Hasil untuk "Engineering geology. Rock mechanics. Soil mechanics. Underground construction"

Rui Zhang, Jian Zhou

As a critical component of the in situ stress state, determination of the minimum horizontal principal stress plays a significant role in both geotechnical and petroleum engineering. To this end, a gene expression programming (GEP) algorithm-based model, in which the data of borehole breakout size, vertical principal stress, and rock strength characteristics are used as the inputs, is proposed to predict the minimum horizontal principal stress. Seventy-nine (79) samples with seven features are collected to construct the minimum horizontal principal stress dataset used for training models. Twenty-four (24) GEP model hyperparameter sets were configured to explore the key parameter combinations among the inputs and their potential relationships with the minimum horizontal principal stresses. Model performance was evaluated using root mean squared error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and coefficient of determination (R2). By comparing predictive performance and parameter composition, two models were selected from 24 GEP models that demonstrated excellent predictive performance and simpler parameter composition. Compared with prevalent models, the results indicate that the two selected GEP models have better performance on the test set (R2 = 0.9568 and 0.9621). Additionally, the results conducted by SHapley Additive exPlanations (SHAP) sensitivity analysis and Local Interpretable Model-agnostic Explanations (LIME) demonstrate that the vertical principal stress is the most influential parameter in both GEP models. The two GEP models have simple parameter compositions as well as stable and excellent prediction performance, which is a viable method for predicting the minimum horizontal principal stresses.

Kumar Aditendra Nath Shah Deo, Anu Priya

The 5th Industrial Revolution (5IR) is reshaping the global business landscape by integrating artificial intelligence, robotics, and the Internet of Things with a renewed focus on human-centered innovation. Talent management (TM), traditionally regarded as a human resources function, must re-envision itself within this paradigm. This paper develops a conceptual framework that applies systems thinking and design thinking to talent management in the context of the 5IR, enabling organizations to remain agile, innovative, and resilient. Systems thinking offers a holistic perspective on understanding the interconnections within the talent ecosystem, while design thinking promotes creative, empathetic, and human-centered solutions. Drawing on recent research on coopetition in SMEs, project-based talent development, global talent practices, and digital readiness in the public sector, the framework highlights the importance of upskilling, leadership support, and the responsible adoption of AI. The outcomes suggest that organizations should adopt holistic and adaptive talent management practices to address skills gaps, foster innovation, and maintain a competitive advantage in the rapidly evolving global environment.

Alexandre Epalle, Isabelle Ramière, Guillaume Latu et al.

Parallel implementation of numerical adaptive mesh refinement (AMR)strategies for solving 3D elastostatic contact mechanics problems is an essential step toward complex simulations that exceed current performance levels. This paper introduces a scalable, robust, and efficient algorithm to deal with 2D and 3D elastostatics contact problems between deformable bodies in a finite element framework. The proposed solution combines a treatment of the contact problem by a node-to-node pairing algorithm with a penalization technique and a non-conforming h-adaptive refinement of quadrilateral/hexahedral meshes based on an estimate-mark-refine approach in a parallel framework. One of the special features of our parallel strategy is that contact paired nodes are hosted by the same MPI tasks, which reduces the number of exchanges between processes for building the contact operator. The mesh partitioning introduced in this paper respects this rule and is based on an equidistribution of elements over processes, without any other constraints. In order to preserve the domain curvature while hierarchical mesh refinement, super-parametric elements are used. This functionality enables the contact zone to be well detected during the AMR process, even for an initial coarse mesh and low-order discretization schemes. The efficiency of our contact-AMR-HPC strategy is assessed on 2D and 3D Hertzian contact problems. Different AMR detection criteria are considered. Various convergence analyses are conducted. Parallel performances up to 1024 cores are illustrated. Furthermore, memory footprint and preconditionners performance are analyzed.

Hashini Gunatilake, John Grundy, Rashina Hoda et al.

