1,721,019 research outputs found
Effect of Electrically Conductive Concrete Layer Thickness on Thermal Performance
Get PDFWhile electrically conductive concrete (ECON) is a viable alternative to traditional snow removal methods involving deicers, this technology has no comprehensive design codes, standards, or guidelines. In developing a mechanistic design approach for ECON HPS, understanding the relationship between ECON layer thickness to its thermal performance is pivotal to avoiding overdesign and waste of resources. Therefore, in this study, five 355 mm long and 100 mm wide carbon fiber (CF)-reinforced ECON beams with thicknesses varying from 37.5 to 87.5 mm at 12.5 mm increments were tested to evaluate the effect of thickness on thermal-energy production. According to the results, the thermal energy produced from ECON changes with its layer thickness. A model was developed for estimating thermal energy from ECON layer thickness, but more comprehensive studies are required to develop a representative model to be utilized in ECON HPS design.This is a manuscript of a proceeding published as Rahman, Md Lutfor, Halil Ceylan, and Sunghwan Kim. "Effect of Electrically Conductive Concrete Layer Thickness on Thermal Performance." In Airfield and Highway Pavements 2023, pp. 14-23. https://ascelibrary.org/doi/abs/10.1061/9780784484906.002. Posted with Permissio
Influence of electrode placement depth on thermal performance of electrically conductive concrete: Significance of threshold voltage for long-term stability
Get PDFSnow and ice accumulation on pavements pose formidable challenges for transportation agencies in cold regions, resulting in diminished traffic speed, traffic flow, and heightened accident risk during winter. While electrically-conductive concrete (ECON) heated pavement systems (HPS) have emerged as an ecologically-sound and cost-effective snow and ice-removal solution, a lack of identification of critical design parameters for ECON HPS impedes the development of precise design criteria for this technology. This research endeavors to comprehensively elucidate the heating process of electrically-conductive concrete (ECON) slabs and to scrutinize how the depth of electrode placement influences thermal performance. The investigation reveals that the electrode-concrete interface zone serves as the predominant heat source for ECON HPS, and if shallower electrode placement depths are used, the surface temperature increase rate of ECON slabs is enhanced, optimizing cost-effective operation. The study also establishes a threshold voltage level for ECON slabs, beyond which significant changes in electrical properties yield relatively ineffective temperature increase rates. The study found 16 VAC and 425 W/m² to be threshold values for the specific ECON slab system studied. These compelling findings offer valuable insights for future ECON slab design and implementation, ensuring efficient and practical snow-removal applications and benefiting transportation agencies and the broader community.This is a preprint from Rahman, Md Lutfor, Halil Ceylan, Sunghwan Kim, and Peter C. Taylor. "Influence of electrode placement depth on thermal performance of electrically conductive concrete: Significance of threshold voltage for long-term stability." Construction and Building Materials 412 (2024): 134883. doi: https://doi.org/10.1016/j.conbuildmat.2024.134883. © 2024 Elsevier Ltd
Identifying the best mixing procedure practice for ready-mix concrete plant production of carbon fibre reinforced electrically conductive concrete
Get PDFElectrically-conductive concrete (ECON) can generate heat for melting pavement ice if an electrical voltage is applied, and this ECON-heated pavement system (HPS) is a viable alternative to the traditional snow removal methods. This study aimed at determining mixture proportions and procedures suitable for ready-mix concrete-plant-produced carbon fibre (CF)-reinforced ECON. Trial batches ECON production involving five different mixture proportions and procedures were performed at a ready-mix concrete plant. Study results suggest that CF begins to degrade with increased mixing time. A twelve-minute mixing time from the start of loading CF onto the mixer until the end produced the best-performing ECON, with an electrical resistivity of 224 Ω-cm and a heat-generation rate of 2°C/min. Scanning electron microscopic (SEM) image analysis shows that CF remained as blobs of fibre instead of being uniformly dispersed. Further research is recommended to find an efficient way of separating individual CF from the blobs and ensuring uniform CF dispersion to reduce the dosage rate and construction cost of ECON.This is a manuscript of an article published as Rahman, Md Lutfor, Amir Malakooti, Halil Ceylan, Sunghwan Kim, and Peter C. Taylor. "Identifying the best mixing procedure practice for ready-mix concrete plant production of carbon fibre reinforced electrically conductive concrete." International Journal of Pavement Engineering 24, no. 1 (2023): 2225119.
