bluuebunny/crossref_metadata_2025 huggingface dataset:
Zur Kenntnis der Sulfen‐ und Selenensäuren und ihrer Derivate. 9. Mitteilung Additions‐ und Substitutionsreaktionen organischer Selenverbindungen mit unpolaren und polaren Äthylenen
Authors: Hölzle G. , Jenny W.
Published: December 2010

Es werden weitere Beispiele für die Addition von Selenenylacetaten an Äthylene beschrieben. Polare Äthylene, welche einseitig mit Elektronendonatoren substituiert sind, reagieren mit Selenenylacetaten unter Bildung von Substitutionsprodukten. Bei Gegenwart von Pyridin gehen auch Selenensäureester, Selenenylhalogenide und Selencyanide mit polaren Äthylenen Substitutionsreaktionen ein. Der Mechanismus der Additions‐ und Substitutions‐ reaktion wird diskutiert.
Über synthetisches d,l‐Muscarin und seine drei Stereoisomeren. Synthese des d,l‐epiallo‐Muscarins. 9. Mitteilung über Muscarin
Authors: Eugster C. H. , Häfliger F. , Denss R. , Girod E.
Published: December 2010

The synthesis and isolation of d,l‐epiallo‐Muscarine are described. The syntheses of d,l‐Muscarine and its three stereoisomers from 2‐Methyl‐5‐dimethylaminomethyl‐2,3‐dihydro‐furan‐3‐one and the properties of their salts are reviewed. The proof for the configurations of d,l‐Muscarine and its three stereoisomers is given.
Zum Problem der Struktur des Lycomarasmins
Authors: Brenner M. , Tamm R. , Quitt P.
Published: December 2010

Im Zusammenhang mit Erwägungen über den Mechanismus der Aminoacyl‐Einlagerungsreaktion ist für das Lycomarasmin eine zum (α‐Hydroxy‐β‐glycyloxy‐propionyl)‐asparagin tautomere bizyklische Struktur in Betracht gezogen worden. Entsprechende synthetische Versuche haben ergeben, dass die postulierte bizyklische Struktur instabil ist und dass das Lycomarasmin deshalb einen anderen Bau muss.
14C‐Umlagerung, Salzeffekte und Ionenpaar‐Rückkehr in der Solvolyse von [2‐(p‐Anisyl)‐äthyl]‐p‐toluolsulfonat
Authors: Jenny E. F. , Winstein S.
Published: December 2010

The solvolysis of 14C‐labelled 2‐p‐anisyl‐1‐ethyl p‐toluenesulfonate p‐CH3O–C6H4–CβH2–*CαH2–OTs (IA) leads to product in which 14C‐scrambling between Cα and Cβ is complete when the solvent is formic acid or acetic acid, but only partial when the solvent is ethanol. These results confirm previous conclusions, based on kinetic evidence, that solvolysis of 2‐p‐anisyl‐1‐ethyl toluenesulfonate is almost exclusively anchimerically assisted in formic and acetic acid solvents, but not in the more nucleophilic solvent, ethanol.
Über fokussierenden Ionenaustausch V. Trennung von Metallionen, insbesondere von radioaktiven Indikatoren durch Austausch mit Protonen
Authors: Schumacher E. , Streiff H. J.
Published: December 2010

Focusing ion exchange (FI) has extensively been studied using a pH‐gradient for producing a gradient in chelating tendency. NTA, EDTA, Chel CD, Chel ME and Chel DE are complexing agents, HCl or HClO4 in suitable concentrations are complex‐destroying agents.
Überführung des (−)‐Sclareols in (+)‐Manool
Authors: Ohloff G.
Published: December 2010

Es wird eine ergiebige Überführung des (−)‐Sclareols in (+)‐Manool beschrieben, die auf der selektiven Esterpyrolyse des Di‐O‐acetyl‐(−)‐sclareols beruht.
Weitere Versuche zur Fettsäurebildung bei Mikroorganismen
Authors: Bernhard Karl , Abisch Leo , Wagner Heribert
Published: December 2010

14C‐acetate was added to the culture medium of Phycomyces Blakesleeanus when the fungus was inoculated. Growth was interrupted on the 4th to 14th day and the fatty acids isolated from the mycelium. As in previous studies, linolenic acid exerted the highest degree of specific activity. The percentage of activity exhibited by each of the fatty acids studied remained constant during the various periods of growth. Hydrogenation of linolic acid and linolenic acid, i.e. conversion of unsaturated acids to saturated acids, did therefore not occur. During the phase of reproduction the fungus converted some active substances originally developed, perhaps reserve materials, into fatty acids.
Segmentation by genres: the case of the Aardklop national arts festival
Authors: Kruger Martinette , Saayman Melville , Ellis Suria
Published: December 2010

The purpose of this study was to distinguish between genre supporters and non‐genre supporters at the Aardklop National Arts Festival. This was done to determine genre supporters' individual needs and wants so that effective marketing strategies can be developed and the festival programme can be designed to attract more genre supporters. Previous research indicated that the future of festivals is dependent on the number of show tickets sold and festivals therefore need to attract more genre supporters. To achieve this goal, a questionnaire survey (N = 495) was conducted, where afterwards independent t‐tests were used to determine the differences between visitors who attend the different ticketed shows/productions and those who do not. Results showed that genre attendees and non‐attendees differ significantly based on socio‐demographic and behaviour characteristics, which gave a comprehensive profile of the two types of visitors at the festival. This method proved to be successful especially in increasing ticket sales. Marketing and management implications for effectively targeting genre supporters were also indicated. Copyright © 2010 John Wiley & Sons, Ltd.
Robotic thyroid surgery: An initial experience with North American patients
Authors: Kuppersmith Ronald B. , Holsinger F. Christopher
Published: December 2010

Objective:

To review the initial experience of gasless transaxillary robot‐assisted endoscopic thyroid surgery in a series of patients and describe modifications of the technique for the North American patients, selection criteria, and other issues related to this technology.

