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The development of the subway system in Shenyang City, China, plays a vital role in alleviating traffic congestion and promoting sustainable societal growth. However, the deformation of the surface caused by the tunneling of the shield presents a significant threat to the structural integrity of Shenyang Subway Line 2 and adjacent geotechnical structures. To tackle this challenge, a set of FEA (finite element analysis) simulations were carried out to examine surface deformation under various construction scenarios for Line 2. These simulations were compared with empirical formulas and numerical analyses conducted using Midas GTS NX 2019 software, in addition to actual site measurements. The outcomes of the finite element analysis (FEA) demonstrated a closer alignment with the empirical data than with traditional formulas. The maximum deformation was observed to be approximately twice as large as the equivalent diameter at the back of the excavation face. The analysis indicated that surface deformation is inversely correlated with overburden thickness (H), soil elasticity (E), and the grout filling rate of the shield tail (ψ), while it is directly proportional to the shield's outer diameter (D). This study provides important methods used in the shield tunneling process employed in the Shenyang subway and suggests that the developed methodologies may be applicable to similar subway projects. [ABSTRACT FROM AUTHOR]

The seismic vulnerability of reinforced concrete (RC) buildings has been an important issue, especially in earthquake-prone regions with limited seismic design codes such as South Sudan. Improving the seismic performance of reinforced concrete buildings is critical for maintaining structural functionality under normal service loads and for rapid recovery after natural disasters such as earthquakes. This research aims to thoroughly assess the methods used to evaluate the seismic vulnerability of RC frame structures in pre- and post-earthquake scenarios. The primary objective is to provide a comprehensive framework that integrates empirical, analytical, and experimental methods, categorizing existing assessment methods and proposing improvements for resource-constrained environments. However, empirical methods have always used historical earthquake data to estimate potential damage. In contrast, analytical methods have used computational tools such as fragility curves to assess the probability of damage at different seismic intensities. Additionally, experimental methods, such as shaking table tests and pseudo-dynamic analyses, have validated theoretical predictions and provided insights into structural behavior under simulated conditions. Furthermore, key findings highlight critical vulnerabilities in RC buildings, quantify damage probabilities, and compare the strengths and limitations of different assessment methods. However, challenges such as limited data availability, computational limitations, and difficulties replicating actual conditions in test setups highlight areas for improvement. By addressing these challenges, the review provides recommendations for future studies, including integrating advanced computational and regional hazard characterization methods, improving experimental methods to enhance the accuracy of vulnerability assessments, and ultimately supporting the design of more resilient RC structures and increasing disaster preparedness. [ABSTRACT FROM AUTHOR]

An empirical model for describing the soil movements induced by tunneling is proposed, then the mathematical relationship between horizontal displacement and vertical displacement is obtained. By analyzing 25 sets of data from field engineering and 35 sets of data from model tests, the formula for the maximum settlement Sv, max(z) is optimized to adapt to different ground conditions. The Modified Gaussian function is developed by introducing the existing width coefficient of the settlement trough i(z) and the optimized Sv, max(z) to describe the surface and subsurface vertical displacement. Subsequently, the formula for the horizontal displacement is derived based on the Modified Gaussian function. H(z) representing the position of the oriented point of the soil movement is a variable in the formula for horizontal displacement. Based on measured results, a logarithmic function and a quadratic polynomial function are proposed to describe the variation of H(z) with depth in the clay stratum and sand stratum, respectively. Then, the rationality of the proposed method is validated by 4 sets of in-situ data and 4 sets of test data. Finally, the implementation process of the proposed method is illustrated, and the inversion results of the ground displacement field in Beijing Metro Line 12 are presented. [ABSTRACT FROM AUTHOR]

Slovakia currently has a relatively large unused potential in the area of electricity production from solar radiation and wind as renewable sources. The conversion of the wind's mechanical energy into electrical energy depends, among other things, on the wind speed and its turbulence. Perhaps the most widely used probability distribution for a wind speed model is the Weibull distribution. In the article, we deal with the comparison of seven methods for estimating the parameters of this distribution - maximum likelihood method, method of moments, empirical method, empirical method of Lysen, power density method, least squares method and weighted least squares method - on wind speed records from the city of Nitra for the period of 2005-2021. The vicinity of this city is one of the places identified as a suitable location for the installation of wind turbines. The performance of individual estimation methods is evaluated based on the indicators - the coefficient of determination R² and the root mean square error RMSE. Based on these values, the most accurate method is the weighted least squares method, although all other methods achieved similarly good results. [ABSTRACT FROM AUTHOR]

