75 research outputs found

    Effects of Changing Surrounding Conditions on the Thermal Analysis of the Moste Concrete Dam

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    This paper deals with the heat transfer analysis of the 63 years old and 60 metres high Moste concrete arch-gravity dam, located in NW Slovenia, which was performed after a new sophisticated monitoring system had been established, making it possible to perform continuous measurements of the temperatures of the concrete, of the water, and of the surroundings of the dam, i.e. the air temperatures and the amount of solar insolation. An equation defining nonlinear and non-stationary heat conduction in the case of a two-dimensional space, for a homogeneous isotropic solid whose thermal conductivity is independent of temperature, was solved numerically by means of the finite element method, taking into account appropriate boundary conditions. The latter involved the effects of changing conditions of the surroundings (i.e. shading, convection, and solar radiation) during the analysed period of 15 consecutive clear days in the summer. The results show that the measured and calculated temperatures of the concrete at different locations, and at different depths, were in very good agreement

    DRUGG - Digitalni repozitorij UL FGG

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    Na Fakulteti za gradbeništvo in geodezijo Univerze v Ljubljani (v nadaljevanju UL FGG) smo decembra 2011 predali namenu Digitalni repozitorij UL FGG – DRUGG. Dosegljiv je na spletni strani fakultete http://eprints.fgg.uni-lj.si/

    Divje babe I - poskus uporabe statistične analize množičnih živalskih ostankov v paleolitski arheologiji. II. Razbite dolge mozgovne kosti jamskega medveda

