Forty-eight specimens with four notch specimen configurations have been extracted from three structural steel grades used in the Indian construction industry. The extracted specimen simulates stress ...states of ductile fracture initiation similar to the sacrificial element installed in seismic-resistant steel structures. All the specimens are monotonically tested under a displacement-controlled loading protocol. With the help of a universal testing machine and digital image correlation, the load versus notch elongation until the point of ductile fracture initiation has been captured for all the specimens. A validated numerical model is then developed to extract the ductile fracture initiation parameters, namely stress Triaxiality (T), Lode function (L - ξ or θ or Lp), and Equivalent Plastic Strain (PEEQ). The extracted T, L, and PEEQ are then used to construct a three-dimensional fracture locus for all three study grades. In addition, a new uncoupled ductile fracture model named the Exponential based Lode parameter Void Growth Model (ELVGM) is proposed to predict the point of ductile fracture initiation and is then compared with six well-established existing uncoupled ductile fracture models using eight error measures. The proposed ELVGM with two free parameters is observed to provide better prediction accuracy for both low and high-yield strength steel corresponding to the considered stress states.
Display omitted
•Fracture locus database is created for three Indian steel grades (E250, E350, E450).•Isotropic hardening and free parameters are calibrated using 48 monotonic results.•New model (ELVGM) shows better prediction accuracy compared to six existing models.
Coupled transcription-translation (CTT) is a hallmark of prokaryotic gene expression. CTT occurs when ribosomes associate with and initiate translation of mRNAs whose transcription has not yet ...concluded, therefore forming "RNAP.mRNA.ribosome" complexes. CTT is a well-documented phenomenon that is involved in important gene regulation processes, such as attenuation and operon polarity. Despite the progress in our understanding of the cellular signals that coordinate CTT, certain aspects of its molecular architecture remain controversial. Additionally, new information on the spatial segregation between the transcriptional and the translational machineries in certain species, and on the capability of certain mRNAs to localize translation-independently, questions the unanimous occurrence of CTT. Furthermore, studies where transcription and translation were artificially uncoupled showed that transcription elongation can proceed in a translation-independent manner. Here, we review studies supporting the occurrence of CTT and findings questioning its extent, as well as discuss mechanisms that may explain both coupling and uncoupling, e.g., chromosome relocation and the involvement of cis- or trans-acting elements, such as small RNAs and RNA-binding proteins. These mechanisms impact RNA localization, stability, and translation. Understanding the two options by which genes can be expressed and their consequences should shed light on a new layer of control of bacterial transcripts fate.
•Seismic analysis of land-based wind turbines is addressed in time domain.•Full model of system includes tower, rotor aerodynamics, nonlinear foundation.•Foundation is modeled by nonlinear springs, ...adding damping in structure modes.•Uncoupled analyses are implemented with aerodynamic damping in seismic response.•Uncoupled analyses prove accurate for 4% aerodynamic damping.
Seismic analysis plays an important role in the design of land-based and offshore wind turbines in areas at seismic hazard. For seismic assessment, International Standards and Guidelines allow combining two separate analyses, one under wind and another under earthquake only, as alternative to computationally expensive, fully-coupled time-domain simulations. In these uncoupled analyses, the separate earthquake response is generally computed using the standard acceleration response spectrum, upon including an additional damping referred to as aerodynamic damping. By a response-spectrum approach, however, important sources of nonlinearity, such as those related to foundation flexibility, cannot be properly accounted for.
Focusing on land-based wind turbines, this paper investigates a time-domain implementation of uncoupled analyses, which may involve a nonlinear foundation model. The case study is a 5MW baseline wind turbine, resting on a pile foundation modeled by nonlinear springs. For different earthquake records and wind velocities, comparisons with fully-coupled simulations show that the combination of uncoupled analyses implemented in the time domain yields accurate results, provided that an appropriate level of aerodynamic damping is included in the model. Notably, it is seen that such aerodynamic damping level agrees with the one generally recommended for response-spectrum based uncoupled analyses.
In this paper, we explore an efficient uncoupled unsourced random access (UURA) scheme for 6G massive communication. UURA is a typical framework of unsourced random access that addresses the problems ...of codeword detection and message stitching, without the use of check bits. Firstly, we establish a framework for UURA, allowing for immediate decoding of sub-messages upon arrival. Thus, the processing delay is effectively reduced due to the decreasing waiting time. Next, we propose an integrated decoding algorithm for sub-messages by leveraging matrix information geometry (MIG) theory. Specifically, MIG is applied to measure the feature similarities of codewords belonging to the same user equipment, and thus sub-message can be stitched once it is received. This enables the timely recovery of a portion of the original message by simultaneously detecting and stitching codewords within the current sub-slot. Furthermore, we analyze the performance of the proposed integrated decoding-based UURA scheme in terms of computational complexity and convergence rate. Finally, we present extensive simulation results to validate the effectiveness of the proposed scheme in 6G wireless networks.
