Structural Conditions Research Articles

Historical Foundations of Green Developmental Policies: Divergent Trajectories in United States and France

ABSTRACTIn recent years, many countries have adopted biodiversity offset policies to internalize the ecological impacts of land developments. Although national policies share the general principle of equalizing ecological harm with gain, there is substantial variation across programs regarding the institutional forms governing offsetting. In this paper, we compare biodiversity governance in the United States and France to reflect more broadly on the factors shaping divergent trajectories of green developmental policies. Both countries have some form of biodiversity offsetting in place, but the major fault line of difference is the more extensive use of market‐based instruments (MBI) in the United States. Using a historical lens, we argue that one important reason for this variation lies in the different legal‐institutional definitions of biodiversity. A narrower definition in the United States focused on individual species, versus a broader definition in France focused on ecosystems, has facilitated a more standardized biodiversity governance arrangement in the United States. Leveraging this standardization, biodiversity markets have expanded in the United States while similar efforts to institutionalize market mechanisms have struggled in France. The comparison allows us to draw insights into the challenges in greening economic development, particularly in showing how historical scientific, legal, and institutional structures condition policy outcomes.

Flame Front Model with the Clusters Condensation

The processes model in a flame during the n-alkanes air mixture combustion initiation is proposed, taking into account the supramolecular structures formation possibility in the peroxide clusters form. This approach is justified by the n-alkanes melting temperatures correlation with their autoignition temperatures and anti-knock indexes. The condensation possibility is provided for such high molecular structures. Boiling temperatures values at flame front pressures characteristic were evaluated. To predict the peroxide clusters melting temperatures, a formula developed earlier for the hydrocarbons condensed state was used, which takes into account the length and molecular weight of modeled clusters. Expected peroxide clusters melting temperatures were predicted for conditions of dimeric and tetrameric structures. A linear dependence was used to recalculation the obtained values in boiling temperatures. It is shown that the calculated clusters phase transitions characteristic temperatures can be realized in the flame front preparatory zone. Based on the condensation theory, the flame front thickness and the minimum non-extinguishing sphere radius during ignition were estimated: the obtained data closely coincide with these parameters known values.

Computational Models of Dynamic Load Sources for Modeling of Construction Structures Operation Used in Monitoring of Technical Condition of Buildings and Structures

This research aims to develop principles for assessing the impact of mega-cyclic vibrodynamic loads on the reliability of construction structures. The relevance of the reasons for the development and improvement of algorithms for numerical modeling of multicycle dynamic loads on building structures is due to the steadily increasing intensity of such loads on buildings and structures in megacities, as well as the acute practical problem of significant differences in the dynamic characteristics of buildings and structures obtained as a result of mathematical modeling and determined by experimental methods. The article presents research materials on computational equivalent models of dynamic load sources for numerical modeling of the behavior of construction structures under their influence, using the method of vibroacoustic analogies. The article examines models of sources of dynamic impact on construction sites. Algorithms and final formulas for computational modeling of the simplest sources of dynamic load are developed using the method of vibroacoustic analogies. The dynamic properties of the simplest dynamic load sources were analyzed. A significant difference between the computational models of real and ideal dynamic load sources. The article presents research and development results intended for calculating the distribution of dynamic loads on elements of construction structures in industrial and civil engineering projects located in areas with high levels of transport vibrodynamic impacts. An important property of the proposed computational equivalent models of sources of dynamic impact on building structures is the possibility of computational verification of critical elements, points, or nodes of load-bearing structures of buildings and structures under dynamic overloads. The position of these critical elements, points, and nodes of load-bearing structures under dynamic loads can differ significantly from their position determined using static and quasistatic computational modeling methods.

