Klein, Helmut

[["dc.bibliographiccitation.firstpage","452"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Advanced Engineering Materials"],["dc.bibliographiccitation.lastpage","458"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Klein, Helmut"],["dc.date.accessioned","2018-11-07T08:28:51Z"],["dc.date.available","2018-11-07T08:28:51Z"],["dc.date.issued","2009"],["dc.description.abstract","Diffraction imaging with hard X-rays (high-energy synchrotron radiation) using the detector sweeping techniques allows measurement of the texture and microstructure of polycrystalline materials with high orientation- and location-resolution. These techniques provide continuous two-dimensional images of different sections and projections of the six-dimensional \"orientation-location\" space. For the high orientation resolution case, it is possible to measure the orientation and location coordinates of up to 105 individual grains simultaneously. From these parameters, the grain size and shape can also be obtained, yielding the complete orientation stereology of the polycrystalline aggregate, which is required for its complete characterization. For the high location resolution case, the intensity at any point of the diagrams; corresponds to a pole density as a function of the orientation-location space."],["dc.description.sponsorship","German Research Foundation DFG; HASYLAB at DESY"],["dc.identifier.doi","10.1002/adem.200800368"],["dc.identifier.isi","000267853400005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16517"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1527-2648"],["dc.relation.issn","1438-1656"],["dc.title","Principles of Highly Resolved Determination of Texture and Microstructure using High-Energy Synchrotron Radiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1381"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of the American Ceramic Society"],["dc.bibliographiccitation.lastpage","1392"],["dc.bibliographiccitation.volume","101"],["dc.contributor.author","Neher, Sigmund H."],["dc.contributor.author","Klein, Helmut"],["dc.contributor.author","Kuhs, Werner F."],["dc.date.accessioned","2020-12-10T18:28:54Z"],["dc.date.available","2020-12-10T18:28:54Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1111/jace.2018.101.issue-3"],["dc.identifier.issn","0002-7820"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/76448"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Determination of crystal size distributions in alumina ceramics by a novel X-ray diffraction procedure"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Marine Geology"],["dc.bibliographiccitation.lastpage","14"],["dc.bibliographiccitation.volume","244"],["dc.contributor.author","Bohrmann, Gerhard"],["dc.contributor.author","Kuhs, Werner F."],["dc.contributor.author","Klapp, Stephan A."],["dc.contributor.author","Techmer, Kirsten S."],["dc.contributor.author","Klein, Helmut"],["dc.contributor.author","Murshed, M. Mangir"],["dc.contributor.author","Abegg, Fritz"],["dc.date.accessioned","2018-11-07T10:57:49Z"],["dc.date.available","2018-11-07T10:57:49Z"],["dc.date.issued","2007"],["dc.description.abstract","The state of preservation of natural gas hydrate samples, recovered from 6 sites drilled during ODP Leg 204 at southern summit of Hydrate Ridge, Oregon Margin, has been investigated by X-ray diffraction (XRD) and cryo-scanning-electron-inicroscopy (cryo-SEM) techniques. A detailed characterization of the state of decomposition of gas hydrates is necessary since no pressurized autoclave tools were used for sampling and partial dissociation must have occurred during recovery prior to the quench and storage in liquid nitrogen. Samples from 16 distinct horizons have been investigated by synchrotron X-ray diffraction measurements at HASYLAB/ Hamburg. A full profile fitting analysis (\"Rietveld method\") of synchrotron XRD data provides quantitative phase determinations of the major sample constituents such as gas hydrate structure I (sI), hexagonal ice (Ih) and quartz. The ice content (Ih) in each sample is related to frozen water composed of both original existing pore water and the water from decomposed hydrates. Hydrate contents as measured by diffraction vary between 0 and 68 wt.