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

Himon Thakur, Armin Moin

The discussion around AI-Engineering, that is, Software Engineering (SE) for AI-enabled Systems, cannot ignore a crucial class of software systems that are increasingly becoming AI-enhanced: Those used to enable or support the SE process, such as Computer-Aided SE (CASE) tools and Integrated Development Environments (IDEs). In this paper, we study the energy efficiency of these systems. As AI becomes seamlessly available in these tools and, in many cases, is active by default, we are entering a new era with significant implications for energy consumption patterns throughout the Software Development Lifecycle (SDLC). We focus on advanced Machine Learning (ML) capabilities provided by Large Language Models (LLMs). Our proposed approach combines Retrieval-Augmented Generation (RAG) with Prompt Engineering Techniques (PETs) to enhance both the quality and energy efficiency of LLM-based code generation. We present a comprehensive framework that measures real-time energy consumption and inference time across diverse model architectures ranging from 125M to 7B parameters, including GPT-2, CodeLlama, Qwen 2.5, and DeepSeek Coder. These LLMs, chosen for practical reasons, are sufficient to validate the core ideas and provide a proof of concept for more in-depth future analysis.

Xianzhong Meng, Chuanbo Zhou, Nan Jiang et al.

Yasaman Abdolvand, Mohammadhossein Sadeghiamirshahidi

Wei Wang, Yanjun Wu, Yong Shi et al.

With the high-intensity mining activities and the selection of interval mining methods, a large amount of high-rank coal resources are left in the underground space (isolated islands). However, due to the complicated mining geological conditions, the coal resources in the isolated islands have not been fully extracted. In this paper, the mechanism of water inrush from limestone aquifers under isolated island panels is discussed from theoretical mechanics analysis, numerical simulation, discriminant criterion, the variation law of surrounding rock stress and water pressure, and floor failure depth. Meanwhile, we take the coal mining of the isolated island shaft in the Zhuzhuang colliery, Huaibei mining area, as an application case and propose the key technique of limestone water disaster prevention and control. Eventually, the treatment effect is validated by the practical work. The study results indicate that (1) the depth of the floor failure zone is 27.51 m and that the risk owing to water inrush of the panel floor in the isolated islands exists. The isolated coal pillar is more affected by the formation stress in numerical simulation, and the distribution of small stress on both sides of the panel floor and large stress in the middle area formed compared to non-isolated islands. The maximum stress of the panel floor is greater than that of mining without isolated islands. (2) The special drilling structures, stepwise gradient pressurization, and segmented sequential downward grouting technique are proposed to ensure the grouting effect under goaf. (3) Finally, the limestone water disaster regional treatment and control for the isolated island shaft is carried out and validated. The water level of ground boreholes and the water yield of underground directional boreholes verified the treatment effect. The theoretical results and engineering application in this study have significant implications for coal mining on other isolated islands affected by panel floor water damage.

SHEN Yang 1, WENG He 1, MA Ke 2

Coral mud is widely distributed in the South China Sea. Studying its deformation law is of great significance for the development of the South China Sea. One-dimensional compression of coral mud in the South China Sea has the typical deformation characteristics of soft soils. At the same time, due to its special properties, the deformation speed of coral mud is faster than that of common soft soil, therefore coral mud is suitable for the study of deformation model. One-dimensional compression deformation of soft soils is often simulated by element models. However, element parameters reflecting the long-term deformation in the element model are fixed, which cannot accurately reflect the delayed plastic deformation. Abel dashpot appling the fractional order theory can better reflect the delayed plastic deformation characteristics of soils than Newton dashpot. Therefore, Burgers model is introduced to correct the fractional order-modified Burgers model. In this study, one-dimensional consolidation compression tests on the coral mud under approximate natural conditions lasting for 8~14 days per stage are carried out. The first 11 hours of readings are used to self-fit Merchant model, Burgers model and fractional order-modified Burgers model, respectively. The model parameters obtained by fitting are used to predict the deformation after 11 hours. The self-fitting accuracy of the three models within 11 hours and the prediction accuracy after 11 hours are compared, and the parameters of each model and the deformation of each part are analyzed. It is found that the self-fitting accuracy of the fractional order-modified Burgers model is 23~65 times that of Merchant model, and 6~18 times that of Burgers model. The prediction accuracy is 5~35 times of Merchant model and 262~6213 times of Burgers model.

