Yield Condition Research Articles

Isotropic yield surfaces for porous ductile materials: complete geometric representation by a computational homogenisation procedure

PurposeThe present paper aims to explore a computational homogenisation procedure to investigate the full geometric representation of yield surfaces for isotropic porous ductile media. The effects of cell morphology and imposed boundary conditions are assessed. The sensitivity of the yield surfaces to the Lode angle is also investigated in detail.Design/methodology/approachThe microscale of the material is modelled by the concept of Representative Volume Element (RVE) or unit cell, which is numerically simulated through three-dimensional finite element analyses. Numerous loading conditions are considered to create complete yield surfaces encompassing high, intermediate and low triaxialities. The influence of cell morphology on the yield surfaces is assessed considering a spherical cell with spherical void and a cubic RVE with spherical void, both under uniform strain boundary condition. The use of spherical cell is interesting as preferential directions in the effective behaviour are avoided. The periodic boundary condition, which favours strain localization, is imposed on the cubic RVE to compare the results. Small strains are assumed and the cell matrix is considered as a perfect elasto-plastic material following the von Mises yield criterion.FindingsDifferent morphologies for the cell imply in different yield conditions for the same load situations. The yield surfaces in correspondence to periodic boundary condition show significant differences compared to those obtained by imposing uniform strain boundary condition. The stress Lode angle has a strong influence on the geometry of the yield surfaces considering low and intermediate triaxialities.Originality/valueThe exhaustive computational study of the effects of cell morphologies and imposed boundary conditions fills a gap in the full representation of the flow surfaces. The homogenisation-based strategy allows us to further investigate the influence of the Lode angle on the yield surfaces.

Conversion of Waste Cooking Oil into Bio-Fuel via Pyrolysis Using Activated Carbon as a Catalyst.

The utilization of activated carbon (AC) as a catalyst for a lab-scale pyrolysis process to convert waste cooking oil (WCO) into more valuable hydrocarbon fuels is described. The pyrolysis process was performed with WCO and AC in an oxygen-free batch reactor at room pressure. The effects of process temperature and activated carbon dosage (the AC to WCO ratio) on the yield and composition are discussed systematically. The direct pyrolysis experimental results showed that WCO pyrolyzed at 425 °C yielded 81.7 wt.% bio-oil. When AC was used as a catalyst, a temperature of 400 °C and 1:40 AC:WCO ratio were the optimum conditions for the maximum hydrocarbon bio-oil yield of 83.5 and diesel-like fuel of 45 wt.%, investigated by boiling point distribution. Compared to bio-diesel and diesel properties, bio-oil has a high calorific value (40.20 kJ/g) and a density of 899 kg/m3, which are within the bio-diesel standard range, thus demonstrating its potential use as a liquid bio-fuel after certain upgradation processes. The study revealed that the optimum AC dosage promoted the thermal cracking of WCO at a reduced process temperature with a higher yield and improved quality compared to noncatalytic bio-oil.

Stability analysis of maize hybrids under different agro-ecological zones of Odisha, India

Thirty maize hybrids were evaluated for stability of yield performance across six locations of Odisha using the additive main effect and multiplicative interaction (AMMI) model. The analysis of variance revealed significant difference among genotypes, environments, G x E interactions, IPCA I, IPCA II and IPCA III scores. Among the high yielding genotypes, ZH17210, ZH159, ZH17223, P3502 and ZH161418 recorded low interaction, 28(ZH159) and 2(ZH161418) exhibited positive interactions (both IPCA 1 and IPCA II had same sign) and 6(ZH17223) revealed negative interaction. Koraput location(E6) was found to be most favorable environment while Banjanagar (E2) indicated as a poor environmental condition for grain yield. Bhubaneswar location with IPCA I and IPCA II scores close to zero seems to have minimum environmental interaction for grain yield. Among the hybrids; ZH17229), VH151139 and ZH161418 showed higher grain yield and minimum interaction (IPCA I) and hence, may be considered most stable. In contrast, the highest yielding hybrid ZH17210 demonstrated differential yield performance over environment and appreciably higher magnitude of G x E interaction (IPCA I) indicating adaptation to specific environment. Bangladesh J. Bot. 52(1): 1-8, 2023 (March)