Empathy, defined as the ability to understand and share others' perspectives and emotions, is essential in software engineering (SE), where developers often collaborate with diverse stakeholders. It is also considered as a vital competency in many professional fields such as medicine, healthcare, nursing, animal science, education, marketing, and project management. Despite its importance, empathy remains under-researched in SE. To further explore this, we conducted a socio-technical grounded theory (STGT) study through in-depth semi-structured interviews with 22 software developers and stakeholders. Our study explored the role of empathy in SE and how SE activities and processes can be improved by considering empathy. Through applying the systematic steps of STGT data analysis and theory development, we developed a theory that explains the role of empathy in SE. Our theory details the contexts in which empathy arises, the conditions that shape it, the causes and consequences of its presence and absence. We also identified contingencies for enhancing empathy or overcoming barriers to its expression. Our findings provide practical implications for SE practitioners and researchers, offering a deeper understanding of how to effectively integrate empathy into SE processes.

Liang Wang, Xue Zhang, Jingjing Meng et al.

In this study, we present a novel nodal integration-based particle finite element method (N-PFEM) designed for the dynamic analysis of saturated soils. Our approach incorporates the nodal integration technique into a generalised Hellinger-Reissner (HR) variational principle, creating an implicit PFEM formulation. To mitigate the volumetric locking issue in low-order elements, we employ a node-based strain smoothing technique. By discretising field variables at the centre of smoothing cells, we achieve nodal integration over cells, eliminating the need for sophisticated mapping operations after re-meshing in the PFEM. We express the discretised governing equations as a min-max optimisation problem, which is further reformulated as a standard second-order cone programming (SOCP) problem. Stresses, pore water pressure, and displacements are simultaneously determined using the advanced primal-dual interior point method. Consequently, our numerical model offers improved accuracy for stresses and pore water pressure compared to the displacement-based PFEM formulation. Numerical experiments demonstrate that the N-PFEM efficiently captures both transient and long-term hydro-mechanical behaviour of saturated soils with high accuracy, obviating the need for stabilisation or regularisation techniques commonly employed in other nodal integration-based PFEM approaches. This work holds significant implications for the development of robust and accurate numerical tools for studying saturated soil dynamics.

Yibing Ning, Huiming Tang, Jianbing Peng et al.

Deep-seated toppling in the upper reaches of the Lancang River, southwest China involves deformations exceeding 100 m in depth. The slope deformation is initiated by river downcutting and evolves distinctive characteristics with a depth of river incision. In this study, we propose a system for evaluating the stability of deep-seated toppled slopes in different evolutionary stages. This system contains identification criteria for each evolutionary stage and provides the corresponding stability evaluation methods. Based on the mechanical and kinematic analysis of slope blocks, the specific stage of slope movement can be identified in the field through outcrop mapping, in situ tests, surface displacement monitoring, and adit and borehole explorations. The stability evaluation methods are established based on the limiting equilibrium theory and the strain compatibility between the undisturbed zone and the toppled zone. Finally, several sample slopes in different evolution stages have been investigated to verify the applicability and accuracy of the proposed stability evaluation system. The results indicate that intense tectonic activity and rapid river incision lead to a maximum principal stress ratio exceeding 10 near the slope surface, thus triggering widespread toppling deformations along the river valley. When considering the losses of joint cohesion during the further rotation process, the safety factor of the slope drops by 7%–28%. The self-stabilization of toppling deformation can be recognized by the layer symmetry configuration after the free rotation of the deflected layers. Intensely toppled rock blocks mainly suffer sliding failures beyond the layer symmetry condition. The factor of safety of the K73 rockslide decreased from 1.17 to 0.87 by considering the development of the potential sliding surface and the toe-saturated zone.

William Woodley, Anatoli Fedynitch, Marie-Cécile Piro

We provide comprehensive calculations of total muon fluxes, energy and angular spectra, and mean muon energies in deep underground laboratories - under flat overburdens and mountains and underwater - using our latest calculation code, MUTE v3. For precise modeling, we compiled rock densities and chemical compositions for various underground labs, as well as topographic map profiles of overburdens, and integrated them into our calculations. Our results show excellent agreement with available data for most underground sites when using the latest surface muon flux model, daemonflux. Moreover, since our calculations do not rely on underground measurements of muons or other secondaries, we can verify the consistency of measurements across different detectors at different sites. MUTE is an open-source, publicly available program, providing a solid framework for accurate muon flux predictions in various underground environments, essential for applications in cosmic ray physics and dark matter searches.

