CHARACTERIZATION OF ASPHALT HEALING AND INCORPORATION IN A FATIGUE DAMAGE MODEL

Healing is defined as the restoration of the material property during the rest period after damage. The healing property of the asphalt binder is opposite to fatigue damage, which occurs due to repeated traffic loading. On the other hand, healing occurs in the rest period between loading. Most of the existing methods for characterizing the fatigue damage and healing of asphalt are empirical in nature and do not consider the mechanism of healing. Although the asphalt concrete is a mixture of asphalt binder, fines and aggregates, most of the healing occurs in the asphalt binder. Therefore, it is important to understand the healing mechanism of the asphalt binder. In this study, the healing mechanism and the effects of several factors and asphalt chemistry are discussed. Then a constitutive fatigue damage model is developed with the incorporation of healing. The overall healing has two parts: instant healing and long-term healing. Instant healing is defined as the instantaneous recovery of damage at the beginning of the rest period due to the wetting of the micro-crack surfaces. Wetting is the process of the crack surfaces coming in contact with each other. It depends on the cohesive strength of the asphalt binder. In this study, energy of separation from tack test is used as a measure of the cohesive strength of the asphalt binder. It is observed that the instant healing is directly proportional to the energy of separation, which is correlated to the asphaltene and resin contents of the binder. Asphaltenes and resins represents larger molecules in the asphalt binder. An increase in the larger molecules in the binder reduces their mobility, which results in a decrease in wettability and instant healing. On the other hand, long-term healing is the time dependent recovery of damage over the rest period due to the inter-molecular diffusion at the micro-crack surfaces. The molecular diffusion rate depends on molecular chain length. In this study, molecular chain length is measured as the methylene to methyl ratio using Fourier Transform Infrared (FTIR). This study shows that the long-term healing rate of the asphalt binder is proportional to the molecular chain length. The effects of aging and moisture conditioning on the healing of asphalt binder is also studied. Results showed that aging and moisture conditioning decrease both instant and long-term healing, resulting in a reduction in overall healing. The grade of the performance grade (PG) binders has significant effect on aging and moisture conditioning. The effects of different filler contents are studied for two different PG binders. Results showed that mastic healing is mostly controlled by the asphalt binder type. The instant and long-term healing of the mastics decrease with the addition of filler. This is expected since the addition of fillers decreases the molecular mobility by interrupting the continuous binder medium, resulting in a decrease in wettability and diffusion rate in the mastic. In this study, a constitutive damage model is utilized to incorporate the healing and fatigue damage of the asphalt binder under cyclic shear loading with and without rest period. Healing is incorporated as a variable in this model. Shear loading is considered since previous studies showed that the force-interaction between the wheel and the pavement generates shear stress, which affects the fatigue damage the most. Motivated by experimental observations, the proposed model divides overall damage evolution into two parts: recoverable and permanent damage. The micro-damage healing is captured by the decrease in recoverable damage during rest periods. At the same time, this damage and healing model is coupled with the viscoelastic and viscoplastic model to simulate the non-linear behavior of the asphalt binder. For continuous loading, initially the permanent damage is almost close to zero. It accumulates with continuous loading which eventually results in the failure of the material. For loading with rest period, the recoverable damage heals during the rest period, resulting in a reduction in overall damage. However, after repetitive loading-rest period sequences the healing decreases and permanent damage becomes larger. The model prediction agrees with the experimental measurements under cyclic loading with and without rest periods. Thus, the model developed in this study can capture the overall response of the asphalt binder under cyclic or repetitive loading with and without rest period. The incorporation of healing in the damage model will provide an accurate measure of fatigue damage in the asphalt binder

On the Integration of Blockchain and SDN: Overview, Applications, and Future Perspectives

Blockchain (BC) and software-defined networking (SDN) are leading technologies which have recently found applications in several network-related scenarios and have consequently experienced a growing interest in the research community. Indeed, current networks connect a massive number of objects over the Internet and in this complex scenario, to ensure security, privacy, confidentiality, and programmability, the utilization of BC and SDN have been successfully proposed. In this work, we provide a comprehensive survey regarding these two recent research trends and review the related state-of-the-art literature. We first describe the main features of each technology and discuss their most common and used variants. Furthermore, we envision the integration of such technologies to jointly take advantage of these latter efficiently. Indeed, we consider their group-wise utilization—named BC–SDN—based on the need for stronger security and privacy. Additionally, we cover the application fields of these technologies both individually and combined. Finally, we discuss the open issues of reviewed research and describe potential directions for future avenues regarding the integration of BC and SDN. To summarize, the contribution of the present survey spans from an overview of the literature background on BC and SDN to the discussion of the benefits and limitations of BC–SDN integration in different fields, which also raises open challenges and possible future avenues examined herein. To the best of our knowledge, compared to existing surveys, this is the first work that analyzes the aforementioned aspects in light of a broad BC–SDN integration, with a specific focus on security and privacy issues in actual utilization scenarios