Еxpansion and crimping of pipes during viscoplastic deformation

The calculation of force modes and damageability of the material of pipe elements during expansion and compression with heating is considered. Stresses are calculated for a viscousplastic anisotropic material using the equilibrium equations and the yield condition. The damageability of a deformable material is calculated based on the equations of fracture kinetics. The results of calculations and samples of products are given. Keywords: viscousplasticity, anisotropy, stresses, deformation, rate, material damageability. vladimir-chudin@yandex.ru

Exploring Adaptation Abilities of Barley Genotypes in Van Growing Conditions for Biomass and Grain Yield

Discovering the variation among genotypes is an important criterion for selecting the suitable cultivar for a certain environment. The study aimed to explore the genetic variation among 17 genotypes of barley based on grain yield and some related traits. Plants were grown under field grown conditions in the 2019-2020 and 2020-2021 growing seasons, and plant height (PH), spike per square meter (SSM), spike length (SL), spikelets per spike (NSS), seed per spike (SPS), biological yield (BY), grain yield (GY), and thousand grain weight (TGW) were measured. Results indicated that PH ranged (51.7 to 81.33 cm) and (58.20 to 79.90 cm), SSM (374 to 582) and (418 to 701), SL (7.10 to 9.63 cm) and (6.87 to 9.13 cm), NSS (9 to 15) and (8 to 17), SPS (21 to 49) and (21 to 51), BY (3466.7 to 5905.3 kg h-1) and (3731.7 to 6080 kg h-1), GY (1442 to 2192 kg h-1) and (811.8 to 1763.7 kg h-1), TGW (34 to 55.67 g) and (33.47 to 52.63 g) for the first and second year of experiment respectively. The advanced lines measurement values were higher in the second year of the experiment. It can be concluded that the advanced lines Anka-08 and Anka-11 are promising in most of the parameters. Some of the old and new cultivars still preserve their yield potential.

Numerical modeling of caldera formation using Smoothed Particle Hydrodynamics (SPH)

SUMMARYCalderas are kilometer-scale basins formed when magma is rapidly removed from shallow magma storage zones. Despite extensive previous research, many questions remain about how host rock material properties influence the development of caldera structures. We employ a mesh-free, continuum numerical method, Smoothed Particle Hydrodynamics (SPH) to study caldera formation, with a focus on the role of host rock material properties. SPH provides several advantages over previous numerical approaches (finite element or discrete element methods), naturally accommodating strain localization and large deformations while employing well-known constitutive models. A continuum elastoplastic constitutive model with a simple Drucker–Prager yield condition can explain many observations from analogue sandbox models of caldera development. For this loading configuration, shear band orientation is primarily controlled by the angle of dilation. Evolving shear band orientation, as commonly observed in analogue experiments, requires a constitutive model where frictional strength and dilatancy decrease with strain, approaching a state of zero volumetric strain rate. This constitutive model also explains recorded loads on the down-going trapdoor in analogue experiments. Our results, combined with theoretical scaling arguments, raise questions about the use of analogue models to study caldera formation. Finally, we apply the model to the 2018 caldera collapse at Kīlauea volcano and conclude that the host rock at Kīlauea must exhibit relatively low dilatancy to explain the inferred near-vertical ring faults.

Novel Insights into the Mechanism Underlying High Polysaccharide Yield in Submerged Culture of Ganoderma lucidum Revealed by Transcriptome and Proteome Analyses.

Polysaccharides are crucial dietary supplements and traditional pharmacological components of Ganoderma lucidum; however, the mechanisms responsible for high polysaccharide yields in G. lucidum remain unclear. Therefore, we investigated the mechanisms underlying the high yield of polysaccharides in submerged cultures of G. lucidum using transcriptomic and proteomic analyses. Several glycoside hydrolase (GH) genes and proteins, which are associated with the degradation of fungal cell walls, were significantly upregulated under high polysaccharide yield conditions. They mainly belonged to the GH3, GH5, GH16, GH17, GH18, GH55, GH79, GH128, GH152, and GH154 families. Additionally, the results suggested that the cell wall polysaccharide could be degraded by GHs, which is beneficial for extracting more intracellular polysaccharides from cultured mycelia. Furthermore, some of the degraded polysaccharides were released into the culture broth, which is beneficial for obtaining more extracellular polysaccharides. Our findings provide new insights into the mechanisms underlying the roles that GH family genes play to regulate high polysaccharide yields in G. lucidum.