Clara M. Toffoli, Marius Milatz, Julian P. Moosmann et al.

The water drop penetration time (WDPT) test consists of placing water drops on a material's surface in order to evaluate how long it takes to penetrate the pores. It is used to evaluate the hydrophobicity of materials. This study aims at investigating in more detail the soil-water interaction during the test, exposing its mechanism. For that, a model soil named Hamburg Sand was coated with a hydrophobic fluoropolymer and then a WDPT test was performed while computed tomography (CT) images were taken. Tomography experiments were performed at the P07 high-energy materials science (HEMS) beamline, operated by Helmholtz–Zentrum Hereon, at the storage ring PETRA III at the Deutsches Elektronen-Synchrotron (DESY) in Hamburg. Using synchrotron radiation, a tomogram can be obtained in about 10 min, way less time than regular laboratory X-ray sources usually owned by universities. The faster imaging enables the observation of the drop penetration during time and thus provides insight into the dynamics of the process. After that, digital discrete image correlation is performed to track the displacement of the grains throughout time. From the results one can observe that, as the drop is absorbed at the material's surface, the grains directly around the droplet base are dragged to the liquid-air interface around the drop, revealing grain kinematics during capillary interactions of the penetrating liquid and sand grains.

Rabarijoely Simon, Lechowicz Zbigniew, Sulewska Maria Jolanta

According to Eurocode 7, limit state design codes generally draw more attention to ultimate limit states than to serviceability limit states. This paper presents the problem of settlement assessment of spread foundations on clays when the foundation design is governed by the serviceability limit state requirements. The paper presents the test results of geotechnical parameters for heavily preconsolidated boulder clays (sandy clay saCl and silty sandy clay sasiCl), which prevail on the Warsaw University of Life Sciences – SGGW campus. The test results were used for settlement calculations of spread foundations. Based on the results of field and laboratory tests, the problem of spatial variability assessment and determination of the characteristic value of soil parameters was addressed. Classical statistics and Bayesian analysis were used in the statistical analysis of the test results. Settlements of spread foundations were calculated based on the soil parameters obtained from cone penetration tests (CPTs) and dilatometer tests (DMTs). Special attention was drawn to the selection of the characteristic values of soil parameters. Determination of the characteristic value of the constrained modulus Mk was performed using two methods: according to the well-known and frequently used formula proposed by Schneider (1997; 1999) and according to the European draft standard prEN 1997-1:2022-09. Settlement calculations of spread foundations were carried out taking into account changes in the stresses and the constrained modulus in the subsoil. The calculated settlements were verified by field measurements performed during the construction of the object. Comparison of settlements obtained from the characteristic values of the constrained modulus Mk estimated according to prEN 1997-1:2022-09 with the measured settlements indicates that the calculated values were significantly higher than the measured values. Smaller differences between the measured and calculated settlements were obtained when the characteristic values of the constrained modulus Mk were determined from Schneider's formula, while smaller differences were obtained when the mean values of the constrained modulus Mmean were used.

Yao Lu, Ming Huang, Jim S. Shiau et al.

The in–situ recycling technique offers a promising solution for the efficient management of the escalating volumes of waste muck or slurry generated during shield tunneling. While foam is extensively utilized for soil conditioning in earth pressure balance (EPB) tunneling, the effects of organic and inorganic flocculants on the in–situ recycling potential of waste EPB shield muck containing residual foams remain underexplored. To bridge this gap, laboratory experiments were conducted using four flocculants: cationic polyacrylamide (CPAM), nonionic polyacrylamide (NPAM), anionic polyacrylamide (APAM), and polyaluminum chloride (PACL), with an enhanced flocculation and press–filtration apparatus. The defoaming–flocculation–dewatering behavior of waste EPB shield muck was systematically investigated by evaluating key parameters, including residual foam height, defoaming ratio, antifoaming ratio, total suspended solids, turbidity, moisture content, and zeta potential, while accounting for both muck dry mass and fines content. Moreover, the microscopic structure of flocculates and filter cakes was characterized using nanoparticle size analysis and scanning electron microscopy. The experimental results reveal that CPAM exhibits constrained flocculation and dewatering efficiency, primarily attributed to diminished charge neutralization resulting from residual anionic surfactants. In contrast, PACL demonstrates superior dewatering performance compared to NPAM and APAM, but exhibits the lowest flocculation and foam–suppression efficiency. Additionally, a consistent linear negative correlation is identified between the flocculation and dewatering indices of EPB shield muck, independent of the flocculant type, whether organic or inorganic.