Junchuan Gui, Jianchun Guo, Yu Sang et al.

The brittleness index plays a significant role in the hydraulic fracturing design and wellbore stability analysis of shale reservoirs. Various brittleness indices have been proposed to characterize the brittleness of shale rocks, but almost all of them ignored the anisotropy of the brittleness index. Therefore, uniaxial compression testing integrated with geophysical logging was used to provide insights into the anisotropy of the brittleness index for Longmaxi shale, the presented method was utilized to assess brittleness index of Longmaxi shale formation for the interval of 3155–3175 m in CW-1 well. The results indicated that the brittleness index of Longmaxi shale showed a distinct anisotropy, and it achieved the minimum value at β = 45°-60°. As the bedding angle increased, the observed brittleness index (BI2_β) decreased firstly and increased then, it achieved the lowest value at β = 40°–60°, and it is consistent with the uniaxial compression testing results. Compared to the isotropic brittleness index (β = 0°), the deviation of the anisotropic brittleness index ranged from 10% to 66.7%, in other words, the anisotropy of brittleness index cannot be ignored for Longmaxi shale. Organic matter content is one of the main intrinsic causes of shale anisotropy, and the anisotropy degree of the brittleness index generally increases with the increase in organic matter content. The present work is valuable for the assessment of anisotropic brittleness for hydraulic fracturing design and wellbore stability analysis.

DENG Huafeng 1, 2, WANG Wendong 1, 2, LI Jianlin 1, 2, FENG Yunjie 1, 2, LI Guanye 1, 2, QI Yu 1, 2, CHEN Xingzhou 3

In the process of reservoir impoundment, some bank slopes show an obvious step-type deformation trend, and the rock mass in the water-level-fluctuation zone is under the action of periodical fluctuation of reservoir water level and periodic repeated shear sequence. Based on this, the water-rock interaction tests on the jointed rock mass are designed, and the repeated shear tests are carried out in different water-rock interaction periods. The results show that: (1) Under the effects of water-rock and repeated shear sequence interaction, the shear mechanical properties of jointed rock mass deteriorate obviously, while the shear strength, shear stiffness and JRC exhibit the degradation trend of "first steep then slow". In comparison, the former six cycles of degradation trend are obvious, and the greater the normal stress, the more obvious the degradation trend. (2) The deterioration trend of the shear strength caused by the repeated shear is particularly obvious in the initial state, and then decreases rapidly with the increase of the water-rock interaction cycle. The deterioration trend of the shear strength caused by the water-rock interaction is obvious in the first six cycles, and then tends to be flat. (3) The damage area of joint surface wall is divided into the water-rock damage area, water-rock and repeated shear sequence damage area. The JRC-JCS shear strength model is modified, and the verification analysis shows that the calculated values by the modified model are in good agreement with the test results. The relevant research methods and results may provide a good reference for the performance degradation analysis of jointed rock mass in the water-level-fluctuation zone of reservoir bank slopes.

Xiao Guo, Wei Guo, Jianqin Liu et al.

With tunnel boring machine being used in underground engineering, accurate geological indicators have been the important basis for tunnel boring machine (TBM) construction. Back propagation neural network (BPNN) has been used to predict the geological indicators of tunnels in previous studies. Nevertheless, these studies ignored the imbalance proportion of surrounding rock grades, leading to the indiscriminate use of data, thus affecting the predictive effect of BPNN. In order to prove the importance of the proportion of surrounding rock grade in geological prediction, we mainly attempt to utilize particle swarm optimization (PSO) to optimize the proportion of sample data, and integrate with BPNN to establish a PSO-BPNN theoretical model to predict geological indicators. At the same time, combined with the actual engineering data, 5 tunneling indicators were selected as input and 4 geological indicators were selected as output by a variety of dimensionality reduction methods. The geological indicators are density, uniaxial compressive strength, internal friction angle (φ) and Poisson's ratio (ε). On this basis, the PSO-BPNN prediction model was established in detail. By comparing the prediction of traditional BPNN, PSO-BPNN and other optimization-integrated models, the result shows that optimized proportion of surrounding rock grades reduces the prediction error and improves the interpretability of the prediction model. Meanwhile, we combined the theory of surrounding rock partition to illustrate the rationality of surrounding rock proportion in PSO result, that is, the proportion of complex surrounding rock should be increased appropriately to improve the prediction result. Ultimately, based on the optimization-integrated models with engineering data and the surrounding rock classification theory, the importance of proportion of surrounding rock grades for tunnel geological prediction is confirmed.