In this letter, we address joint channel and power allocation in a device-to-device (D2D) network underlaying a cellular network in a time-varying environment. A fully distributed solution, which ...does not require information exchange, is proposed to allocate channel and power levels to D2D pairs while ensuring the quality of service (QoS) of the cellular user equipments (CUEs). The problem is modeled as a Stackelberg game with pricing. At the leader level, base station sets prices for the channels to ensure the QoS of the CUEs. At the follower level, D2D pairs use an uncoupled stochastic learning algorithm to learn the channel indices and power levels while minimizing the weighted aggregate interference and the price paid. The follower game is shown to be an ordinal potential game. We perform simulations to study the convergence of the algorithm.
Display omitted
•A new charge structure of which the explosive is not coupled with the casing has been designed and studied.•The fragmentation shows a partition distribution in space and the velocity ...shows a piecewise acceleration in time.•The velocity direction of the uncoupled shell is consistent with its normal direction.•The high-pressure zone affects the acceleration of fragments and formation of cracks.•Dynamic pressure and static pressure co-dominated the uncoupled explosive driving process.
Charge structure, which can instantly release much energy, is a significant research point in explosive protection and warhead. The distribution of the fragment velocity from uncoupled charge structures with segmental shaped explosive were studied. Numerical calculation research was carried out based on the CEL method. The X-ray photographic images of fragmentation were obtained from explosion experiment, which provided experimental support for numerical simulation research. The results show that the fragmentation and velocity distribution of the charge structure with segmental explosive show obvious segmental characteristics compared with the traditional cylindrical shell charge. The explosive loadings of the shell under uncoupled conditions is not only determined by the detonation wave and the static pressure of the detonation products but by the impact dynamic pressure of the detonation products at low pressure and high speed and the static pressure generated by the detonation products expansion and convergence, leading to the significant difference among the coupled side, the uncoupled side and the transition area. In this paper, the fragmentation and velocity distribution of the charge with segmental explosive was obtained, the uncoupled explosive driving mechanism was investigated and verified. The conclusion provides a foundation for exploring and establishing the uncoupled explosive driving theory.
The study aim was 2-fold (i) to describe and compare the in-season variations of acute: chronic workload ratio (ACWR) coupled, ACWR uncoupled, and exponentially weighted moving average (EWMA) through ...session-rated perceived exertion (s-RPE), total distance (TD), high-speed running distance (HSRD), and sprint distance across different periods of a professional soccer season (early, mid, and end-season) between starters and non-starters; (ii) to analyze the relationship the aforementioned measures across different periods of the season for starters and non-starters. Twenty elite soccer players (mean ± SD age, 29.4 ± 4.4 y; height, 1.8 ± 0.1 m; and body mass, 74.8 ± 2.3 kg). They were divided into starter and non-starter groups and were evaluated for 20 weeks. ACWR had general changes throughout the season. At the beginning and end of the mid-season, the highest ACWR was observed in three parameters: s-RPE, TD, and HSRD. ACWR and EWMA through sprint distance were higher at the beginning of the early-season than at any other time of the season. The ACWR coupled of s-RPE shows a significant higher value for non-starters than starters (
= 0.015;
= -1.01 -1.98, -0.09) and the ACWR coupled of TD shows a significant higher value for starters than non-starters in early-season (
< 0.01;
= 3.01 1.78, 4.46) and shows a significant higher value for non-starters than starters in mid-season (
< 0.01;
= -2.52 -3.83, -1.39), and end-season (
< 0.01;
= -2.57 -3.89, -1.43). While the EWMA of TD shows a significant higher value for starters than non-starters in early-season (
< 0.01;
= 2.25 1.17, 3.49) and mid-season (
< 0.01;
= 2.42 1.31, 3.71), and shows a significant higher value for non-starters than starters in end-season (
< 0.01;
= -2.23 -3.47, -1.16). Additionally, we found some correlations between external and internal load measures during three periods of the in-season. The study's main finding was that the indexes of ACWR and EWMA were useful to detect differences between period and between playing status with the exception for the sprint variable. In addition, the necessary work for non-starter players' improvement is not done during training, and these players lose their readiness as the season progresses. Consequently, these players perform poorly during the match. Therefore, coaches and their staff should consider devising new activities to keep non-starter players physically fit. This deficit must be accounted for in training because they compete in fewer matches and have less burden than starters.