Methods:

Retrospective review of the first 31 consecutive cases at a single institution.

Results:

Thirty‐one patients underwent robotic thyroid surgery. Twenty thyroid lobectomies and 11 total thyroidectomies were performed. Improvements in the length of time to perform components of the procedure were noted from the early group of cases to later group of cases. No major or permanent complications occurred.

Conclusions:

Robotic thyroid surgery is feasible in North American patients and can be safely performed. The procedure has potential complications and a definite learning curve exists for both surgeons and operating room staff. Training methods need to be validated to ensure safe adoption. More studies need to be performed to further evaluate the relative benefits of this technique. Laryngoscope, 2011
An Iterative Method for Producing Equilibrated Symmetric Three‐Arm Star Polymer Melts in Molecular Dynamics
Authors: Subramanian Gopinath
Published: December 2010

Melts of symmetric three‐arm stars are generated using a novel iterative method. In this method, an equilibrated low molecular weight configuration is used to generate progressively higher molecular weights by affine scaling and equilibration. At each stage in the progression, the synthetically lowered entanglement density allows bypassing of the exponentially large relaxation times of branched polymers. The quality of equilibration was assessed by measuring the mean dimensions, distribution of dimensions, and internal length scales of the polymers. The total time required to generate the progression of equilibrated configurations was seen to scale as the Rouse time of the highest molecular weight.

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Molecular mechanisms for chemoprevention of colorectal cancer by natural dietary compounds
Authors: Pan Min‐Hsiung , Lai Ching‐Shu , Wu Jia‐Ching , Ho Chi‐Tang
Published: December 2010

Colorectal cancer is one of the major causes of cancer‐related mortality in both men and women worldwide. This review focuses on preventing the initiation and promotion of neoplastic growth in colorectal cancer, particularly with natural dietary compounds. Chemoprevention is defined as the use of natural dietary compounds and/or synthetic substances that can delay, prevent, or even reverse the development of adenomas, as well as the progression from adenoma to carcinoma. The molecular mechanisms of their chemopreventive action are associated with the modulation of signaling cascades, gene expressions involved in the regulation of cell proliferation, differentiation, and apoptosis and the suppression of chronic inflammation, metastasis, and angiogenesis. Here, we summarize the currently known targets and signaling pathways whereby natural dietary compounds interfere with the development of colorectal cancer, and thus providing evidence for these substances in colonic cancer chemopreventive action.
Fire protection of polypropylene and polycarbonate by intumescent coatings
Authors: Jimenez M. , Duquesne S. , Bourbigot S.
Published: December 2010

An innovative way to improve fire‐retardant properties of different polymers by applying intumescent coatings on their surface has been studied. Two polymers have been investigated: polypropylene and polycarbonate. The surfaces were first subjected to a flaming treatment in order to clean them and to increase their wettability and thus improve the adhesion of the coatings. Two different formulations were then applied: a transparent intumescent varnish, based on an acrylic resin, and an intumescent coating based on polyvinylacetate resin. Different parameters have been obtained using several fire tests. The cone calorimeter, the limiting oxygen index and UL94 tests have been carried out to evaluate the fire‐retardant properties obtained for both the intumescent coating and the intumescent varnish. Results clearly evidence an outstanding improvement of the fire‐retardant properties using intumescent coatings without any incorporation of flame retardants in the bulk. Copyright © 2010 John Wiley & Sons, Ltd.
Carbendazim‐loaded electrospun poly(vinyl alcohol) fiber mats and release characteristics of carbendazim therefrom
Authors: Thitiwongsawet Patcharaporn , Supaphol Pitt
Published: December 2010

Ultra‐fine poly(vinyl alcohol) (PVA) electrospun fiber mats containing carbendazim were successfully fabricated by electrospinning from the neat PVA solution containing carbendazim in various amounts based on the weight of PVA. The morphological appearance of both the neat and the carbendazim‐loaded electrospun PVA fibers were smooth and the incorporation of carbendazim in the neat PVA solution did not affect the morphology of the resulting fibers. The average diameters of the neat and the carbendazim‐loaded electrospun PVA fibers ranged between 155 and 160 nm. The chemical integrity of the as‐loaded carbendazim in the carbendazim‐loaded electrospun PVA fiber mats was intact as verified by the 1H‐nuclear magnetic resonance spectroscopy. Thermal properties of the carbendazim‐loaded electrospun PVA fiber mats were analyzed by differential scanning calorimetry and thermogravimetric analysis. The release characteristics of the carbendazim‐loaded electrospun PVA mats were investigated by the total immersion method in distilled water at 30°C. The carbendazim‐loaded electrospun PVA mats exhibited greater amount of carbendazim released than the carbendazim‐loaded as‐cast films. Copyright © 2010 John Wiley & Sons, Ltd.
Thermal properties and flame retardancy of novel epoxy based on phosphorus‐modified Schiff‐base
Authors: Liu Huan , Xu Kai , Cai Hualun , Su Jiangxun , Liu Xin , Fu Zien , Chen Mingcai
Published: December 2010