An Experimental Assessment Using Acoustic Emission Sensors to Effectively Detect Surface Deterioration on Steel Plates

Acoustic emission (AE) testing is used for the continuous evaluation of structural integrity and the monitoring of damage evolution in structural components and materials. During operation, the environmental and loading conditions of metal structures can result in corrosion and surface wear damage. The early detection of surface degradation flaws is crucial, as they can serve as local stress concentration points, leading to crack initiation and failure. In this work, the effectiveness of AE in monitoring corrosion and surface wear flaw formation was experimentally evaluated. AE sensors were installed on steel test plates during the artificial induction of corrosion and surface wear in order to detect and record the generated AE signals. Corrosion-related AE signals typically exhibit low amplitude, count, and energy values. The direct detection of active corrosion can be challenging in noisy environments, but it can be carried out under certain conditions using dedicated AE sensor groups. Surface-wear-related AE signals exhibit high amplitude, energy, and count values, with long duration values that are associated with wear and grinding conditions. It was found that AE sensors can be utilised to detect corrosion and surface degradation events. The effectiveness of the AE method in detecting surface degradation in noisy environments can be improved by implementing a filtering methodology. This will limit the recording of noise-related signals that can mask out actual surface degradation AE events.

Re-Examining the Narrative of Structural Transformation: Insights from India’s Development Experience

The narrative of structural transformation, based on the experience of global North, posits that the process of development involves gradual ‘modernisation’ of the overall structure of the economy, where the traditional/low-productivity sectors give way to and support the modern/high-productivity sectors. However, much of the global South has not been able to experience this process along the anticipated lines, as a significant proportion of their workforce is still engaged in the low-productivity agriculture and non-agriculture informal sectors for their livelihood. We highlight that the dominant narrative does not take into account the importance of specific historical conditions, particularly the role of colonialism, that facilitated the process of structural transformation in the global North. The altered structural conditions in the post-colonial era, both at global and domestic level, question the possibilities of a similar process unfolding in the global South. In this regard, we analyse India’s development experience, both at macro and micro level, focusing on two villages of the Indian state of Tamil Nadu, surveyed in 1994 and later in 2018. We illustrate that the process of labour and employment transition across sectors is highly complex and heterogeneous. Rather than being driven solely by productivity growth, the nature and direction of these changes are characterised by economic distress. We argue that the prevailing narrative, which presents a linear understanding focused on productivity differentials across sectors, is inadequate to understand the nature of this transition in the South. Instead, the process needs to be understood in the particular socio-economic and ecological context specific to a given space and time.

Regeneration, predatory inclusion, and migrant experiences in declining rural areas in Spain and Germany

ABSTRACT Declining rural areas have become central sites for migrant settlement. In the hope that migration will counteract rural shrinkage, migrants are increasingly portrayed as catalysts to revitalize communities. This article critically examines migration to declining rural areas vis-à-vis rural reception and regeneration policies. Drawing on qualitative research including interviews, focus group discussions, and participant observations, we compare migrants’ settlement experiences and their positions in rural revitalization processes in northeast Spain and eastern Germany. Our research illustrates that local reception and regeneration policies do not only sideline the role of newcomers as rural place-makers, who contribute to the sustainment (or expansion) of local services and infrastructures. They also result in conditions of ‘predatory inclusion’, in which migrants’ settlement is shaped regarding their potential ‘use’ for revitalizing local economies and housing markets in exploitative terms and along racialized lines. Facing precarious labor and housing conditions, migrants tend to reside only temporarily in our investigated areas. This article contributes to a growing body of migration research in rural areas and explains that attempts at regeneration through migration can run the risk of ignoring migrants' structural conditions, needs, mobility aspirations and life plans, thereby reinforcing racial and class-based inequalities present in rural areas.

Machine learning analysis/optimization of auxetic performance of a polymeric meta-hybrid structure of re-entrant and meta-trichiral

In the ever-evolving field of materials science, the quest for innovative design solutions continues. One such area of research is the optimization of auxetic performance in meta-hybrid structures. This study delves into the application of machine learning analysis to enhance the properties of a specific meta-hybrid structure combining re-entrant and meta-trichiral designs. The polymeric meta-hybrid structure is subjected to finite element (FE) analysis to determine its Poisson's ratio. Various machine learning methods, such as linear, quadratic, and non-linear approaches, are employed to accurate forecast the Poisson's ratio of the polymeric meta-hybrid structure. Although both linear and quadratic machine learning algorithms have shown some success in predicting Poisson's ratios, they cannot be considered outstanding. As a result, a non-linear machine learning algorithm has been developed to enhance the accuracy of Poisson's ratio prediction. The results indicate that non-linear machine learning techniques out performs both linear and quadratic methods when it came to predicting Poisson's ratio. Specifically, the non-linear model achieved an impressive R-sq value of 93.68%, demonstrating its exceptional accuracy and overall excellence in fitting the data. The optimum conditions for the meta-hybrid structure are determined to be a thickness of 4.35 mm, a temperature of 15 °C, and a strain rate of 1%. Under these specific parameters, the Poisson's ratio of the meta-hybrid structure is measured to be −3.899, well outside isotropic stability limit but acceptable for auxetic structures.