Over the last years, in a search for sustainable and biodegradable alternatives to petrol-based plastics, biotechnological applications turned to the potentialities of mixed microbial cultures (MMC) ...for producing polyhydroxyalkanoates (PHAs). Under a feast and famine regime, an uncoupled carbon (C) and nitrogen (N)-feeding strategy may be adopted by dosing the C-source at the beginning of the feast and the N-source at the beginning of the famine in order to stimulate a PHA storage response and microbial growth. Even though this strategy has been already successfully applied for the PHA production, very few information is to date available regarding the MMC operating in these systems and the influence of Organic Loading Rate (OLR) on their selection and enrichment. To fill the gap, this study investigated the effect of the OLR on the selection of PHA-accumulating microorganisms in a sequencing batch reactor (SBR) operated with an uncoupled C and N feeding strategy. The SBR cycle length was set at 12 h and four OLRs values (4.25, 8.50, 12.75 and 18 gCOD L−1 d−1) were tested by changing the concentration of the feeding solution, made of a synthetic mixture of acetic (85% of the overall COD) and propionic (15%) acids. The PHA-storage yield increased by increasing the OLR (up to 0.69 COD/COD at 12.75 gCOD L−1 d−1) but significantly decreased (0.27 COD/COD) at 18 gCOD L−1 d−1 concomitantly with a longer feast phase and a lower PHA content in the biomass at the end of the feast phase. The selective pressure induced by the applied OLRs strongly influenced the microbiome composition revealing a high content of putative PHA-storing bacteria, such as Rhodobacter, Thauera and Paracoccus, in the SBR operated at OLRs 4.25, 8.50 and 12.75 g COD L−1 d−1 (up to 97.4% of total reads) and a low content (5.4%) in the SBR at 18 g COD L−1 d−1where the predominance of genus Nitrinicola was instead observed.
Display omitted
•OLR affected PHA production and microbial selection in a SBR with uncoupled C/N feeding.•The increase of OLR increased PHA production; the process failed at 18 g COD L−1d−1.•Rhodobacter, Thauera and Paracoccus were associated with the highest PHA production.•Nitrinicola were associated with the highest applied OLR and lowest storage yield.
This effort is to improve CuO’s chemical-looping characteristics by introducing iron ore, chrysolite and limestone to obtain high power efficiency in chemical looping combustion (CLC) power plants. ...The reactivity and oxygen uncoupling behavior were evaluated by thermogravimetric analysis (TGA) in N2 and CO2 atmosphere under different heating rate. CuO modified by chrysolite and limestone showed better performance than iron ore-added CuO oxygen carrier (OC) in a CLC system. CO2 could play an important role in the gasification of char only when the temperature is above 800 °C. Two peaks were found in the Differential thermal gravity (DTG) curve when modified CuO reacted with char. That could be the solid-solid reaction turned into gas-solid reaction with temperature increasing. Scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) technique analysis indicated an enhancement of high temperature tolerance of Cu-based OCs, while CuO occurred sever sinter and agglomeration. Higher temperature tolerance means higher temperature off-gas from the fuel reactor entering the heat utilization power generation system, which could obtain higher efficiency in CLC power plants.
•CuO modified by Chrysolite shows better performance in a chemical looping combustion (CLC) system.•The gasification of CO2 in the CLC process happened when temperature is above 800 °C.•No agglomeration or sintering happened on CuO modified by three different ore.•The conversion of three OCs reacted with biomass char reached over 90% under N2 atmosphere and 95% under CO2 atmosphere.
Recent research focusing on brown adipose tissue (BAT) function emphasizes its importance in systemic metabolic homeostasis. We show here that genetic and pharmacological inhibition of the mevalonate ...pathway leads to reduced human and mouse brown adipocyte function in vitro and impaired adipose tissue browning in vivo. A retrospective analysis of a large patient cohort suggests an inverse correlation between statin use and active BAT in humans, while we show in a prospective clinical trial that fluvastatin reduces thermogenic gene expression in human BAT. We identify geranylgeranyl pyrophosphate as the key mevalonate pathway intermediate driving adipocyte browning in vitro and in vivo, whose effects are mediated by geranylgeranyltransferases (GGTases), enzymes catalyzing geranylgeranylation of small GTP-binding proteins, thereby regulating YAP1/TAZ signaling through F-actin modulation. Conversely, adipocyte-specific ablation of GGTase I leads to impaired adipocyte browning, reduced energy expenditure, and glucose intolerance under obesogenic conditions, highlighting the importance of this pathway in modulating brown adipocyte functionality and systemic metabolism.
Display omitted
•The mevalonate pathway is important for adipose tissue browning in mouse and human•Statin use is inversely correlated with brown fat activity in humans•Geranylgeranylation of small GTP-binding proteins promotes adipocyte browning•Small GTP-binding proteins regulate F-actin formation and YAP1/TAZ stability
Through genetic and pharmacological in vivo and in vitro approaches, Balaz et al. show that the mevalonate pathway is important for adipocyte browning. The importance of this pathway is supported by a retrospective clinical study and a small volunteer trial with fluvastatin. The authors identify geranylgeranyl pyrophosphate as the key mevalonate intermediate driving adipocyte browning.
PDF