Sara Cardona, Mathias Peirlinck, Behrooz Fereidoonnezhad

The fields of mechanobiology and biomechanics are expanding our understanding of the complex behavior of soft biological tissues across multiple scales. Given the intricate connection between tissue microstructure and its macroscale mechanical behavior, unraveling this mechanistic relationship remains an ongoing challenge. Reconstituted fiber networks serve as valuable in vitro models to simplify the intricacy of in vivo systems for targeted investigations. Concurrently, advances in imaging enable microstructure visualization and, through generative pipelines, modeling as discrete element networks. These mesoscale models provide insights into macroscale tissue behavior. However, there is still no clear way to systematically incorporate experimentally observed microstructural changes into in silico models of biological networks. In this work, we develop a novel framework to generate topologically-driven discrete fiber networks using high-resolution images that account for how environmental changes during polymerization influence the resulting structure. Leveraging these networks, we generate models of interconnected load-bearing fiber components that exhibit softening under compression and are bending-resistant. The generative topology framework enables control over network-level features, such as fiber volume fraction and cross-link density, along with fiber-level properties, like length distribution, to simulate changes driven by different polymerization conditions. We validate the robustness of our simulations against experimental data in a collagen-specific study case where we examine nonlinear elastic responses of collagen networks across varying conditions. TopoGEN provides a tool for tissue biomechanics and engineering, helping to bridge microstructural insights and bulk mechanical behavior by linking image-derived microstructural topological organization to soft tissue mechanics.

Charalampos Konstantinou, Yuze Wang

Microbially induced calcium carbonate precipitation (MICP) is an innovative biocementation technique that facilitates the formation of calcium carbonate within a pore network. Initially gaining prominence in the field of geotechnical engineering, MICP has attracted significant attention since its inception (the last three decades) and expanded its reach across various engineering disciplines. Examples include rock mechanics, geology and the oil and gas industry fields through the generation of rock-like specimens, and plugging of fractures, in civil and architectural engineering and material science for concrete repair, protection, and for self-healing of building materials, and in environmental engineering for the study of biomimetic materials. In response to this burgeoning interest, the current paper aims to present a comprehensive review of the main biochemical mechanisms underlying MICP (bacterial ureolytic activity, reactions duration and settling times, and chemical solution properties), their direct relevance to altering hydraulic and mechanical properties, both at the microscale and macroscale responses, and the precipitation mechanisms, particularly in relation to water resources and hydrology applications. Four main categories of relevant applications are identified, namely, the groundwater and soil remediation, the applications related to the generation of a low hydraulic conductivity barrier, those related to gaining cohesion, and the applications related to fluid flow studies in artificially generated porous media. Moreover, this comprehensive review not only aims to identify the existing applications of MICP within hydrological fields but also strives to propose novel and promising applications that can further expand its utility in this domain. Along with the investigation of the potential of MICP to revolutionize water resources and hydrology, it is imperative to delve deeper into its environmental implications to ensure sustainable and ecologically responsible implementation.

Ahmed Elgamal, Nissreen Elfaris

The tunnel boring method (TBM) is a widely used and effective tunneling technology in various rock mass quality circumstances. A “faulted rock mass” can range from a highly fractured rock mass to a sheared weak rock mass, making the ground conditions challenging for tunneling, especially for TBMs. “Faulted rock” significantly affects hard rock TBMs, primarily due to the TBM’s high geological risk and poor flexibility. TBMs require careful planning and preparation, starting with preliminary assessments. This study investigates the impact of establishing an isolation material between a circular tunnel and the adjacent faulting rock on seismic response. The two parts of the parametric analysis for the isolation material utilized in the model look at how changes in the mechanical characteristics of the material, such as the shear modulus of the rock and the fault, affect the stresses created in the tunnel. The second section examines how changes in the isolation width concerning the fault width affect the stresses and displacements produced in the tunnel. Additionally, the effectiveness of isolating the tunnel during sudden changes in the characteristics of the rock was investigated under seismic loading perpendicular to the tunnel and parallel to the tunnel. The finite element approach was utilized to model the TBM tunnel and the neighboring rock with a fault or sudden change in the rock using Midas/GTS-NX, simulating the interactions between the rock and the tunnel. Time-history analysis using the El Centro earthquake was conducted to calculate the stresses in the tunnels during seismic events. Peak ground accelerations between 0.10 g and 0.30 g were utilized for excitation. A time step of 0.02 s and a length of 10 s for the seismic event were used in the analysis, with traditional grout pea gravel vs. the isolation layer. Comparisons were made between the absolute stresses (the greatest possible values) in the normal tunnel section (Sxx) and those induced in the tunnel with traditional grout and with isolation. Furthermore, the study of vertical displacement was taken into consideration. The seismic isolation method is highly effective in improving the seismic safety of bored tunnels. The results show that the significant values of the ratio between the shear modulus of isolation and the surrounding soil should be between 0.2% and 0.4%. Where parts of the tunnel run through a fault, the effective length of isolation should be between one and two times the fault width. The dynamic behavior of the tunnel with isolation is better than that with traditional grout. Generally, when isolation is used for any length, it reduces the stresses at the area of sudden change. Consequently, engineering assessments from both structural and geotechnical engineering viewpoints are now required for these unique constructions. An underground structure’s safety should be evaluated by the designer to ensure that it can sustain various applied loads, taking into account seismic loads in addition to construction and permanent static loads. Tunnels may be especially vulnerable in areas where the composition of the soil or rock varies.