Shallow tunnels in urban areas are close to adjacent buildings and municipal pipelines. Ground surface settlement (GSS) due to tunnelling can cause damage to those infrastructures surrounded. Many methods have been proposed for evaluating ground settlement induced by tunnelling, including empirical, analytical, numerical and artificial intelligence methods. This paper reviews the proposed methods in detail based on published 677 articles within past ten years. The principles, assumptions and application scope of those methods are summarized and the advantages and limitations of each method are discussed. Since artificial intelligence (AI) become popular in recent few years, the application of AI in the aspect of tunnelling-induced ground deformation is introduced emphatically. Finally, the challenges of ground displacement prediction by machine learning (ML) are clarified and future research directions are suggested.

In this work, the study of the crustal structure of the Babouri-Figuil and Mayo Oulo-Lere sedimentary basins was carried out through the interpretation of gravity data. These data were obtained by combining the terrestrial gravity data obtained from the Earth Gravitational Model 2008. The analysis of the terrestrial Bouguer anomaly maps reveals both negative and positive anomalies. Negative anomalies, i.e., low-density signatures, are interpreted as specific rock types on the basis of the geological knowledge of the region while the positive anomalies are attributed to basaltic rocks underlying a generally granitic environment. The empirical method was used to distinguish anomalies due to deep structures from those due to near-surface structures. This method testifies that the residual map of degree 4 is appropriate. Six profiles are drawn on this residual Bouguer anomaly map and are interpreted using spectral analysis and 2D modeling methods. The results indicate that the mean depths of mass sources at the near-surface of the Babouri-Figuil and Mayo Oulo-Lere sedimentary basins are located at 1.50 km and 1.55 km, respectively. Moreover, the Babouri-Figuil Basin is constituted of two formations while the Mayo Oulo-Lere Basin exhibits three distinct formations. These models also help clarify the geological structure of the study area as well as the thicknesses of the sedimentary basins. [ABSTRACT FROM AUTHOR]

Axial bearing capacity is an important factor in designing of foundation. It must be able to carry the load of upper structure without any significant deformation due to important role in pile design. A part from empirical and numerical methods, axial pile bearing capacity can be predicted by pile driving analyzer test that use wave equation analysis during the test. Prediction of the axial bearing capacity and its distribution can be achieved by combining wave equation analysis with dynamic pile monitoring. This paper compares the axial capacity of pile obtained from PDA records with predicted axial capacities obtained using empirical, numerical, and interpretation of static load test method. The empirical method used NSPT data from bore testing that conduct in site, finite element method that uses in this study is Plaxis 8.6. Both of them was compared with PDA test result of axial bearing capacity. There is a difference value of the calculation results of axial pile bearing capacity and foundation settlement. Comparing with PDA, from empirical method has smallest deviation for axial bearing capacity which equal to -268.45 kN with percentage -6.05%, smallest settlement equal to 0,0044 m. Plaxis result shows that distinction between Qult result equal to -11.00 kN with percentage -0.24% and settlement of foundation equal to 0,005 m. From interpretation of static loading test method smallest deviation for Qult which equal to -40,00 kN, with percentage -0,90%, and smallest settlement equal to 0,0055 m. So, from all method the smallest deviation for Qult and PDA result is used finite element method. This is due to many data parameters has been inputted and analyzed in the Plaxis program, so the results of calculation analysis are more detailed and closer to the situation in the research site. Differences in axial bearing capacity can be caused by the test was carried out which depends on the accuracy of operator and parameters that used in the calculations.

Rainfall-induced landslides threaten lives and properties globally. To address this, researchers have developed various methods and models that forecast the likelihood and behavior of rainfall-induced landslides. These methodologies and models can be broadly classified into three categories: empirical, physical-based, and machine-learning approaches. However, these methods have limitations in terms of data availability, accuracy, and applicability. This paper reviews the current state-of-the-art of rainfall-induced landslide prediction methods, focusing on the methods, models, and challenges involved. The novelty of this study lies in its comprehensive analysis of existing prediction techniques and the identification of their limitations. By synthesizing a vast body of research, it highlights emerging trends and advancements, providing a holistic perspective on the subject matter. The analysis points out that future research opportunities lie in interdisciplinary collaborations, advanced data integration, remote sensing, climate change impact analysis, numerical modeling, real-time monitoring, and machine learning improvements. In conclusion, the prediction of rainfall-induced landslides is a complex and multifaceted challenge, and no single approach is universally superior. Integrating different methods and leveraging emerging technologies offer the best way forward for improving accuracy and reliability in landslide prediction, ultimately enhancing our ability to manage and mitigate this geohazard. [ABSTRACT FROM AUTHOR]