Metal‐Free Iodine‐Promoted Oxidative Dehydrogenative Aromatization of Pyrazolidin‐3‐ones and Pyrazolines: An Efficient and Practical Approach to Functionalized Arylpyrazoles

AbstractAn efficient and practical iodine‐promoted oxidative aromatization of pyrazolidin‐3‐ones and pyrazolines has been developed under metal‐free, additive‐free and external‐oxidant‐free conditions in good yields with a broad functional group tolerance. In this transformation, a series of functionalized arylpyrazole derivatives could be obtained successfully. More importantly, the current methodology can be utilized as a convenient handle to elaborate pharmaceutical candidates.

Synthesis of Alkynyl Hydrazones from Unprotected Hydrazine and Their Reactivity as Diazo Precursors.

Alkynyl hydrazones are synthesized conveniently from 2-oxo-3-butynoates and hydrazine by suppressing the susceptible formation of pyrazoles. The resultant hydrazones are transformed into alkynyl diazoacetates under metal-free and mild oxidative conditions in excellent yields. Further, the alkynyl cyclopropane and propargyl silane carboxylates are synthesized in good yields by developing an unprecedented copper-catalyzed alkynyl carbene transfer reaction.

Fermentation of Sweet Sorghum (Sorghum bicolor L. Moench) Using Immobilized Yeast (Saccharomyces cerevisiae) Entrapped in Calcium Alginate Beads

As the population grows, there is a need to address the continuous depletion of non-renewable energy sources and their negative effects on the environment. This led to a substantial assessment of possible innovations and raw materials to increase the volumetric productivity of alternative fuels to supply the energy needed worldwide. In addition to its environment-friendly properties, a biofuel derived from plant-based sources is also a sustainable material. For high ethanol production from plant-based biofuel, several techniques have been developed, including cell or enzyme immobilization. The key purposes of utilizing immobilized cells or enzymes are to improve bioreactor yield with upgraded enzyme establishment and to increase enzyme utilization. The fermentation of sweet sorghum extract to produce ethanol was conducted in this study, and it was found that the optimum sodium alginate concentration for immobilizing yeast is 3% w/v. It was also found that the free yeast has a shorter optimum fermentation period which is four days (96 h), in comparison with the immobilized yeast, which is five days (120 h). The immobilized yeast has a higher ethanol concentration produced and percent conversion compared to the free yeast. The immobilized yeast entrapped in calcium alginate beads permitted ten five-day (120 h) reuse cycles which are still in stable final ethanol concentration and percent conversion. Due to a lack of experimental support in the necessary condition (optimum level of the number of fermentation days and the concentration of sodium alginate) for the optimal ethanol yield from the extract of sweet sorghum, this study was conducted. This study also tried to address the global demand for ethanol by specifying the optimum conditions necessary for efficient fermentation, specifically for ethanol production using an extract from sweet sorghum. Furthermore, this experimental work serves as a basis for further investigations concerning ethanol production from Agri-based materials, such as sweet sorghum.

A stress-state-dependent damage criterion for metals with plastic anisotropy

The paper discusses the effect of stress state and of loading direction on the onset and evolution of damage in anisotropic ductile metals. A series of experiments with uniaxially and biaxially loaded specimens covering a wide range of stress states and different loading directions is used in combination with corresponding numerical simulations to develop damage criteria. The underlying continuum damage model is based on kinematic definition of damage tensors. The strain rate tensor is additively decomposed into elastic, plastic and damage parts. The anisotropic plastic behavior of the investigated aluminum alloy sheets is governed by the Hoffman yield condition taking into account the strength-differential effect revealed by uniaxial tension and compression tests. Based on this yield criterion generalized anisotropic stress invariants as well as the generalized stress triaxiality and the generalized Lode parameter are defined characterizing the stress state in the anisotropic ductile metal. A damage criterion formulated in terms of these anisotropic stress invariants is proposed and damage mode parameters allow adequate consideration and combination of different damage processes on the micro-level. At the onset of damage the anisotropic stress parameters are determined. With these experimental-numerical data the damage mode parameters are identified depending on stress state and loading direction.