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    On the basis of the standardized sample containing all determinable long marrow bones of cave bear (T. 1), and consisting of 16 archaeologically fertile and 7 archaeologically sterile arbitrarily-chosen staratified units (cf. I. Turk, J. Dirjec, Fig. 1), the hypothesis has been tested that the antropogenic breaking-open of the long marrow bones of cave bear had once occured, presumably for the consumption or extraction of marrow, on the newly discovered palaeolithic cave site at Divje babe I, near Cerkno (Slovenia, Yugoslavia). Previously, the marrow of the recent brown bear had been analysed for the purpose of determining the marrow's nutritiousness and, above all, the content values of some of the essential substances. These had been found to be present in substantially larger quantities than e.g. in the analysed marrow of red deer (Tt. 2, 3). The bones from the sample have been classified as shown in T. 1 and Fig. 2. The classification has followed major quantitative differences between the marrow in the bones of adult (group I) and juvenile specimens (group II) (R.J. Blumenschine, 1986, 37, 132; D.C. Thomas. E. Broughton, 1978). These differences are also found to be observed by the now living predators and scavengers in the consumption of marrow in terms of a definite preference for the bones of adult animals (R.J. Blumenschine, 1986, 58). Furthermore, the classification has been made in adherence to the significant differences in the amount of marrow between the subgroup humerus-femur-tibia (Aa) and radius-ulna-fibula (Bb). These differences have been expected to produce some global differences between the two subgroups if the extraction of marrow had been confirmed. The distribution of the two subgroups into bones integral (A,B) and bones broken open (a,b) is irrelevant in the present case. The only thing that is relevant here is the number of fragments which will increase in direct proportion to the degree of fragmentation of bones. Since an increase in fragmentation tends to affect the proportion of determinable to indeterminable fragments, the decision has been made to additionally keep account of the proportions between the archaeologically fertile and archaeologically sterile units. This latter division has been made to conform to any of the possible global differences between the units expected to be detected if the palaeolithic visitors to the cave had indeed taken to extracting marrow. Freshly accumulated long marrow bones of adult cave bear subjects could only have been crushed by hyenas, bears themselves, and especially by ancient men. Since no osteoodontological or other remains of cave hyena, which are only rarely traced in the palaeolithic sites of Slovenia m general, had been unearthed at the site treated here, the only two biogenic agents left for consideration are man and cave bear. Yet the high degree of fragmentation so typical of the Divje babe I site can never be the result of mere intensive decomposition of bones caused by natural agencies because the bones in general are in a very good state of preservation, with most fragments displaying rounded adges of fractures that had mostly originated in the time prior to the final integration of the fragments into the sediment. This was the reason why all of the tests had been prepared so as to make it possible for any global differences that could be associated with the activities of man to become visible, as well as to bring down to the lowest possible degree various disturbances caused by other living and non-living agencies that should be taken into consideration as well. In testing the hypothesis concerning the anthropogenic causes for the fragmentary state of the long marrow bones of cave bear from Divje babe I, only non-parametric statistics has been used, since it is known to impose fewer tasks on the person analysing the data, although it usually yields rather rough results. The results of Friedman's Fc test for dependent samples, p=0. 05 (H. Biining, G. Trenkler, 1978, 217 ff.), which had been used to test the global differences between the (a) and (b) subgroups in the units exhibiting cultural remains and features, have proved different taphonomical features for the humerus-femur-tibia subgroup in comparsion with those of the radius-ulna-fibula subgroup, both in adult and juvenile specimens (Fig. 2). The homogeneous character of the bones containing larger amounts of marrow (humerus-femur-tibia) is above all significant with the adult specimens, since it has been testified to both between the bones and between the units. The results of the test are in agreement with the hypothesis of the extraction of marrow, however they fail to yield any further details on the fact. This leaves us room enough to make different alternative explanations, which, however, have nothing to do with the hypothesis proposed above. The results of Wilcoxon's one-sided test for dependent samples and the exact distribution, p=0.05 (H. Biining, G. Trenkler, 1978, 186 ff.), which had been used to test the differences between the (a) and (b) subgroups in the units exhibiting cultural remains and features, have shown significantly lower values in adult specimens' bones that contained larger amounts of marrow, whereas the analougous bones of juvenile specimens have displayed just the opposite results (Fig. 3). One way of explaining this fact is to seek the cause in the increased fragmentary state of the bones from certain subgroups within the two groups, and the minimized determinabilty of osteological fragments related to it. For this reason the proportion of determinable to indeterminable fragments in the 16 archaeologically fertile and 7 archaeologically sterile units have been put to Wilcoxon's one-sided test for independent samples, p=0.05, with the result of establishing that the proportions in the archaeologically fertile units are significantly higher than those in the archaeologically sterile units (cf. p. 36), which is direct opposition to the conjecture of a higher amount of indeterminable fragments in the archaeologically fertile units owing to the more intensive process of fragmentation. Another disturbing point is the complementarity of the results in both subgroups of long marrow bones of both the adult and juvenile specimens. One of the possible alternative interpretation of the given situation is the most direct one, i.e. that the fragments represent the natural state of affaires, which, of course, is in direct opposition to the hypothesis as it has been proposed above. The results of Wilcoxon's one-sided test for independent samples and the exact distribution, p=0.05 (H. Biining, G. Trenkler, 1978, 145 ff.), between the archaeologically fertile and archaelogically sterile units, have shown that the former will invariably yield more remains (T. 4). In addition to the absolute ones, a measure of qualitative aberrations between the two groups and further subgroups of the long bones would naturally be expected to be found in the course of testing the above hypothesis. Some inexplicable qualitative aberrations that had already been established in the analysis of skeletal elements (I. Turk, J. Dirjec, 1989) had completely blurred major absolute quantitative differences between the two groups of units. That is why the proportion of the humerus-femur-tibia to radius-ulna-fibula subgroups have additionally been tested both in adults and cubs. Wilcoxon's one-sided test for independent samples, p=0.05, has shown these proportions to be significantly higher in the archaeologically fertile units both in the juvenile and adult specimens, which means that, very likely, there are no relevant differences between the two groups. Both the ponderings of the naive intuitive and the formal quantitative techniques would suggest the following conclusions: The analysed remains of cave bear had been accumulating at the entrance to the cave most probably because of the natural dying-off subjects and the autopodal accumulation of their skeletal remains. The agency of early men in this process must have been negligible, if at all present. The fact that ancient men would break open the bones of cave bear, and even some of the human long marrow bones which resembled them (in their morphological and structural features) (P. Villa et al., 1986), has indeed been proven by a number of finds from later archaeological periods. The analyses of recent brown bear's marrow have confirmed the edibility and nutritional value of the marrow, and even the presence of some essential substances. However, the results of the executed statistical analysis do not admit of the hypothesis of the anthropogenic breaking-open of the long marrow bones of cave bear from the Divje babe I site on the basis of the criteria proposed above. Therefore, the conclusion can be drawn that the broken-open limb bones of cave bear reveal no solid evidence of any activities of the palaeolithic visitors to the Divje babe I cave. There are several alternative explanations for the fragmentary state of the bones with predatory animals as the principal agencies, especially the cave bear himself. There is also a very simple, and also very probable alternative: All the analysed remains represent the natural state of affairs, in which the bones that have been shattered by whatever reason to a higher degree always outnumber those which have been less shattered. Logically, such an explanation can only be accepted within the two groups (adult-juvenile) but not between them

