Academic literature on the topic 'Local strain rate'

A combined experimental-numerical approach has been developed to quantify the strain rate variation of the workpiece in the roll bite region. In this approach, cold rolling experiments at a production mill were conducted first. Then tensile and microhardness tests were performed on workpieces before and after cold rolling to establish the relationship between the microhardness and plastic strain of the material. Microhardness measurements were also conducted in the roll bite region on a partially cold rolled workpiece. A finite element rolling simulation was performed to predict the spatial variations of the strain and strain rate. Through microhardness matching, it was found that the finite-element predicted strains agree very well with those actually existing in the rolled workpiece. Consequently, the finite-element predicted strain rates, whose time-accumulation directly gave strains which matched the actual strains, were verified. Finally, a finite-element simulation of both cold and hot rolling was conducted to assess the effect of several major rolling parameters on the strain rate variation in the bite region. Results show that the spatial variations of strain rate in the roll bite region are extremely nonuniform for both cold and hot rolling.

A noncontact optical system using high speed image analysis to measure local tissue deformations and axial strains along skeletal muscle is described. The spatial resolution of the system was 20 pixels/cm and the accuracy was ±0.125mm. In order to minimize the error associated with discrete data used to characterize a continuous strain field, the displacement data were fitted with a third order polynomial and the fitted data differentiated to measure surface strains using a Lagrangian finite strain formulation. The distribution of axial strain along the muscle-tendon unit was nonuniform and rate dependent. Despite a variation in local strain distribution with strain rate, the maximum axial strain, Exx = 0.614 ± 0.045 mm/mm, was rate insensitive and occurred at the failure site for all tests. The frequency response of the video system (1000 Hz) and the measurement of a continuous strain field along the entire length of the structure improve upon previous noncontact optical systems for measurement of surface strains in soft tissues.

Abstract In the framework of turbulence-flame interaction, the flame is characterized by the gradient of a reactive scalar such as the progress variable, whereas the turbulence is represented by the vorticity and the strain rate. Quantitative assessment of this interaction is performed trough the study of the coupled transport between these quantities that are subject to the effects of heat release and chemical reactions. The present analysis aims at improving the understanding of the small scale turbulence – flame interaction properties, through the introduction of an additive decomposition of the strain rate and vorticity fields into their local and non-local components. The respective role of the local and non-local effects is studied for a broad range of Karlovitz numbers, by virtue of direct numerical simulations (DNS) of turbulent, premixed, lean, and statistically planar flames of methane-air. In the conditions of the present study, the alignment between flame front normals and the strain rate is found to be dominated by the local contribution from the strain rate tensor.

The study was conducted at the fish farm of the Department of Fish Sciences, Faculty of Agricultural Technology and Fish Sciences, Al-Neelain University. The purpose of the study is to compare the growth performance of different local strains of Nile tilapia (Oreochromis niloticus) to provide the necessary information for conducting research leading to genetic improvement of the locally farmed Nile tilapia. Fish fry used in the study were spawned by brooders collected from, Jebel Aulia Dam Reservoir (White Nile strain A) , Sennar Dam Reservoir (Sennar strain B), Lake Nubia (Halfa strain C) and khashm elgirba reservoier( Khashm elgirba strain D). The study was conducted for six weeks in twelve happas, each stocked with 30 fry in three replicates for each strain, averaging 5 g. Fish were fed by diet with a protein level of 35%. Statistical analysis showed Sennar strain was the best growth rate with a percent weight gain of 1529%, followed by white nile strain with a percent weight gain of 1114%, followed by khashm elgerba strain with a percent weight gain of 993% and finally Halfa strain with a percent weight gain of 829%. Daily Growth Rate gain was 0.9g/day for sennar strain, followed by other strain with no significant(≥0.05). Food Conversion Ratios (FCR) were best in sennar and white nile strain ,survival rate with the same no significant(≥0.05) between treatments. finally results indicated that there is significant( ≤ 0.05) between treatments so sennar and white nile strains is better than two strains in this study.

Microscopic strain and strain-induced phase transformation during plastic deformation in metastable austenitic steel were investigated at different strain rates. Quasi in-situ tension tests were performed sequentially with well-defined elongation intervals at room temperature at strain rates of 10−3 s−1 and 10−1 s−1. The tests were monitored by high-resolution optical imaging with a microscopic lens at a resolution of 0.23 µm/pixel. The macroscopic temperature was also measured with an infrared (IR) camera. The microstructure-level strain localizations were observed on the surface of the etched specimens by means of microscale digital image correlation (µDIC). Additionally, the microstructure was characterized by electron backscatter diffraction (EBSD) at the same location before and after deformation. The results of the study indicated that microscopic strain localizations favored the formation of α′-martensite particles. At the lower strain rate, high local strain concentrations formed at several locations in the microstructure, correlating with the areas where the formation of large martensite islands occurred. Martensite particles of various sizes formed nearby each other at the lower strain rate, whereas at the higher strain rate, martensite islands remained small and isolated. Although the macroscopic increase in temperature at both the studied strain rates was very low, at the higher strain rate, local heating on the microscopic scale could take place at the newly nucleated martensite embryos. This inhibited the further growth of the martensite particles, and local strain distribution also remained more homogeneous than at the lower strain rate.

The deformation behavior of a 2024 aluminum alloy sheet at elevated temperatures was studied by uniaxial hot tensile tests over the nominal initial strain rate range of 0.001–0.1 s−1 and temperature range of 375–450 °C. In order to analyze the deformation behavior with higher accuracy, a digital image correlation (DIC) system was applied to determine the strain distribution during hot tensile tests. Local stress-strain curves for different local points on the specimens were calculated. The strain rate evolution of each point during the tensile tests was investigated under different deformation conditions. Then, an improved Fields–Backofen (FB) model, taking into account the local strain rate evolution instead of the fixed strain rate, was proposed to describe the constitutive behaviors. It has been found that obvious non-uniform strain distribution occurred when the true strain was larger than 0.3 during hot tensile tests. The strain rate distribution during deformation was also non-uniform. It showed increasing, steady, and decreasing variation tendencies for different points with the increasing of strain, which led to the local flow stress being different at different local points. The flow stresses predicted by the improved FB model showed good agreement with experimental results when the strain rate evolutions of local points during tensile tests were considered. The prediction accuracy was higher than that of traditional FB models.