Weibull Distribution is the most widely used distribution in wind power assessment. Two parameters Weibull distribution is commonly used for wind distribution modeling. The wind turbine converts wind energy into electrical energy. According to Betz law, No wind turbine can convert more than 59% of the available wind energy into electrical energy. The available method to find the parameters, e.g., Empirical Method (EM), Method of Moment (MoM), Energy Pattern Factor Method (EPFM), Maximum Likelihood Method (MLM), Modified Maximum Likelihood Method (MMLM), measure an overestimated value of wind power. An attempt has been made to develop a new method to evaluate Weibull parameters to measure wind potential close to the actual one. The new methods depend on the Quartiles of the wind distribution, Method of Quartile. Wind speed data for twelve months, January to December of 2016, for the cities Hyderabad, Karachi, and Quetta is used in this study. The new method results are compared with the five methods of Weibull parameter determination, EM, MoM, EPFM, MLM, and MMLM. The new method’s average wind speed is closer to the actual average wind speed than those measured by other methods. The Root Mean Square Error (RMSE), Mean Absolute Error (MABE), and chi-square statistic calculated by all methods are close. The Akaike Information Criterion (AIC) model selection criterion was used for each method and month. It is found that the AIC values for every month and every city are the lowest for MoQ. It also suggests that the new method, MoQ, is the best among the existing method. [ABSTRACT FROM AUTHOR]

In Europe, 1132 Mt of sand and gravel were mined in 2019, which causes major changes to the hydrogeological cycle. Such changes may lead to significantly raised or lowered groundwater levels. Therefore, the aggregate sector has to ensure that impacts on existing environmental and water infrastructures are kept to a minimum in the post-mining phase. Such risk assessments are often made by empirical methods, which are based on assumptions that do not meet real aquifer conditions. To investigate this effect, predictions by empirical and numerical methods about hydraulic head changes caused by a pit lake were compared. Wrobel's equation, which is based on Sichardt's equation, was used as the empirical method, while a numerical groundwater flow model has been solved by means of the finite-element method in FEFLOW. The empirical method provides significantly smaller ranges of increased/decreased groundwater levels caused by the gravel pit lake as the numerical method. The underestimation of the empirical results was related to the finding that field measurements during pumping tests show a larger extent of groundwater drawdown than calculations with the Sichardt's equation. Simplifications of the 2D model approach have been evaluated against hydraulic head changes derived from a 3D groundwater model. Our results clearly show that the faster and cheaper empirical method—Wrobel's equation, which is often preferred over the more expensive and time-consuming numerical method, underestimates the drawdown area. This is especially critical when the assignment of mining permits is based on such computations. Therefore, we recommend using numerical models in the pre-mining phase to accurately compute the extent of a gravel/sand excavation's impacts on hydraulic head and hence more effective protection of groundwater and other related environmental systems. [ABSTRACT FROM AUTHOR]

The EPB shield tunnelling for mass rapid transit (MRT) Line 1 of Ho Chi Minh City (HCMC) is the first tunnel excavation in Vietnam to use a tunnel boring machine (TBM). A comprehensive instrumentation programme was developed for safety control and to obtain a better understanding of the characteristics of induced ground movement and the forecasts. The observed ground surface settlement is summarized and interpreted with respect to the tunnelling operation parameters. The settlement trough is compared with the forecast data by applying the empirical Gaussian function and numerical 2D finite‐element analysis (FEA). The trough width parameter in the city's sandy subsoil is determined. The relation between the volume loss of the ground surface and that of the tunnel (contraction ratio) is identified. The result of the investigation is useful for future shield tunnel projects in HCMC and elsewhere in Vietnam. [ABSTRACT FROM AUTHOR]