Through addition reaction of Schiff‐base terephthalylidene‐bis‐(p‐aminophenol) (DP‐1) and diethyl phosphite (DEP), a novel phosphorus‐modified epoxy, 4,4'‐diglycidyl‐(terephthalylidene‐bis‐(p‐aminophenol))diphosphonate ether (EP‐2), was obtained. An modification reaction between EP‐2 and DP‐1 resulted in an epoxy compound, EP‐3, possessing both phosphonate groups and CN imine groups. The structure of EP‐2 was characterized by Fourier transform infrared (FTIR), elemental analysis (EA), 1H, 13C, and 31P NMR analyses. The thermal properties of phosphorus‐modified epoxies cured with 4,4'‐diaminodiphenylmethane (MDA) and 4,4'‐diaminodiphenyl ether (DDE) were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The activation energies of dynamic thermal degradation (Ed) were calculated using Kissinger and Ozawa's methods. The thermal degradation mechanism was characterized using thermogravimetric analysis/infrared spectrometry (TG‐IR). In addition, the flame retardancy of phosphorus‐modified epoxy thermosets was evaluated using limiting oxygen index (LOI) and UL‐94 vertical test methods. Via an ingenious design, phosphonate groups were successfully introduced into the backbone of the epoxies; the flame retardancy of phosphorus‐modified epoxy thermosets was distinctly improved. Due to incorporation of CN imine group, the phosphorus‐modified epoxy thermosets exhibited high thermal stabilities; the values of glass‐transition temperatures (Tgs) were about 201–210°C, the values of Ed were about 220–490 kJ/mol and char yields at 700°C were 49–53% in nitrogen and 45–50% in air. These results showed an improvement in the thermal properties of phosphorus‐modified epoxy by the incorporation of CN imine groups. Copyright © 2010 John Wiley & Sons, Ltd.
Preparation and properties of ionic cross‐linked sulfonated copolyimide membranes containing pyrimidine groups
Authors: Jin Rizhe , Li Yuhan , Xing Wei , Qiu Xuepeng , Ji Xiangling , Gao Lianxun
Published: December 2010

A series of sulfonated copolyimides containing pyrimidine groups (SPIs) were synthesized by random copolymerization of 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTDA), 2‐(4‐aminophenyl)‐5‐aminopyrimidine (PAPRM), and 4,4′‐diaminodiphenyl ether‐2,2′‐disulfonic acid (ODADS). Proton exchange treatment in 1.0 M sulfuric acid solution resulted in ionic cross‐linking of the sulfonated copolymers due to the acid (sulfonic acid)‐base (pyrimidine group) interactions and the membrane with more basic PAPRM moiety could absorb sulfuric acid to favor the proton transfer. The effects of the structure of the diamines on the properties of SPI membranes were evaluated by studying the membrane parameters including water uptake, proton conductivity, water stability, and methanol permeability. The basic pyrimidine groups introduced in the main chains could effectively resist membrane swelling due to the strong interchain interactions through basic pyrimidine groups and sulfonic acid groups. Compared with the corresponding uncross‐linked copolyimides (NTDA/ODADS/ODA), the acid–base copolyimides displayed excellent water stability. The SPI membranes also exhibited improved mechanical properties and decreased methanol permeability. However, the cross‐linked membranes showed lowered proton conductivities than the uncross‐linked ones because a small part of the sulfonic acid groups had been consumed during the cross‐linking process. Copyright © 2010 John Wiley & Sons, Ltd.
Thermal stability and fire retardancy of PMMA (nano)composites with layered metal hydroxides containing dodecyl sulfate anions
Authors: Zhu Liying , Su Shengpei , Hossenlopp Jeanne M.
Published: December 2010

Layered double hydroxides (LDHs) with Mg/Al, Zn/Al, Ca/Al metal hydroxide layers, and a Zn/Ni hydroxy double salt (HDS) were prepared with a common anion, dodecyl sulfate [CH3(CH2)10COO−, DS]. The LDH and HDS additives were melt blended with poly(methyl methacrylate) (PMMA). The dispersion and morphology were characterized via X‐ray diffraction (XRD) and transmission electron microscopy. Mg/Al‐DS and Zn/Al‐DS LDHs were found to form nanocomposites with PMMA, exhibiting good dispersion and some degree of exfoliated morphology for the Zn/Al‐DS/PMMA combination and mixed intercalation and exfoliation behavior for Mg/Al‐DS in PMMA. The Ca/Al‐DS LDH and Zn/Ni‐DS HDS formed microcomposites with PMMA. Thermal stability was investigated via thermogravimetric analysis; each of the additives increased the thermal stability of PMMA. Cone calorimetry was used to measure the fire properties; the microcomposite of Zn/Ni‐DS HDS at 10% loading provided the best improvement in peak heat release rate, with a 40% reduction over the pure polymer. The residue composition after burning the composites was investigated. Copyright © 2010 John Wiley & Sons, Ltd.
Biocomposites based on ramie fibers and poly(L‐lactic acid) (PLLA): morphology and properties
Authors: Chen Dakai , Li Jing , Ren Jie
Published: December 2010

We herein report effects of morphology of PLLA and natural fiber on combination properties of biocomposites based on PLLA and ramie fibers. For this purpose, short ramie fiber (FIB), ramie fabric (FAB), PLLA film (FPLLA), and PLLA powder (PPLLA) were used to investigate the structure–property relationship of PLLA biocomposites with 30 wt% ramie fiber prepared by hot compression molding. It is revealed that mechanical properties of biocomposites are strongly dependent on the morphology of PLLA and FAB. DMA test shows that the improved storage modulus was due to the better dispersion of FIB. DSC and POM tests show that PLLA/FIB biocomposites have the highest spherulite growth rate. TGA test shows that char residue at high temperature is affected by the dispersion of PLLA and ramie fiber. SEM images exhibit the different interfacial adhesion character of FIB and FAB in the PLLA matrix after the ramie fiber treated with alkali and silane. PLLA/FAB biocomposites have not only better anti‐dripping properties when burning but also better aging resistance in UV‐irradiation hydrothermal aging, and which can be attributed to fiber bundle and laminated PLLA biocomposites structure. Copyright © 2010 John Wiley & Sons, Ltd.
The potentially inappropriate prescription of new drug: thiazolidinediones for patients with type II diabetes in Taiwan
Authors: Wen Yu‐Wen , Tsai Yi‐Wen , Huang Weng‐Foung , Hsiao Fei‐Yuan , Chen Pei‐Fen
Published: December 2010

Purpose

To examine the potentially inappropriate prescription of thiazolidinediones (TZD).