Study of lipid profiles high and normal body mass index in polycystic ovary syndrome women in Aljouf, Saudi Arabia

Background: For women of reproductive age, polycystic ovary syndrome (PCOS) is the most prevalent endocrinological condition. Hyperandrogenism, persistent ovulatory dysfunction, obesity, and insulin resistance have all been associated with PCOS. However, recently PCOS is detected in high-body weight and normal-body-weight women. No information was available to evaluate specific lipid profiles. The goal of this study is to analyze the lipid profiles of women with polycystic ovarian syndrome who have high or normal body weight. Methods: This polycystic ovarian syndrome (PCOS) retrospective study was carried out between January 2021 and January 2022 at Sakaka’s Maternity and Children Hospital (MCH), Aljouf, Saudi Arabia. A total of 68 PCOS women were included in the study; we divided them into high (n=34) and normal body weight (n=34) according to the calculation of BMI. We obtain the test results of lipid profiles and demographic data from hospital record files. Results: We noticed changes but no significance in our research of lipid profiles in high and normal PCOS participants. The CHOL, TG, HDL, and LDL, 159.30±4.193, 97.89±7.140, 60.91±9.564, and 99.47±9.22 shown in the high BMI PCOS women respectively. While, 129.28±3.702, 83.69±4.49, 46.84±1.68 and86.53±4.36 were detected in normal BMI PCOS women respectively. There were none that were statistically significant, with the exception of cholesterol p=0.001. Conclusions: Our results show that POCS women with normal body weight and PCOS women with high BMI have different changes in their lipid profiles, but no significance has been found other than higher cholesterol levels. Therefore, losing weight can stop lipid profiles from altering, which may reduce difficulties in the future

Correlations of Heavy Quarks Produced at Large Hadron Collider

We study the correlations of heavy quarks produced in relativistic heavy ion collisions and find them to be quite sensitive to the effects of the medium and the production mechanisms. In order to put this on a quantitative footing, as a first step, we analyze the azimuthal, transverse momentum, and rapidity correlations of heavy quark-anti quark ($Q\overline{Q}$) pairs in $pp$ collisions at $\cal{O}$($\alpha_{s}^{3}$). This sets the stage for the identification and study of medium modification of similar correlations in relativistic collision of heavy nuclei at the Large Hadron Collider. Next we study the additional production of charm quarks in heavy ion collisions due to multiple scatterings, {\it viz.}, jet-jet collisions, jet-thermal collisions, and thermal interactions. We find that these give rise to azimuthal correlations which are quite different from those arising from prompt initial production at leading order and at next to leading order.Comment: 26 pages, 15 figures. Three new figures added, comparison to experimental data included, abstract and discussion expande

The barley S-adenosylmethionine synthetase 3 gene HvSAMS3 positively regulates the tolerance to combined drought and salinity stress in Tibetan wild barley

Drought and salinity are two of the most frequently co-occurring abiotic stresses. Despite recent advances in the elucidation of the effects of these stresses individually during the vegetative stage of plants, significant gaps exist in our understanding of the combined effects of these two frequently co-occurring stresses. Here, Tibetan wild barley XZ5 (drought tolerant), XZ16 (salt tolerant), and cultivated barley cv. CM72 (salt tolerant) were subjected to drought (D), salinity (S), or a combination of both treatments (D+S). Protein synthesis is one of the primary activities of the green part of the plant. Therefore, leaf tissue is an important parameter to evaluate drought and salinity stress conditions. Sixty differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) and classified into 9 biological processes based on Gene Ontology annotation. Among them, 21 proteins were found to be expressed under drought or salinity alone; however, under D+S, 7 proteins, including S-adenosylmethionine synthetase 3 (SAMS3), were exclusively upregulated in drought-tolerant XZ5 but not in CM72. HvSAMS3 carries both N-terminal and central domains compared with Arabidopsis and activates the expression of several ethylene (ET)-responsive transcription factors. HvSAMS3 is mainly expressed in the roots and stems, and HvSAMS3 is a secretory protein located in the cell membrane and cytoplasm. Barley stripe mosaic virus-based virus-induced gene silencing (BSMV-VIGS) of HvSAMS3 in XZ5 severely compromised its tolerance to D+S and significantly reduced plant growth and K+ uptake. The reduced tolerance to the combined stress was associated with the inhibition of polyamines such as spermidine and spermine, polyamine oxidase, ethylene, biotin, and antioxidant enzyme activities. Furthermore, the exogenous application of ethylene and biotin improved the tolerance to D+S in BSMV-VIGS:HvSAMS3-inoculated plants. Our findings highlight the significance of HvSAMS3 in the tolerance to D+S in XZ5

Improving the productivity of acid sulfate soils for cultivation using limestone, basalt, organic fertilizer and/or their combinations