One of the controversial issues in the religious experience is the reality of the "transcendent". The "transcendent" is one of the most important positive features of religious experience, which the constructivists consider it to be born in the mind or as a human subconscious. Norman L. Geisler, as an essentialist, claims that the object of a religious experience is something real. In his book Philosophy of Religion, in proving the reality of the transcendence, he has put forward an argument which, in his own interpretation, is based on the "empirical method". This method is based on the combination of the two components of "inner need" and "external experience". In this article we explain and analyze Geisler's argument and also explore his rational and empirical foundations including: empirical method, comprehensiveness principle, necessity of verification of the existence of the transcendent, preference of empirical credibility over the logical possibility of deception, the experience of supplying the human’s real needs, uncredibility of the denial of the reality of the transcendent, the generality and reality of the religious experience, the basicness of the need for the transcendent (sense of origination and dependence), the possibility of satisfying the need for the “transcendent”, and the existential need for the "transcendent". After evaluating the the presuppositions of the argument (i.e. common nature of human beings, the similarity between physical and mental needs, the problem of transcendence in atheism, being based on induction, the transmission from general to particular, relativism in addressing religion) we finally came to the conclusion that such a belief is justified for him, because this belief originates from an inner need. Moreover, for the subject of experience, this belief is also "true", because the objectivity of the transcendent is approved.

With the continuous development of conventional oil and gas resources, the strategic transformation of energy structure is imminent. Shale condensate gas reservoir has high development value because of its abundant reserves. However, due to the multi-scale flow of shale gas, adsorption and desorption, the strong stress sensitivity of matrix and fractures, the abnormal condensation phase transition mechanism, high-speed non-Darcy seepage in artificial fractures, and heterogeneity of reservoir and multiphase flows, the multi-scale nonlinear seepage mechanisms are extremely complicated in shale condensate gas reservoirs. A certain theoretical basis for the engineering development can be provided by mastering the percolation law of shale condensate gas reservoirs, such as improvement of productivity prediction and recovery efficiency. The productivity evaluation method of shale condensate gas wells based on empirical method is simple in calculation but poor in reliability. The characteristic curve analysis method has strong reliability but a great dependence on the selection of the seepage model. The artificial intelligence method can deal with complex data and has a high prediction accuracy. Establishing an efficient shale condensate gas reservoir development simulation technology and accurately predicting the production performance of production wells will help to rationally formulate a stable and high-yield mining scheme, so as to obtain better economic benefits. [ABSTRACT FROM AUTHOR]

Ground movements caused by the construction of tunnels and excavation are inevitable. Estimation of such movements is a very important for risk management in tunnel design. This paper presents a case study of ground settlements induced by twin shield tunnelling in Copenhagen using analytical and numerical methods and their predictions. The predictions are compared with the monitored settlements. The comparison shows that the predictions are sufficiently conservative.

The tunnel of controller construction is located in Panton Bunot Village, Tiro Sub District, Pidie District, Aceh Province. The tunnel construction aims to flow the water from Kr. Tiro River to Rukoh inundation for water supply to Rukoh Dam in Keumala Sub District, Pidie District. The research aimed to comprehend engineering geological condition in the study area and determine excavation method at the inlet and proper tunnel support system. The determination of proper excavation method becomes crucial and it is required in maintaining affectivity and efficiency during tunnel construction process. Than excavation method determination is carried out calculation by using empirical method based on output parameter of laboratory test to the rock samples from core drilling in the tunnel track. The outputs are rock conditions as rock mass quality (RQD), discontinuity area density of the rock and rock stress strength. The condition of tunnel track was dominated by silt stone having very poor quality. UCS value was 3 Mpa – 10 Mpa. Joins spacing was less that 60 mm. Empirical analysis of excavation method explained that tunnel opening of Rukoh Controller Construction was highly weathered (HW) and required ripping as excavation type.

This article considers and compares two theories that were developed by British linguists of the 20th century. The firsttheory is called systemic-functional approach, or systemic grammar, its author was Michael Halliday. The other theory isintegrational linguistics, or integrationism, it appeared some decades later and was offered by Roy Harris. While MichaelHalliday was John Firth’s immediate follower and belonged to the London School, Roy Harris worked independently, oftenquestioned many ideas developed and introduced by previous linguists and set up his own approach to studying linguisticproblems. At the end of the article the author gives some names of Russian linguists that dealt with the problems and appliedthe theories to their research. The method of comparative analysis is used. The author comes to the conclusion that despitebeing separate theoretical approaches that appeared in different time periods there is much in common as both of them form acharacteristic feature of British linguistic approach where schools and ideas are interconnected and interdependent.