Tetsuo Tobita, Takashi Kiyota, Seda Torisu et al.

In response to the significant earthquakes that struck Turkey and Syria on February 6, 2023, a collaborative reconnaissance team, consisting of researchers and engineers from Japan and Turkey, was formed by the Japan Association for Earthquake Engineering, the Architectural Institute of Japan, the Japan Society of Civil Engineers, and the Japanese Geotechnical Society. This coalition conducted an in-depth on-site investigation from March 28 to April 2, two months after the catastrophic seismic events. In Islahiye, a landslide resulted in the formation of a landslide dam. Another landslide occurred in Tepehan on a relatively gentle slope formed of limestone, with possible correlations to fault movements. Iskenderun encountered not just building collapses on soft ground, but also instances of the tilting of buildings and ground subsidence attributed to the liquefaction of reclaimed coastal soil. Golbasi witnessed significant liquefaction-induced damage to structures with shallow foundations on soft ground, involving tilting and settling. However, a more comprehensive investigation is required to accurately map the extent of the liquefied soil layers. Antakya and Kahramanmaras emerged as regions where building damage coincided with surface ground vibrations. Despite severe building collapses, Antakya's relatively stable ground showed an average S-wave velocity exceeding AVS30 400 m/s. This suggests potential wave amplification due to underlying geological structures. Kahramanmaras displayed notable building damage concentrated in alluvial fan formations.

Zhao Sun, Yong-Gui Chen, Wei-Min Ye et al.

In high-level nuclear waste (HLW) repositories, concrete and compacted bentonite are designed to be employed as buffer materials, which may raise a problem of interactions between concrete and bentonite. These interactions would lead to mineralogy transformation and buffer performance decay of bentonite under the near field environment conditions in a repository. A small-scale experimental setup was established to simulate the concrete-bentonite-site water interaction system from a potential nuclear waste repository in China. Three types of mortars were prepared to correspond to the concrete at different degradation states. The results permit the determination of the following: (1) The macro-properties of Gaomiaozi (GMZ) bentonite (e.g. swelling pressure, permeability, the final dry density, and water content of reacted samples); (2) The composition evolution of fluids from the synthetic site water-concrete-bentonite interaction systems; (3) The sample characterization including Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). Under the infiltration of the synthesis Beishan site water (BSW), the swelling pressure of bentonite decreases slowly with time after reaching its second swelling peak. The flux decreases with time during the infiltrations, and it tends to be stable after more than 120 d. Due to the cation exchange reactions in the BSW-concrete-bentonite systems, the divalent cations (Ca and Mg) were consumed, and the monovalent cations (Na and K) were released. The dissolution of minerals in the bentonite such as albite causes Si increasing in the pore water. It was concluded that the hydro-mechanical property degradation of bentonite takes place when it comes into contact with concrete mortar, even under low-pH groundwater conditions. The soil dispersion, the uneven water content, and the uneven dry density in bentonite samples may partly contribute to the swelling decay of bentonite. Therefore, the direct contact with concrete has an obvious effect on the performance of bentonite.

Lianlang Hou, Xiangjun Liu, Lixi Liang et al.