doi: https://doi.org/10.1080/10298436.2023.2225119. Posted with Permission. CC BY-NC. Copyright The Authors 2023
Evaluating Full-Scale Electrically Conductive Concrete Heated-Pavement Systems to Identify Key Design Parameters
Get PDFWhile Electrically-Conductive Concrete (ECON) Heated-Pavement Systems (HPS) is a promising alternative to traditional snow removal methods, the lack of design guidelines for future ECON projects hinders their widespread adoption. This study addresses the gap by identifying critical design parameters for future ECON systems. In order to achieve this goal, the performance of two existing full-scale demonstration ECON projects, Des Moines International Airport (DSM) and the Iowa Department of Transportation (DOT), was evaluated. A laboratory investigation was conducted to gain a deeper insight into the heating mechanism of the ECON HPS. Critical design parameters for developing a comprehensive design methodology for ECON systems were identified through construction and performance data analysis. These parameters include
electrode-concrete interface area, electrode placement depth, electrode spacing, the electrical resistivity of the concrete, and applied voltage. Laboratory results suggest that each ECON system has a threshold voltage level, and if the applied voltage is beyond that threshold voltage, the heating performance of the system may deteriorate and can take longer to melt the pavement ice, increasing the energy consumption cost. The insights provided by this study contribute to understanding the long-term performance and critical design considerations for ECON HPS, and the findings emphasize the importance of adhering to appropriate design parameters to ensure optimal system performance and longevity. Moreover, the identified critical design parameters serve as a foundation for developing comprehensive design guidelines for facilitating the implementation of ECON systems used for efficient snow removal on pavements.This is a manuscript of an article published as Rahman, Md Lutfor, Amir Malakooti, Halil Ceylan, Sunghwan Kim, and Peter C. Taylor. "Evaluating Full-Scale Electrically Conductive Concrete Heated-Pavement Systems to Identify Key Design Parameters." Journal of Transportation Engineering, Part B: Pavements 151, no. 2 (2025): 04025001. doi: https://doi.org/10.1061/JPEODX.PVENG-1542
Muhammad Ali Sircar the first of the world's officially recognized student-author from British India
No full textBiography of Muhammad Ali Sircar, b. 1923, retired civil servant from Bangladesh, who wrote Assam own copy book, a textbook in English for primary students, while he was a student of class X
YIELD PERFORMANCE OF SOYBEAN VARIETIES UNDER DIFFERENT FERTILIZER LEVEL
Get PDFA Thesis
Submitted to the Faculty of Agriculture
Sher-e-Bangla Agricultural University, Dhaka,
in partial fulfillment of the
requirements for the degree of
MASTER OF SCIENCE
IN
AGRONOMYA field experiment was conducted in the experimental field of Sher-e-Bangla
Agricultural University to find out the combination effect of variety and different
fertilizer level on the yield of soybean, cultivated during December, 2021 to April,
2022. The experiment was laid out in a Randomized Complete Block Design (RCBD)
with three replications. The four varieties included in this study were BINAsoybean5;
BU soybean 2; BARI Soybean-5 and BARI Soybean-6. There were four fertilizer
combinations. Such as F
0
= No fertilizer, F
1
= 50% less than recommended dose of
fertilizer (RDF); F
2
= Recommended dose of fertilizer (RDF); F
3
= 50% more than
recommended dose of fertilizer (RDF). Among all the varieties, BU soybean 2 (V
2
)
emerged as the superior performer, showcasing the tallest plant height at harvest
(59.55 cm), highest dry weight plant
-1
at harvest (6.94 g), maximum number of pod
plant
-1
(29.75), seed pod
-1
(2.60), weight of 100 seeds (14.03 g) and leading seed and
stover yield of 3.20 t ha
-1
and 5.53 t ha
-1
, respectively. On the other hand, among the
fertilizer doses, F
3
(50% more than recommended dose of fertilizer), proved most
effective, yielding the tallest plant at harvest (60.28 cm), highest dry weight plant
at
harvest (6.76 g), maximum number of pod plant
-1
(32.73), seed pod
-1
(2.44), weight of
100 seeds (12.29 g), and the leading seed and stover yield of 3.21 t ha
respectively. But in the case of combination between varieties and different doses of
fertilizer, V
2
F
3
(BU soybean 2 with 50% more fertilizer than the recommended dose)
treatment gave the best results. The tallest plant at harvest (67.55 cm), highest dry
weight plant
-1
at harvest (7.49 g), maximum number of pod plant
-1
-1
and 5.75 t ha
(35.61), seed pod
(3.00), weight of 100 seeds (15.52 g), leading seed and stover yield of 4.52 t ha
and
7.22 t ha
-1
was recorded in V
2
F
3
(BU soybean 2 with 50% more fertilizer than the
recommended dose). It may be concluded that the BU soybean 2 (V
2
) variety and the
F
3
fertilizer dose individually exhibited notable results, but their combination in the
V
2
F
3
treatment yielded unparalleled performance, achieving the most impressive
growth and highest seed and stover yields, highlighting the profound impact of
optimizing both variety and fertilizer
Quality of Health Care in Bangladesh: A Study on Selected Upazila Health Complexes
Get PDFQuality of care is an overwhelming issue in the context of health services of developing countries including Bangladesh. Performance of health care professionals and institutions determines the quality of care provided by the health facilities which in turn depends on governance as well as factors like access, safety, equity, appropriateness, timeliness, acceptability, reliability, assurance, responsiveness and empathy of care providers, health improvement and continuity of care etc. Though the governance issues affect massively the quality of care, in this article, an attempt has been taken to explore the factors which affect quality of care in health sector of Bangladesh. This paper also identifies the problems threat towards providing quality of health care in Bangladesh. Finally, this study recommends some policy options to ensure quality care in health sector and thus a healthy nation. To conduct this research and achieve the above mentioned objectives, upazila health complexes, the part and parcel of the public health sector in Bangladesh, has been selected as a case. Keywords: Quality Health Care, Public Health Sector , Upazila Health Comple
Recommended from our members
Towards Improving Cybersecurity and Augmenting Human Training Performance Using Brain Imaging Techniques
Get PDFHuman behaviors can weaken the security of cyber-physical systems. However, conventional security research focuses more on hardware and software security than analyzing and improving human behaviors to provide better protection for digital systems. In this regard, we study the neural insights of computer systems users to identify cyber-attacks, such as phishing, and improve cybersecurity. First, we analyze neural activities to detect phishing attacks. We demonstrate that the variations in neural activity levels can be utilized to identify phishing websites with improved data preprocessing and feature extraction methods. Second, we study users' neural activities to learn their high-level intents when they use applications. The inferred intents are then used to ensure the security and privacy of sensitive resources, such as cameras and multi-media files. Finally, we design an adaptive training model that enables users to differentiate between benign and malicious scenarios. We consider both behavior and neural metrics to develop adaptive logic. Our experimental results show that participants trained with our approach outperform in the transfer task than those trained with non-adaptive and behaviorally adaptive designs
- …
