2,110 research outputs found
Experimental Study of Large-scale RC Beams Shear-Strengthened with Basalt FRP Sheets
Over the last three decades, many experimental studies have been conducted to investigate the behavior of Reinforced Concrete (RC) beams, shear strengthened with externally bonded Fiber-Reinforced Polymer (FRP) composite. However, the majority of experimental studies have focused on small- to medium-scale beam specimens. As a result, most design equations that have been developed as part of these studies may thus not be accurate at predicting the shear strength of large-scale RC beams shear-strengthened with FRP sheets. This study thus involved performing tests on six specimens to study the effect of the larger scale, along with new variables such as beam width, new varieties of FRP sheets (basalt FRP (BFRP)), and the strengthening configuration (U-jacketing), on the prediction of the ultimate load of RC beams strengthened with externally bonded FRP composite. The experimental results were analyzed and showed that all these variables affected the lateral strain along the bottom and the top of the beams. It was found that variations in the depth to width ratio of the beams caused the failure angle to vary as well. For beams strengthened with BFRP sheets, both the cracking and ultimate load increased to 1.19 and 1.94 times the cracking and ultimate load of the control beams under identical conditions
Numerical Analysis of Single-Angle Steel Member Under Tension Force with Different End Deformations
Steel members with a single-angle cross-section are widely used, but some of their behaviours under loads are not considered by design codes, necessitating related research. This study is carried out on fifty steel single-angle members focused on the stress distribution behaviour and the ultimate axial load capacities under different end deformations through 3-dimensional Finite Element (FE) simulations and comparison with previous experimental findings. FE modeling is capable of modeling steel structures with high accuracy. Based on the results, the length of the angle affects neither the shape of the stress distribution nor the ultimate load capacity of the element. The end deformations affect the stress distribution on the member angle cross-section, including the ultimate load capacity. The end deformations which restricted deformations in the two directions perpendicular to the load axis are found to be optimal, with an average increase in load capacity by a factor of 1.96 for an equal angle and 2.21 for an unequal angle compared with the capacities calculated for single angles with deformations allowed in all directions. The appearance of a compression zone on the unconnected angle leg reduces the ultimate load capacity. The current design code (ANSI/AISC-360) can be adopted to calculate the ultimate load in the case of no deformation in the y-axis direction and no deformations in the x- and y-axis directions where the mean ratios of PNum/Pcode are 1.24 and 1.34 respectively. However, the code does not agree with the end deformations of free deformations and no deformation in the x-axis direction for either equal or unequal angles where the mean ratios of PNum/Pcode are 0.64 and 0.79 respectively, which is unsafe
A New Method for Biomechanical Data Acquisition in Remote Laboratory Delivery During the COVID-19 Pandemic
Background: Delivery of a hands-on laboratory experience is a real challenge in the present pandemic environment. Many instructors tend to acquire and record experimental data, and then instruct their students to analyze such data to produce results and lab reports in an online course mode. Such a process considerably diminishes students’ motivation, engagement, and eagerness to explore further knowledge, as students appreciate more experimental data that they gather themselves. Such drawbacks are even more profound in a practical field such as biomechanics, where students need to feel the sense of kinematic and kinetic data of their own body motions and muscle forces.Purpose: The aim of this paper is to communicate with engineering educators facing challenges in the current pandemic time, a new teaching method that allows students to remotely gain a hands-on knowledge by applying the principles of mechanics on their body motions using a computer vision kinematics laboratory module that can be easily applied at home.Methods: In this research, students first capture their selected body motion with a webcam at home. They are provided a video tracking algorithm that calculate spatial locations of the body segment motion. Students then perform calculations to estimate further kinematic and kinetic data, plot them, and comment on their own estimated muscle forces. The students’ perceived workload and effort in completing the lab requirements can also be evaluated. The proposed computer vision approach is utilized to calculate the participants’ kinematic data in an interactive motion analysis problem.Results: As a work in progress study, initial results showed that 97% of the participating students successfully applied the computer vision-based kinematics module, supported by the generation and submission of full laboratory reports including critical data analysis of their body motion experience.Conclusions: The proposed computer vision experimental approach may enhance the learning experience of biomechanics students at home in such an isolating pandemic environment. The demonstrated methods can be applied to many teaching fields including biomechanics and robotics
In Silico Characterization of a Cyclin Dependent Kinase -A (CDKA) and its Coding Gene in some Oryza Species