The acoustic wave propagation characteristics of carbonate rocks have important application value. The systematic analysis of the effects of fluid type, fluid pressure, temperature and confining pressure on acoustic wave velocity and spectrum characteristics of carbonate rocks still needs to be strengthened. Carbonate rocks with pores and fractures mined from the Dengying Formation in the Hechuan and Tongnan areas, Sichuan Basin, were selected to carry out acoustic transmission experiments under different conditions. The effects of confining pressure, pore pressure, pressure difference, temperature and fluid category on the acoustic velocity of carbonate rocks and the dominant frequency characteristics of transmitted acoustic waves were analyzed. The results show that the sensitivity of acoustic velocity to pressure change in saturated formation water is lower than that in saturated nitrogen. In the process of pressure change, the variation amplitude of acoustic velocity is positively correlated with the porosity of rock samples. Within the experimental temperature range, with increasing temperature, the P-wave velocity and S-wave velocity of the saturated formation water and nitrogen samples decreases lightly. When the differential stress is low, the acoustic velocity corresponding to the way of changing the differential stress by changing the pore pressure is greater than that by changing the confining pressure, and the conclusion is opposite when the differential stress is high. Under the same differential stress condition, the acoustic velocity is more sensitive to changes in the confining pressure than the changes of pore pressure. The included angle and slope difference of the two acoustic velocity-differential stress curves corresponding to constant confining pressure and constant pore pressure can qualitatively reflect the relative size of the dynamic Biot effective stress coefficient of carbonate rock samples. With increasing differential stress, the contribution of pore pressure to effective stress decreases gradually. With increasing pore pressure, the dominant frequency amplitudes of the P-wave and S-wave gradually decrease. With increasing confining pressure, the dominant frequency amplitudes of the P-wave and S-wave gradually increase. With increasing temperature, the dominant frequency amplitudes of the P-wave and S-wave gradually increase. The research results are helpful to the theoretical research and engineering application of pore pressure predictionin carbonate formation based on logging acoustic information.

Ali Amraeiniya, Soroush Shojaei, Amir Ali Mohseni et al.

The purpose of this research is to look into the augmentation of silica nanoparticles (NPs) with low salinity (LowSal) brine for EOR. A series of analyses, including oil/water interfacial tension (IFT) and rock wettability tests were undertaken to determine an optimal dispersion to flood into a porous carbonate core with a defined pore size distribution. At 60°C and 14.5 psi, the maximum drop (i.e., roughly 12.5 mN/m) in oil/water IFT by 0.3 wt% brine occurred, but when 0.08 wt% silica was added to the brine, the IFT reduced to 14.51 mN/m at 60°C and 14.5 psi. The wettability analysis revealed a significant reduction in contact angle, from 142° to 72° and 59°, using 0.04 and 0.08 wt% silica in LowSal brine, but the extent reduced by brine alone was insufficient. The results of rock pore size characterization were discussed in terms of the accomplishment of operating EOR in the porous medium in the presence of NPs. The addition of 0.08 wt% silica to the injected brine resulted in an additional oil recovery of 16.3% OOIP as well as a significant shift in the endpoints/cross-points of the oil/water relative permeability curves. The findings of this research might help improve oil recovery from asphaltenic oil reservoirs or, more environmentally friendly, remediate petroleum crude-oil polluted soil.