Purpose. To investigate the efficiency of various approaches to predict surface settlements due to tunnel excavation. Methodology. To appreciate the surface displacements, our study is focalized on the case of a real tunnel in a layered ground (Algiers’s Metro), where a tunnel boring machine was driven for the first time in this country. Firstly, the surface settlement trough was calculated with empirical, analytical, and numerical (FEM) methods. Secondly, a set of numerical analyses was carried out to inspect the evolution of surface settlement as the TBM progresses. Finally, a parametric study was performed to examine the construction step most productive for surface settlement. Findings. FEM is a useful tool for predicting surface displacements due to tunnelling, especially when assigning an adequate and sophisticated behaviour model. Originality. A reference numerical model which represents well the construction procedures of the Algiers tunnel has been established. Practical value. This study illustrates that the results obtained by FEM with the use of Hardening Soil as a constitutive model to represent the soil are almost identical to those measured during the tunnel excavation. On the other hand, the empirical formulas available in the literature are not always efficient to predict surface movements. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Europe, 1132 Mt of sand and gravel were mined in 2019, which causes major changes to the hydrogeological cycle. Such changes may lead to significantly raised or lowered groundwater levels. Therefore, the aggregate sector has to ensure that impacts on existing environmental and water infrastructures are kept to a minimum in the post-mining phase. Such risk assessments are often made by empirical methods, which are based on assumptions that do not meet real aquifer conditions. To investigate this effect, predictions by empirical and numerical methods about hydraulic head changes caused by a pit lake were compared. Wrobel’s equation, which is based on Sichardt’s equation, was used as the empirical method, while a numerical groundwater flow model has been solved by means of the finite-element method in FEFLOW. The empirical method provides significantly smaller ranges of increased/decreased groundwater levels caused by the gravel pit lake as the numerical method. The underestimation of the empirical results was related to the finding that field measurements during pumping tests show a larger extent of groundwater drawdown than calculations with the Sichardt’s equation. Simplifications of the 2D model approach have been evaluated against hydraulic head changes derived from a 3D groundwater model. Our results clearly show that the faster and cheaper empirical method—Wrobel’s equation, which is often preferred over the more expensive and time-consuming numerical method, underestimates the drawdown area. This is especially critical when the assignment of mining permits is based on such computations. Therefore, we recommend using numerical models in the pre-mining phase to accurately compute the extent of a gravel/sand excavation’s impacts on hydraulic head and hence more effective protection of groundwater and other related environmental systems.

Wind power generation highly depends on the determination of wind power potential, which drives the design and feasibility of the wind energy production investment. This gives an important role to wind power estimation, which creates the need for an accurate wind data analysis and wind energy potential assessments for a given location. Such assessments require the implementation of an accurate and suitable wind distribution model. Therefore, in the quest for a well-fitted model, eight methods for estimating the Weibull parameters are investigated in this paper. The methods were then investigated by employing statistical tools, and their performances have been discussed in terms of various error indicators such as root mean squared error (RMSE), regression error (R2), chi-square (X2), and mean absolute error (MAE). Meteorological data for diverse terrain from 14 provinces with 30 sites scattered across Iran were employed to examine the performance of the investigated methods. The results demonstrated that the empirical method has superiority over the investigated technique in terms of errors. [ABSTRACT FROM AUTHOR]

This article presents a methodology for predicting the absolute methane emission rate for longwall caving extraction based on the determination of destressing zones generated by longwall mining operations, by means of numerical modelling. This methodology was applied for the conditions of the K-2 longwall panel in the KWK Pniówek mine. The finite difference method code FLAC2D was employed as an element of the methodology to determine the destressing zones. All results including the numerical modelling results, empirical results and the measured (in situ) results were gathered in the comparative analysis. As the final results, the accuracy and reliability of the proposed methodology were evaluated. [ABSTRACT FROM AUTHOR]

The return period or average time between events as a function of position along an avalanche path is a primary determiner for zoning in snow avalanche terrain. Areas with long times between the occurrences are sought to enable permissions for occupied structures and placement of infrastructure facilities. Generally, both the avalanche frequency and potential destructive effects decrease proceeding down into the runout zone where applications reside. Both the avalanche frequency and the estimated destructive effects are used in zoning methods. In typical zoning problems, the allowable return period exceeds 25 years. In most cases, there are not enough prior data on avalanche occurrences for an avalanche path to specify return periods accurately which implies that models must be used. Both avalanche dynamics and empirical, probabilistic models are used to predict zones for rare avalanche occurrences. However, the return period is a probabilistic quantity which places emphasis on empirical models. In this paper, the common methods for determining return period of avalanches are reviewed. The main emphasis in this paper is on verification, accuracy and quantification of the methods for determining return period through use of case histories. From a scientific perspective, the results here suggest some deficiencies in commonly used zoning strategies. [ABSTRACT FROM AUTHOR]