Abstract An impact experiment is designed to obtain the deformation and fracture characteristics of SBR specimens under tensile impact loading. The experimental apparatus is capable of achieving very large strains (about 300%) and high strain rates (between 10 and 1000 s−1) in the specimen. Dynamic stress-strain curves reveal that SBR goes through several phases of deformation and fracture as the strain rate increases in the specimen. In the first phase, the initial modulus, yield stress, tensile strength, and fracture strain increase, while the final modulus remains fairly constant with increasing strain rate. Increases in the initial modulus, tensile strength, and strain at fracture with increasing strain rate are due to a lack of stress relaxation in constituents that have longer relaxation times than the load duration. Local scale relaxation times are shorter than the load duration in this phase so that the final modulus is almost insensitive to strain rate. In the second phase, the initial modulus and the yield stress remain roughly constant while the final modulus increases with increasing strain rate. The tensile strength also increases, but the fracture strain decreases as the strain rate increases. Increases in the final modulus and tensile strength are due to a lack of relaxation on a local scale. The tensile fracture strain decreases because convolutions do not have sufficient time to slip completely. In the third phase, all stress-strain curves follow a master curve, but both the tensile strength and fracture strain decrease with increasing strain rate. The decrease in tensile strength as the strain rate increases could be due to stress concentration at the tip of microcracks within the SBR.

Dans ce travail, des modèles thermomécaniques basés sur une approche non-locale sont proposés pour décrire le comportement des Alliages à Mémoire de Forme (AMF) avec la prise en compte des effets de la localisation et de la chaleur latente lors de la transformation de phase. Ces modèles sont obtenus comme des extensions d’un modèle local existant. Pour décrire la localisation de la transformation de phase, l’extension du modèle initial a consisté à le réécrire dans un contexte non-local par l’introduction d’une nouvelle variable, définie comme la contrepartie non-locale de la fraction volumique de martensite déjà présente dans le modèle local. L’exploitation de ce modèle a nécessité le développement d’un élément fini spécial dans ABAQUS avec la fraction volumique non-locale de martensite comme un degré de liberté supplémentaire. Les simulations réalisées montrent la pertinence d’une telle approche dans la description de la transformation de phase dans des structures minces en AMF, soumises à des chargements thermomécaniques. Pour décrire les effets de la chaleur latente, une équation d’équilibre thermique ayant comme terme source des contributions dépendant de la transformation de phase a été adjointe au modèle initial. Là encore, l’exploitation du modèle a nécessité le développement d’un élément fini qui prend en compte le couplage thermomécanique et la formulation proposée pour l’équilibre thermique. Les simulations numériques réalisées ont montré l’effet retardant sur la transformation de phase de la chaleur latente, et le caractère hétérogène possible de la transformation dans ce cas. Ces effets sont d’autant plus importants que la vitesse de déformation est élevée
In this Phd thesis, thermo-mechanical models based on a nonlocal approach are proposed in order to describe the behavior of Shape Memory Alloys (SMA), taking into account localization and latent heat effects during phase transformation. These models are obtained as extensions of an existing local model. In order to describe the localization of phase transformation, the extension of the initial model consisted of rewriting it in a nonlocal context through the introduction of a new variable, defined as the nonlocal counterpart of the martensite volume fraction. The use of this model has required the development of a specific finite element in ABAQUS with the nonlocal martensite volume fraction as an additional degree of freedom. The simulations show the relevance of such an approach in the description of the phase transformation occurring in thin SMA structures subjected to thermo-mechanical loadings. To achieve the description of the latent heat effects, a heat balance equation with a source term depending on contributions of the phase transformation was added to the constitutive equations of the initial model. Even there, the use of the model required the development of a finite element which takes into account the thermo-mechanical coupling and considers the proposed formulation for the thermal balance. Numerical simulations have shown the delaying effect of the latent heat on phase transformation and the possible heterogeneous character of the phase transformation in this case. These effects are even more important as the strain rate is high

With the end of the Soviet Union in 1991, a major turning point in all former Soviet Republics, Central Asian and Caucasian countries began to reflect on their history and identities. As a consequence of their opening up to the global exchange of ideas, various strains of Islam and trends in Islamic thought have nourished the Islamic revival that had already started in the context of glasnost and perestroika—from Turkey, Iran, the Arabian Peninsula, and from the Indian subcontinent, the four regions with strong ties to Central Asian and Caucasian Islam before Soviet occupation. Bayram Balci seeks to analyze how these new Islamic influences have reached local societies and how they have interacted with pre-existing religious belief and practices. Combining exceptional erudition with rare first-hand research, Balci's book provides a sophisticated account of both the internal dynamics and external influences in the evolution of Islam in the region.

AbstractA multiscale analysis is performed to investigate deformation and fracture in the aluminum-alumina composite and steel with a boride coating as an example. Model microstructure of the composite materials with irregular geometry of the matrix-particle and substrate-coating interfaces correspondent to the experimentally observed microstructure is taken into account explicitly as initial conditions of the boundary value problem that allows introducing multiple spatial scales. The problem in a plane strain formulation is solved numerically by the finite-difference method. Physically-based constitutive models are developed to describe isotropic strain hardening, strain rate and temperature effects, Luders band propagation and jerky flow, and fracture. Local regions experiencing bulk tension are found to occur during compression that control cracking of composites. Interrelated plastic strain localization in the steel substrate and aluminum matrix and crack origination and growth in the ceramic coating and particles are shown to depend on the strain rate, particle size and arrangement, as well as on the loading direction: tension or compression.