Ali Morshedi

Introduction In determining the evapotranspiration (ET) of a crop species, factors such as type, crop density, growth stage, climate of the region, physicochemical characteristics and soil fertility, have a significant effect. Therefore, it has a significant complexity. In recent years, new technologies are used to estimate ET, such as surface energy balance algorithm for land (SEBAL), which estimates actual evapotranspiration, using satellite data and some ground data. The purpose of this research is to estimate the actual ET and water requirement of Rosa damascena using SEBAL during three crop growth years in a part of the Shahrekord high plain. Materials and Methods The studied farm with an area of 16.38 ha is located in the Shahrekord plain, Karoun watershed. The remote sensing data included 42 cloud-free images of Landsat 7 and Landsat 8 satellites (2017, 2018, and 2019). The growth period lasted from the beginning of April to the end of November of each crop year. Images were processed in ERDAS Imagine 2015 software for radiometric correction and subsequent calculations using SEBAL algorithm. In order to estimate the actual evapotranspiration, the energy balance equation is used. For this purpose, all energy fluxes such as, Rn: the net incoming radiation flux to the considered surface, H: the sensible heat flux, G0: the soil heat flux and lET: the latent heat flux of evapotranspiration should be taken into account. The first step in the SEBAL process is to calculate the net radiation flux of the Rn. The second, soil heat flux G0 that is the rate of heat capacity in the soil and vegetation resulting from heat conduction or heat energy used to heat or cools the volume of the soil mass. The third is to calculate sensible heat flux (H) is the rate of heat loss to the air by conduction and convection phenomena, which is caused by the thermal difference. In SEBAL process, two "anchor" pixels are used to create boundary conditions for energy balance. These include as "cold (wet)" and "warm (dry)" pixels that are determined in the study area. A cold pixel is selected at the surface of open water or the surface covered by a well-watered alfalfa crop. It is assumed that the temperature of the surface and the temperature of the air near the surface are the same in this pixel. The "warm" pixel is selected in dry agricultural lands and its ET is considered zero. It is necessary for SEBAL model to establishing a linear equation between the surface temperature (Ts) and the air-surface temperature difference (dT) for each pixel using hot (dry) and cold (wet) pixels. Results and Discussion Based on the results of three years of research in a 16.38 hectare Golmohammadi farm in the Shahrekord plain, using the Sabal algorithm and the number of 42 images on the days of Landsat 7 and Landsat 8 satellites passing, as well as using the modified Penman-Mantith-Fao mathematical relationship. It was found that the amount of evaporation and transpiration of hollyhocks in the studied area was on average 1043.8 mm during the growth period. According to the results of other researchers, which have been conducted using lysimeter data and field studies, it necessarily requires higher costs than remote sensing methods. In this research, the ability of the Sabal algorithm (as one of the best remote sensing algorithms) to estimate evaporation And the actual transpiration and determination of the water requirement of the chrysanthemum plant with a low cost and an easy method compared to the results of other researchers, which were done with difficult and expensive lysimetric methods, were proved and it is suitable to be used for other plant species and in other geographical areas. Results showed that actual evapotranspiration value of rose crop (ETC) obtained from the SEBAL during the three years of experiment were 1089.4, 1021.3, and 1020.6 mm per growth period. In the same period, reference crop evapotranspiration (ET0) values were 1214.8, 1100.5, and 1135.5 mm during the growth period, respectively. In other words, average value for ETC was 1043.8 mm in growth period. ConclusionBased on the results of three years of research in a 16.38 hectare Golmohammadi farm in the Shahrekord plain, using the Sabal algorithm and the number of 42 images on the days of Landsat 7 and Landsat 8 satellites passing, as well as using the modified Penman-Mantith-Fao mathematical relationship. It was found that the amount of evaporation and transpiration of hollyhocks in the studied area was on average 1043.8 mm during the growth period. According to the results of other researchers, which have been conducted using lysimeter data and field studies, it necessarily requires higher costs than remote sensing methods. In this research, the ability of the Sabal algorithm (as one of the best remote sensing algorithms) to estimate evaporation And the actual transpiration and determination of the water requirement of the chrysanthemum plant with a low cost and an easy method compared to the results of other researchers, which were done with difficult and expensive lysimetric methods, were proved and it is suitable to be used for other plant species and in other geographical areas.

Kimberly Do, Rock Yuren Pang, Jiachen Jiang et al.

Computer science research has led to many breakthrough innovations but has also been scrutinized for enabling technology that has negative, unintended consequences for society. Given the increasing discussions of ethics in the news and among researchers, we interviewed 20 researchers in various CS sub-disciplines to identify whether and how they consider potential unintended consequences of their research innovations. We show that considering unintended consequences is generally seen as important but rarely practiced. Principal barriers are a lack of formal process and strategy as well as the academic practice that prioritizes fast progress and publications. Drawing on these findings, we discuss approaches to support researchers in routinely considering unintended consequences, from bringing diverse perspectives through community participation to increasing incentives to investigate potential consequences. We intend for our work to pave the way for routine explorations of the societal implications of technological innovations before, during, and after the research process.