% in the samples we measured. Samples with low hydrate content usually show micro-structural features in cryo-SEM ascribed to extensive decomposition. Comparing the appearance of hydrates at different scales, the grade of preservation seems to be primarily correlated with the contiguous volume of the original existing hydrate; the dissociation front appears to be indicated by micrometer-sized pores in a dense ice matrix. (c) 2007 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.margeo.2007.05.003"],["dc.identifier.isi","000250150800001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50340"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0025-3227"],["dc.title","Appearance and preservation of natural gas hydrate from Hydrate Ridge sampled during ODP Leg 204 drilling"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","550"],["dc.bibliographiccitation.journal","Journal of Synchrotron Radiation"],["dc.bibliographiccitation.lastpage","556"],["dc.bibliographiccitation.volume","18"],["dc.contributor.author","Raue, Lars"],["dc.contributor.author","Klein, Helmut"],["dc.date.accessioned","2018-11-07T08:54:50Z"],["dc.date.available","2018-11-07T08:54:50Z"],["dc.date.issued","2011"],["dc.description.abstract","Obtaining information about the intrinsic structure of polycrystalline materials is of prime importance owing to the anisotropic behaviour of individual crystallites. Grain orientation and its statistical distribution, i.e. the texture, have an important influence on the material properties. Crystallographic orientations play an important role in all kinds of polycrystalline materials such as metallic, geological and biological. Using synchrotron diffraction techniques the texture can be measured with high local and angular resolving power. Here methods are presented which allow the spatial orientation of the crystallites to be determined and information about the anisotropy of mechanical properties, such as elastic modulus or thermal expansion, to obtained. The methods are adapted to all crystal and several sample symmetries as well as to different phases, for example with overlapping diffraction peaks. To demonstrate the abilities of the methods, human dental enamel has been chosen, showing even overlapping diffraction peaks. Likewise it is of special interest to learn more about the orientation and anisotropic properties of dental enamel, since only basic information is available up to now. The texture of enamel has been found to be a tilted fibre texture of high strength (up to 12.5x). The calculated elastic modulus is up to 155 GPa and the thermal expansion up to 22.3 x 10(-6) degrees C(-1)."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG); HASYLAB/DESY"],["dc.identifier.doi","10.1107/S0909049511011071"],["dc.identifier.isi","000292105500003"],["dc.identifier.pmid","21685670"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22763"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","0909-0495"],["dc.title","Calculation of anisotropic properties of dental enamel from synchrotron data"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","222"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Advanced Engineering Materials"],["dc.bibliographiccitation.lastpage","227"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Tommaseo, Caterina Elisabetta"],["dc.contributor.author","Klein, Helmut"],["dc.date.accessioned","2018-11-07T08:45:07Z"],["dc.date.available","2018-11-07T08:45:07Z"],["dc.date.issued","2010"],["dc.description.abstract","The development of the recrystallization and annealing textures of Al-Mn alloys with 0.4, 0.7 and 1 wt.-% manganese is analyzed using specific techniques that allow the detection of changes in grain orientation during in situ annealing. In order to investigate the evolution of texture components during annealing, highly rolled samples were annealed from room temperature to 500 C at a constant heating rate. The advantage of in situ annealing experiments using synchrotron radiation is the detection of grain orientations over time, which allows observation of the development of the recrystallization and annealing textures in a sample. In fact, the recrystallization and annealing textures in the Al-0.4Mn are characterized by an interruption in the detection of most of the grain orientations between 380 and 425 C and by competition between the cube {001}< 100 >, {011}< 1-33 >, {011}< 0-11 > and rotated-cube {001}< 110 > grain orientations, where the latter is detected until the end of the experiment. In the Al-0.7Mn sample a competition between the cube {001}< 100 >, {011}< 100 >, and rotated cube {001}< 110 >, {011}< 0-11 > grain orientations is observed. In the sample with the highest manganese concentration (1 wt.-%) an unhindered grain growth of all possible grain orientations with a high amount of the {011}< 0-11 > grain orientation is observed. The evolution of the resulting local textures is discussed in terms of preferentially oriented grain growth depending on the temperature and manganese concentration."