Yayun Dang

Objective The Yinggehai Basin's Dongfang area is a significant area for oil and gas exploration, characterized by the presence of large-scale submarine fan complexes. As exploration advances, the focus has shifted from structural traps to lithological-stratigraphic traps. The 1st Member of the Huangliu Formation exhibits the development of multistage submarine fan complexes with complex sand-body stacking patterns. Therefore, understanding the stages, distribution, and evolution of submarine fans, as well as sand body patterns, is crucial for further oil and gas exploration. Methods In this study, we conducted a comprehensive investigation of the seismic sedimentology of the 1st Member of the Huangliu Formation in the eastern Yinggehai Basin using core, logging, and 3D seismic data. We identified the T30 and T31 horizons as the top and bottom interfaces of the 1st Member of the Huangliu Formation, respectively, with the T301 boundary representing the first flooding surface. The submarine fan complex is bounded by the T31 and T301 interfaces, representing the lowstand system tract of the 1st Member of the Huangliu Formation. Results Seismic-lithological calibration and proportional slice mapping revealed a four-phase evolution of submarine fan complex development. The earlier two phases exhibited channelized lobe geometry on the seismic geomorphology plane, characterized by weak-amplitude mound-like cluttered reflections and sporadic strong-amplitude reflections. V- or U-shaped channels overlapped with each other, with the lithology primarily consisting of thin-bedded siltstone interbedded with mudstone. In contrast, the third phase displayed a highly typical channelized configuration, with the lithology predominantly composed of fine-grained sandstone, creating favorable reservoir and accumulation conditions. During the fourth phase, the submarine fan complex significantly contracted due to insufficient supply, resulting in a lobe-like geometry. Conclusion Based on the seismic sedimentology results, we established a two-stage deposition model for the submarine fan complex of the 1st Member of the Huangliu Formation, providing technical support for reservoir prediction, as well as oil and gas exploration and development in the Yinggehai Basin, China.

Rui-fang Meng, Hui-feng Yang, Xi-lin Bao et al.

The North China Plain is one of the main grain producing areas in China. However, over-exploitation has long been unsustainable since the water supply is mainly from groundwater. Since 2014, the South-to-North Water Diversion Project’s central route has been charted to the integrated management of water supply and over-exploitation, which has alleviated the problem to a certain extent. Although the Ministry of Water Resources has made many efforts on groundwater recharge since 2018 most of which have been successful, the recharge has not yet been sufficiently focused on the repair of shallow groundwater depression zones. It still needs further optimization. This paper discusses this particular issue, proposes optimized recharge plan and provides the following recommendations: (1) Seven priority target areas are selected for groundwater recharge in alluvial and proluvial fans in the piedmont plain, and the storage capacity is estimated to be 181.00×108 m3; (2) A recharge of 31.18×108 m3/a is required by 2035 to achieve the repair target; (3) It is proposed to increase the recharge of Hutuo River, Dasha River and Tanghe River to 19.00×108 m3/a and to rehabilitate Gaoliqing-Ningbailong Depression Zone; increase the recharge of Fuyang River, Zhanghe River and Anyang River to 7.05×108 m3/a and rehabilitate Handan Feixiang-Guangping Depression Zone; increase the recharge of Luanhe River by 0.56×108 m3/a and restore Tanghai Depression Zone and Luanan-Leting Depression Zone; moderately reduce the amount of water recharged to North Canal and Yongding River to prevent excessive rebound of groundwater; (4) Recharge through well is implemented on a pilot basis in areas of severe urban ground subsidence and coastal saltwater intrusion; (5) An early warning mechanism for groundwater quality risks in recharge areas is established to ensure the safety. The numerical groundwater flow model also proves reasonable groundwater level restoration in the depression zones by 2035.