AbstractThe chapter is devoted to the analysis of the features of local structural rearrangementsin nanostructured materialsunder shear loadingand nanoindentation. The study was carried out using molecular dynamics-based computer simulation. In particular, we investigated the features of symmetric tilt grain boundary migration in bcc and fcc metals under shear loading. The main emphasis was on identifying atomic mechanisms responsible for the migration of symmetric tilt grain boundaries. We revealed that grain boundaries of this type can move with abnormally high velocities up to several hundred meters per second. The grain boundary velocity depends on the shear rate and grain boundary structure. It is important to note that the migration of grain boundary does not lead to the formation of structural defects. We showed that grain boundary moves in a pronounced jump-like manner as a result of a certain sequence of self-consistent displacements of grain boundary atomic planes and adjacent planes. The number of atomic planes involved in the migration process depends on the structure of the grain boundary. In the case of bcc vanadium, five planes participate in the migration of the Σ5(210)[001] grain boundary, and three planes determine the Σ5(310)[001] grain boundary motion. The Σ5(310)[001] grain boundary in fcc nickel moves as a result of rearrangements of six atomic planes. The stacking order of atomic planes participating in the grain boundary migration can change. A jump-like manner of grain boundary motion may be divided into two stages. The first stage is a long time interval of stress increase during shear loading. The grain boundary is motionless during this period and accumulates elastic strain energy. This is followed by the stage of jump-like grain boundary motion, which results in rapid stress drop. The related study was focused on understanding the atomic rearrangements responsible for the nucleation of plasticity near different crystallographic surfaces of fcc and bcc metals under nanoindentation. We showed that a wedge-shaped region, which consists of atoms with a changed symmetry of the nearest environment, is formed under the indentation of the (001) surface of the copper crystallite. Stacking faults arise in the (111) atomic planes of the contact zone under the indentation of the (011) surface. Their escape on the side free surface leads to a step formation. Indentation of the (111) surface is accompanied by nucleation of partial dislocations in the contact zone subsequent formation of nanotwins. The results of the nanoindentation of bcc iron bicrystal show that the grain boundary prevents the propagation of structural defects nucleated in the contact zone into the neighboring grain.

Many flows involve a sense of rotation. Clear examples include cyclones, whirlpools, and eddies. Less apparent, perhaps, is the interesting result that a one-dimensional shearing flow—for example, Couette flow—possesses a rotational component. As we will see below, the idea of fluid vorticity provides a way to characterize the rotational qualities of such flows. In addition, our treatment of vorticity will provide a way to distinguish between simple shear and pure shear of a fluid. Because shearing motions involve viscous dissipation of energy in real fluids, our descriptions of vorticity and shear will form an important part of the development of dynamical equations for flows that involve viscous forces (Chapter 12). The idea of vorticity also is useful in visualizing the onset of flow separation (Example Problem 11.4.2), very viscous flow behavior (Example Problem 12.6.5), and certain aspects of turbulence (Chapters 14 and 15). Beyond this, our treatment of vorticity is not emphasized. Let us envision a vorticity meter made of two small orthogonal vanes, with the end of one vane marked for easy identification. (Such meters can readily be constructed and used as described next.) Consider placing this meter at some position within a fluid that is rotating like a rigid body. The vorticity meter in this case rotates with the fluid in such a way that its orientation relative to the axis of rotation of the fluid remains fixed. As we will see below, the fluid possesses a definite vorticity that is reflected in the observation that the vorticity meter rotates with respect to its own axis. In this regard, we also may observe that the angular velocity of this local rotation of the meter is the same regardless of its distance from the fluid axis. Now consider a one-dimensional (Couette) shear flow. A vorticity meter placed at any position within this flow also rotates about its center due to the streamwise velocity differential over the span of the meter. Judging from the behavior of the meter, this flow also possesses a definite vorticity. We also may envision that the rate of rotation varies directly with the velocity gradient du/dy.

The narrative halts temporarily, for some analysis of structures. The steep decline of urbanism documented later in the Roman successor state (Byzantium) had not yet set in, but a first stage in the centralization of government functions was already discernible. The costs of the war bore heavily on both belligerents, but there was more strain on Roman finances. The Sasanians were able to draw on the resources of the occupied Roman provinces, but were careful not to increase the rate of taxation. They also showed sensitivity in handling local elites and minimizing changes to administrative practices. At home confidence grew in ultimate victory and preparations were made for its commemoration in monumental rock reliefs.

The design, control, and optimization of forming processes require (1) analytical knowledge regarding metal flow, stresses, and heat transfer, as well as (2) technological information related to lubrication, heating and cooling techniques, material handling, die design and manufacture, and forming equipment. The purpose of using analysis in metal forming is to investigate the mechanics of plastic deformation processes, with the following major objectives. • Establishing the kinematic relationships (shape, velocities, strain-rates, and strains) between the undeformed part (billet, blank, or preform) and the deformed part (product); i.e., predicting metal flow during the forming operation. This objective includes the prediction of temperatures and heat transfer, since these variables greatly influence local metal-flow conditions. • Establishing the limits of formability or producibility; i.e., determining whether it is possible to perform the forming operation without causing any surface or internal defects (cracks or folds) in the deforming material. • Predicting the stresses, the forces, and the energy necessary to carry out the forming operation. This information is necessary for tool design and for selecting the appropriate equipment, with adequate force and energy capabilities, to perform the forming operation. Thus, the mechanics of deformation provides the means for determining how the metal flows, how the desired geometry can be obtained by plastic deformation, and what the expected mechanical properties of the produced part are. For understanding the variables of a metal-forming process, it is best to consider the process as a system, as illustrated in Fig. 2.1 in Chap. 2. The interaction of most significant variables in metal forming are shown, in a simplified manner, in Fig. 3.1. It is seen that for a given billet or blank material and part geometry, the speed of deformation influences strain-rate and flow stress. Deformation speed, part geometry, and die temperature influence the temperature distribution in the formed part. Finally, flow stress, friction, and part geometry determine metal flow, forming load, and forming energy. In steady-state flow (kinematically), the velocity field remains unchanged, as is the case in the extrusion process; in nonsteadystate flow, the velocity field changes continuously with time, as is the case in upset forging.

In this paper, a structural dynamic response comparison between jacket foundation large-scale offshore wind turbines (OWTs) and monopile ones under wind and seismic loads is demonstrated. The interaction between flexible soil and pile foundation is described by Winkler soil-structure interaction (SSI) model. The National Renewable Energy Laboratory (NREL) 5 MW large-scale OWT is studied via the finite element model. The structural transient dynamic response of these two structures under normal operating conditions at rated wind speed and earthquake is calculated. The results show that under the action of seismic and turbulent wind, the jacket has better wind and seismic resistance, and the displacement of the top of the tower is small, which can effectively protect the blades and the nacelle. Compared with monopile, the range of the Mises equivalent stress amplitude of the jacket wind turbine was reduced and the average value was decreased at the time of the seismic. The study also found that the existing jacket design will have a local strain energy surge.

