster Susanne , Johnson Casey D. , Peña Carla A. , Geisler Lukas J. , Papouchado Bettina G. , Hoffman Hal M. , Feldstein Ariel E.
Published: September 2017

The NLRP3 inflammasome, a caspase‐1 activation platform, plays a key role in the modulation of liver inflammation and fibrosis. Here, we tested the hypothesis that interleukin 17 (IL‐17) and tumor necrosis factor (TNF) are key cytokines involved in amplifying and perpetuating the liver damage and fibrosis resulting from NLRP3 activation. To address this hypothesis, gain‐of‐function Nlrp3

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knock‐in mice were bred onto il17a and Tnf knockout backgrounds allowing for constitutive Nlrp3 activation in myeloid derived cells in mice deficient in IL‐17 or TNF. Livers of Nlrp3

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knock‐in mice exhibited severe liver inflammatory changes characterized by infiltration with neutrophils, increased expression of chemokine (C‐X‐C motif) ligand (CXCL) 1 and CXCL2 chemokines, activated inflammatory macrophages, and elevated levels of IL‐17 and TNF. Mutants with ablation of il17a signal showed fewer neutrophils when compared to intact Nlrp3

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mutants, but still significant inflammatory changes when compared to the nonmutant il17a knockout littermates. The severe inflammatory changes associated with mutant Nlrp3 were almost completely rescued by Tnf knockout in association with a marked decrease in circulating IL‐1β levels. Intact Nlrp3

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mutants showed changes in liver fibrosis, as evidenced by morphometric quantitation of Sirius Red staining and increased mRNA levels of profibrotic genes, including connective tissue growth factor and tissue inhibitor of matrix metalloproteinase 1. Il17a lacking mutants exhibited amelioration of the aforementioned fibrosis, whereas Tnf‐deficient mutants showed no signs of fibrosis when compared to littermate controls. Conclusion: Our study uncovers key roles for TNF and, to a lesser extent, IL‐17 as mediators of liver inflammation and fibrosis induced by constitutive NLRP3 inflammasome activation in myeloid‐derived cells. These findings may lead to therapeutic strategies aimed at halting the progression of liver injury and fibrogenesis in various liver pathogeneses driven by NLRP3 activation. (Hepatology 2018;67:736‐749).
Hydrologic processes that govern stormwater infrastructure behaviour
Authors: Eger Caitlin G. , Chandler David G. , Driscoll Charles T.
Published: September 2017

Using water budget data from published literature, we demonstrate how hydrologic processes govern the function of various stormwater infrastructure technologies. Hydrologic observations are displayed on a Water Budget Triangle, a ternary plot tool developed to visualize simplified water budgets, enabling side‐by‐side comparison of green and grey approaches to stormwater management. The tool indicates ranges of hydrologic function for green roofs, constructed wetlands, cisterns, bioretention, and other stormwater control management structures. Water budgets are plotted for several example systems to provide insight on structural and environmental design factors, and seasonal variation in hydrologic processes of stormwater management systems. Previously published water budgets and models are used to suggest appropriate operational standards for several green and grey stormwater control structures and compare between conventional and low‐impact development approaches. We compare models, characterize and quantify water budgets and expected ranges for green and grey infrastructure systems, and demonstrate how the Water Budget Triangle tool may help users to develop a data‐driven approach for understanding design and retrofit of green stormwater infrastructure.