Comparison of Different Extracellular Vesicles Populations Derived from Adipose Tissue Derived Stromal Cells Depending on Conditioning Period

Introduction: Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSC) became an important player in regenerative medicine over past years. The most common protocol to isolate EVs from cell culture, includes a period of fetal calf serum (FCS)-free conditioning. Different conditioning periods are common ranging from 12h up to 96h. Recent guidelines(MISEV 2018) only paid little attention to this variable without any recommendations. The aim of this study was to investigate EVs released from adipose tissue stromal cells (ADSCs) in different periods. Materials and Methods: For EV preparation, condition medium from primary ADSC culture was collected each 24h by replacing it with fresh FCS-free GM for 72h. Thus, we obtained EVs released within first 24h (24h), 48h-72h (48h), and 48h-72h (72h). The groups were compared by their size, number, phenotype, and amount of protein. The proliferation potential was assessed by a coculture with primary Schwann cells. Results: EVs from all the groups (24h, 48h, and 72h) fulfilled the characterization criteria according to MISEV 2018. However, the properties of EVs differed significantly by size, number, EV to protein ratio and the expression profiles CD9, CD63, CD81. Further, Schwann cells treated with “24h” EVs exhibited a significant increase in proliferation. The proliferative effect of EVs was diminished with longer conditioning period. Conclusion: For groups working with EVs it might be enticing to prefer longer FCS-free conditions for a higher yield. More, as EVs from all groups fulfilled the minimal criteria, which generates an erroneous belief of a coherent population. With our approach, we identified distinct populations of EVs with significantly different proliferative potential. For the sake of reproducibility, our data demonstrate the urgent need for a regulation of the FCS-free period for at least EVs from primary ADSCs. Future experiments are needed to validate our results for EVs from immortalized cells, or for further cell lines.

Deformation State Analysis and Design Method of Bottom-Confined Gravity Retaining Walls

The deformation failure modes of gravity retaining walls include overturning, toppling, deep sliding, and eccentric failure. The complex eccentric failure mode, which involves the multi-stage deformation of retaining walls, suffers from a lack of mechanical models and design theories. Based on the basic theory of reinforced concrete construction, this study established a deformation calculation model of bottom-confined reinforced concrete gravity retaining walls (RC-GRWs), which are composed of tensile, compressive, and rigid zones. Then, this study defined RC-GRWs’ normal-operation, cracking, yield, and ultimate limit states, as well as the displacement of RC-GRWs in these states, according to the concrete cracking and steel reinforcement yield conditions. Accordingly, this study proposed a design method and process to determine the deformation of bottom-confined RC-GRWs. A project case shows that the calculation method for RC-GRW deformation proposed in this study can effectively assess the deformation state of in-service retaining walls and that optimized cracked retaining walls can meet the deformation-based design requirements.

CRISPR/Cas9 editing of wheat Ppd-1 gene homoeologs alters spike architecture and grain morphometric traits.

Mutations in Photoperiod-1 (Ppd-1) gene are known to modify flowering time and yield in wheat. We cloned TaPpd-1 from wheat and found high similarity among the three homoeologs of TaPpd-1. To clarify the characteristics of TaPpd-1 homoeologs in different photoperiod conditions for inflorescence architecture and yield, we used CRISPR/Cas9 system to generate Tappd-1 mutant plants by simultaneous modification of the three homoeologs of wheat Ppd-1. Tappd-1 mutant plants showed no off-target mutations. Four T0-edited lines under short-day length and three lines under long-day length conditions with the mutation frequency of 25% and 21%, respectively. These putative transgenic plants of all the lines were self-fertilized and generated T1 and T2 progenies and were evaluated by phenotypic and expression analysis. Results demonstrated that simultaneously edited TaPpd-1- A1, B1, and D1 homoeologs gene copies in T2_SDL-8-4, T2_SDL-4-5, T2_SDL-3-9, and T2_LDL-10-9 showed similar spike inflorescence, flowering time, and significantly increase in 1000-grain weight, grain area, grain width, grain length, plant height, and spikelets per spike due to mutation in both alleles of Ppd-B1 and Ppd-D1 homoeologs but only spike length was decreased in T2_SDL-8-4, T2_SDL-4-5, and T2_LDL-13-3 mutant lines due to mutation in both alleles of Ppd-A1 homoeolog under both conditions. Our results indicate that all TaPpd1 gene homoeologs influence wheat spike development by affecting both late flowering and earlier flowering but single mutant TaPpd-A1 homoeolog affect lowest as compared to the combination with double mutants of TaPpd-B1 and TaPpd-D1, TaPpd-A1 and TaPpd-B1, and TaPpd-A1 and TaPpd-D1 homoeologs for yield enhancement. Our findings further raised the idea that the relative expression of the various genomic copies of TaPpd-1 homoeologs may have an impact on the spike inflorescence architecture and grain morphometric features in wheat cultivars.