Several continuum-based shock models have been proposed to understand the dynamic compressive behavior of cellular materials, but they are mainly based on the quasi-static stress–strain relation and thus lack sufficient dynamic stress–strain information. A virtual ‘test’ of irregular honeycombs under constant-velocity compression is carried out using the finite element method. A method based on the optimization of local deformation gradient by using the least square method is employed to calculate the one-dimensional strain distribution in the loading direction of the specimen. Meanwhile, a method based on the cross-sectional engineering stress is developed to obtain the one-dimensional stress distribution in the loading direction. The two typical features of cellular materials under dynamic crushing, namely deformation localization and strength enhancement, can be characterized by the strain and stress distributions, respectively. The results also confirm the existence of plastic shock front propagation in cellular structures under high-velocity impact, from which the shock wave speed can be estimated. The shock wave speed obtained from the local strain field method coincides with that from the cross-sectional stress method. The results of shock wave speed are also compared with those predicted by continuum-based shock models. It is shown that the shock wave speed predicted by the R-PP-L (rate-independent, rigid–perfect plastic–locking) shock model or the R-LHP-L (rate-independent, rigid–linearly hardening plastic–locking) shock model is overestimated, but that predicted by the R-PH (rate-independent, rigid–plastic hardening) shock model is close to those obtained from the local strain and cross-sectional stress calculations using the cell-based finite element model.

Polyethylene (PE) pipes have been applied in transportation of key energy medium such as natural gas in the past decades. The mechanical property of PE is of great importance for better design and safer application of PE pipeline system. The large deformation behavior is a key character of PE, not only for its significant strain rate sensitivity, but also for localized necking process after yielding. In this paper, a new constitutive modeling method was proposed to charaterize the rate-denpendent large deformation behavior of PE, in which the true stress is regarded as a function of true stain and true strain rate alone. Uniaxial tensile tests of PE were conducted under various cross-head speeds, and a digital camera was used to record the real-time deformation of specimens. By separating the composite effect into respective effect of local true strain and strain rate on the local true stress in the necking region, a phenomenological model for describing the rate-dependent deformation behavior under uniaxial tension was ealstablished. Model results were validated and found in good agreement with experimental data.

In certain alloys non-homogeneous plastic flow is observed. A category of jerky flow, also called the Portevin-Le Chatelier (PLC) effect, is attributed to the competition between dislocation aging by solute atoms and plastic strain rate. In this study, the PLC effect was examined in an aluminum-magnesium alloy using digital image correlation (DIC) techniques. A cold rolling procedure was developed for Al5052-T0 specimens that resulted in repeatable jerky flow when tested in tension at nominal displacement rates that spanned three orders of magnitude. The tests were successful in producing repeatable propagating type bands of serrated flow, which resulted in serrations or stress drops on the stress versus time curve. Deforming specimens were photographed during testing, and the images were correlated using commercially available DIC software to determine local strains and local strain rates. The present study focuses upon type B, or hopping, bands. The DIC results revealed that the strain front moved along the length of the specimen and strains 1 to 2% higher were observed in the wake of the propagating bands. In addition, at least an order of magnitude increase in local strain rate corresponded to the band front as it moved through the specimen. At slower nominal displacement rates, the magnitude of the stress drops for type B bands was greater, but the number of stress drops was fewer for a given nominal displacement. The repeatability of this study shows that DIC provides an effective way to characterize this type of non-homogeneous or localized plastic flow.

This paper reports the cellular photosynthetic rates of the green algae Chlamydomonas reinhardtii wild strain and its truncated chlorophyll antenna transformant, tla1, as a function of local irradiance. It is hypothesized that reduction in the pigmentation of algae cells can enhance light peneration in mass cultures and increase productivity. Thus, an experimental setup was designed to expose each cell within planktonic algae cultures to a nearly uniform irradiance. An oxygen microsensor was used to monitor the photosynthetic rate as the irradiance onto the sample was varied. The results showed that the cellular photosynthetic rate of the wild strain, CC125, was greater than that of tla1 at all irradiances, by a factor that ranged from 1.7 to 4. Photoinhibition was observed in both strains, although the effect was more pronounced in CC125. Although less pigmented cells enable deeper light penetration in photobioreactors, their reduced phosotynthetic rate can negate this benefit.

Abstract In this study, Johnson-Cook fracture strain model considering the effect of stress triaxiality and strain rate is determined for austenitic stainless steel 304. Tensile test data of four different stress triaxiality and six different strain rate conditions are used to determine the parameters in the J-C fracture strain model. To see the effect of local variation of stress triaxiality and strain rate in the specimen, the J-C fracture models are determined in two different ways. The first case uses the initial stress triaxiality and nominal strain rate, and the second case uses the average value of local stress triaxiality and strain rate obtained from finite element analysis. The use of initial stress triaxiality gives conservative estimate of fracture strain at low stress triaxiality, and non-conservative estimate at high stress triaxiality. The use of nominal strain rate gives overall conservative estimate of fracture strain.

Swirling flows are widely used in industrial burners and gas turbine combustors for flame stabilization. Several prior studies have shown that these flames exhibit complex dynamics under near-blowoff conditions, associated with local flamelet extinction and alteration in the vortex breakdown flow structure. These extinction events are apparently due to the local strain rate irregularly oscillating above and below the extinction strain rate values near the attachment point. In this work, global, temporally resolved and detailed spatial measurements were obtained of hydrogen/methane flames. Supporting calculations of extinction strain rates were also performed using detailed kinetics. It is shown that flames become unsteady (or local extinctions happen) at a nearly constant extinction strain rate for different hydrogen/methane mixtures. Based upon analysis of these results, it is suggested that classic Damkohler number correlations of blowoff are, in fact, correlations for the onset of local-extinction events, not blowoff itself. Corresponding Mie scattering imaging of near-blowoff flames also was used to characterize the spatio-temporal dynamics of holes along the flame that are associated with local extinction.

