199 research outputs found
Coordination behavior of chelidamic acid With VV, NiII, FeIII, and CaII: Syntheses, X-ray characterization and DFT studies
No full textFour new complexes of chelidamic acid (H3cda) in the presence of 2-aminopyrimidine (apym) or 2,4,6-triamino-1,3,5-triazine (tata) as external ligands, namely (apymH)[VO2(Hcda)]⋅H2O (1), [Ni(Hcda)(apym)(H2O)2]⋅H2O (2), (apymH)[Fe(Hcda)2] (3), and (tataH)2(tata)2[Ca2(cda)2(H2O)6]⋅H2O (4) were synthesized. X-ray diffraction analysis of 1-4 revealed the formation of 3D frameworks generally involving weak interactions (mainly H-bonds) between metal complexes of chelidamic acid, protonated or deprotonated external ligands apym or tata and co-crystallized water molecules. Some complexes present remarkable assemblies in the solid state governed by unconventional noncovalent interactions that have been analyzed by means of DFT calculations. Solution studies were also performed to fully characterize the new compounds
Dynamic Analysis of Construction and Demolition Waste Management System (A Case Study of Tehran, Iran)
No full textIncreasing construction and demolition (C&D) waste generation has faced serious challenges in the metropolitan areas of Iran. The objective of this research is to present a system dynamics model for C&D waste management of Tehran. In particular, variables such as energy consumption and carbon dioxide (CO2) emissions for the city of Tehran to the horizon of 2041 are studied and predicted. Increasing the rate of construction of housing and urban infrastructure will increase C&D waste and, on the other hand, increase the demand for raw materials, which is contrary to the principles of sustainable development. The increase in quarries exploitation and the increase in C&D waste generation can reduce the buildable area of the city. The impacts of such factors are in a cyclic and systemic approach that either reinforces a destructive factor or balances the existing solution. In general, the assessment of the implementation or nonimplementation of C&D waste recycling in each city requires a system insight that examines the aspects of the subject with a systemic perspective over time. To this end, the system dynamic approach, along with the environmental and economic approach of the life cycle, can clarify the hidden dimensions of the problem. One of the important limitations of the research is the large number of variables in the model and finding reliable historical information for these variables
Environmental Impact Assessment of Building Materials Using Life Cycle Assessment
No full textIn pursuit of environmental sustainability in the construction sector, this study employs a comprehensive life cycle assessment (LCA) approach to evaluate the environmental impact of widely used building materials in Iran, with a particular focus on energy consumption and carbon footprint. The investigation encompasses 22 widely used building materials, utilizing the Ecoinvent v3 database and Simapro8 software to assess critical environmental variables, including carbon dioxide (CO2) emission, required primary energy, water consumption, and thermal conductivity. The findings unveil the diverse environmental profiles of these materials, with thermal conductivity typically hovering around zero to 2 W/m.K for most, but with exceptions such as lime, aluminum, rebar, and steel exhibiting significantly higher values. Moreover, aluminum, ceramics, PVC pipe, and expanded polystyrene (EPS) foam are identified as higher energy consumers during their life cycle, in contrast to concrete and cement mortar characterized by lower primary energy demands. The materials identified as high-carbon building materials are steel, stone, plaster, rebar, bitumen, concrete, glass, cement, gravel, and EPS foam. On the other hand, the materials identified as low-carbon building materials are masonry blocks, wood, tiles, bricks, drywall, MDF, and cement mortar. This research provides valuable insights for material selection and sustainable construction practices, emphasizing low-carbon materials to reduce environmental impact and contribute to the global effort to mitigate climate change through responsible construction choices
Damage accumulation analysis of cfrp cross-ply laminates under different tensile loading rates
No full textThis paper investigates the loading rate effect on both mechanical properties and damage accumulation process of [0°2/90°4]S carbon fiber-polymer laminates under tensile loading. In-situ edge observations, Acoustic Emission and Digital Image Correlation techniques were utilized simultaneously to monitor the state of damage in real time. Results showed that the axial modulus and strength were less sensitive to loading rates than failure strain, which increased with the decrease of the loading rate. In the viewpoint of damage accumulation process, high density and uniform distribution of transverse matrix cracks, and H-shape crack patterns, incorporating inter-laminar cracks, were more likely to occur at low loading rates while variable crack spacing occurred at higher rates. When loading rates were lower than a certain level, maximum transverse matrix crack density decreased slightly due to the restriction of relatively widely generated inter-laminar cracks. Furthermore, the cumulative acoustic emission energy of low-frequency signals was linearly correlated to transverse matrix crack density, providing a promising way to quantify crack accumulation in real time. Finally, spatial consistence was observed between transverse matrix cracks at edges and stress concentrations at the exterior 0° ply, and the peaks of axial strain at local concentration regions locate either near the newest cracks or at the place with minimum crack spacing.Structural Integrity & Composite
Webis-Argument-Framing-19
No full text<p>The dataset comprises 12,326 arguments that are labeled with their topics and frames. The following fields are stored for each argument</p>
<p>conclusion, premise, frame, topic, stance, argument_id, topic_id, frame_id</p>
<p>For more information please refer to our paper "Modeling Frames in Argumentation".</p>
<p> </p>If you use the dataset please cite our paper:
@InProceedings{stein:2019q,
author = {Yamen Ajjour and Milad Alshomary and Henning Wachsmuth and Benno Stein},