Acid sulfate soils are generally not suitable for the crop production unless they are efficiently improved. A study was conducted to improve the productivity of acid sulfate soils for rice cultivation using ground magnesium limestone (GML), basalt and organic fertilizer. The study was conducted on rice in laboratory, glasshouse and field. The pH of acid sulfate soils was low and exchangeable Al was very high which affected rice growth. The application of GML and basalt increased soil pH and reduced Al toxicity. GML required to ameliorate the soils for rice cultivation was 4 t ha-1. Basalt in combination with organic fertilizer was a good soil amendment, but required to be applied a few months ahead of rice cultivation. Due to GML or basalt application, rice plants grew well even though water pH was below 5. The highest rice yield obtained was 4.0 t ha-1 season-1 for Sulfaquepts and it was 7.5 t ha-1 season-1 for Sulfosaprists. In general, the application of GML or basalt in combination with organic fertilizer improved the productivity of acid sulfate soils and consequently enhanced rice yield

Arsenic management in contaminated irrigation water for rice cultivation

Arsenic (As) contaminated irrigation water (groundwater) is a threat to irrigated rice cultivation. Studies were conducted during three consecutive Boro seasons (fully dependent on irrigation) at highly As contaminated areas in Bangladesh to determine a suitable water management practice to reduce As accumulation in rice. In this study, two water management techniques were evaluated: 1) alternate wetting and drying (AWD) and continuous standing water (CSW) with surface (25 μg L-1 As); and 2) groundwater (419 μg L-1 As). A high yielding rice variety, BRRI dhan28, was grown. Results showed that the yield obtained by two management techniques were almost similar, except in CSW with groundwater application where significant yield reduction was observed. Significantly lower As content was found in the straw (77.23%) and rice grain (38.14%) of AWD with groundwater and CSW (straw 70.41% and 26.36%) with surface water application compared to CSW with ground water application. Among the water management practices, AWD with groundwater application showed similar benefit to CSW with surface water irrigation. Thus, alternate wetting and drying (AWD) with groundwater or surface water irrigation with CSW can be advocated as an appropriate agronomic practice for rice cultivated in As contaminated soils of Bangladesh

Template matching techniques for iris recognition system

Security and authentication is one of the major parts of our daily life. Iris is one of the most reliable forms of identification object in the human body. To develop an iris authentication algorithm for personal identification, this paper describes techniques for matching two bitwise biometric templates. The experimental result shows that the developed algorithm has good performance to check whether two templates are generated from same iris or not. The algorithm performs perfect recognition of a set of 94 eye images courtesy of The Chinese Academy of Sciences – Institute of Automation (CASIA). Algorithm showed 0% false accepted and 4% false rejection rate

Guiding Principles for the Conduct of Violence Study of Healthcare Workers and System (ViSHWaS): Insights from a Global Survey

Background Globally many studies have reported on violence faced by healthcare workers. However, there is still a lack of homogeneous data to give us a concrete understanding of the present scenario on a global scale. Conducting a global survey required a robust team organization structure, unique dissemination strategies accounting for the regional limitations, and continual networking to maintain and propagate the pool of survey collaborators and responders. This study aims to describe the strategies that helped carry out a global survey- based study, the lessons learned, and recommendations for future studies.   Methods This cross-sectional survey-based study was based on methodology of the “Hub and Spoke” model with the core team and sub-groups about different regions and managing country leads. The study was conducted across eight weeks from 6th June 2022 to 8th August 2022. The key steps included team organization, strategy formulation for survey dissemination and data collection, launching the project on social media, and conducting a post-survey amongst the collaborators. The Core Team convened weekly via video conference platforms to discuss the modus operandi, including the responsibilities of team members in communicating with HCWs from each country; strategies for data extraction and analysis. A standard message was created for the survey in English, which was spread via text, audio and video messages; the message was tailored according to the target region and population. The language barrier was managed by creating an audio translation or shifting to “an interviewer-administered” questionnaire. Call for leads and collaborators was organized through social media platforms and incentivized by proposing collaborative authorship   Results A core team of 11 members from 7 countries was assembled, which expanded to 40 country leads from around 110 countries. We also amassed more than 75 regional collaborators who worked to provide feedback and spread the message. The “Violence Study of Healthcare Workers and Systems” (VISHWAS) amassed 5500 responses across the world. A weekly alternating trend in the number of survey responses was observed for eight weeks. Guiding principles garnered through this collaborative project include focusing on 1. Effective team organization, 2. Ensuring external validation of survey tool, 3. Personalized communication, 4. Global networking, 5. Timely communication for maintaining momentum, and 6. Addressing regional limitations. The post-survey analysis showed that WhatsApp messaging was the most common modality used for survey dissemination, followed by in-person meetings and text messaging. The successful techniques were noted to be 1. Direct communication with respondents, 2. Regular progress updates, 3. Responsiveness for regional and country lead’s needs  4. Timely troubleshooting. The most common barriers for the respondents were limitations in language proficiency, technical fallouts, lack of compliance with, and difficulty understanding the questionnaire.   Conclusion In this global survey-based study of more than 5500 responses from over 110 countries, valuable lessons in team management, survey dissemination, and addressing barriers to collaborative research. We thereby recommend incorporating the guiding principles from this study to design future surveys on a global scale