Computational study of propene selectivity and yield in the dehydrogenation of propane via process simulation approach

Abstract Propene is a vital feedstock in the petrochemical industry with a vast range of applications. And there is a continuous rise in propene demand. To gain insight into how the on-purpose method could help meet the demand in the propene market, we investigated the impact of temperature (T) and pressure (P) on product distribution in terms of product yield and selectivity using the process simulation approach. Existing related studies were deployed to identify possible products that could be evaluated in the simulation. In the study, we used Gibbs minimization (with Gibb’s reactor) to predict the likely products obtained at different T and P. The impact of feed purity on product distribution was also evaluated. The study was aided by using the Aspen HYSYS process simulator, while Design Expert was used to search for the optimum conditions for higher conversion, yield, and selectivity. Results obtained for the modeling and simulation of the process show that operating the production process at a lower pressure would favor higher selectivity within the temperature range of 500–600 °C. In comparison, the one run at a higher pressure was predicted to be only promising, showing better selectivity within the range of 550–650 °C. The feed purity significantly impacts the propene amount, especially for one with sulfur impurity, leading to the formation of smaller olefins and sulfide compounds. Our study reveals the importance of reviewing feed purity before charging them into the dehydrogenation reactor to prevent poisoning, coking, and other activities, which do lead to undesired products like methane and ethylene. A catalyst can also be designed to efficiently dehydrogenate the propane to propene at a lower temperature to prevent side reactions.

Enhancing lutein extraction from marigolds through ultrasound-assisted optimization using response surface methodology

This research aimed to enhance and optimize the ultrasound-assisted extraction (UAE) of lutein from marigold flowers. The Response Surface Methodology (RSM) was the primary optimization technique. Three key independent variables were considered to determine the best conditions for the highest lutein yield: ultrasonic amplitude, extraction temperature, and extraction time. These variables were systematically varied following the Central Composite Design (CCD). Lutein quantitation was achieved using ultraviolet-visible spectrophotometry analysis. Using both the RSM and CCD frameworks, the study established specific ranges for the operational conditions: 21.6–38.4% for ultrasonic amplitude, 23.18–56.82 °C for extraction temperature and 3.18–36.82 minutes for extraction duration. The study determined the optimal extraction conditions to be 32.76% ultrasonic amplitude, 40.08 °C extraction temperature, and 25.82 minutes of extraction time. Under these optimized conditions, the experimental lutein yield closely matched the yield predicted by the RSM model, thus confirming the model's accuracy. The UAE demonstrated a notably superior lutein yield compared to traditional extraction techniques. The RSM is a robust tool for refining and determining optimal UAE conditions for lutein extraction from marigold flowers. With its efficiency, speed, and eco- friendliness, the optimized UAE technique presents significant potential for widespread industrial use.

