Research of stress strain state of power structural elements with functional holes under uniaxial cyclic loading

Методом скінченних елементів обчислено одновісне пружно-пластичне деформування пластини з центральним деформаційно зміцненим отвором діаметром 8 мм, 10 мм після дорнування з натягом із алюмінієвого сплаву Д16чТ 1%, 2%, 3%. Побудовано розподіл розмаху локальних напружень, максимальних та мінімальних напружень та в околі отвору залежно від кількості циклів навантаження та відносного натягу дорнування. У середній ділянці циліндричної поверхні отвору ( ) розрахункові локальні коефіцієнти асиметрії циклу у другому півциклі навантаження знижуються зі збільшенням відстані від краю отвору та зі збільшенням відносного натягу дорнування. Найменші локальні коефіцієнти асиметрії циклу навантаження R=-4…-5 для натягу дорнування 3% і сталі по товщині зразка ( мм).Using finite element method taking advantage of the software module ANSYS Explicit Dynamics elastic-plastic deformation of the plate with 8 mm, 10 mm central strain hardened hole diameter with burnishing tension 1%, 2%, 3% have been calculated. To calculate the stress strain state in the threshold of the functional hole after burnishing with different tension and cyclic loading finite-element models of a quarter of the sample with a central hole were built. The load was applied to one surface of the edge of sample model and the other surface was fixed and limited by vertical movement (along the direction of application of force). The cyclic elastic-plastic deformation of aluminum D16chT alloy plate under of soft load at and has been studied. Characteristics of mechanical properties are and . Scale distribution of local stresses , maximum and minimum local stress and in the threshold of the hole depending on the number of loading cycles and burnishing tension has been built. Local stresses and , while calculating taking advantage of the finite element method has been stabilized already for two load half-cycles. The largest range of local stresses occur in the middle part of the hole thickness without burnishing (i = 0%, ) and on the edge of the mandrel entrance after burnishing with the tension (1% ... 3%, ). For burnished holes initiation and propagation of crack from the edge of the mandrel entrance are the characteristics. It is caused by the fact, that the compressive residual stresses caused by burnishing and the range of local strains for study of tightened burnishing (i = 1% ... 3%) on the hole edge are much smaller than in the middle part. Distribution of local coefficients of asymmetry of loading cycles for burnishing tension 1%, 2%, 3% and without burnishing obtained by finite element calculation has been built. In the middle section of the cylindrical surface of the hole ( ) calculation local coefficients of asymmetry in the second half cycle load decrease with the increase of distance from the edge of the hole and with the increase of burnishing tension. Local load cycle asymmetry coefficients decrease with the threshold of depth of the cylindrical surface of the hole along the X axis for the average in depth section along the axis Z ( ) The smallest local load cycles of asymmetry coefficients R = -4 ... -5 are for burnishing tension 3% and are stable for all thickness of the sample ( mm)

Atmospheric Forcing Drives the Winter Sea Ice Thickness Asymmetry of Hudson Bay

Recently, we highlighted the presence of a strong west‐east asymmetry in sea ice thickness across Hudson Bay that is driven by cyclonic circulation. Building on this work, we use satellite altimetry and a unique set of in situ observations of ice thickness from three moored upward looking sonars to examine the role of atmospherically driven ice dynamics in producing contrasting regional ice thickness patterns. Ultimately, north‐northwesterly winds coupled with numerous reversals during winter 2016/2017 led to thicker ice in southern Hudson Bay, while enhanced west‐northwesterly winds during winter 2017/2018 led to thicker ice in eastern Hudson Bay that delayed breakup and onset of the summer shipping season to coastal communities. Extending the analysis over the 40‐year satellite observation period, we find that these two different patterns of atmospheric forcing alter the timing of breakup by 30 days in eastern Hudson Bay and offer some skill in seasonal predictions of breakup

Correlation of bone density of individual jaw sections according to Hounsfield with the length of the adentiary section in the cone-beam computer tomography program