Methods

Data on TZD prescriptions were collected from Taiwan's National Health Insurance dataset from 2001 to 2006. TZDs were considered inappropriately prescribed when they were prescribed to patients who were (1) under 18 years old, (2) pregnant, who had (3) type 1 diabetes, (4) severe heart failure, (5) hepatic insufficiency, or (6) renal insufficiency and taking TZD + metformin in combination. We aggregated potentially inappropriate prescriptions of TZD for each health‐care institution in each month starting from March 2001, when TZD was introduced to Taiwan's market.

Results

The potentially inappropriate prescription of TZD increased from 9.41% in 2001 to 12.50% in 2006. Prior inappropriate prescription led to a 0.06% (95%CI: 0.04–0.08) further increase in its later inappropriate prescription. Accumulated months of experience prescribing TZD was found associated with higher proportion of inappropriate prescription of TZD (0.03%, 95%CI: 0.01–0.05). However, it was negatively associated with new incidence of inappropriate prescription of TZD (−0.20, 95%CI: −0.22 to −0.18). The greater the volume of prior TZD prescription (−0.87%, 95%CI: −0.93 to −0.81) and the greater the number of accumulated months since adoption (−0.14%, 95%CI: −0.16 to −0.12), the greater the decrease in rates of new inappropriate prescriptions.

Conclusions

Along with the quick penetration of the new DM drug came an increased possibility that it would be prescribed inappropriately, a trend that persisted over time. Copyright © 2010 John Wiley & Sons, Ltd.
Non‐expert's theories of three major personality disorders
Authors: Furnham Adrian , Kirkby Victoria , Mcclelland Alastair
Published: December 2010

Background The aims of this study were to assess lay people's ability to recognize personality disorders as psychological ‘illnesses’ and to establish their beliefs concerning causes and treatment of each disorder.

Methods Two hundred fourteen participants answered a questionnaire, consisting of three case vignettes describing paranoid, narcissistic and obsessive–compulsive personality disorders, according to DSM‐IV‐TR, each followed by 20 attitudinal statements concerning aetiology and treatment.

Results Narcissistic personality disorder was the disorder least recognized as a psychological ‘illness’. Overall, psychological causes and treatments were given more prominence than biological ones. Results suggest that personal experience of mental health problems (whether theoretical or practical) seems to improve ‘illness’ recognition.

Conclusion To the extent that personality disorders were recognized as psychological ‘illnesses’, recognition was increased if the personality disorder was related to a similar Axis I disorder. Experience of mental health problems and knowledge of psychology or psychiatry improves ‘illness’ recognition, although not for every personality disorder. Psychological causes were endorsed more strongly than biological causes for all disorders—but again, the extent to which a disorder was thought to have a psychological rather than biological cause varied as a function of the disorder. A similar pattern was observed for treatment preferences. Copyright © 2010 John Wiley & Sons, Ltd.
Shared Human Capital in Project Management: A Systematic Review of the Literature
Authors: Suhonen Marjo , Paasivaara Leena
Published: December 2010

From the viewpoint of project success, the importance of human capital in projects cannot be overemphasized. Despite this, previous studies have only explored some segments of human capital in projects (e.g., commitment or trust). The aim of this study is to gather studies on the concept of human capital in project management and create an aggregating concept of recent studies. We report and discuss the findings from a systematic review of the research literature. This article focuses particularly on shared human capital (common meanings on the interfaces of the individual and team), and we conclude that the constructive elements of shared human capital are values, tacit knowledge, and social support.
Binding energies of excitons in strained [0001]‐oriented wurtzite AlGaN/GaN double quantum wells
Authors: Zhu J. , Ban S. L. , Ha S. H.
Published: December 2010

A variational method combined with a numerical computation is adopted to investigate binding energies of excitons in wurtzite AlGaN/GaN double quantum wells. The strain modification on material parameters and the built‐in electric fields (BEFs) produced by spontaneous and strain‐induced piezoelectric polarization are taken into account. The dependences of excitonic binding energies on the structural dimension including the widths of asymmetric wells and central barrier are presented. The results indicate that the BEF, which is very strong and can be exactly modulated by the structural dimension, plays a dominant role in determining the binding energy. The exciton is almost indirect one for an asymmetric well influenced by the BEF. The binding energy is very small and is insensitive to the structural dimension. The variation of binding energy versus the widths of both the wells and central barrier in an asymmetric structure is rather different from that in a symmetric one.
Resonant photoemission shake‐up satellites from semiconductors with shallow 3d and 4d core levels
Authors: Klein Andreas , Siepchen Bastian , Späth Bettina , Mankel Eric , Mayer Thomas , Jaegermann Wolfram
Published: December 2010