Intersecting structural and psychosocial conditions: investigating injection drug use and HIV among transgender women.

Transgender women continue to face a significant burden of health disparities with HIV infection as a critical public health concern. Substance use is higher among transgender women compared to cisgender women. However, little is known about transgender women who inject drugs and risk for HIV in the United States. The objectives were to explore HIV prevalence, injection-related behaviors, and HIV prevention and care outcomes among transgender women who inject drugs and to compare transgender women to a general sample of people who inject drugs (PWID). Participants from National HIV Behavioral Surveillance were recruited via respondent-driven sampling, interviewed, and tested for HIV infection in 2019-2020. Log-linked Poisson regression models were used to test for associations between injection drug use and selected characteristics. Among 1,561 transgender women, 7% injected drugs in the past 12 months. HIV prevalence was higher among transgender women who inject (aPR=1.5, 95%CI=1.2-1.8) than those who do not. Multiple psychosocial conditions were associated with injection drug use. Among transgender women with HIV, those who inject were less likely to take antiretroviral therapy (aPR=0.8, 95%CI=0.7-1.0) than those who do not. Methamphetamine was the most commonly injected drug (67%); most accessed a syringe services program (66%). Transgender women who inject have substantial challenges related to health outcomes including high HIV prevalence and exposure to psychosocial conditions, such as homelessness, incarceration, and exchange sex, that may exacerbate risks associated with injection drug use. This population may benefit from increased access to non-judgmental and culturally competent harm reduction services.

Wind turbine tower dynamic behavior investigation

The vibration characteristics of wind turbine may affect the stability, performance and life-time of the system. This research used the theoretical and experimental approaches to predict and investigate the wind turbine dynamic behavior. Three finite element models which were wind turbine with flow, wind turbine structure only, tower only model and tower and base model, were used to calculated the wind turbine's natural frequencies. The actual measurements were used to validation the model correctness. It is expected used the deformation mode under different external forces, base conditions for further identify the critical factors for the structural health conditioning of the wind turbine tower.

Calculation of the radius of influence with a specified error at transient filtration mode

A transient filtration mode leads to an increased load on drainage systems and can potentially violate the normal operating conditions of structures. The mode is yet to be investigated in science and methodology. Various methodologies used for calculating the key parameter of the transient filtration mode – the radius of influence of the depression cone – often fail to obtain the same values and to provide a means to determine the error in the calculations performed. A systematic review of scientific, regulatory and educational literature on the calculation of parameters in the transient filtration mode was carried out using general analysis and synthesis, as well as mathematical analysis. The results of the study described two main theoretical approaches for determining the radius of influence; however, neither of them takes into account the errors in the calculations performed. The authors of the present paper provide a mathematical justification for calculating the radius of influence with a specified error using information technologies.

Experimental studies of sensors based on fiber Bragg gratings embedded in the internal structure of composite plates

The main purpose of this article is to study the structural characteristics of carbon fiber samples printed on a 3D printer, including embedded sensors, during 3D printing, through numerical and experimental studies. There is a widespread tendency to replace metals with modern composite materials. Various methods can be used to measure the destruction of the composite structure. Fiber Bragg array sensors are known as intelligent localized and global structural condition prediction devices for all kinds of structural applications, especially those using composite materials. In this work, we created control plates by impregnating a selected number of layers of carbon fabric with epoxy resin. Fiber-optic Bragg sensors were additionally located between the layers of carbon fabric. In the course of experimental studies, a fiber Bragg grating sensor was embedded in the middle of the sample, and a second sensor was attached to the finished surface of the sample. We conducted environmental tests to examine the durability of the additively manufactured standard’s components and the impact of integrated sensors on the composite sample. We applied the concept of equations, known as conjugate modes, and used the transition matrix method to solve them numerically. The scientific novelty of the work is the development of a new method and technology for measuring spatial deformation in composite materials using fiber-optic Bragg gratings.