يعد الأرز طعاما أساسيا لمعظم سكان العالم. تساهم بروتينات الفسفرة المعتمدة على السيكلين من المجموعة (CDKA) A فى الإنتقال عبر المراحل المختلفة لدورة الخلية و كذلك تساهم فى تخليق الأمشاج. و قد هدفت الدراسة الحالية إلى توصيف أحد هذه البروتينات و الجين المسئول عنها فى ,O. glumipatula ,O. barthii ,O. glaberrima ,O. sativa Indica Group O. nivara ,O. brachyantha O. punctata ,O. longistaminata ,O. meridionalis و O. rufipogonبإستخدام التقنيات الحاسوبية. كشفت النتائج إختلافات فى بعض تتابعات الأحماض الأمينية التى تنظم عمل البروتين محل الدراسة فى كلا من O. longistaminata و O. brachyantha و ذلك مقارنة بالبروتين ذاته فى باقى الأنواع. إفتقد البروتين محل الدراسة فى O. longistaminata أحد تتابعات الأحماض الأمينية المسئولة عن تثبيط عمل البروتين كما لوحظ إختلاف فى تتابع الأحماض الأمينية المسئولة عن الإرتباط بالسيكلين (PSTAICE بدلا منPSTAIRE ) مما قد يسفر عن توصيف لمجموعة فرعية جديدة متفردة من هذه البروتينات. فى O. brachyanth تم تسجيل إختلاف فى تتابع الأحماض الأمينية بالموضع المسئول عن النشاط المرتبط بلسيكلين. توصى الدراسة بالأستفادة من الإختلافات سابقة الذكر فى التحكم فى الإنقسام الخلوى و النمو فى الأنواع المزروعة من جنس Oryza بإستخدام طرق التربية التقليدية او الطرائق الجزيئية.Rice (Oryza sativa) is a fundamental food for the majority of world population. Cyclin Dependent Kinase -A (CDKA) accelerates transition through different stages of cell cycle and contributes in gametes formation. In the present investigation, a CDKA encoding gene along with the corresponding protein were characterized in O. sativa Indica Group, O. glaberrima, O. barthii, O. brachyantha, O. glumipatula, O. longistaminata, O. meridionalis, O. nivara, O. punctata and O. rufipogon using in silico analyses. The results reflected little variation in most species except O. longistaminata and O. brachyantha. Compared with the remaining species, O. longistaminata lacked a negative regulatory binding site and had a modified cyclin binding site (PSTAICE instead of PSTAIRE) that may lead to future characterization of a new distinct subclass of CDKAs. O. brachyantha had a modified SUC/CKS (suppressor of CDC2/cyclin dependent-kinase regulatory subunit)-binding motif. The observed variations can be exploited through traditional breeding or molecular approaches to manipulate cell division and growth of cultivated Oryza species
REVISITING SAUDI UNIVERSITY EFL LEARNERS’ ENGAGEMENT TO TEACHERS WRITTEN CORRECTIVE FEEDBACK FROM A SOCIO-COGNITIVE PERSPECTIVE
The empirical studies addressing learners’ engagement to teachers’ corrective feedback on their writing tasks in the Saudi EFL context as well as its impact on the students’ improvement of writing skill are still a few. Therefore, the proposed research project aims to empirically address the Saudi EFL learners’ responses to teachers’ written corrective feedback on their writing tasks. Addressing the EFL learners’ engagement in the teachers’ written feedback is a key issue in improving learners’ writing skills. As a result, the proposed project attempts to measure Saudi learners’ engagement with their learners’ feedback from a multi-dimension perspective; learners’ uptake, affective engagement, cognitive engagement, and meta-cognitive engagement, and behavioral engagement. Investigating the learners’ responses to their teacher’s feedback, the proposed project uses a socio-cognitive method that contributes to realizing the differences in EFL responses toward their teacher’s corrective feedback. The proposed study relies on different sources of data that include students’ writing assignments, semi-structured questionnaires. The sample of the study consists of 90 elementary level students belonging to the applied college at PSAU, 30 pre-intermediate students belonging to Business administration College, and 30 intermediate level students belonging to the college of humanities and sciences. The collected data reflect to what extent learners are engaged with the corrective feedback of their teachers, which can be partly accounted for their ideas and experiences about the written corrective feedback and second language writing and the learning context in which the feedback was received and processed. The findings of the research projects proposes that the EFL instructors should have a deeper understanding of the students’ cognitive and behavioral, engagement, feedback processing. This deeper understanding of students’ responses to written correct feedback would largely contribute to improving learners’ writing skills
Microcontroller Implementation of Fuzzy Guidance
In the last few years microcontrollers found a big place in industrial applications. It had been
used in many applications such as washing machines, textile machines and many other fields.
Microchip PIC microcontrollers are one of the most used types of microcontroller. In this paper
we consider a method which can be used to implement a fuzzy control system and the
description of this implementation technique. The proposed method will be applied to
implement the fuzzy guidance systems on a microchip PIC16F877A
microcontroller system
Super Resolution and 3D Alignment Effects on Unsupervised Face Recognition in the Wild
Majority of face recognition algorithms use query faces captured from uncontrolled, in the wild, environment. It is common for these captured facial images to be blurred or low resolution. Super resolution algorithms are therefore crucial in improving the resolution of such images especially when the image size is small requiring enlargement. This paper aims to demonstrate the effect of one of the state-of-the-art algorithms in the field of image super resolution. To demonstrate the functionality of the algorithm, various before and after 3D face alignment cases are provided using the images from the Labeled Faces in the Wild (lfw). Resulting images are subjected for testing on a closed set face recognition protocol using unsupervised algorithms with high dimension extracted features
Encapsulated polycaprolactone with triazole derivatives and selenium nanoparticles as promising antiproliferative and anticancer agents
Background and purpose
Polycaprolactone nanocapsules incorporated with triazole derivatives in the presence and absence of selenium nanoparticles were prepared and evaluated as antiproliferative and anticancer agents. Polycaprolactone nanoparticles were prepared using the emulsion technique.
Experimental approach
The prepared capsules were characterized using FT-IR, TEM and DLS measurements. The synthesized triazolopyrimidine derivative in the presence and absence of selenium nanoparticles encapsulated in polycaprolactone was tested for its in vitro antiproliferative efficiency towards human breast cancer cell line (MCF7) and murine fibroblast normal cell line (BALB/3T3) in comparison to doxorubicin as a standard anticancer drug.
Key results
The results indicated that encapsulated polycaprolactone with selenium nanoparticles (SeNPs) and triazole-SeNPs were the most potent samples against the tested breast cancer cell line (MCF7). On the other hand, all compounds showed weak or moderate activities towards the tested murine fibroblast normal cell line (BALB/3T3).
Conclusion
As the safety index (SI) was higher than 1.0, it expanded the way for newly synthesized compounds to express antiproliferative efficacy against tumour cells. Hence, these compounds may be considered promising ones. However, they should be examined through further in-vivo and pharmacokinetic studies
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