Photoemission spectra from shallow 3d and 4d levels of ZnTe, ZnSe, CdTe, CdS, and tin‐doped In2O3 (ITO) using synchrotron radiation from the BESSY II storage ring are presented. All compounds show pronounced resonant shake‐up satellites at the excitation threshold of the 3p and 4p‐levels. The resonance intensity profiles are compared to 3p and 4p photoemission. Electron correlation energies U of 10.15, 10.75, 6.15, and 7.3 eV are derived for ZnTe, ZnSe, CdTe, and ITO, respectively.
Calculations for the linear and nonlinear optical coefficients of ZCTC crystals
Authors: Feng Chao , Lu Guiwu , Wang Xinqiang , Zhang Peng , Zhou Guanggang , Yang Hongwang , Jiao Yuqiu
Published: December 2010

The structural, electronic, linear and nonlinear optical properties of ZnCd(SCN)4 (ZCTC) single crystal were studied by using quantum‐mechanical calculations based on the density functional theory (DFT) and pseudopotential method. The optimized lattice constant can be compared with the experimental values when the effects of temperature are considered. Combining with partial density of states of ZCTC crystal, it was found that C2p, N2p and S3p orbitals occur obvious hybrid, which is the main source of the second‐order nonlinear optical effect of ZCTC crystal. Then DFT has been used to calculate the hyperpolarizability of ZCTC single crystal, from which the second harmonic generation (SHG) coefficients was calculated using ionic group theory. The calculated SHG coefficients are d14 = 1.08 ∼ 1.93 pm/V and d15 = 4.01 ∼ 4.79 pm/V. Both of them are in agreement with the tendencies shown by the experimental results (d14 = 3.2 pm/V and d15 = 7.6 pm/V). It was also found that the greatest contribution for SHG of ZCTC crystal is from SCN anionic group.
Triplet exciton in polymeric electroluminescence
Authors: Gu Lei , Li Sheng , George Thomas F. , Sun Xin
Published: December 2010

Due to self‐trapping in polymer, a triplet exciton can be combined with a polaron to form a charged exciton with spin S = 1/2 or 3/2. The former one is emissive. This combination opens a charged exciton channel to make the triplet exciton emissive, enabling the electroluminescence efficiency to increase from 25 to 50%. A precondition is determined for opening this new channel, namely that the injected current density should exceed a certain threshold which depends on the lifetime of the triplet exciton.
A surgical navigation system for oral and maxillofacial surgery and its application in the treatment of old zygomatic fractures
Authors: Chen Xiaojun , Lin Yanping , Wang Chengtao , Shen Guofang , Zhang Shilei , Wang Xudong
Published: December 2010

Background

Nowadays, there is a trend towards computer‐aided oral and maxillofacial surgery. However, due to complicated preoperative planning, traditional neurosurgery‐orientated navigation systems are not suitable and have to be adapted.

Methods

A surgical navigation system is presented for oral and maxillofacial surgery, named AccuNavi, which integrates 3D medical modelling, preoperative surgical planning and intraoperative tracking. Various algorithms were introduced, for each of which a set of dynamic link libraries (DLLs) were developed using C++, as well as the VTK and ITK, via object‐orientated programming methodology, allowing for expandability, accessibility and maintainability in our system.

Results

The advantage of AccuNavi is validated through clinical applications, especially in a case report about the planning and subsequent precise treatment of old zygomatic fractures. The postoperative 3D‐reconstructed CT image demonstrated that the fractured zygoma was fixed in the appropriate position and orientation.

Conclusions

The clinical application demonstrates tyhe feasibility and reliability of AccuNavi, and it can be extended to various areas in oral and maxillofacial surgery. Copyright © 2010 John Wiley & Sons, Ltd.
Differences in managerial discretion across countries: how nation‐level institutions affect the degree to which ceos matter
Authors: Crossland Craig , Hambrick Donald C.
Published: December 2010

The concept of managerial discretion provides a theoretical fulcrum for resolving the debate about whether chief executive officers (CEOs) have much influence over company outcomes. In this paper, we operationalize and further develop the construct of managerial discretion at the national level. In an empirical examination of 15 countries, we find that certain informal and formal national institutions—individualism, tolerance of uncertainty, cultural looseness, dispersed firm ownership, a common‐law legal origin, and employer flexibility—are associated with the degree of managerial discretion available to CEOs of public firms in a country. In turn, we show that country‐level managerial discretion is associated with how much impact CEOs have on the performance of their firms. We also find that discretion mediates the relationship between national institutions and CEO effects on firm performance. Finally, we discuss two inductively derived institutional themes: autonomy orientation and risk orientation. Copyright © 2011 John Wiley & Sons, Ltd.
Metallurgical and Mechanical Characterization of Laser Spot Welded Low Carbon Steel Sheets
Authors: Masoumi M. , Marashi S.P.H. , Pouranvari M.
Published: December 2010

This paper aims at investigating metallurgical and mechanical characterization of low carbon steel laser spot welds. Microstructural examinations, microhardness tests and quasi‐static tensile‐shear tests were preformed. Mechanical properties of the welds were described in terms of peak load and failure mode. The effects of laser spot welding parameters including pulse frequency, laser energy, welding speed, pulse width and welded circle diameter, on low carbon steel laser spot weld performance were studied using the Taguchi design of experiment method. It was found that the effective laser pulse energy is the controlling factor in the determination of mechanical strength of laser spot welds.
Effect of Cooling Rate on the Microstructure of Proeutectoid Ferrite under a High Magnetic Field in Fe‐0.52C
Authors: Wang S. J. , Zhao X. , Xiao N. , Zuo L.
Published: December 2010