Simple modeling of reinforced masonry arches for associated and non-associated heterogeneous limit analysis

This paper proposes a limit analysis heterogeneous model for masonry arches in presence of innovative strengthening, rigid blocks, and joints reduced to interfaces. The reinforcement is considered in a simplified but effective way in the context of limit analysis, suitably modifying the admissibility conditions of the constitutive law that governs the behavior of contact joints. First, the force resultants at the interface after the reinforcement is investigated. Based on that, the yield condition and flow rule in the standard heterogeneous limit analysis formulation are updated. This approach is applied to solve both associated and non-associated sliding cases. For benchmarking purposes, the collapse of a 2D arch with both-side Fiber Reinforced Polymer (FRP) reinforcement is analyzed, followed by several parametric studies and a cost-benefit study. Collapse analysis of a real arch tested in-situ is also presented for further verification. The results show that in some cases an incorrect collapse mechanism and an overestimated ultimate load would be obtained through associated limit analysis. Such overestimation may become very significant once the reinforcement is taken into account. The presented cases illustrate that the maximum overestimation of the load could reach in meaningful cases of technical interest 91% of the associated prediction. This suggests the use of a non-associated flow rule to accurately predict the collapse load increase of reinforced arches. According to the cost-benefit study, it is recommended to strengthen at least half of the joints to guarantee an acceptable effect of the strengthening. The simulation of the collapse of the in-situ tested arch further proves the reliability of the proposed approach.

Efficient one‐pot tandem conversion of saccharides to 2,5‐dimethylfuran by adjusting the wettability of 2DMOF catalysts

AbstractOne‐pot multiple tandem synthesis of DMF from biomass saccharides including monosaccharides, disaccharides, and polysaccharides is of great importance for biomass fuels and chemicals. Due to the complexity of reactions, current catalytic systems often suffer from inferior activity, low yield, and harsh reaction conditions. Here, a Pd‐supported hydrophobic acidic 2DMOF (Pd/NUS‐PhSO3H‐Ph) was first prepared by continuous grafting of benzenesulfonic acid and tert‐butylbenzene groups followed by Pd impregnation methods. It shows catalytic efficiency for the DMF synthesis from saccharides under the reduction of polymethylhydrosiloxane (PMHS), which are previously unattainable in all reported catalysts. Controlled experiments and detailed characterizations show that hydrophobic 2D nanosheet structure promotes the wettability of feedstocks and intermediates for the active sites. This work proposes a new door toward an efficient and facile synthesis of DMF via designing a powerful 2DMOF‐based catalyst with cooperative acid‐hydrogenation catalysis.

Exploration of optimal reaction conditions on lactic acid production from glucose photoreforming over carbon nitride

Biomass valorization by photoreforming approach provides a promising and alternative strategy to generate value-added chemicals and fuels. In this work, we demonstrate the selective production of lactic acid from glucose photoreforming over pristine graphitic carbon nitride (g-C3N4) photocatalyst. Control experiments screen the best condition for the highest yield of lactic acid, including modulating pH, catalyst loading, and reaction time. 100% glucose conversion is achieved along with almost 100% lactic acid yield under the optimized condition. Density functional theory (DFT) calculations reveal that the rate-determining step (RDS) of the overall reaction on g-C3N4 is the conversion of pyruvaldehyde, where an electron transfer takes place. This present work provides experimental insights and theoretical understanding for selective lactic acid production from biomass photoreforming.

Hermetia illucens frass improves the physiological state of basil (Ocimum basilicum L.) and its nutritional value under drought.

To counterbalance the growing human population and its increasing demands from the ecosystem, and the impacts on it, new strategies are needed. Use of organic fertilizers boosted the agricultural production, but further increased the ecological burden posed by this indispensable activity. One possible solution to this conundrum is the development and application of more environmentally neutral biofertilizers. The aim of this study was to compare the effectiveness of two doses of Hermetia illucens frass (HI frass) with the commercial cattle manure in the cultivation of basil under drought. Soil without the addition of any organic fertilizer was used as a baseline control substrate for basil cultivation. Plants were grown with cattle manure (10 g/L of the pot volume) or HI frass at two doses (10 and 12.5 g/L). The health and physiological condition of plants were assessed based on the photosynthetic activity and the efficiency of photosystem II (chlorophyll fluorescence). Gas exchange between soil and the atmosphere were also assessed to verify the effect of fertilizer on soil condition. In addition, the mineral profile of basil and its antioxidant activity were assessed, along with the determination of the main polyphenolic compounds content. Biofertilizers improved the fresh mass yield and physiological condition of plants, both under optimal watering and drought, in comparison with the non-fertilized controls. Use of cattle manure in both water regimes resulted in a comparably lower yield and a stronger physiological response to drought. As a result, using HI frass is a superior strategy to boost output and reduce the effects of drought on basil production.