Modeling the Slump-Type Landslide Tsunamis Part I: Developing a Three-Dimensional Bingham-Type Landslide Model

This paper incorperates Bingham and bi-viscosity rheology models with the Navier–Stokes solver to simulate the dynamics and kinematics processes of slumps for tsunami generation. The rheology models are integrated into a computational fluid dynamics code, Splash3D, to solve the incompressible Navier–Stokes equations with volume of fluid surface tracking algorithm. The change between un-yield and yield phases of the slide material is controlled by the yield stress and yield strain rate in Bingham and bi-viscosity models, respectively. The integrated model is carefully validated by the theoretical results and laboratory data with good agreements. This validated model is then used to simulate the benchmark problem of the failure of the gypsum tailings dam in East Texas in 1966. The accuracy of predicted flood distances simulated by both models is about 73% of the observation data. To improve the prediction, a fixed large viscosity is introduced to describe the un-yield behavior of tailings material. The yield strain rate is obtained by comparing the simulated inundation boundary to the field data. This modified bi-viscosity model improves not only the accuracy of the spreading distance to about 97% but also the accuracy of the spreading width. The un-yield region in the modified bi-viscosity model is sturdier than that described in the Bingham model. However, once the tailing material yields, the material returns to the Bingham property. This model can be used to simulate landslide tsunamis.

Enhanced landslide mobility by basal liquefaction: The 2014 State Route 530 (Oso), Washington, landslide

Landslide mobility can vastly amplify the consequences of slope failure. As a compelling example, the 22 March 2014 landslide near Oso, Washington (USA), was particularly devastating, traveling across a 1-km+-wide river valley, killing 43 people, destroying dozens of homes, and temporarily closing a well-traveled highway. To resolve causes for the landslide’s behavior and mobility, we conducted detailed postevent field investigations and material testing. Geologic and structure mapping revealed a progression of geomorphological structures ranging from debris-flow lobes at the distal end through hummock fields, laterally continuous landslide blocks, back-rotated blocks, and finally colluvial slides and falls at the landslide headscarp. Primary structures, as well as stratigraphic and vegetation patterns, in the landslide deposit indicated rapid extensional motion of the approximately 9 × 106 m3 source volume in a closely timed sequence of events. We identified hundreds of transient sand boils in the landslide runout zone, representing evidence of widespread elevated pore-water pressures with consequent shear-strength reduction at the base of the slide. During the event, underlying wet alluvium liquefied and allowed quasi-intact slide hummocks to extend and translate long distances across the flat valley. Most of the slide material itself did not liquefy. Using geotechnical testing and numerical modeling, we examined rapid undrained loading, shear and collapse of loose saturated alluvium, and strong ground shaking as potential liquefaction mechanisms. Our analyses show that some layers in the alluvium can liquefy when sheared, as could occur with rapid undrained loading. Simultaneous ground shaking could have contributed to pore-pressure generation as well. Two key elements, a large and rapid failure overriding wet liquefiable sediments, enabled the landslide’s high mobility. Basal liquefaction may enhance mobility of other landslides in similar settings.

Bridge over the Vistula river in Toruń (Poland)

<p>The construction of the arch bridge in Toruń was one of the greatest and more spectacular engineering projects implemented during the recent years. In December 2013 the Poland’s largest arch bridge was completed and opened. The bridge has two spans, 270m long each, and is used as a bridge crossing over the Vistula river (Fig.1). The bridge is over 1.9 km long counting the access overbridges (viaducts). The erection procedure of the bridge was unique and individual, as the structural scale suggests. Generally, the assembly covered junction of arch elements on the assembly site near the Vistula river bank and the pontoon water transport of arch girders, which were settled on the arch abutments. A unique affordable structural solution deals with the support footing of a great number of small concrete pre-cast piles transferring a giant horizontal force into the subsoil. The steel-arch is modeled by a hingeless system without a tie, transferring horizontal force into supports. A original solution of assembly geometry control system and monitoring system was applicate to floating erection. Innovation was done of introducing material for the pot bearings, whose durability was 5-times longer than the ordinary ones. A novel slide material PTFE was used, the so-called grey teflon of improved abrasion ability. The new PTFE solutions were recently applied for the spherical bearings, but never they have been for the pot bearings. The bearings worked out an individual product specification, based on experiments conducted in the EU laboratory. The world's pioneering enterprise is application of a hundred pot bearings for the bridge and viaducts.</p>

Annotated list of the scale insects of Guatemala

An annotated checklist of the soft scale insects (Hemiptera: Coccidae) is given for the Central American country of Guatemala. Host and locality data is presented for each species, along with notes on its taxonomic status. The list was developed from study of materials collected in Guatemala by the author and others during the years 1990-2007, and from a review of the literature and records and slide material in the United States National Museum Coccoidea Collection. A study of these materials has increased the number of soft scale insects currently known from Guatemala to 29 species belonging to 23 genera. Guatemala currently ranks second in the number of soft scale insects known from Central American countries below Panama, which has 36 recorded species belonging to 18 genera.