For steels, cooling rate is a key factor affecting and deciding the morphology, amount, size and distribution of proeutectoid phase during cooling after austenitizing. In this study, the influence of cooling rate on the formation of proeutectoid ferrite in a high purity Fe‐0.52C alloy during transformation from austenite to ferrite under a high magnetic field was investigated. Results showed that the high magnetic field of 12 T can significantly change the morphology and distribution of proeutectoid ferrite. As compared with the specimens transformed without applying a magnetic field, the proeutectoid ferrite grains were elongated and aligned along the field direction, and only small amounts of acicular proeutectoid Widmanstätten ferrite were observed. The amount of acicular proeutectoid Widmanstätten ferrite in the specimens transformed under the magnetic field increased with increasing cooling rate. The reasons for the observed phenomena were discussed on the basis of free energy, interfacial energy and elastic strain energy of the involved phases transformed under the high magnetic field.
Update on the Equilibrium between Liquid Fe‐Ti‐O Slags and Metallic Iron
Authors: Seim S. , Kolbeinsen L.
Published: December 2010

The current work is an update on the equilibrium between a synthetic high titania slag and metallic iron at temperatures above the slag melting point. The experimental setup is essentially the same as previously shown in the literature, thus employing a cold crucible in a high frequency induction furnace. A new addition to the experimental setup is the temperature measurement by a spectropyrometer. The temperature measurements will give the liquidus temperature for the slags. This temperature shows a decreasing trend as the FeO content in the slag increases. 24 slags have been successfully produced with iron saturation with a FeO content ranging from 6 to 33 wt%. The slags show a clear trend and provide a solid foundation to the location of the slag‐metal equilibrium line in the investigated area. The experiments are in agreement with previously published experimental data but not with previously calculated results using thermodynamical software.
Influence of Sequential Contact with Two Melts on the Wetting Angle of the Ladle Slag and Different Steel Grades on Magnesia‐Carbon Refractories
Authors: Heikkinen E.‐P. , Kokkonen T. , Mattila R. , Fabritius T.
Published: December 2010

The chemical wear mechanism in the slagline of a steel ladle has been investigated by measuring the wetting between molten steels and slags and MgO‐C‐refractories using an optical dilatometer and SEM‐analysis. The results support the wear mechanism in which the graphite is dissolved in steel while the oxide part is destroyed due to dissolution of MgO grains into the slag.
Influence of the Cold Rolling and Annealing Sequence on the Ridging Behaviour of Ti‐Stabilized 18% Cr Ferritic Stainless Steel
Authors: Jung I. , Mola J. , Chae D. , De Cooman B. C.
Published: December 2010

The influence of the cold rolling and annealing sequence on the ridging resistance and the crystallographic texture distribution of AISI 439 type ferritic stainless steel was studied in order to determine optimal processing conditions for surface quality improvement. In the present study, the effect of two sequences of cold rolling and annealing were analysed: a single cold rolling and annealing, and an interrupted cold rolling with an intermediate and a final anneal. In the conventional single step cold rolling, the ridging resistance was found to deteriorate with increasing cold reduction ratio. For a fixed total cold reduction ratio in the two stage cold rolling, ridging was less pronounced when a higher reduction was applied in the second step. Band‐like clusters of grains with similar crystallographic orientations were observed in the mid‐thickness of sheets with severe ridging. The results show that severe ridging is related to the presence of band‐like clusters of 〈111〉//ND oriented grains. The two stage cold rolling was found to result in less band‐like clusters and an improved surface quality.
Relaxation and Stability of Welding Residual Stresses in High Strength Steel under Mechanical Loading
Authors: Farajian M. , Wimpory Robert C. , Nitschke‐Pagel Th.
Published: December 2010

The relaxation of near surface welding residual stresses in S1100QL under static and cyclic mechanical loadings was studied. By increasing static loads the residual stress relaxes continuously. Under cyclic loading the residual stresses behave depending on the initial status, local yield strength and maximum applied load. If the von Mises stress as a function of residual stress, load and mean stresses, exceeds the local yield strength, plastic deformation and thus relaxation occurs. The first load cycle is of importance in which a considerable portion of the initial residual stress field relaxes. Afterwards regardless of whether in high or low cycle fatigue conditions, the relaxation rates were the same and comparatively smaller than the first relaxation. When no relaxation in the first load cycle occurred, the number of cycles did not change the residual stress. The specimens were loaded until failure or a maximum of 2x106 numbers of cycles.
Tragverhalten von Scher‐Lochleibungsverbindungen mit dem Beginn des Gewindes in der Nähe der Scherfuge
Authors: Friede Roland , Lange Jörg , Nicolay Thorsten
Published: December 2010

Im Nachweisverfahren einer Scher‐Lochleibungsverbindung wird unterschieden, ob der Schaft oder das Gewinde in der Scherfuge liegt. Mit der Umstellung der Schraubennorm von der DIN 6914 auf die DIN EN 14399‐4 haben sich die Schraubengeometrien teilweise geändert. Dies führt dazu, dass das Gewinde in vielen Fällen näher an bzw. häufiger in der Scherfuge liegt. In der aktuellen Normung wird nicht näher definiert, bei welchen Bedingungen der Schaftquerschnitt angesetzt werden darf und bis zu welcher Position der Scherfuge der ungünstigere Gewindequerschnitt angesetzt werden muss. Es wurden Versuche mit dem Ziel durchgeführt, das Tragverhalten von scherbelasteten Schraubengarnituren zu untersuchen, insbesondere im Übergangsbereich zum Gewinde. Dabei wurde die Position der Scherfuge verändert. Der Einfluss der neuen Schraubengeometrien und die Ergebnisse der Abscherversuche werden nachfolgend genauer beschrieben.