booktitle = {2019 Conference on Empirical Methods in Natural Language Processing and 9th Internationl Joint Conference on Natural Language Processing (EMNLP 2019)},
doi = {},
month = nov,
publisher = {ACL},
site = {Hong Kong},
title = {{Modeling Frames in Argumentation}},
url = {},
year = 2019
Optimizing Ready Mixed Concrete Production Plants via a Genetic Algorithm Approach Used for Batching Plant Equipment Layout
No full textIdentifying and Prioritizing Green Building Parameters in the Implementation of Sustainable Development Management with an Energy Approach
No full textJoint Trajectory and Power Allocation Design for Secure Artificial Noise Aided UAV Communications
No full textThis paper investigates an average secrecy rate (ASR) maximization problem for an unmanned aerial vehicle (UAV) enabled wireless communication system, wherein a UAV is employed to deliver confidential information to a ground destination in the presence of a terrestrial passive eavesdropper. By employing an artificial noise (AN) injection based secure two-phase transmission protocol, we aim at jointly optimizing the UAV's trajectory, network transmission power, and AN power allocation over a given time horizon to enhance the ASR performance. Specifically, we divide the original non-convex problem into four subproblems, and propose a successive convex approximation based efficient iterative algorithm to solve it suboptimally with guaranteed convergence. Simulation results demonstrate significant security advantages of our designed scheme over other known benchmarks, particularly for stringent flight durations.Manuscript received June 16, 2020; revised November 11, 2020 and December 14, 2020; accepted February 2, 2021. Date of publication February 5, 2021; date of current version April 2, 2021. This work was supported by Australian Research Council under Discovery Project DP210100412. The review of this article was coordinated by Dr. S. Misra. (Corresponding author: Milad Tatar Mamaghani.) The authors are with the Department of Electrical and Computer Systems Engineering, Faculty of Engineering, Monash University, Melbourne, VIC 3800, Australia (e-mail: [email protected]; [email protected]). Digital Object Identifier 10.1109/TVT.2021.3057397Peer-reviewe
Barely visible impact damage assessment in laminated composites using acoustic emission
No full textDespite the key advantages of Fiber Reinforced Polymer (FRP) composites, they are susceptible to Barely Visible Impact Damage (BVID) under transverse loadings. This study investigates BVID in two quasi-isotropic carbon/epoxy laminates under quasi-static indentation and Low-Velocity Impact (LVI) loadings using Acoustic Emission (AE). First, the evolution of interlaminar and intralaminar damages is studied by analyzing the AE signals of the indentation test using b-value and sentry function methods. Then, the specimens are subjected to the LVI loading and the induced damages are compared with the indentation test and the percentage of each damage mechanism is calculated using Wavelet Packet Transform (WPT). In consistent with the mechanical data, ultrasonic C-scan and digital camera images of the specimens, the AE results show a considerable similarity between the induced BVID under quasi-static indentation and LVI tests. Finally, the obtained results show that AE is a powerful tool to study BVID in laminated composites under quasi-static and dynamic transverse loadings.</p
KEY SUCCESS FACTORS IN ROAD MAINTENANCE MANAGEMENT PROJECTS (A CASE STUDY OF MAYSAN PROVINCE, IRAQ)
No full textDeveloping roads is a crucial and essential activity, but maintaining them regularly is equally important to improve their performance. A well-maintained road network facilitates economic, industrial, cultural, and social growth. Once the construction phase of a road is complete, its operating phase commences, which is subject to wear and tear due to various factors like traffic and weather conditions. Hence, regular and continuous road maintenance activities are essential to increase the useful life of roads and manage national resources effectively. However, road maintenance management in Iraq, particularly in the province of Maysan, is suffering from poor performance due to the absence of an effective maintenance management system. Therefore, this research aims to identify the critical success factors of road maintenance projects, with a focus on the Maysan province as a case study of Iraq. The study identified and analyzed 27 key success factors in road maintenance projects, which were classified into three groups: management, technical, and resources. Based on the analysis of the literature review and field study in Maysan province, the top five key success factors were determined to be: 1. Adequate funds; 2. Timely payment to contractor and employees; 3. Quality of materials; 4. Use of advanced technology to detect or evaluate road defects; and 5. Communication and coordination among parties.
ABSTRAK: Pembangunan jalan adalah sangat penting bagi aktiviti harian, tetapi penyelenggara secara berkala adalah sama penting bagi menambah baik prestasi jalan. Jaringan jalan yang terpelihara membantu dalam ekonomi, industri, budaya, dan perkembangan sosial. Sebaik fasa pembangunan jalan siap, fasa operasi bermula, bergantung pada tahap jalan disebabkan pelbagai faktor seperti trafik dan kondisi jalan. Oleh itu, penyelenggaraan jalan berkala dan berterusan sangat penting kepada jangka hayat jalan dan ianya dapat menyumbang kepada pengurusan sumber negara dengan efektif. Walau bagaimanapun, penyelenggaraan jalan di Iraq, khususnya di daerah Maysan, memiliki kekurangan dalam penyelenggaraan jalan disebabkan oleh ketiadaan sistem pengurusan jalan yang efektif. Oleh itu, kajian ini menumpukan tentang mencari faktor kejayaan penting sesebuah projek penyelenggaraan jalan, sebagai fokus kes kajian ini dipilih di daerah Maysan, di Iraq. Kajian ini merincikan dan menilai 27 kunci kejayaan dalam projek penyelenggaraan jalan di bawah 3 kumpulan: pengurusan, teknikal dan sumber. Berdasarkan analis dapatan kajian terdahulu dan bidang kajian di daerah Maysan, lima kunci faktor kejayaan didapati dari: 1. Sumber yang mencukupi; 2. Pembayaran tepat kepada kontraktor dan pekerja; 3. Material kualiti; 4. Pengunaan teknologi moden bagi mengesan dan menganalisa kerosakan jalan; dan 5. Komunikasi dan koordinasi antara semua yang terlibat
- …