This paper describes an approach for utilizing in-situ measurements of shear wave velocity Vs to carry out preliminary and check design calculations for shallow and deep foundations. For estimates of foundation movements, Vs can be used directly to estimate the small-strain stiffness of the soil or rock strata, while for ultimate capacity calculations, use is made of empirical correlations between Vs and penetration resistance measures, which in turn are correlated to the foundation resistance characteristics. The approach is applied to a series of published tests on shallow footings, and on a series of pile load tests for a very tall building. For these cases, comparisons of the calculated with the measured load—settlement behaviour indicates that the suggested approach provides a reasonable, albeit somewhat conservative, level of agreement. [ABSTRACT FROM AUTHOR]

The station temperature of China-Russia Eastern Gas Pipeline Project is designed low to －45 ℃, which poses new challenges to the brittle fracture prevention capability of pipeline facilities, so it is necessary to set up scientific and reasonable toughness index requirements to prevent brittle fracture of in-service components under low temperature conditions. The development process of brittle fracture control technology, from empirical method to fracture analysis diagram method and then to fracture mechanics method, was systematically described. The empirial method based technical status on brittle fracture control of oil and gas pipelines was analyzed with China-Russia Eastern Gas Pipeline as the example. Meanwhile, through the comparison and analysis with the brittle fracture control requirements in ASME Boiling and Pressure Vessel Code (BPVC), the deficiencies of brittle fracture control measures for oil and gas pipeline fittings were pointed out. Analysis shows that the experience-based Charpy impact toughness index may be insufficient to prevent brittle fracture when applied to high toughness pipeline steel. Therefore, it is suggested to ① build a perfect fracture mechanicsbased brittle fracture control index system for high-grade high-toughness pipeline steel, ② add Nil-Ductility Transition (NDT) test requirements based on the existing brittle fracture control indexes, ③ and establish brittle fracture control requirements based on fracture mechanics evaluation.

Copyright of Araucaria is the property of Araucaria-Revista Iberoamericana de Filosofia, Politica y Humanidades and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the coefficients of Weibull Distribution Function (WDF) were calculated at two different heights using by six different methods. One-year wind data were used to determine the coefficients of WDF at different heights, and the wind data were obtained from a metrology station with a height of 10 m and a real wind turbine with a height of 80 m in Turkey's Hatay region. The used methods in this study were Graphical Method (GM), Empirical Method, Energy Pattern Method (EPM), Energy Trend Method, Maximum Likelihood Method and Moment Method.\ Three different statistical error analysis tests were used to compare the performance of the used methods at two different heights. Estimated mean wind speed and power values are the most important indicators to evaluate the performance of the used methods. In this study, mean wind speeds and powers were estimated in all methods for both heights using the WDF. These obtained values were compared with the actual real data and the best performing method was determined at both different heights for selected region. When the results were evaluated in general at both different heights, it was seen that the best performance method was the EPM and the worst performance method was the GM. [ABSTRACT FROM AUTHOR]

Centrifugal compressor performance map prediction is of primary importance for safe and effective operation of turbochargers. This article is a contribution on compressor map prediction using empirical relations based on automotive turbocharger manufacturers' performance maps. The present method evaluates the minimum and the maximum air flow rates, as well as the maximum compressor pressure ratio by original empirical equations exploiting impeller geometrical data. Newly introduced equations based on the mass flows and the maximum pressure ratio acquired above provide the compressor characteristic lines. The method is validated by applying it to various commercial automotive turbochargers with known performance maps from their manufacturers. At intermediate values of impeller speed, where the turbocharger is expected to match the engine, the computed compressor map agrees to the manufacturer's data, while, differences are observed at the maximum impeller speed line. From the cases examined, it can be stated that the present model can be applied to predict small diameter, high rotational speed compressor performance, particularly at the high efficiency region that the turbocharger is supposed to match the IC engine. [ABSTRACT FROM AUTHOR]