    Hydrogen embrittlement mechanisms in advanced high strength steel

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    Hydrogen embrittlement is increasingly important in advanced high strength steels (AHHS) as strength levels increase well above 1000MPa. This work developed a detailed understanding of the embrittling mechanism in model AHHS steels based on Fe-Ti-Mo and Fe-V-Mo, both strengthened through interphase precipitation. Hydrogen charging led to an increase in the dislocation density and an enlarged strain field around precipitates, resulting in an increase in residual stress. This was much greater for the Ti-Mo steel compared to the V-Mo. Important differences in the hydrogen trapping behaviour was seen between the two steels, with hydrogen believed to be trapped at the matrix/precipitate interface for the Ti-Mo steel, but within the precipitate for the V-Mo steel. The effects of hydrogen were investigated in detail for slow strain rate tensile tests and double notched tensile samples. Hydrogen charging resulted in a loss in strength and ductility, with the Ti-Mo steel failing at yield, while the V-Mo steel exhibited a ∼13% loss in strength and a ∼ 35% loss of ductility. Crack initiation in tensile samples occurred at high strain gradient dislocation boundaries. However, crack propagation rapidly became quasi-cleavage, along the {100} plane in ferrite, and also along the martensite/ferrite grain boundaries on the {110} plane in the martensite. Minimal plasticity was observed associated with the crack tip, which was believed to be a result of the suppression of dislocation emission at the crack tip by the hydrogen

    Regulatory Elements within the Prodomain of Falcipain-2, a Cysteine Protease of the Malaria Parasite Plasmodium falciparum

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    Falcipain-2, a papain family cysteine protease of the malaria parasite Plasmodium falciparum, plays a key role in parasite hydrolysis of hemoglobin and is a potential chemotherapeutic target. As with many proteases, falcipain-2 is synthesized as a zymogen, and the prodomain inhibits activity of the mature enzyme. To investigate the mechanism of regulation of falcipain-2 by its prodomain, we expressed constructs encoding different portions of the prodomain and tested their ability to inhibit recombinant mature falcipain-2. We identified a C-terminal segment (Leu155–Asp243) of the prodomain, including two motifs (ERFNIN and GNFD) that are conserved in cathepsin L sub-family papain family proteases, as the mediator of prodomain inhibitory activity. Circular dichroism analysis showed that the prodomain including the C-terminal segment, but not constructs lacking this segment, was rich in secondary structure, suggesting that the segment plays a crucial role in protein folding. The falcipain-2 prodomain also efficiently inhibited other papain family proteases, including cathepsin K, cathepsin L, cathepsin B, and cruzain, but it did not inhibit cathepsin C or tested proteases of other classes. A structural model of pro-falcipain-2 was constructed by homology modeling based on crystallographic structures of mature falcipain-2, procathepsin K, procathepsin L, and procaricain, offering insights into the nature of the interaction between the prodomain and mature domain of falcipain-2 as well as into the broad specificity of inhibitory activity of the falcipain-2 prodomain

    Effect of ageing on the microstructural evolution in a new design of maraging steels with carbon

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    A new maraging steel, based on carbide precipitation, is described. Two alloys were designed namely Fe-10Mn-0.25C-2Cr-1Mo wt% (2CrMo) and Fe-10Mn-0.25C-1Cr-2Mo wt% (Cr2Mo). These compositions were chosen to achieve ultra-high strength and high tensile elongation; the former and latter are promoted through the simulatenous precipitation of Cr- and Mo-rich carbides and Mn-rich reverted austenite. The alloys were manufactured through the standard melting, casting and hot working route. Following a solution treatment at 870 °C and quench, which gave a fully martensitic structure, the alloys were aged for various times at 510 °C. The microstructure and tensile properties were investigated in detail as a function of ageing time. The microstructure observed was dominated by micron scale and nanometre scale Mn segregation which determined the local Ac3 temperature. Austenite reversion occurred in both alloys, peaking at 16 h in both cases. In the 2CrMo alloy, the reverted austenite was mainly globular in morphology due the Ac3 temperature being lower than the ageing temperature, but was acicular in the Cr2Mo with Ac3 similar to the ageing temperature of 510 °C. Moreover, acicular austenite was promoted by Mn segregation at martensite lath boundaries in Cr2Mo. In the 2CrMo steel, carbide precipitation (M3C and M7C3) occurred during heating to the ageing temperature, but the carbides gradually dissolved with further ageing. In contrast, in the Cr2Mo alloy, precipitation of carbides (M7C3 and M2C) occurred during ageing, the volume fraction of which increased with ageing time. In both alloys a TRIP effect was observed, but the extent of this was greater for the Cr2Mo alloy. The complex microstructure obtained after 16 h led to an excellent combination of strength of 1.3 GPa and elongation of 18%. Physics-based models for the microstructure in martensite, precipitation kinetics, as well as for TRIP in austenite were employed to explain and predict the individual strengthtening contributions of the microstructure to the total strength, confirming that the maximum strength-elongation relationship found after 16 h is due to an optimal combination of a slightly overaged - but still strong- martensite and 30% of reverted austenite, for increased work hardening and ductility

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    Measurement of the W boson polarisation in ttˉt\bar{t} events from pp collisions at s\sqrt{s} = 8 TeV in the lepton + jets channel with ATLAS

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    Measurement of jet fragmentation in Pb+Pb and pppp collisions at sNN=2.76\sqrt{{s_\mathrm{NN}}} = 2.76 TeV with the ATLAS detector at the LHC

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