DING Yu 1, 2, WEI Wei-bing 1, 2, PAN Bo 3, HUANG Qun-zhi 1, 2, LIU Zhen-xian 1, 2, LIU Da-xiang 1, 2

This study attempts to investigate the constitutive model and damage evolution law of the fiber-reinforced vegetation concrete substrate. Taking the two factors of confining pressure and fiber content into account, a statistical damage model that can reflect the mechanical properties of the substrate is established based on the Weibull distribution. The method for determining model parameters is given, and the relationship among the Weibull distribution parameters, the confining pressure and the fiber contents is discussed. The model is then used to verify the results of the triaxial tests on the substrate. According to the destruction criterion of the substrate, the method for determining the damage threshold is deduced. By analyzing the damage evolution characteristics and the failure process of the micro-element, the stress-strain relationship and the law of damage softening of the substrate are elaborated. The results show that the model curves agree well with the tests, which can reflect the damage softening characteristics during the loading process of the fiber-reinforced substrate. Besides, the ratio of the damage threshold to the peak strain is found to range from 0.4 to 0.6. This study provides a theoretical reference for the accurate analysis and evaluation of the mechanical properties of substrate.

Newton La Scala, Alexandre Souto Martinez, Kurt Arnold Spokas et al.

Despite all the efforts, there is no agreement on how temperature affects soil carbon decay and consequently soil CO2 emission, due to overlapping of environmental constraints. To gain further insight into the driving forces of soil microbial processes, we herein examine the abiotic physical environment and its potential influence on microbial activity. In this work we discuss a mechanism which is related to temperature sensitivity of soil carbon stability following a first-order kinetic theory. Soil carbon decomposition is linked to diffusion and consequently to water viscosity, splitting the effects of temperature from viscosity, here we suggest that viscosity could be a controlling factor on bacterial mobility and nutrient diffusion. As a result, viscosity effect on the potential soil carbon losses is demonstrated and could be an important influence in the feedbacks of climate change on soil carbon cycling kinetics.

Fengchang Bu, Lei Xue, Mengyang Zhai et al.

The concept of joint persistence has been widely used to study the mechanics and failure processes of rock masses benefitting from the simplicity of statistical linear weighing of the discontinuity. Nevertheless, this term neglects the scale effects of rock bridges, meaning that the same joint persistence may refer to different numbers and spacings of rock bridges, leading to erroneous equivalent rock mass responses. To fill in this gap, an intact rock bridge was dispersed as multi rock bridges while maintaining a constant joint persistence, subjected to direct shear by conducting numerical simulations employing Universal Distinct Element Code (UDEC). In this way, scale effects of rock bridges were investigated from the perspective of load-displacement curves, stress and displacement fields, crack propagations and AE characterizations. Results revealed that the shear resistance and the area and value of stress-concentration decreased with increasing dispersion. Furthermore, uneven distribution of displacement fields in an arc manner moving and degrading away from the load was first observed, indicating the sequential failure of multi rock bridges. It was also found that the propagation of wing cracks was insensitive to scale, while the asperity of macro shear fracture mainly formed by secondary cracks decreased with increasing dispersion. In addition, increasing dispersion of rock bridges would overlap the failure precursors identified by intense AE activities. Based on the abovementioned results, we evaluated existing methods to characterize the joint persistence, and a threshold was observed to possibly define a rock bridge.

Xiangdong Yin, Shu Jiang, Peng Wu et al.

The pH value of plaeofluid exerts great influence on the formation of the secondary pores of sandstones.In the paper, the control of the acid and alkaline diagenetic fluid environment on the reservoir quality was analyzed in the Upper Paleozoic tight sandstones in the Ordos basin.Based on the plenty of survey of casting thin section, scanning electron microscope, X-ray diffraction, routine testing of physical properties, and high pressure mercury injection, the characteristics of petrology and mineralogy, physical properties, diagenesis, genetic types of pores, and pore-throat structure within the Upper Paleozoic tight sandstones were detailedly investigated in the Linxing and Shenfu district, eastern Ordos Basin.The identification, zonage, and distribution of the acid and alkaline diagenetic environment within tight sandstones as well as the evolution of diagenetic fluid environment and its reponse of the physical properties were investigated.Results showed that the upper strata underwent a diagenetic fluid evolution of alkaline-acid-alkaline mode during the burial process, whereas the lower strata experienced a mode of acid-alkaline.Acid diagenetic environment was characterized by feldspar dissolution, quartz overgrowth, and deposition of authigenic kaolinite, in which feldspar dissolution pores, intercrystalline pores of clay minerals developed with relatively large pore radius and better reservoir quality.Alkaline diagenetic environment was featured by quartz dissolution and deposition of authigenic chlorite, in which quartz dissolution pores and intercrystalline pores of clay minerals developed with relatively small pore radius and poor reservoir quality.The case of transitional zone of acid and alkaline zone(TZAA) falls in between acid zone(AZ) and alkaline zone(AlZ).Nevertheless, the physical properties are best in the AZ, followed by TZAA.The distribution of the AZ, AIZ and TAZZ and their responds to the physical properties are significant to the reservoir evaluation.