The tree canopy around Merapi Volcano, Yogyakarta, Indonesia, has a unique structure. The frequency of volcanic eruptions influences the uniqueness of the structure, as it is a response to volcanic ash and rainfall characteristics. This research was conducted on eight species that have different canopy structures. In contrast to the trees canopy that was not affected by eruptions, the tree canopy around the Volcano has more dynamic canopy surface characteristics during the recovery period. The redistribution of rainfall in the tree canopy was traced by calculating unit area discharge and droplets' probability in each canopy structure segment. The results of empirical throughfall calculation and throughfall direct observation were tested using ANOVA. Most of the throughfall occurs simultaneously under the canopy during rain with a depth of 3.5 - 72.5 mm or intensity of 10 - 20 mm/hour (observed = 58% and empirical = 57%). The existing range of rainfall intensity or rainfall depth shows that the process of redistribution of rainfall in the canopy has time constraints and canopy storage capacity constrain. The canopy surface characteristics have a more significant effect than the canopy structure on the redistribution of rainfall. The canopy surface serves as a sheet of rainfall concentration to the next section. The important canopy surface structure parameters to rainfall concentration are leaves characteristics, branches stiffness, and crown density. Knowledge of the tree canopy's rainfall flow distribution process will help manage conservation-based rehabilitation activities in areas prone to volcanic disasters. [ABSTRACT FROM AUTHOR]

In this paper, a method called "least-work solution" was empirically simplified to evaluate shear lag stress in the steel box moment connections with internal diaphragms in order to serve for the preliminary design. This approach considered the effects of column flange flexibility and depth of the beam web, and their relations on the stress distribution. The stress equations were manually obtained with a complicated form. Therefore, a simplified method was proposed to facilitate the calculation procedure. The results showed that least-work solution could be simplified to provide valid stress distribution and can thus be authenticated by FEM and existing test. [ABSTRACT FROM AUTHOR]

• Investigate the effect of the under-consolidated state on deformation induced by shield tunneling. • Develop a sophisticated 3D numerical model of shield tunneling in under-consolidated ground. • The magnitude and distribution of long-term surface settlement are obtained by numerical simulation. • The empirical method is proposed for estimating the long-term surface settlement in under-consolidated ground. The scenario of shield tunneling in under-consolidated soft ground becomes more and more frequent in newly reclaimed areas of coastal cities. For shield tunnel in under-consolidated soft ground, the effect of stress relief induced by tunneling and the effect of self-weight consolidation coexist, leading to a more complex long-term deformation behavior. Profound understanding of the long-term deformation behavior is fundamental for formulating more rational and economical ground improvement scheme. This study focuses on the long-term surface settlement, an important index of the long-term deformation, induced by shield tunneling in under-consolidated soft ground. A sophisticated 3D numerical model is first proposed and validated on the basis of the field monitoring data of Shanghai Metro Line 2. Then, a series of numerical analyses are conducted to investigate the effect of the under-consolidated state on long-term surface settlement induced by shield tunneling. The modeling results show that the short-term surface settlement troughs exhibit an identical pattern in both normally- and under- consolidated cases, while significantly larger long-term surface settlement occurs in under-consolidated soft ground, which follows a hump-shaped distribution. Under-consolidated soft ground with lower initial average consolidation degree, thicker surface fill and deeper tunnel axial depth tends to produce larger long-term surface settlement. Moreover, this study proposes an empirical method for estimating the long-term surface settlement induced by shield tunneling in under-consolidated soft ground. [ABSTRACT FROM AUTHOR]

Despite the decline in partially (PM10) and fully (PM2.5) inhalable particles observed in recent decades, Santiago in Chile shows high levels of particle and ozone pollution. Attainment plans have emphasized measures aimed at curbing primary and, to some extent, secondary particles, but little attention has been paid to photochemical pollution. Nevertheless, ozone hourly mixing ratios in Eastern Santiago regularly exceed 110 ppbv in summer, and in winter maximum mixing ratios often reach 90 ppbv. Moreover, the sum of ozone and nitrogen dioxide shows an increasing trend of more than 3.5 ppbv per decade at 5 out of 8 stations. This trend is driven by increasing NO2, possibly associated with increasing motorization but also with changes in photochemistry. To estimate the fraction of secondary particles in PM2.5 and due to the lack of long-term speciation data for particles, we use carbon monoxide as a proxy of primary particles and ozone daily maxima as a proxy for secondary particle formation. We find a growing fraction of secondary particles due to an increase in the oxidizing capacity of Santiago’s atmosphere. This stresses the need for new curbing measures to tackle photochemical pollution. This is particularly needed in the context of a changing climate.