Failure strain at any point on a structure is not a constant but is a function of several factors, such as stress state, strain rate, and temperature. Failure strain predicted from the uniaxial tensile testing cannot be applied to the bi-axial or tri-axial stress state. ASME Sec VIII-Div-2, and −3 codes give methods to predict the failure strain for multi-axial stress state by considering the triaxiality factor, which is defined as the ratio of mean stress to the equivalent stress. Failure strain predicted by the ASME method (based on the Rice-Tracey ductile failure model) is an exponential curve that relates the failure strain to the triaxiality factor. The ASME VIII-3 method also gives procedures to calculate failure strain for various material types: ferritic, stainless steel, nickel alloy, aluminum, etc. Experimental results of failure strain at various stress states show that the failure strain is not only a function of the triaxiality factor, but also a function of the Lode angle. The Lode angle takes on the value of 1, 0, and −1 for tension, pure shear, and compression stress state, respectively. Experimental data shows that the failure strain is a 3D surface which has an exponential relation with triaxiality and a parabolic relation with the Lode angle. To validate the ASME failure strain prediction, this paper compares experimental failure strain test data from literature with the ASME predictions. The ASME predictions are non-conservative especially for moderately ductile materials such as aluminum and high strength carbon steel. A reduction factor on failure strain for low ductile material is presented using the relation between the R (yield/ultimate) and the stress ratio (shear/tensile stress). The ASME method does not account for the environmental effects while calculating the failure strain. High pressure, high temperature (HPHT) subsea components designed using ASME VIII-3 code are subjected to various environments in subsea, such as seawater, seawater with cathodic protection (CP) and production fluid (crude oil). Experimental data shows that the Elongation (EL) and/or Reduction in Area (RA) from tensile testing decrease in these environments. Therefore, to account for any environment effect on the failure strain, reduced EL and RA can be used to predict the failure strain.

Brucella Mutagenesis (TAMU) The working hypothesis for this study was that survival of Brucella vaccines was directly related to their persistence in the host. This premise is based on previously published work detailing the survival of the currently employed vaccine strains S19 and Rev 1. The approach employed signature-tagged mutagenesis to construct mutants interrupted in individual genes, and the mouse model to identify mutants with attenuated virulence/survival. Intracellular survival in macrophages is the key to both reproductive disease in ruminants and reticuloendothelial disease observed in most other species. Therefore, the mouse model permitted selection of mutants of reduced intracellular survival that would limit their ability to cause reproductive disease in ruminants. Several classes of mutants were expected. Colonization/invasion requires gene products that enhance host-agent interaction or increase resistance to antibacterial activity in macrophages. The establishment of chronic infection requires gene products necessary for intracellular bacterial growth. Maintenance of chronic infection requires gene products that sustain a low-level metabolism during periods characterized little or no growth (1, 2). Of these mutants, the latter group was of greatest interest with regard to our originally stated premise. However, the results obtained do not necessarily support a simplistic model of vaccine efficacy, i.e., long-survival of vaccine strains provides better immunity. Our conclusion can only be that optimal vaccines will only be developed with a thorough understanding of host agent interaction, and will be preferable to the use of fortuitous isolates of unknown genetic background. Each mutant could be distinguished from among a group of mutants by PCR amplification of the signature tag (5). This approach permitted infection of mice with pools of different mutants (including the parental wild-type as a control) and identified 40 mutants with apparently defective survival characteristics that were tentatively assigned to three distinct classes or groups. Group I (n=13) contained organisms that exhibited reduced survival at two weeks post-infection. Organisms in this group were recovered at normal levels by eight weeks and were not studied further, since they may persist in the host. Group II (n=11) contained organisms that were reduced by 2 weeks post infection and remained at reduced levels at eight weeks post-infection. Group III (n=16) contained mutants that were normal at two weeks, but recovered at reduced levels at eight weeks. A subset of these mutants (n= 15) was confirmed to be attenuated in mixed infections (1:1) with the parental wild-type. One of these mutants was eliminated from consideration due to a reduced growth rate in vitro that may account for its apparent growth defect in the mouse model. Although the original plan involved construction of the mutant bank in B. melitensis Rev 1 the low transformability of this strain, prevented accumulation of the necessary number of mutants. In addition, the probability that Rev 1 already carries one genetic defect increases the likelihood that a second defect will severely compromise the survival of this organism. Once key genes have been identified, it is relatively easy to prepare the appropriate genetic constructs (knockouts) lacking these genes in B. melitensis Rev 1 or any other genetic background. The construction of "designer" vaccines is expected to improve immune protection resulting from minor sequence variation corresponding to geographically distinct isolates or to design vaccines for use in specific hosts. A.2 Mouse Model of Brucella Infection (UWISC) Interferon regulatory factor-1-deficient (IRF-1-/- mice have diverse immunodeficient phenotypes that are necessary for conferring proper immune protection to intracellular bacterial infection, such as a 90% reduction of CD8+ T cells, functionally impaired NK cells, as well as a deficiency in iNOS and IL-12p40 induction. Interestingly, IRF-1-/- mice infected with diverse Brucella abortus strains reacted differently in a death and survival manner depending on the dose of injection and the level of virulence. Notably, 50% of IRF-1-/- mice intraperitoneally infected with a sublethal dose in C57BL/6 mice, i.e., 5 x 105 CFU of virulent S2308 or the attenuated vaccine S19, died at 10 and 20 days post-infection, respectively. Interestingly, the same dose of RB51, an attenuated new vaccine strain, did not induce the death of IRF-1-/- mice for the 4 weeks of infection. IRF-1-/- mice infected with four more other genetically manipulated S2308 mutants at 5 x 105 CFU also reacted in a death or survival manner depending on the level of virulence. Splenic CFU from C57BL/6 mice infected with 5 x 105 CFU of S2308, S19, or RB51, as well as four different S2308 mutants supports the finding that reduced virulence correlates with survival Of IRF-1-/- mice. Therefore, these results suggest that IRF-1 regulation of multi-gene transcription plays a crucial role in controlling B. abortus infection, and IRF-1 mice could be used as an animal model to determine the degree of B. abortus virulence by examining death or survival. A3 Diagnostic Tests for Detection of B. melitensis Rev 1 (Kimron) In this project we developed an effective PCR tool that can distinguish between Rev1 field isolates and B. melitensis virulent field strains. This has allowed, for the first time, to monitor epidemiological outbreaks of Rev1 infection in vaccinated flocks and to clearly demonstrate horizontal transfer of the strain from vaccinated ewes to unvaccinated ones. Moreover, two human isolates were characterized as Rev1 isolates implying the risk of use of improperly controlled lots of the vaccine in the national campaign. Since atypical B. melitensis biotype 1 strains have been characterized in Israel, the PCR technique has unequivocally demonstrated that strain Rev1 has not diverted into a virulent mutant. In addition, we could demonstrate that very likely a new prototype biotype 1 strain has evolved in the Middle East compared to the classical strain 16M. All the Israeli field strains have been shown to differ from strain 16M in the PstI digestion profile of the omp2a gene sequence suggesting that the local strains were possibly developed as a separate branch of B. melitensis. Should this be confirmed these data suggest that the Rev1 vaccine may not be an optimal vaccine strain for the Israeli flocks as it shares the same omp2 PstI digestion profile as strain 16M.