Aim. To study the existence of a relationship between the density of bone tissue and the length of the edentulous part of the tooth row. Materials and methods. Evaluation of the density of the spongy substance of the jaws by the maximum and average value of HU. The density of cancellous bone was evaluated only in the areas available for implant placement. The groups consisted of the localization and extent of the dentition defect. Statistical methods included the estimation of the arithmetic mean (M), standard deviation (σ), error of the mean (m), confidence interval (95 % CI), estimation of the median (Me) and interquartile range ([Q1; Q2]), Student’s test (t criterion). Results. Maximum and average indicators of cancellous bone density in defects of the upper (562.4 [347.1; 777.8] and 301.5 [163.0; 439.9], respectively (р = 0.84) and lower (1379.0 [1116.2; 1641.9] HU and 848.6 [630.6; 1066.6] HU, respectively, p = 0.96) jaws in the areas of molars and premolars with “large” defects are significantly different from the indicators “small” defects (299.7 [176.9; 422.4] and 642.6 [470.4; 814.9], 1061.1 [866.5; 1255.7] and 608.3 [440.5; 776.1, respectively). The average bone density of the alveolar process of the upper jaw is almost the same in defects of different lengths. The average density of the cancellous bone of the alveolar part of the lower jaw in “large” defects has significant differences from “average” ones (p = 0.02) and “small” (p = 0.005) defects. Conclusions. The average density of cancellous bone of the alveolar part of the lower jaw in “large” defects has significant differences from “medium” (p = 0.02) and “small” (p = 0.005) defects, and regardless of the extent of the dentition defect corresponds to class D3 (350–850 HU) according to the Misch classification. The average density of cancellous bone of the alveolar process of the upper jaw in the areas of molars and premolars does not have significant differences depending on the extent of the dentition defect and corresponds to class D4 (150–350 HU) according to the Misch classification. Since one class includes a large range of values, the clinical classification of Misch does not allow taking into account individual bone density indicators that have statistically significant differences in different areas of the dentition

A baseline evaluation of oceanographic and sea ice conditions in the Hudson Bay Complex during 2016-2018

In this paper, we examine sea surface temperatures (SSTs) and sea ice conditions in the Hudson Bay Complex as a baseline evaluation for the BaySys 2016–2018 field program time frame. Investigated in particular are spatiotemporal patterns in SST and sea ice state and dynamics, with rankings of the latter to highlight extreme conditions relative to the examined 1981–2010 climatology. Results from this study show that SSTs in northwestern Hudson Bay from May to July, 2016–2018, are high relative to the climatology for SST (1982–2010). SSTs are also warmer in 2016 and 2017 than in 2018 relative to their climatology. Similarly, unusually low sea ice cover existed from August to December of 2016 and July to September of 2017, while unusually high sea ice cover existed in January, February, and October of 2018. The ice-free season was approximately 20 days longer in 2016 than in 2018. Unusually high ice-drift speeds occurred in April of 2016 and 2017 and in May of 2018, coinciding with strong winds in 2016 and 2018 and following strong winds in March 2017. Strong meridional circulation was observed in spring of 2016 and winter of 2017, while weak meridional circulation existed in 2018. In a case study of an extreme event, a blizzard from 7 to 9 March 2017, evaluated using Lagrangian dispersion statistics, is shown to have suppressed sea ice deformation off the coast of Churchill. These results are relevant to describing and planning for possible future pathways and scenarios under continued climate change and river regulation

A baseline evaluation of atmospheric and river discharge conditions in the Hudson Bay Complex during 2016-2018

In this article, we examine atmospheric and river discharge conditions within the Hudson Bay Complex for the BaySys 2016–2018 field program time frame. Investigated in particular is a subset of European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis - Interim (ERA-Interim) atmospheric forcing variables, namely 2-m surface temperature, 10-m surface winds, precipitation, and sea-level pressure, in addition to river discharge. Results from this assessment show that 2016 was characterized by unusually warm conditions (terrestrial and marine) throughout the annual cycle; 2017 by strong cyclone activity in March and high precipitation in January, October, and November; and 2018 by cold and windy conditions throughout the annual cycle. Evaluation of terrestrial conditions showed higher than normal land surface temperatures (the Hudson Bay physical watershed) for all of the 2016–2018 period (excluding a colder than normal spell August–November 2018), particularly in January (2016 and 2017), higher than normal precipitation in October (2016 and 2017), and higher than normal terrestrial discharge to the Hudson Bay Complex in March (2016 and 2017), with drier than average June through October (2016–2018)

Simulated impacts of relative climate change and river discharge regulation on sea ice and oceanographic conditions in the Hudson Bay Complex