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The successful launch of the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) provides a new and advanced tool for sea ice thickness (SIT) estimations in the Arctic. However, the performance of ICESat-2 for SIT estimations still remains unknown. In the present study, SIT estimates derived from ICESat-2 are examined using three retrieval methods, namely, two buoyancy methods with the merged snow depth and empirical snow depth (BMA and BME, respectively) and one empirical estimation method (EEM), and these estimates are compared to near-simultaneous airborne measurements from the IceBird mission in April 2019. Overall, the ICESat-2 total freeboard registers quite well with that from the near-concurrent IceBird mission with a mean bias of 2.5 cm, which demonstrates the high reliability of ICESat-2 data for SIT estimation. However, the much more evident difference between SIT estimations than total freeboard from ICESat-2 and IceBird indicates that other parameters (e.g., snow depth and snow/ice densities) may bring increased uncertainties to the SIT estimation. Overall, BMA is the best method for SIT estimation and has the closest thickness distribution to that of IceBird data with a mean bias of 0.11 m, followed by the BME and EEM methods. The dominate error sources for SIT estimation using the buoyancy method are ice density and snow depth that require further investigation in future studies. [ABSTRACT FROM AUTHOR]

The material ability to conduct the heat transfer is called thermal conductivity which is defined by Fourier's equation. Thermodynamic data on environmentally acceptable refrigerants have maximum interest for industries to optimize and design equipment of refrigeration such as exchangers and heat compressors. Because source empirical findings are not applicable for all temperature ranges in industries, correlation approaches are usually preferred. In this research, a novel simple correlation has been developed to predict the thermal conductivity of liquid refrigerants using regression approaches. The variance analysis was applied to study the rationality of regression model. Around 15,874 experimental data of 27 refrigerants were examined to obtain the main effects between the independent parameters. Independent parameters are temperature, boiling and reduced temperatures. The calculations show that the accuracy of the proposed correlation using the average absolute relative deviation (AARD) and root mean square deviation has priority over the previous relations. The results indicated that the AARD of the proposed model is 1.1% which is 68% lower than of the most accurate previous model (Latini–Sotte). [ABSTRACT FROM AUTHOR]

To identify an empirical method for identifying patients with 'high expectations' of orthodontic treatment with fixed appliances using a questionnaire-based approach. Secondary analysis of data from four studies which collected data on patients' expectations of orthodontic treatment using the same questionnaire. Secondary care orthodontic services. All four datasets comprised new patients aged 12–15 years, with no history of orthodontic treatment, who fulfilled the criteria for NHS treatment using the Index of Orthodontic Treatment Need (IOTN). Unpublished dataset 1 comprised 100 participants, while dataset 2 had 70 participants, dataset 3 had 67 participants and dataset 4 comprised 40 participants. The questionnaire utilised in all studies had a question which asked respondents to rate seven different expectations of outcome relating to straight teeth, better smile, ease of eating, speaking, cleaning teeth, improved career prospects and social confidence. Dataset 1 was analysed to determine the proportion of patients who had rated all seven outcome expectation items at a maximum score. Similar analyses were performed for the other three datasets to explore the trend in the proportion of patients with high expectations over time. For dataset 1, 2.0% of participants had high expectations, as defined by their scores on the questionnaire. The proportions for the datasets 2, 3 and 4 were 4.0%, 4.5% and 2.5%, respectively. The method outlined provides an empirical basis for identifying patients with statistically infrequent high expectations. This can potentially help clinicians in the management of such patients. [ABSTRACT FROM AUTHOR]

Despite the decline in partially (PM10) and fully (PM2.5) inhalable particles observed in recent decades, Santiago in Chile shows high levels of particle and ozone pollution. Attainment plans have emphasized measures aimed at curbing primary and, to some extent, secondary particles, but little attention has been paid to photochemical pollution. Nevertheless, ozone hourly mixing ratios in Eastern Santiago regularly exceed 110 ppbv in summer, and in winter maximum mixing ratios often reach 90 ppbv. Moreover, the sum of ozone and nitrogen dioxide shows an increasing trend of more than 3.5 ppbv per decade at 5 out of 8 stations. This trend is driven by increasing NO2, possibly associated with increasing motorization but also with changes in photochemistry. To estimate the fraction of secondary particles in PM2.5 and due to the lack of long-term speciation data for particles, we use carbon monoxide as a proxy of primary particles and ozone daily maxima as a proxy for secondary particle formation. We find a growing fraction of secondary particles due to an increase in the oxidizing capacity of Santiago's atmosphere. This stresses the need for new curbing measures to tackle photochemical pollution. This is particularly needed in the context of a changing climate. [ABSTRACT FROM AUTHOR]