اعظم محمدزاده, امیر لکزیان, علیرضا کریمی et al.

سابقه و هدف: پتاسیم به همراه نیتروژن و فسفر از عناصر پر نیاز گیاهان است که در فرآیندهای فیزیولوژیکی گیاه نقش بسزایی دارد. بخش زیادی از پتاسیم خاک در ساختمان کانی‌های سیلیکاته از جمله میکاها قرار دارد و غیر قابل دسترس برای گیاه است. استفاده از باکتری‌های حل‌کننده پتاسیم به عنوان کودهای زیستی از روش‌های بیولوژیکی تأمین پتاسیم برای گیاه است. در نتیجه پژوهش حاضر با هدف جداسازی، انتخاب و شناسایی گونه برتر باکتری‌های حل‌کننده پتاسیم و همچنین اثر تلقیح آن بر رهاسازی پتاسیم از کانی بیوتیت و بر عملکرد گیاه ذرت انجام شد.مواد و روش‌ها: در تحقیق حاضر تعداد 15 جدایه از باکتری‌های ریزوسفری پنج گیاه مختلف (گندم، گوجه فرنگی، یونجه، ذرت و ریحان) جداسازی و خالص‌سازی شدند. تعیین توانایی حل‌کنندگی پتاسیم جدایه‌ها در دو بخش به صورت جداگانه انجام شد. در بخش اول توانایی حل‌کنندگی پتاسیم توسط جدایه‌های باکتریایی در محیط کشت الکساندروف مایع در قالب طرح کاملاً تصادفی با آرایش فاکتوریل در سه تکرار انجام شد. فاکتورهای آزمایش شامل 15 جدایه باکتری و 3 زمان انکوباسیون (7، 14 و 21 روز) بودند. بخش دوم پژوهش در قالب طرح کاملاً تصادفی جهت ارزیابی تأثیر جدایه‌های انتخابی باکتری‌های حل‌کننده پتاسیم بر رشد گیاه ذرت رقم سینگل کراس 640 در یک خاک با کلاس بافتی لوم شنی انجام شد. تیمار‌های آزمایش شامل شاهد مثبت (کود سولفات پتاسیم (SK))، شاهد منفی (خاک بدون کود (S))، 2500 میلی‌گرم در کیلوگرم بیوتیت (SM1)، 5000 میلی‌گرم در کیلوگرم بیوتیت (SM2)، جدایه B5 + SM1 (SM1B5)، جدایه B11 + SM1 (SM1B11)، جدایه B13 + SM1 (SM1B13)، جدایه B5 + SM2 (SM2B5)، جدایه B11 + SM2 (SM2B11)، و جدایه B13 + SM2 (SM2B13) بودند. تجزیه و تحلیل داده‌ها با استفاده از نرم‌افزار JMP 8 و مقایسه میانگین داده‌ها با استفاده از آزمون توکی در سطح احتمال 5 درصد انجام شد و نمودارها با نرم افزار اکسل رسم شد. یافته‌ها: نتایج بخش اول نشان داد که بیشترین آزادسازی پتاسیم (4/16 میلی‌گرم در لیتر) و کمترین pH (04/3) مربوط به جدایه B11 پس از 21 روز انکوباسیون مشاهده شد. نتایج بخش دوم نشان داد که بیشترین غلظت پتاسیم توسط اندام هوایی (81/2 درصد) و ریشه (956/0 درصد) به ترتیب در تیمار کود سولفات پتاسیم (شاهد مثبت) و SM2B11 ملاحظه شد. ارتفاع، شاخص سبزینگی و وزن خشک ریشه گیاه در تیمارهای دارای جدایه‌های انتخابی نسبت به شاهد بیشتر بود. بر اساس نتایج حاصله جدایه B11 به عنوان جدایه برتر انتخاب شد. در نهایت جدایه برتر با استفاده از تعیین ردیف بازهای آلی ژن 16SrRNA شناسایی و 37/99 درصد با باکتری Paenibacillus stellifer شباهت داشت.نتیجه‌گیری: این پژوهش نشان داد که باکتری‌های حل‌کننده پتاسیم توانایی آزادسازی پتاسیم از کانی بیوتیت را در دو بخش آزمایشگاهی و گلخانه‌ای دارند. در هر دو مطالعه انجام شده جدایه B11 (Paenibacillus stellifer) بیشترین تأثیر را در آزادسازی پتاسیم معدنی از کانی بیوتیت داشته است. بنابراین کاربرد آن به عنوان کود زیستی می‌تواند مدنظر قرار گیرد.