Structural digital Twin for damage detection of CFRP composites using meta transfer Learning-based approach

Using deep learning approaches to identify and locate defects in composite structures made of Carbon Fiber Reinforced Plastics (CFRP) is becoming increasingly popular. However, when the training data is limited, the existing deep learning methods do not work well. Moreover, the lack of data for damaged conditions of CFRP structures causes a severe data imbalance, which makes this problem even harder. In this paper, we present a novel damage detection method called DFMTR which stands for Digital Twin based Few-shot Meta Transfer Learning. It creates numerical model as the digital twin to generate a large amount of virtual data under different damage conditions for model training. Then, it applies relational network and domain adaptive techniques to achieve effective few-shot transfer. That means, it can detect damage accurately with only a very small amount of real data. This is very useful and practical for damage detection of high-end CFRP equipment. In experiments, our approach outperforms existing methods in all commonly used metrics. The classification accuracy can be improved to more than 82% from 55% by using only 4 real samples, and the accurate localization of damaged area is also successfully achieved.

Optimization of ventilation efficiency in tunnel-type underground spaces using response surface methodology: a case study of Yunlong Mountain civil defense in Xuzhou

Civil defense projects, designed as wartime underground spaces, often lack effective natural ventilation and have considerable depth, which complicates their use as public spaces in peacetime. However, the application of passive ventilation technologies can create effective airflow channels within these structures, significantly enhancing ventilation efficiency and thus improving the overall thermal comfort level. For this study, air age, along with average wind speed, temperature, and relative humidity as stipulated by the “Requirements for Environmental Sanitation of Civil Air Defense Works during Peacetime Use” (GBT 17216-2012), were selected as evaluation metrics. This paper compares the ventilation effectiveness between single ventilation shafts and multiple ventilation shafts under positive and negative pressure conditions in underground civil defense structures. The results indicate that negative pressure ventilation in multiple shaft configurations performs optimally across various ventilation approaches. Subsequently, the Response Surface Methodology (RSM) was utilized to further optimize the positioning of multiple ventilation shafts. The study examined the impact of three ventilation shaft locations on average wind speed, temperature, relative humidity, and air age, leading to an optimized design. Specifically, the optimal positions are 54.76 m for Shaft A, 51.45 m for Shaft B, and 79.85 m for Shaft C, achieving an average wind speed of 0.222 m/s, a temperature of 26 °C, a relative humidity reduction to 85.47%, and an average air age of 10.57 s. This research provides practical insights for the optimization of ventilation in underground civil defense facilities.

Multicenter study of the performance of NTM Elite agar for the detection of nontuberculous mycobacteria from patients with cystic fibrosis.

The performance of a novel selective agar was evaluated against the performance of conventional mycobacterial cultures, i.e., a combination of the mycobacterial growth indicator tube (MGIT) with Löwenstein-Jensen (LJ), for the detection of nontuberculous mycobacteria (NTM) in sputum samples from people with cystic fibrosis (pwCF). Two hundred eighty-three sputum samples (231 fresh sputum and 52 spiked sputum) from 143 pwCF were collected. They were inoculated without prior decontamination on NTM Elite agar (30°C ± 2°C for 28 days) and inoculated on both MGIT and LJ (35°C-37°C for 6-8 weeks) after N-acetyl-L-cysteine-2% sodium hydroxide decontamination. NTM were identified by Matrix-Assisted Laser Desorption Ionization/Time of Flight Mass Spectrometry and/or PCR, and whole-genome sequencing. A total of 67 NTM were recovered overall by the combination of all culture media. NTM Elite agar allowed the recovery of 65 NTM (97%), compared to 22 for the conventional MGIT and LJ media combination (32.8%), including 22 NTM for MGIT (32.8%) and 3 NTM with the LJ medium (4.5%). For Mycobacterium abscessus complex, the sensitivity of NTM Elite agar was 95% compared with a sensitivity of 30% for the conventional MGIT and LJ media combination. Overall, 17.3% of cultures on NTM Elite agar were contaminated with other micro-organisms vs 46.3% on MGIT and 77% on LJ. This study shows that the novel selective agar (NTM Elite agar) significantly outperforms the conventional MGIT and LJ media combination in terms of sensitivity, selectivity, and ease of culture, without the requirement of an L3 laboratory.IMPORTANCENontuberculous mycobacteria (NTM) are significant pulmonary pathogens in patients with pre-existing structural lung conditions such as cystic fibrosis, bronchiectasis, or chronic obstructive pulmonary disease. Mycobacterium avium complex and Mycobacterium abscessus complex (MABSC) are the most frequently isolated organisms. Compared to the recommended culture method for NTM, which combines solid and liquid culture media, NTM Elite agar enables a faster/easier diagnosis and speeds up identification and susceptibility testing as the final reading is at 28 days instead of 6-8 weeks for the conventional mycobacterial cultures. In addition, for the NTM Elite agar, no decontamination stage before inoculation is necessary, unlike the conventional mycobacterial cultures. NTM Elite agar is derived from a formulation of medium adapted to rapidly growing mycobacteria (RGM). The medium enables the growth of RGM while suppressing other flora. It is supported with published clinical data showing the benefits of this medium.