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [KL1402/2-1]"],["dc.identifier.doi","10.1002/adem.200900267"],["dc.identifier.isi","000277297300019"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20358"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1438-1656"],["dc.title","Oriented Grain Growth Analyses With In Situ Annealing Experiments Using High Energy Synchrotron Radiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","Circulation"],["dc.bibliographiccitation.volume","118"],["dc.contributor.author","De Ferrari, Gaetano M."],["dc.contributor.author","Sanzo, Antonio"],["dc.contributor.author","Borggrefe, Martin M."],["dc.contributor.author","Wolpert, Christian"],["dc.contributor.author","Kuschyk, Jürgen"],["dc.contributor.author","Schoene, Antonina"],["dc.contributor.author","Crijns, Harry J. G. M."],["dc.contributor.author","Dennert, Robert"],["dc.contributor.author","Milasinovic, Goran"],["dc.contributor.author","Raspopovic, Srdjan"],["dc.contributor.author","Klein, Helmut"],["dc.contributor.author","Smid, Jan"],["dc.contributor.author","Gavazzi, Antonello"],["dc.contributor.author","Iacovoni, Attilio"],["dc.contributor.author","Zabel, Markus"],["dc.contributor.author","Schwartz, Peter J."],["dc.date.accessioned","2018-11-07T11:09:52Z"],["dc.date.available","2018-11-07T11:09:52Z"],["dc.date.issued","2008"],["dc.identifier.isi","000262104502355"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53095"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Lippincott Williams & Wilkins"],["dc.publisher.place","Philadelphia"],["dc.relation.conference","81st Annual Scientific Session of the American-Heart-Association"],["dc.relation.eventlocation","New Orleans, LA"],["dc.title","Chronic Vaguer Nerve Stimulation in Patients with Chronic Heart Failure is Feasible and Appears Beneficial"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","116"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Marine and Petroleum Geology"],["dc.bibliographiccitation.lastpage","125"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","Klapp, Stephan A."],["dc.contributor.author","Bohrmann, Gerhard"],["dc.contributor.author","Kuhs, Werner F."],["dc.contributor.author","Murshed, M. Mangir"],["dc.contributor.author","Pape, Thomas"],["dc.contributor.author","Klein, Helmut"],["dc.contributor.author","Techmer, Kirsten S."],["dc.contributor.author","Heeschen, Katja U."],["dc.contributor.author","Abegg, Friedrich"],["dc.date.accessioned","2018-11-07T08:48:06Z"],["dc.date.available","2018-11-07T08:48:06Z"],["dc.date.issued","2010"],["dc.description.abstract","Gas hydrate samples from various locations in the Gulf of Mexico (GOM) differ considerably in their microstructure. Distinct microstructure characteristics coincide with discrete crystallographic structures, gas compositions and calculated thermodynamic stabilities. The crystallographic structures were established by X-ray diffraction, using both conventional X-ray sources and high-energy synchrotron radiation. The microstructures were examined by cryo-stage Field-Emission Scanning Electron Microscopy (FE-SEM). Good sample preservation was warranted by the low ice fractions shown from quantitative phase analyses. Gas hydrate structure II samples from the Green Canyon in the northern GOM had methane concentrations of 70-80% and up to 30% of C-2-C-5 of measured hydrocarbons. Hydrocarbons in the crystallographic structure I hydrate from the Chapopote asphalt volcano in the southern GOM was comprised of more than 98% methane. Fairly different microstructures were identified for those different hydrates: Pores measuring 200-400 nm in diameter were present in structure I gas hydrate samples; no such pores but dense crystal surfaces instead were discovered in structure II gas hydrate. The stability of the hydrate samples is discussed regarding gas composition, crystallographic structure and microstructure. Electron microscopic observations showed evidence of gas hydrate and liquid oil co-occurrence on a micrometer scale. That demonstrates that oil has direct contact to gas hydrates when it diffuses through a hydrate matrix. (C) 2009 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.marpetgeo.2009.03.004"],["dc.identifier.isi","000272308200010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21128"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Sci Ltd"],["dc.relation.issn","0264-8172"],["dc.title","Microstructures of structure I and II gas hydrates from the Gulf of Mexico"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","77"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Practical Metallography"],["dc.bibliographiccitation.lastpage","96"],["dc.bibliographiccitation.volume","46"],["dc.contributor.author","Tommaseo, Caterina Elisabetta"],["dc.contributor.author","Klein, Helmut"],["dc.date.accessioned","2018-11-07T08:33:18Z"],["dc.date.available","2018-11-07T08:33:18Z"],["dc.date.issued","2009"],["dc.description.abstract","Annealed AlMn alloys with different amounts of Manganese (0.4; 0.7 and 1 wt.