Situated in a complex region of the world, Puntland State in Somalia is dealing with a range of threats and instabilities such as droughts, floods, locusts, the movement of internally displaced people (IDPs), and armed actors. COVID-19 has added yet another strain on its tremendously fragile infrastructure. The impact of the pandemic has been far reaching, affecting livelihoods and hampering unpaid and underpaid care work and responsibilities. The multitude of crises and rates of inflation have left the majority of families food insecure and without income, halted education and health services, and exacerbated existing vulnerabilities and the incidence of violence. This gender analysis was conducted and funded by the German Federal Foreign Office (GFFO), in partnership with Oxfam in Somalia and KAALO, to better help local government bodies, agencies, NGOs, and INGOs grasp the differentiated impact of the crises on women, men, boys, and girls, and host and IDP communities, during this time of intense loss and instability. The analysis provides an overview of the experiences of the affected communities, and gives recommendations on how to address immediate concerns and plan future programming.

Background Lung cancer is the number one cause of cancer death worldwide.(1) It is the fifth most commonly diagnosed cancer in Australia (12,741 cases diagnosed in 2018) and the leading cause of cancer death.(2) The number of years of potential life lost to lung cancer in Australia is estimated to be 58,450, similar to that of colorectal and breast cancer combined.(3) While tobacco control strategies are most effective for disease prevention in the general population, early detection via low dose computed tomography (LDCT) screening in high-risk populations is a viable option for detecting asymptomatic disease in current (13%) and former (24%) Australian smokers.(4) The purpose of this Evidence Check review is to identify and analyse existing and emerging evidence for LDCT lung cancer screening in high-risk individuals to guide future program and policy planning. Evidence Check questions This review aimed to address the following questions: 1. What is the evidence for the effectiveness of lung cancer screening for higher-risk individuals? 2. What is the evidence of potential harms from lung cancer screening for higher-risk individuals? 3. What are the main components of recent major lung cancer screening programs or trials? 4. What is the cost-effectiveness of lung cancer screening programs (include studies of cost–utility)? Summary of methods The authors searched the peer-reviewed literature across three databases (MEDLINE, PsycINFO and Embase) for existing systematic reviews and original studies published between 1 January 2009 and 8 August 2019. Fifteen systematic reviews (of which 8 were contemporary) and 64 original publications met the inclusion criteria set across the four questions. Key findings Question 1: What is the evidence for the effectiveness of lung cancer screening for higher-risk individuals? There is sufficient evidence from systematic reviews and meta-analyses of combined (pooled) data from screening trials (of high-risk individuals) to indicate that LDCT examination is clinically effective in reducing lung cancer mortality. In 2011, the landmark National Lung Cancer Screening Trial (NLST, a large-scale randomised controlled trial [RCT] conducted in the US) reported a 20% (95% CI 6.8% – 26.7%; P=0.004) relative reduction in mortality among long-term heavy smokers over three rounds of annual screening. High-risk eligibility criteria was defined as people aged 55–74 years with a smoking history of ≥30 pack-years (years in which a smoker has consumed 20-plus cigarettes each day) and, for former smokers, ≥30 pack-years and have quit within the past 15 years.(5) All-cause mortality was reduced by 6.7% (95% CI, 1.2% – 13.6%; P=0.02). Initial data from the second landmark RCT, the NEderlands-Leuvens Longkanker Screenings ONderzoek (known as the NELSON trial), have found an even greater reduction of 26% (95% CI, 9% – 41%) in lung cancer mortality, with full trial results yet to be published.(6, 7) Pooled analyses, including several smaller-scale European LDCT screening trials insufficiently powered in their own right, collectively demonstrate a statistically significant reduction in lung cancer mortality (RR 0.82, 95% CI 0.73–0.91).(8) Despite the reduction in all-cause mortality found in the NLST, pooled analyses of seven trials found no statistically significant difference in all-cause mortality (RR 0.95, 95% CI 0.90–1.00).(8) However, cancer-specific mortality is currently the most relevant outcome in cancer screening trials. These seven trials demonstrated a significantly greater proportion of early stage cancers in LDCT groups compared with controls (RR 2.08, 95% CI 1.43–3.03). Thus, when considering results across mortality outcomes and early stage cancers diagnosed, LDCT screening is considered to be clinically effective. Question 2: What is the evidence of potential harms from lung cancer screening for higher-risk individuals? The harms of LDCT lung cancer screening include false positive tests and the consequences of unnecessary invasive follow-up procedures for conditions that are eventually diagnosed as benign. While LDCT screening leads to an increased frequency of invasive procedures, it does not result in greater mortality soon after an invasive procedure (in trial settings when compared with the control arm).(8) Overdiagnosis, exposure to radiation, psychological distress and an impact on quality of life are other known harms. Systematic review evidence indicates the benefits of LDCT screening are likely to outweigh the harms. The potential harms are likely to be reduced as refinements are made to LDCT screening protocols through: i) the application of risk predication models (e.g. the PLCOm2012), which enable a more accurate selection of the high-risk population through the use of specific criteria (beyond age and smoking history); ii) the use of nodule management algorithms (e.g. Lung-RADS, PanCan), which assist in the diagnostic evaluation of screen-detected nodules and cancers (e.g. more precise volumetric assessment of nodules); and, iii) more judicious selection of patients for invasive procedures. Recent evidence suggests a positive LDCT result may transiently increase psychological distress but does not have long-term adverse effects on psychological distress or health-related quality of life (HRQoL). With regards to smoking