Shear bearing of bolted connections with the beginning of the thread near the shear plane. In bolted connections the shear load is calculated with the cross section of the bolt. It is important whether the shank or the thread is in the shear plane. In the new code for bolts DIN EN 14399‐4 the dimension of the bolts are modified. Compared to the previous code, the DIN 6914, in many situations the thread is closer to the shear plane or even in the shear plane. In the current standards there is no requirement about how long the shank has to protrude into the shear plane. Tests were performed to assess the ultimate load of bolts in shear connections with different positions of the shear plane. In the paper the differences of the codes DIN 6914 and DIN EN 14399‐4 are shown and the results of the tests are presented.
Flughafen Sheremetyevo, Moskau – Planung und Fertigung der Stahldächer und Brücke
Authors: Drawer Oliver , Fahlbusch Mark , Thiel Matthias
Published: December 2010

Im Zuge einer deutlichen Erweiterung der Fluggastkapazitäten und Modernisierung ist in Moskau das dritte Terminal am Flughafen Sheremetyevo entstanden (Bild 1). Unter der Leitung der Arnold AG übernahm das Büro B+G Ingenieure Bollinger und Grohmann GmbH (B+G) die Planung mehrerer Vordächer und einer Fußgängerbrücke zwischen Parkhaus und Terminal. In der weiteren Entstehung wurden die Firmen Müller Offenburg GmbH & Co. KG (MOG), Heinrich Lamparter Stahlbau GmbH & Co. KG (StaLA) und Radabau GmbH für die Fertigung verpflichtet. Der folgende Beitrag befasst sich mit den Besonderheiten der Planung sowie der Fertigung der einzelnen Bauteile in diesem speziellen Projekt.

Sheremetyevo Airport, Moscow, Russia – Structural design and fabrication of steel roofing and bridge. The new Terminal 3 was built as part of the significant expansion and modernization to increase passenger capacities at Sheremetyevo Airport in Moscow (Figure 1). Bollinger + Grohmann Ingenieure carried out the structural design for various canopies and a footbridge between parking garage and terminal building under the supervision of the Arnold AG. In the later stage of the project Müller Offenburg GmbH & Co. KG (MOG), Heinrich Lamparter Stahlbau GmbH & Co. KG (StaLA) and the Radabau GmbH were assigned the manufacturing contract. The following article deals with the peculiarities during the design stage and fabrication of individual structural elements of this particular project.
Die Instandsetzung der Old White Nile Bridge in Khartoum/Sudan
Authors: Haumer Wolfram , Gebert Gregor , Ehrlicher Frank , El‐Dawi Khalid
Published: December 2010

Die Old White Nile und die Old Blue Nile Bridge waren die ersten beiden Brücken überhaupt, die in Khartoum, der Hauptstadt des Sudan über den Nil führten. Sie wurden von der Britischen Baufirma Dorman Long Ltd. in den Jahren 1908 und 1928 gebaut und erfüllen bis heute in nahezu unveränderter Form ihren Dienst. Sie stellen damit funktionstüchtige, ingenieurtechnische Denkmale dar und zeugen von der außergewöhnlichen Ingenieurleistung, die hier unter schwierigen klimatischen und technologischen Bedingung erbracht wurde.

Der folgende Beitrag befasst sich mit der Instandsetzung der Old White Nile Bridge, welche im Zeitraum von 2004 bis 2007 durchgeführt wurde. Die Schüßler‐Plan Ingenieurgesellschaft wurde von der Brückenbauverwaltung der Stadt Khartoum mit verschiedenen Untersuchungen im Zusammenhang mit dem Sanierungskonzept betraut. Der Aufsatz befasst sich neben einem historischen Rückblick mit der Entscheidung, ob ein Auswechseln der 80 Jahre alten, in ihrer Funktion stark eingeschränkten Brückenlager aus statischer Sicht notwendig ist oder diese am Bauwerk belassen werden können. Auch für die Old Blue Nile Bridge ist in den kommenden Jahren eine grundlegende Instandsetzung vorgesehen. Da die Konstruktion vergleichbar ist, können die bei der Old White Nile Bridge gewonnenen Erkenntnisse hierbei einen wertvollen Beitrag leisten.

Rehabilitation of old steel bridges over the Nile in Khartoum/Sudan. The Old White Nile Bridge and the Old Blue Nile Bridge were the first bridges ever to cross the Nile at Khartoum – Capital of the Sudan. They were build In 1928 and 1908 by the British Company Dorman Long Ltd. and till today service the traffic in Khartoum in their since then unchanged form. They represent as such a functional technical monument and an attest of the unusual engineering achievement, which was realised under the most extreme climatic and technological conditions.

The following report is about the rehabilitation of the Old White Nile Bridge, which was carried out from 2004 till 2007. The Schüßler‐Plan Ingenieurgesellschaft was contracted by the Bridge Department of the State of Khartoum with several analysis related with the rehabilitation concept. The report starts with an historic review of the bridge and continuous with the decision weather it is statically necessary to exchange the nearly 80 year old bearings that are strongly hindered in their function, or weather they could be left unchanged. For the Blue Nile Bridge also, a complete rehabilitation is planned in the near future. Since the two bridge structures are comparable, the knowledge collected at the Old White Nile Bridge could be of great advantage for the Blue Nile rehabilitation.
Schlüssiges Nachweisformat biegesteifer Verbindungen geschweißter Kastenprofile
Authors: Strehl Christian
Published: December 2010

Für Knotenverbindungen mit großen geschweißten Kastenprofilen – wie im Kesselgerüstbau erforderlich – wird im vorliegenden Beitrag ein Nachweisformat vorgestellt. Als Beispiel dient ein Knoten an einer Stütze mit Anschluss zu zwei Riegeln und vier Diagonalen. Die Annahmen für die Aufteilungen der Schnittgrößen im Knotenbereich sind in Bildern und Formeldarstellungen für ein Tabellenkalkulationsprogramm dargelegt. Zusätzliche tabellarisch aufgeführte Zahlenwerte ermöglichen anhand des fiktiven Beispiels eine Kontrolle des Berechnungsalgorithmus. Der komprimierte Berechnungsgang leitet zu einer ausführlichen praktischen Anwendung an.