LIANG Yue 1, 2, DAI Lei 1, 2, WEI Qi 3

Seepage erosion is one of the main reasons for the instability and failure of hydraulic engineering. In the process of seepage erosion, the fine particles of the soil are gradually lost, and the permeability of the soil is enhanced, which further affects the loss of particles, and eventually even leads to instability and destruction. The seepage erosion is a typical fluid-solid coupling problem. To explore the interaction between fluid movement and particle loss in the process of seepage erosion from the mesoscopic level, by use of the transparent soil technology, a set of seepage erosion test system based on the double light source PIV/PTV is developed. The fused quartz and solution of CaBr2 are used as transparent soil and pore fluid. The movement of pore solution and fine particles in the soil during seepage erosion is observed and recorded. The flow velocity of different sections is compared with the macroscopic flow velocity of the sample, and it is found that when the hydraulic gradient is small, the measured flow velocity of the section is larger than the macroscopic flow velocity of the sample. With the increase of hydraulic gradient, the macroscopic velocity of the sample is gradually larger than the measured velocity of the cross-section, and the closer to the center of the sample, the smaller the difference between the macroscopic velocity and the cross-section velocity. At the same time, the fine particles in the sample gradually transitioned from a stable state to move perpendicular to the plane of the water inlet and outlet, and gradually lose. Compared with the calculated results of the critical hydraulic gradient formula for cohesive soil, it is found that the critical hydraulic gradient obtained through the experiment is slightly lower than the theoretical result. However, the regularity reflected by the experimental results is consistent with the traditional test results. It is shown that the test system has high reliability in the meso-simulation of seepage erosion, and has significance for the study of seepage erosion from the meso-level.

مریم نیازی, وحید براتی, حمید رضا بوستانی et al.

سابقه و هدف: مقدار عناصر پرمصرف تحت تأثیر عوامل مختلف محیطی از جمله تنش شدید آبی پس از گلدهی قرار می‌گیرد. استفاده از باکتری آزوسپیریلوم به‌عنوان کود زیستی و افزایش ماده آلی خاک توسط بقایا، از روش‌های کاهش تنش آبی در مزارع می-باشد اما، با وجود اثرات مطلوب کاربرد باکتری آزوسپیریلوم و بقایای گیاهی در کاهش تنش آبی، مطالعات اندکی در زمینه‌ی اثرات این عوامل بر محتوای عناصر پرمصرف گیاه جو در مناطق گرم و خشک جنوب ایران صورت گرفته است. بنابراین، هدف از این پژوهش بررسی اثرات باکتری آزوسپیریلوم و بقایای گیاهی در شرایط تنش خشکی بر محتوای برخی عناصر پرمصرف در گیاه جو بود.مواد و روش: این پژوهش به‌صورت اسپلیت فاکتوریل در قالب طرح بلوک کامل تصادفی با سه تکرار در مزرعه تحقیقاتی دانشکده کشاورزی و منابع طبیعی داراب- دانشگاه شیراز در سال زراعی 97- 1396 بر روی گیاه جو (رقم زهک) انجام شد. تیمار‌ها در این پژوهش شامل: دو سطح آبیاری به‌عنوان عامل اصلی [1- آبیاری مطلوب (بدون تنش آبی): آبیاری بر اساس نیاز آبی گیاه تا مرحله رسیدگی فیزیولوژیک و 2- کم آبیاری (تنش آبی): آبیاری بر اساس نیاز آبی گیاه تا انتهای مرحله‌ی گلدهی (قطع آبیاری پس از مرحله گلدهی)] بود. همچنین، عامل‌های فرعی شامل دو سطح بقایای گیاهی [1- حذف بقایا و 2- برگرداندن 30 درصد بقایای گیاهی (کاه گندم) به خاک] و چهار منبع کودی [1- شاهد: صفر کیلوگرم نیتروژن در هکتار، 2- کاربرد 100 کیلو‌گرم نیتروژن در هکتار به‌صورت (اوره 46 درصد نیتروژن) با توجه به آزمون خاک 3- استفاده تلفیقی از باکتری آزوسپیریلوم (Azospirillum brasilense) و نیتروژن به مقدار نصف نیاز نیتروژنی گیاه (50 کیلو‌گرم نیتروژن در هکتار به‌صورت (اوره 46 درصد نیتروژن)) و 4- تلقیح بذر‌ها با باکتری آزوسپیریلوم)] بود. یافته‌ها: اثر برهمکنش بقایا × منبع نیتروژن بر محتوای نیتروژن دانه نشان داد که بیشترین محتوای نیتروژن دانه (7/161 کیلوگرم بر هکتار) در تیمار حذف بقایا و کود تلفیقی و کمترین میزان محتوای نیتروژن دانه (43 کیلوگرم بر هکتار) در تیمار حضور بقایا و کود زیستی مشاهده شد. همچنین، محتوای نیتروژن کاه تحت تأثیر برهمکنش آبیاری × بقایا × منبع نیتروژن، قرار گرفت. بیشترین محتوای نیتروژن کاه در تیمار تنش آبی و حفظ بقایا و کود نیتروژن (9/62 کیلوگرم بر هکتار) و کمترین محتوای نیتروژن کاه در تیمار تنش آبی و حفظ بقایا و شاهد نیتروژن (7/5 کیلوگرم بر هکتار) به دست آمد. بالاترین مقدار محتوای فسفر دانه (35/1 کیلوگرم بر هکتار) مربوط به تیمار کود تلفیقی و بالاترین مقدار محتوای فسفر کاه (12/1 کیلوگرم بر هکتار) مربوط به تیمار کود نیتروژن بود. اثر برهمکنش آبیاری × بقایا × منبع نیتروژن نشان داد که بیشترین محتوای پتاسیم دانه در تیمار تنش آبی و حذف بقایا و کود نیتروژن (6/12 کیلوگرم بر هکتار) و کمترین محتوای پتاسیم دانه در تیمار تنش آبی و حفظ بقایا و شاهد نیتروژن (0/4 کیلوگرم بر هکتار) به دست آمد. همچنین، اثر برهمکنش آبیاری × منبع نیتروژن نشان داد که بیشترین محتوای پتاسیم کاه (4/114 کیلوگرم بر هکتار) در تیمار آبیاری مطلوب و کود تلفیقی و کمترین میزان محتوای پتاسیم کاه (3/33 کیلوگرم بر هکتار) در تیمار تنش آبی و کود زیستی مشاهده شد. نتیجه‌گیری: بر اساس یافته‌های این آزمایش، تیمار کود تلفیقی به‌منظور دستیابی به حداکثر محتوای عناصر پرمصرف در شرایط مطلوب رطوبتی مناسب است. بنابراین، با توجه به ملاحظات زیست‌محیطی، اقتصادی و دستیابی به سطوح بالای محتوای عناصر پرمصرف، این تیمار کودی قابل توصیه می‌باشد.