cessation, there is no evidence to suggest screening participation invokes a false sense of assurance in smokers, nor a reduction in motivation to quit. The NELSON and Danish trials found no difference in smoking cessation rates between LDCT screening and control groups. Higher net cessation rates, compared with general population, suggest those who participate in screening trials may already be motivated to quit. Question 3: What are the main components of recent major lung cancer screening programs or trials? There are no systematic reviews that capture the main components of recent major lung cancer screening trials and programs. We extracted evidence from original studies and clinical guidance documents and organised this into key groups to form a concise set of components for potential implementation of a national lung cancer screening program in Australia: 1. Identifying the high-risk population: recruitment, eligibility, selection and referral 2. Educating the public, people at high risk and healthcare providers; this includes creating awareness of lung cancer, the benefits and harms of LDCT screening, and shared decision-making 3. Components necessary for health services to deliver a screening program: a. Planning phase: e.g. human resources to coordinate the program, electronic data systems that integrate medical records information and link to an established national registry b. Implementation phase: e.g. human and technological resources required to conduct LDCT examinations, interpretation of reports and communication of results to participants c. Monitoring and evaluation phase: e.g. monitoring outcomes across patients, radiological reporting, compliance with established standards and a quality assurance program 4. Data reporting and research, e.g. audit and feedback to multidisciplinary teams, reporting outcomes to enhance international research into LDCT screening 5. Incorporation of smoking cessation interventions, e.g. specific programs designed for LDCT screening or referral to existing community or hospital-based services that deliver cessation interventions. Most original studies are single-institution evaluations that contain descriptive data about the processes required to establish and implement a high-risk population-based screening program. Across all studies there is a consistent message as to the challenges and complexities of establishing LDCT screening programs to attract people at high risk who will receive the greatest benefits from participation. With regards to smoking cessation, evidence from one systematic review indicates the optimal strategy for incorporating smoking cessation interventions into a LDCT screening program is unclear. There is widespread agreement that LDCT screening attendance presents a ‘teachable moment’ for cessation advice, especially among those people who receive a positive scan result. Smoking cessation is an area of significant research investment; for instance, eight US-based clinical trials are now underway that aim to address how best to design and deliver cessation programs within large-scale LDCT screening programs.(9) Question 4: What is the cost-effectiveness of lung cancer screening programs (include studies of cost–utility)? Assessing the value or cost-effectiveness of LDCT screening involves a complex interplay of factors including data on effectiveness and costs, and institutional context. A key input is data about the effectiveness of potential and current screening programs with respect to case detection, and the likely outcomes of treating those cases sooner (in the presence of LDCT screening) as opposed to later (in the absence of LDCT screening). Evidence about the cost-effectiveness of LDCT screening programs has been summarised in two systematic reviews. We identified a further 13 studies—five modelling studies, one discrete choice experiment and seven articles—that used a variety of methods to assess cost-effectiveness. Three modelling studies indicated LDCT screening was cost-effective in the settings of the US and Europe. Two studies—one from Australia and one from New Zealand—reported LDCT screening would not be cost-effective using NLST-like protocols. We anticipate that, following the full publication of the NELSON trial, cost-effectiveness studies will likely be updated with new data that reduce uncertainty about factors that influence modelling outcomes, including the findings of indeterminate nodules. Gaps in the evidence There is a large and accessible body of evidence as to the effectiveness (Q1) and harms (Q2) of LDCT screening for lung cancer. Nevertheless, there are significant gaps in the evidence about the program components that are required to implement an effective LDCT screening program (Q3). Questions about LDCT screening acceptability and feasibility were not explicitly included in the scope. However, as the evidence is based primarily on US programs and UK pilot studies, the relevance to the local setting requires careful consideration. The Queensland Lung Cancer Screening Study provides feasibility data about clinical aspects of LDCT screening but little about program design. The International Lung Screening Trial is still in the recruitment phase and findings are not yet available for inclusion in this Evidence Check. The Australian Population Based Screening Framework was developed to “inform decision-makers on the key issues to be considered when assessing potential screening programs in Australia”.(10) As the Framework is specific to population-based, rather than high-risk, screening programs, there is a lack of clarity about transferability of criteria. However, the Framework criteria do stipulate that a screening program must be acceptable to “important subgroups such as target participants who are from culturally and linguistically diverse backgrounds, Aboriginal and Torres Strait Islander people, people from disadvantaged groups and people with a disability”.(10) An extensive search of the literature highlighted that there is very little information about the acceptability of LDCT screening to these population groups in Australia. Yet they are part of the high-risk population.(10) There are also considerable gaps in the evidence about the cost-effectiveness of LDCT screening in different settings, including Australia. The evidence base in this area is rapidly evolving and is likely to include new data from the NELSON trial and incorporate data about the costs of targeted- and immuno-therapies as these treatments become more widely available in Australia.