Features of construction at low temperatures

The present paper considers the features of construction at low temperatures and introduces the previous studies on improving the reliability of metal and reinforced concrete structures. Low temperatures adversely affect penetration of the edges of metal products during welding. Notably, design engineers consider the results of investigations and calculations, and incorporate steel products made of lowalloy, stainless steels, and nickel alloys. These materials demonstrate high viscosity, good weldability, retain strength in the process of manufacturing structures and their operation. The paper analyzes the construction works in winter conditions and considers installation as one of the main technological processes in construction. In addition, the paper lists the restrictions for welding and concreting, as well as indicates the conditions for structures to be installed using bolts or manual arc welding. Manufacturing plants are known to treat metal products and structures with protective coatings prior to transportation to the construction site. These technological operations are aimed at protecting metal from corrosion and at retaining heat within buildings. All winter concreting techniques are indicated to be implemented on the construction site at temperatures below 5°C. Gaining the required strength of the cement needs more time in cold temperatures than at a temperature of +20°C. The method of artificial heating, presented in the paper, is intended to create durable concrete and reinforced concrete products and structures.

Under pressure: a critical scoping review of scales and instruments used in work with people in over-indebtedness

ABSTRACT Social work is a field in which budget and debt counselling are offered, and instruments have been developed to map this type of problem. The aim of this paper is to present a scoping review of validated instruments in budget and debt counselling with over-indebted people. The study’s questions are: How do the instruments studied address problems related to over-indebtedness? What assumptions about the causes and remedies of over-indebtedness do the instruments for budget and debt counselling rest on? How can the ways in which these instruments address over-indebtedness be understood as micro-managing this social problem? How may the use of these instruments affect the possibility of budget and debt counsellors taking structural conditions and barriers into account? The study results show that most of the instruments are designed to map resources or problems related to the household economy. Using these instruments, social workers can be seen as part of the governance of citizens through reformatory technology and micro-management of subjects in a financialized society. On the one hand, they can be used to support clients. On the other hand, the instruments can also shift the focus away from structural conditions in society and the consequences of economic inequality.

Transformer Based Pluralistic Image Completion With Reduced Information Loss.

Transformer based methods have achieved great success in image inpainting recently. However, we find that these solutions regard each pixel as a token, thus suffering from an information loss issue from two aspects: 1) They downsample the input image into much lower resolutions for efficiency consideration. 2) They quantize 2563 RGB values to a small number (such as 512) of quantized color values. The indices of quantized pixels are used as tokens for the inputs and prediction targets of the transformer. To mitigate these issues, we propose a new transformer based framework called "PUT". Specifically, to avoid input downsampling while maintaining computation efficiency, we design a patch-based auto-encoder P-VQVAE. The encoder converts the masked image into non-overlapped patch tokens and the decoder recovers the masked regions from the inpainted tokens while keeping the unmasked regions unchanged. To eliminate the information loss caused by input quantization, an Un-quantized Transformer is applied. It directly takes features from the P-VQVAE encoder as input without any quantization and only regards the quantized tokens as prediction targets. Furthermore, to make the inpainting process more controllable, we introduce semantic and structural conditions as extra guidance. Extensive experiments show that our method greatly outperforms existing transformer based methods on image fidelity and achieves much higher diversity and better fidelity than state-of-the-art pluralistic inpainting methods on complex large-scale datasets (e.g., ImageNet).