Seyed Mohammad Tajbakhsh, Zahra Gohari, Asadollah Mahmoodzadeh Vaziri

Introduction Watershed management projects with different objectives require some kinds of prioritization due to the natural condition prevailing in the watershed, including socio-economic issues, technical and financial constraints. The main purpose of the paper is to provide and apply the concept and techniques of multi-criteria decision-making (MCDM) under a fuzzy environment in the prioritization and selection of projects in portfolio management. In order to priority watershed management practices and evaluate the ecological potential of Ferizi and Rig-Sefid watersheds (Chenaran city, Khorasan Razavi province), the Fuzzy-TOPSIS method has been used as a powerful tool in multi-criteria decision making.Materials and Methods In this study, the preference weights of the criteria were identified using fuzzy AHP. Then, the weights are embraced in fuzzy-TOPSIS to improve the gaps of projects (alternatives) to achieve the organizational objectives as well as interactions between projects. The hybrid Fuzzy-AHP and Fuzzy TOPSIS methods made it more systematic and helpful for the decision maker to choose the best alternative from watershed management practices. In this respect, there are three phases performed in this study, the first phase of data is collected via questionnaire by experts. Next, determining criteria weights via Fuzzy-AHP was the main purpose of the second phase. In the third phase, the output obtained from Fuzzy-AHP with regard to criteria weights is used as input to be applied in fuzzy-TOPSIS for defining the optimal alternative and capturing the complex relationships between the assessment criteria and alternatives.Results and DiscussionThe comparison of the prioritization with the Fuzzy-TOPSIS method in this study and studies in 2010 indicate their similarity to some items, while in the second category priorities, the differences are more than the third and fourth priorities. The results indicate that multi-criteria decision models suggest the best location due to the usage of several criteria quantitatively and qualitatively with respect to objectives. In addition, it can be provided valuable information on prioritizing executive operations for integrated watershed management. It is also revealed that in the Fuzzy-TOPSIS technique, calculating the weights of criteria is essential and they can adjust the rating for other projects. Therefore, Fuzzy-TOPSIS will additionally help to select the optimal management project for the decision-making process.Conclusion It was found that many researchers applied many kinds of MCDM methods to help the decision makers understand and have more concentration on the high rank of criteria and also provide the ranking of the best alternatives in different problems and situations.