1.1 Macroeconomic summary In September, headline inflation (11.4% annually) and the average of core inflation indicators (8.6% annually) continued on a rising trend, and higher increases than expected were recorded. Forecasts increased again, and inflation expectations remained above 3%. Inflationary surprises in the third quarter were significant and widespread, and they are the result of several shocks. On the one hand, international cost and price shocks, which have mainly affected goods and foods, continue to exert upwards pressure on national inflation. In addition to these external supply shocks, domestic supply shocks have also affected foods. On the other hand, the strong recovery of aggregate demand, especially for private consumption and for machinery and equipment, as well as a higher accumulated depreciation of the Colombian peso and its pass-through to domestic prices also explain the rise in inflation. Indexation also contributes, both through the Consumer Price Index (CPI) and through the Producer Price Index (PPI), which continues to have a significant impact on electricity prices and, to a lesser degree, on other public utilities and rent. In comparison with July’s report, the new forecast trajectory for headline and core inflation (excluding food and regulated items) is higher in the forecast horizon, mainly due to exchange rate pressures, higher excess demand, and indexation at higher inflation rates, but it maintains a trend of convergence towards the target. In the case of food, a good domestic supply of perishable foods and some moderation in international processed food prices are still expected. However, the technical staff estimates higher pressures on this group’s prices from labor costs, raw material prices, and exchange rates. In terms of the CPI for regulated items, the new forecast supposes reductions in electricity prices at the end of the year, but the effects of indexation at higher inflation rates and the expected rises in fuel prices would continue to push this CPI group. Therefore, the new projection suggests that, in December, inflation would reach 11.3% and would decrease throughout 2023 and 2024, closing the year at 7.1% and 3.5%, respectively. These forecasts have a high level of uncertainty, due especially to the future behavior of international financial conditions, external price and cost shocks, the persistence of depreciation of the Colombian peso, the pace of adjustment of domestic demand, the indexation degree of nominal contracts, and the decisions that would be made regarding domestic fuel and electricity prices. Economic activity continues to surprise on the upside, and the projection of growth for 2022 rose from 6.9% to 7.9% but lowered for 2023 from 1.1% to 0.5%. Thus, excess demand is higher than estimated in the previous report, and it would diminish in 2023. Economic growth in the second quarterwas higher than estimated in July due to stronger domestic demand, mainly because of private consumption. Economic activity indicators for the third quarter suggest that the GDP would stay at a high level, above its potential, with an annual change of 6.4%, and 0.6% higher than observed in the second quarter. Nevertheless, these numbers reflect deceleration in its quarterly and annual growth. Domestic demand would show similar behavior, with a high value, higher than that of output. This can be explained partly by the strong behavior of private consumption and investment in machinery and equipment. In the third quarter, investment in construction would have continued with mediocre performance, which would still place it at levels lower than those observed before the pandemic. The trade deficit would have widened due to high imports with a stronger trend than that for exports. It is expected that, in the forecast horizon, consumption would decrease from its current high levels, partly as a consequence of tighter domestic financial conditions, lower repressed demand, higher exchange rate pressures on imported goods prices, and the deterioration of actual income due to the rise in inflation. Investment would continue to lag behind, without reaching the levels observed before the pandemic, in a context of high financing costs and high uncertainty. A lower projected behavior in domestic demand and the high levels of prices for oil and other basic goods that the country exports would be reflected in a reduction in the trade deficit. Due to all of this, economic growth for all of 2022, 2023, and 2024 would be 7.9%, 0.5%, and 1.3%, respectively. Expected excess demand (measured via the output gap) is estimated to be higher than contemplated in the previous report; it would diminish in 2023 and could turn negative in 2024. These estimates remain subject to a high degree of uncertainty related to global political tension, a rise in international interest rates, and the effects of this rise on demand and financial conditions abroad. In the domestic context, the evolution of fiscal policy as well as future measures regarding economic policy and their possible effects on macroeconomic imbalances in the country, among others, are factors that generate uncertainty and affect risk premia, the exchange rate, investment, and the country’s economic activity. Interest rates at several of the world’s main central banks continue to rise, some at a pace higher than expected by the market. This is in response to the high levels of inflation and their inflation expectations, which continue to exceed the targets. Thus, global growth projections are still being moderated, risk premia have risen, and the dollar continues to gain strength against other main currencies. International pressures on global inflation have heightened. In the United States, core inflation has not receded, pressured by the behavior of the CPI for services and a tight labor market. Consequently, the U.S. Federal Reserve continued to increase the policy interest rate at a strong pace. This rate is expected to now reach higher levels than projected in the previous quarter. Other developed and emerging economies have also increased their policy interest rates. Thus, international financial conditions have tightened significantly, which reflects in a widespread strengthening of the dollar, increases in worldwide risk premia, and the devaluation of risky assets. Recently, these effects have been stronger in Colombia than in the majority of its peers in the region. Considering all of the aforementioned, the technical staff of the bank increased its assumption regarding the U.S. Federal Reserve’s interest rate, reduced the country’s external demand growth forecast, and raised the projected trajectory for the risk premium. The latter remains elevated at higher levels than its historical average, within a context of high local uncertainty and of extensive financing needs from the foreign sector and the public sector. All of this results in higher inflationary pressures associated to the depreciation of the Colombian peso. The uncertainty regarding external forecasts and its impact on the country remain elevated, given the unforeseeable evolution of the conflict between Russia and Ukraine, of geopolitical tensions, and of the tightening of external financial conditions, among others. A macroeconomic context of high inflation, inflation expectations and forecasts above 3%, and a positive output gap suggests the need for contractionary monetary policy, compatible with the macroeconomic adjustment necessary to eliminate excess demand, mitigate the risk of unanchoring in inflation expectations, and guarantee convergence of inflation at the target. In comparison with the July report forecasts, domestic demand has been more dynamic, with a higher observed output level that surpasses the economy’s productive capacity. Headline and core inflation have registered surprising rises, associated with the effects of domestic and external price shocks that were more persistent than anticipated, with excess demand and indexation processes in some CPI groups. The country’s risk premium and the observed and expected international interest rates increased. As a consequence of this, inflationary pressures from the exchange rate rose, and in this report, the probability of the neutral real interest rate being higher than estimated increased. In general, inflation expectations for all terms and the bank’s technical staff inflation forecast for 2023 increased again and continue to stray from 3%. All of the aforementioned elevated the risk of unanchoring inflation expectations and could heighten widespread indexation processes that push inflation away from the target for a longer time. In this context, it is necessary to consolidate a contractionary monetary policy that tends towards convergence of inflation at the target in the forecast horizon and towards the reduction of excess demand in order to guarantee a sustainable output level trajectory. 1.2 Monetary policy decision In its September and October of 2022 meetings, Banco de la República’s Board of Directors (BDBR) decided to continue adjusting its monetary policy. In September, the BDBR decided by a majority vote to raise the monetary policy interest rate by 100 basis points (bps), and in its October meeting, unanimously, by 100bps. Therefore, the rate is at 11.0%. Boxes 1 Food inflation: a comparison with other countries