Construction of tissue microarrays using pre-existing slides as source of tissue when paraffin blocks are unavailable

AimTo develop and validate a technique for construction of intermediate density tissue microarray (TMA) slides based on the transfer of tissue from pre-existing routine slides provided for pathology diagnosis with validation to show preservation of morphology and antigenicity of the transferred tissue.MethodsProstate cancer patch TMAs were constructed using 20 cores acquired from radical prostatectomy histology slides. The preservation of morphology and antigenicity of these patch TMAs were tested with immunohistochemistry (IHC) in comparison to a traditional TMA.ResultsAfter IHC staining, 35 of 39 cores (89.7%) on the patch TMA were intact compared with 39 of 40 cores (97.5%) on the traditional TMA. Expression patterns and density of the antigens (34BE12, p63 and AMACR) on the patch TMA were almost identical to the traditional TMA.ConclusionsPatch TMA represents a viable alternative for tissue-based IHC studies when paraffin blocks are unavailable. This may be a valuable tool for allowing use of archival slide material for IHC and enable a standardized TMA platform to be used when the slides sent for review from other institutions are the only source of tissue available.

The mesostigmatid mite (Acari: Parasitiformes) fauna of Svalbard: a revised inventory of a high Arctic archipelago

The need for comprehensive studies of the invertebrate fauna in the high Arctic is increasingly acknowledged in order to more fully understand ecosystem functioning, resilience and to project future changes in the biodiversity and species ranges. Information on the mesostigmatid fauna in the high Arctic is scarce and scattered. Large regions of the high Arctic archipelago of Svalbard, including most of the areas in the east of the island group, have never been surveyed for the mesostigmatid fauna. Furthermore, most of the current knowledge on the mesostigmatid fauna of this important region in the European high Arctic originates from studies in the early 20 th century. Much of the associated slide material no longer exists, either being mislaid or deliberately destroyed, resulting in an ambiguous and potentially misleading mesostigmatid fauna checklist in which identifications and potential synonyms cannot be reliably assessed. Determination of fresh material sampled between 2007–2010 may be an ideal procedure to resolve the great number of uncertainties about the mesostigmatid fauna of the Svalbard archipelago. Twelve out of the 27 species recorded from the Svalbard archipelago were found in the new samples collected from a large number of localities and microhabitats. No new species were identified in the current campaign, and most of the non-observed species are considered to be past missidentifications or potential synonyms. Combining this study with recent publications provides a total mesostigmatid mite diversity for Svalbard of 22 species. This represents the most accurate checklist of the mesostigmatid mite fauna of the archipelago to date.

Geotechnical Centrifuge Modelling Techniques for Submarine Slides

The gradual shift of hydrocarbon developments into deeper waters has presented fresh challenges for offshore geotechnical engineering. Many installations in deep water require export pipelines to shore which can be many hundreds of kilometers in length. These pipelines must negotiate unstable regions of soft seabed around the steep continental shelf and variable terrain including canyons with depths ranging from tens of meters to a several hundred meters. These challenging conditions present potential geohazards for which little understanding has been developed so far. One of the major geohazards is the impact of a submarine landslide on nearby pipelines which could potentially damage the pipeline. Consequently, a Joint Industry Project (JIP) has been initiated at the Centre for Offshore Foundation Systems to improve methods for assessing the potential damage to pipelines and to provide information to assist re-routing of a pipeline to a safer alignment if necessary. This paper presents an overview of the development of specific modeling techniques to (i) trigger a submarine landslide in a geotechnical centrifuge, (ii) measure the strength properties of the slide material before, during, and after the slide failure and (iii) measure the interaction between the runout material and the seabed.

The fate of chromium and nickel in subalpine soils derived from serpentinite

Weathering of serpentinitic parent material, naturally rich in both Cr and Ni, provides soils that generally contain elevated concentrations of both metals. In this study, soil development as well as the fate of Cr and Ni in Dystric Eutrochrepts derived from serpentinitic rock slide material were investigated in the Swiss Alps under subalpine climatic conditions. Exchangeable Ni was ≤ 0.2 mmol kg−1, but exchangeable Cr was always < 0.01 mmol kg−1. Linear correlation between dithionite-extractable Cr and Fe was positive, but negative between pyrophosphate extractable Cr and total soil carbon. Total Ni and Mg generally increased with depth. While most of the Cr was located in refractory primary minerals (pyroxene, garnet and spinels), a minor part was found in secondary Fe oxides; therefore, Cr tended to accumulate in the upper mineral part of the soil profiles and was generally less mobile than Ni. Soil Cr was not readily available for plant uptake. In some soils, exchangeable Ni reached concentrations potentially toxic to plants. Key words: Serpentinite, weathering, chromium, nickel, iron, subalpine zone

Lipase isoforms and amylase isoenzymes: assays and application in the diagnosis of acute pancreatitis

Pancreatic juice and serum from patients with acute pancreatitis contain three enzymes that have lipolytic activity: L1 and L2, which are pancreatic isoenzymes or isoforms of lipase (EC 3.1.1.3), and L3, which is probably pancreatic carboxyl ester lipase, also known as cholesterol esterase (EC 3.1.1.13). These enzymes are readily separated electrophoretically on agarose and can be developed with an overlay of Kodak Ektachem lipase slide material. The latter acts as a dry-reagent developing substrate, with the enzymes producing blue bands in the slide material. We found L1 in about one-half of normal persons, L2 in none, and L3 in all. We assayed for amylase (EC 3.2.1.1), amylase isoenzymes, lipase, and lipase isoforms in the sera of 100 patients with suspected acute pancreatitis. L2 lipase has the greatest diagnostic efficiency for the diagnosis of pancreatitis, compared with total amylase, P3 amylase, and total lipase. Lipase and L2 could replace amylase, an inefficient test, for the diagnosis of patients with suspected acute pancreatitis. In patients receiving organ transplants, a serum amylase value of greater than 300 U/L or a lipase of greater than 1000 U/L discriminated well between patients with and without complications and (or) acute rejection.