-%) were analyzed with texture and microstructure imaging techniques using high-energy synchrotron radiation. These techniques allow getting reliable information about grain shape and grain size distribution the different crystallographic directions due high orientation and location resolution. The)served trends of the grain growth in dependence on the AlMn alloys composition and the crystallographic directions, are well correlated with the different texture components occurring with increasing annealing time. In comparison to the SEM/EBSD technique, these methods allow get orientation dependent information about the grain size and shape related with additionally good statistics."],["dc.description.sponsorship","Deutsche Forchungsgemeinschaft (DFG)"],["dc.identifier.isi","000263661900002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17545"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Carl Hanser Verlag"],["dc.relation.issn","0032-678X"],["dc.title","Grain Growth Analyses of AlMn Alloys Using Texture and Microstructure Imaging Techniques with High-Energy Synchrotron Radiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","S71"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Journal of Cardiac Failure"],["dc.bibliographiccitation.lastpage","S72"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","De Ferrari, Gaetano M."],["dc.contributor.author","Sanzo, Antonio"],["dc.contributor.author","Crijns, Harry J. G. M."],["dc.contributor.author","Dennert, Robert"],["dc.contributor.author","Milasinovic, Goran"],["dc.contributor.author","Raspopovic, Srdjan"],["dc.contributor.author","Borggrefe, Martin M."],["dc.contributor.author","Wolpert, Christian"],["dc.contributor.author","Kuschyk, Juergen"],["dc.contributor.author","Schoene, Antonina"],["dc.contributor.author","Klein, Helmut"],["dc.contributor.author","Smid, Jan"],["dc.contributor.author","Gavazzi, Antonello"],["dc.contributor.author","Iacovoni, Attilio"],["dc.contributor.author","Zabel, Markus"],["dc.contributor.author","Schwartz, Peter J."],["dc.date.accessioned","2018-11-07T11:12:29Z"],["dc.date.available","2018-11-07T11:12:29Z"],["dc.date.issued","2008"],["dc.identifier.doi","10.1016/j.cardfail.2008.06.194"],["dc.identifier.isi","000258565100227"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53680"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Churchill Livingstone Inc Medical Publishers"],["dc.publisher.place","Philadelphia"],["dc.relation.conference","12th Annual Scientific Meeting of the Heart-Failure-Society-of-America"],["dc.relation.eventlocation","Toronto, CANADA"],["dc.relation.issn","1071-9164"],["dc.title","Chronic vagus nerve stimulation (CANS) - A new target for treatment of congestive heart failure"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","85"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Marine Geology"],["dc.bibliographiccitation.lastpage","94"],["dc.bibliographiccitation.volume","274"],["dc.contributor.author","Klapp, Stephan A."],["dc.contributor.author","Hemes, Susanne"],["dc.contributor.author","Klein, Helmut"],["dc.contributor.author","Bohrmann, Gerhard"],["dc.contributor.author","MacDonald, Ian"],["dc.contributor.author","Kuhs, Werner F."],["dc.date.accessioned","2018-11-07T08:40:22Z"],["dc.date.available","2018-11-07T08:40:22Z"],["dc.date.issued","2010"],["dc.description.abstract","Methane hydrates are present in marine seep systems and occur within the gas hydrate stability zone. Very little is known about their crystallite sizes and size distributions because they are notoriously difficult to measure. Crystal size distributions are usually considered as one of the key petrophysical parameters because they influence mechanical properties and possible compositional changes, which may occur with changing environmental conditions. Variations in grain size are relevant for gas substitution in natural hydrates by replacing CH(4) with CO(2) for the purpose of carbon dioxide sequestration. Here we show that crystallite sizes of gas hydrates from some locations in the Indian Ocean, Gulf of Mexico and Black Sea are in the range of 200-400 mu m; larger values were obtained for deeper-buried samples from ODP Leg 204. The crystallite sizes show generally a log-normal distribution and appear to vary sometimes rapidly with location. (C) 2010 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.margeo.2010.03.007"],["dc.identifier.isi","000279524100007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19216"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0025-3227"],["dc.title","Grain size measurements of natural gas hydrates"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]