Sebastian Gajek, Matti Schneider, Thomas Böhlke

In this work, we propose a fully coupled multiscale strategy for components made from short fiber reinforced composites, where each Gauss point of the macroscopic finite element model is equipped with a deep material network (DMN) which covers the different fiber orientation states varying within the component. These DMNs need to be identified by linear elastic precomputations on representative volume elements, and serve as high-fidelity surrogates for full-field simulations on microstructures with inelastic constituents. We discuss how to extend direct DMNs to account for varying fiber orientation, and propose a simplified sampling strategy which significantly speeds up the training process. To enable concurrent multiscale simulations, evaluating the DMNs efficiently is crucial. We discuss dedicated techniques for exploiting sparsity and high-performance linear algebra modules, and demonstrate the power of the proposed approach on an industrial-scale three-dimensional component. Indeed, the DMN is capable of accelerating two-scale simulations significantly, providing possible speed-ups of several magnitudes.

Qing Gao

Chaotic inflation is inconsistent with the observational constraint at 68\% CL. Here, we show that the enhancement mechanism with a peak function in the noncanonical kinetic term not only helps the chaotic model $V(φ)=V_0φ^{1/3}$ satisfy the observational constraint at large scales but also enhances the primordial scalar power spectrum by seven orders of magnitude at small scales. The enhanced curvature perturbations can produce primordial black holes of different masses and secondary gravitational waves with different peak frequencies. We also show that the non-Gaussianities of curvature perturbations have little effect on the abundance of primordial black holes and energy density of the scalar-induced secondary gravitational waves.

Dulaji Hidellaarachchi, John Grundy, Rashina Hoda et al.

Requirements Engineering (RE) requires the collaboration of various roles in SE, such as requirements engineers, stakeholders and other developers, and it is thus a highly human dependent process in software engineering (SE). Identifying how human aspects such as personality, motivation, emotions, communication, gender, culture and geographic distribution might impact RE would assist us in better supporting successful RE. The main objective of this paper is to systematically review primary studies that have investigated the effects of various human aspects on RE. A systematic literature review (SLR) was conducted and identified 474 initial primary research studies. These were eventually filtered down to 74 relevant, high-quality primary studies. Among the studies, the effects of communication have been considered in many RE studies. Other human aspects such as personality, motivation and gender have mainly been investigated to date related to SE studies including RE as one phase. Findings show that studying more than one human aspect together is beneficial, as this reveals relationships between various human aspects and how they together impact the RE process. However, the majority of these studied combinations of human aspects are unique. From 56.8% of studies that identified the effects of human aspects on RE, 40.5% identified the positive impact, 30.9% negative, 26.2% identified both impacts whereas 2.3% mentioned that there was no impact. This implies that a variety of human aspects positively or negatively affects the RE process and a well-defined theoretical analysis on the effects of different human aspects on RE remains to be defined and practically evaluated. Findings of this SLR help researchers who are investigating the impact of various human aspects on RE by identifying well-studied research areas, and highlight new areas that should be focused on in future research.