In this analysis, we examine relative contributions from climate change and river discharge regulation to changes in marine conditions in the Hudson Bay Complex using a subset of five atmospheric forcing scenarios from the Coupled Model Intercomparison Project Phase 5 (CMIP5), river discharge data from the Hydrological Predictions for the Environment (HYPE) model, both naturalized (without anthropogenic intervention) and regulated (anthropogenically controlled through diversions, dams, reservoirs), and output from the Nucleus for European Modeling of the Ocean Ice-Ocean model for the 1981–2070 time frame. Investigated in particular are spatiotemporal changes in sea surface temperature, sea ice concentration and thickness, and zonal and meridional sea ice drift in response to (i) climate change through comparison of historical (1981–2010) and future (2021–2050 and 2041–2070) simulations, (ii) regulation through comparison of historical (1981–2010) naturalized and regulated simulations, and (iii) climate change and regulation combined through comparison of future (2021–2050 and 2041–2070) naturalized and regulated simulations. Also investigated is use of the diagnostic known as e-folding time spatial distribution to monitor changes in persistence in these variables in response to changing climate and regulation impacts in the Hudson Bay Complex. Results from this analysis highlight bay-wide and regional reductions in sea ice concentration and thickness in southwest and northeast Hudson Bay in response to a changing climate, and east-west asymmetry in sea ice drift response in support of past studies. Regulation is also shown to amplify or suppress the climate change signal. Specifically, regulation amplifies sea surface temperatures from April to August, suppresses sea ice loss by approximately 30% in March, contributes to enhanced sea ice drift speed by approximately 30%, and reduces meridional circulation by approximately 20% in January due to enhanced zonal drift. Results further suggest that the offshore impacts of regulation are amplified in a changing climate

Sediment-laden sea ice in southern Hudson Bay: Entrainment, transport, and biogeochemical implications

During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an average freeboard of 2.2 m, which corresponds to an estimated total thickness of 18 m, far greater than expected within a seasonal ice cover. Samples of the upper portion of the ice floe revealed that it was isothermal and fresh in areas with sediment present on the surface. Fine-grained sediment and larger rocks were visible on the ice surface, while a pronounced sediment band was observed in an ice core. Initial speculation was that this ice had formed in the highly dynamic Nelson River estuary from freshwater, but δ^{18}O isotopic analysis revealed a marine origin. In southern Hudson Bay, significant tidal forcing promotes both sediment resuspension and new ice formation within a flaw lead, which we speculate promotes the formation of this sediment-laden sea ice. Historic satellite imagery shows that sediment-laden sea ice is typical of southern Hudson Bay, varying in areal extent from 47 to 118 km2 during June. Based on an average sediment particle concentration of 0.1 mg mL^{–1} in sea ice, an areal extent of 51,924 km2 in June 2018, and an estimated regional end-of-winter ice thickness of 1.5 m, we conservatively estimated that a total sediment load of 7.8 × 106 t, or 150 t km^{–2}, was entrained within sea ice in southern Hudson Bay during winter 2018. As sediments can alter carbon concentrations and light transmission within sea ice, these first observations of this ice type in Hudson Bay imply biogeochemical impacts for the marine system

Anti-tumor activity against multiple myeloma by combination of KW-2478, an Hsp90 inhibitor, with bortezomib

Heat shock protein 90 (Hsp90) is a promising target for anti-tumor therapy. We previously reported the anti-tumor activity of a novel Hsp90 inhibitor, KW-2478, in multiple myeloma (MM) as a single agent. In this study, we examined the combinational effect of KW-2478 and bortezomib, a proteasome inhibitor, in vitro and in vivo. In vitro, KW-2478 enhanced bortezomib-induced cell growth inhibition, both in MM cell lines and primary patient MM cells. The combination of KW-2478 and bortezomib also induced caspase activation in MM cell lines. Interestingly, the combination synergistically enhanced the expression of Hsp70B, a homolog of Hsp70, in human MM cells and peripheral blood mononuclear cells, indicating Hsp70B could be a surrogate biomarker for the combination of Hsp90 and proteasome inhibitors. In vivo, the combination of KW-2478 with bortezomib showed synergistic anti-tumor activity without significant body weight loss in a subcutaneously inoculated human myeloma model. Furthermore, the combination also showed synergistic reduction of tumor burden in bone marrow in an orthotopic myeloma model. Our results strongly suggest that combination of KW-2478 with bortezomib could exhibit enhanced anti-tumor activity against human myeloma