Insight into failure mechanisms of rainfall induced mudstone landslide controlled by structural planes: From laboratory experiments

The role of structural planes in controlling mudstone landslides is a key issue in the study of the geo-disasters in the Loess Plateau of China. In this study, the effects of sliding-control structures on the mechanisms of mudstone landslides are investigated via three model experiments with different slope structures. The results show that the hydrological response and failure mode of the experimental slope vary with the structural conditions. The vertical joints serve as preferential seepage paths, which accelerate rainfall infiltration, resulting in earlier responses of volumetric water content and pore water pressure. With the incorporation of vertical joints, the slope failure mode tends to transform from shallow failure to deep-seated failure. The presence of a weak interlayer leads to significant increases in the velocity and runout of the sliding mass. The variation in the slope failure extent and deformation characteristics with varying sliding-control structures further changes the temporal and spatial distributions of volumetric water content and pore water pressure. The different slope failure modes correspond to different sliding-control mechanisms, which are dominated by the types of structural planes and their interactions with hydrological responses. In the action of these mechanisms, pore water pressure and seepage force play significant roles in the reduction of effective stress and shear strength.

A pore-scale investigation of viscous coupling effect on immiscible two-phase flow in porous media

Viscous coupling effect plays a significant role in immiscible two-phase flow within porous media, while its influence on relative permeability remains uncertain. In this paper, an improved MRT-based viscosity-modified multicomponent multiphase (MCMP) pseudopotential lattice Boltzmann model, capable of handling high viscosity ratio, is employed to simulate two-phase flow with different viscosities in a cross-array circular structure and a real rock structure, respectively. The applicability of this model for two-phase flow with various viscosity ratios has been verified by some typical tests. Systematically, the effects of viscosity ratio, structural configuration, and wetting condition on the relative permeability curves are investigated in conjunction with their component distributions and velocity fields at different two-phase saturations. These results indicate that due to the two-phase flow competition under different structural conditions, the viscous coupling effect has varying degrees of impacts on the mobility of thin phase and viscous phase. Further, the mechanism of two-phase lubricating effect is also discussed under different wetting conditions at Darcy flow regime.

Development of fully controlled rock crushing method and its vibration impact during rockfall risk reduction at Assos ancient port: Experimental and field studies

Historical sites are vulnerable to significant damage caused by natural disasters such as earthquakes, rockfalls, floods, landslides, and fires. Protecting these invaluable regions necessitates preemptive measures against such disasters. This study delves into the rockfall risk assessment and remediation techniques for Assos, an ancient port with a history spanning over 2000 years. Initially, field surveys were conducted to identify active rockfall potential and precarious blocks within the area. Subsequently, intervention methods were devised, involving the removal of numerous hazardous blocks. A novel approach to rock crushing/breaking was developed specifically for the historical locale, comprising three distinct techniques: Fully Controlled, Splash Controlled, and Free Rock Crushing/Blasting. Additionally, two types of materials, namely Chemical Rock Breaking Powder and Cartridges Containing Pyrotechnic Class Explosives, were employed in refining the method. The subsequent phase of the research aims to evaluate the impact of recorded vibrations on historical artifacts and structures within the ancient site, with a particular focus on potential structural damage. To this end, seven rock crushing/breaking experiments were conducted, employing five different accelerometers strategically placed near the experimental site to measure vibrations in the historical structures. The findings have been analyzed in accordance with international standards, including DIN 4150/3, USBM RI-8507, and the Environmental Noise Assessment and Management Regulation. The assessment specifically scrutinized the condition of historical structures. In summary, during rock crushing operations employing chemical rock crusher powder (W=17 kg), the highest maximum particle velocity recorded at the closest distance to the operation point was 0.031 mm/s. These measurements fell comfortably below the specified damage criterion outlined in the norms. As a result, utilizing this method, over 7500 m³ of hazardous rock blocks were successfully broken and removed from the slope, while concurrently erecting rockfall protection structures. Ultimately, this comprehensive approach led to a reduction in regional rockfall risk, facilitating the safe reopening of Assos to visitors.