Conclusive calculation algorithm for rigid connections with welded box sections. For the construction of nodes with large welded plates in kind of rectangular profiles, as for example required for racks in power plants, a calculation algorithm is presented. The geometry of a node is determined by a column with two girders and four struts. The assumptions for the distribution of the internal forces in the region of the nodes are shown in kind of figures and formulas for a table calculation program. The calculation algorithm can be checked by given values for a fictitious example. For a practical application it is recommended to distribute the calculation over several sheets in the table calculation program by supplementing this with explaining text. Furthermore, it is also recommended to check the complex geometry of the schemes as shown in figures 1 and 2 after input of the parameters by a plot.
Ein Konzept für den Traglastnachweis gurtgelagerter doppeltsymmetrischer I‐Träger unter Berücksichtigung der Profilverformung
Authors: Geldmacher Georg , Lange Jörg
Published: December 2010

Biegeträger aus I‐Profilen werden aus verschiedenen Gründen ohne Auflagersteifen, also nur an den Gurten gelagert, ausgeführt. Dabei wird die Stabilität gegen das Biegedrillknicken dieser Träger durch Profilverformung in den Auflagerbereichen vermindert, was die gängigen Nachweisformeln und Hilfsmittel in der Regel nicht berücksichtigen. In diesem Aufsatz werden die Ergebnisse einer Dissertation vorgestellt, in der durch analytische Betrachtungen ein Ersatzmodell zur Ermittlung der Verzweigungslast abgeleitet wurde. Durch experimentelle und numerische Traglastuntersuchungen wurden Traglastkurven entwickelt, so dass ein praxisnahes Nachweiskonzept für gurtgelagerte Träger vorgestellt werden kann.

A model for the determination of the ultimate load of doublesymmetric I‐shaped beams on seats considering distortional effects. For several reasons, I‐shaped beams are built without stiffeners at the bearings, and because of this they are seated on one flange only. The stability against lateral torsional buckling of these beams is therefore reduced by distortional effects that occur close to the bearings, but this is normally not taken into account by the common design‐formulae and guidelines. This article presents the results of a doctoral thesis where an analogous model for the determination of buckling‐loads has been derived. By experimental and numerical investigations buckling curves for the determination of ultimate loads have been developed, in order to provide a design concept for beams on seats.
Aktuell: Stahlbau 12/2010
Authors: Stroetmann Richard , Hanek Dieter
Published: December 2010

60 Jahre Krebs und Kiefer

Buchveröffentlichung anlässlich des 111. Geburtstags “Diplom‐Ingenieurs”

Stahl trifft Natur – ein Turm aus Stufen
Crystal Structure of Iron(II) Acetate
Authors: Weber Birgit , Betz Richard , Bauer Wolfgang , Schlamp Stephan
Published: December 2010

In this paper the X‐ray structure and magnetic properties of iron(II) acetate – starting material for the synthesis of a wide range of iron complexes – are presented. The compound crystallises in the space group Pbcn and was identified as 2D coordination polymer consisting of iron atoms and acetate moieties with all the iron atoms hexacoordinate and different coordination modes for the acetate moieties. Additional hydrogen bond contacts lead to a porous coordination polymer with 1D channels in the size of mesopores. Temperature dependent magnetic measurements confirm that the complex is a high‐spin compound in the entire temperature range investigated with a room temperature magnetic moment of 5.4 μB. Field‐dependent magnetisation measurements reveal a slightly sigmoidal curve progression typical for metamagnetism.
Malignant Melanoma of the Skin: Long‐term Follow‐up and Time to First Recurrence
Authors: Hohnheiser Annika M. , Gefeller Olaf , Göhl Jonas , Schuler Gerold , Hohenberger Werner , Merkel Susanne
Published: December 2010

Background

Surgical excision can cure most patients with malignant melanoma of the skin. However, the risk of recurrence remains for years. The aim of our study was to identify factors that influence time to recurrence and survival after the first recurrence with a special interest in late recurrences.

Methods

Data from 2487 patients with malignant melanoma and primary treatment between 1978 and 1997 at the Department of Surgery or the Department of Dermatology, University Hospital Erlangen, Germany, were prospectively collected in the Melanoma Registry of the University Hospital Erlangen. After a median follow‐up period of 13 years, overall survival, the time to first recurrence and survival after the first relapse were examined in univariate and multivariate analyses.

Results

Overall survival was found to be significantly worse in older patients, men, melanoma of the head or trunk, and melanoma with high pT and pN categories. In 523 patients, relapse from malignant melanoma was observed after a median of 24 months. Among patients with recurrences, young age and low pT and pN categories proved to be independent factors that prolonged the disease‐free interval. Advanced age at the time of the recurrence diagnosis, male sex, high pN category, and distant metastases as the first manifestation of recurrence were associated with a poor prognosis after the first recurrence.

Conclusions

Although thin lesions have a favorable prognosis, among a cohort with recurrences they showed a relatively high rate of late recurrences. These late recurrences have an extremely poor prognosis when they present with distant metastases.