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Go to Editorial ManagerNoise effects on the students include both auditory and non-auditory effects and cause ?the lack of concentration and disability of learning? ?and communication. The Faculty of ?Engineering was chosen to conduct the questionnaire ?because the students have both ?theoretical and practical courses and they ?spend one-third of their day in the ?laboratories, so it is expected they exposure to noise more than other faculties’ students ?A questionnaire was conducted to understand the effect of noise on student behavior ?and whether they could classify the sounds that they heard as noise and determine the ?noise sources (indoor, outdoor) and the noisiest places (classroom, laboratory, and ?campus). 438 students participated in this questionnaire from all stages, and they ?covered eight engineering departments in the Faculty of Engineering, Mustansiriyah ?University. A statistical analysis of the questionnaire found that 39.5%, 46%, 32% and ??49% of students suffered from noise in classrooms, laboratories, open spaces and closed ?spaces (campus), respectively. In the actual situation, the effects that students ?experience can be arranged in the following descending order: feeling discomfort, ?hearing difficulty, raising the voice when speaking, lack of concentration, headache, ?tinnitus and nausea. Using a sound and vibration meter with the analyzer, the noise ?levels in dBA were measured in the noisiest places that the students mentioned. The ?noise levels exceed the standard limitation that organizations and agencies such as the ?WHO determined. ??
In this paper an experimental works conducted to study the behavior of R.C. beam with large web opening at different locations and fortified with reactive powder composite (RPC) at the extreme tension zone (bottom edge of opening) and/or extreme compression zone (Top edge of opening). The experimental study is investigate the behavior of twelve beams and study the ability of using normal strength concrete together with RPC in the same section to exploit the advantages of these two materials in optimal way. The main variables are RPC layers locations in tension zone and/or in compression zone and the locations of openings. The ultimate loads, load mid-span deflection behavior and strain for steel and concrete were discussed. The experimental results showed that the ultimate strength was decreased with increasing number of opening about 4% for beams with two openings located in shear zone and 21% for beams with three openings, thus indicating that the stiffness decreases accordingly. The using RPC layers effectively enhanced performance of hybrid beams when compared with using the normal strength concrete layers only. The using RPC layers in compression and tension zones increased the ultimate load about 47 % for beams with two opening located in shear zone, when using RPC in the tension zone and normal strength concrete in the compression zone the ultimate flexural load and ultimate deflection increase little compared with normal concrete.
Cascade single mode-No Core - single mode fiber structure (SNS) optical filters have garnered a lot of interest as dependable optical devices. These devices' simplicity, compactness, affordability, all-fiber design, low transmission loss, and ability to continuously adjust the laser wavelength at a particular spectral range contribute to their dependability. The operation's foundation is multimode interference (MMI) and self-image phenomena. SNS filter based on optimized 4th self-imaging condition for different NCF- Specifications was theoretically optimized a tunable filter based on a cascade single mode-no core-single mode (SNS) fiber structure encircled by Ferrofluid was experimentally investigated. The findings indicate that reducing the NCF diameter can enhance the filter's tunability. device has applications in fiber laser technology, spectroscopy, and optical communication.
High-performance polymer nanocomposites utilizing different-sized nanofillers had a lot of interest recently. Due to their distinct structural, and thermal characteristics. Multi-wall carbon nanotubes (MWCNT) and nanoclay (NC) have the most interest among the numerous types of reinforcing as filler elements for a polymer. The formation of hybrid from MWCNT and NC at various loadings (0.5%, 1%, and 2wt%) on the characteristics of epoxy polymer have been assessed in this work. The specimens have been created using solution blending procedures with the addition of solvent ethanol at a ratio of 1:1 for dispersed nanofillers, and then they have been re-mixed with epoxy. Tests like X-Ray diffraction (XRD), and thermal conductivity were used to identify properties of epoxy. According to the test results, the thermal conductivity rise as the filler content rises at 1wt%, then start to decrease after 1wt%. The sample with the hybrid filler loading of 1 wt% produced the best performance. Since hybrid epoxy exhibits the best result of the thermal conductivity 135% over MWNT and NC nanocomposites of 1 wt.% reached 0.3568 W/m.K in the increased thermal conductivity property. By examining the EP nanocomposites XRD pattern. The hybrid of epoxy nanocomposites exhibits all of the NC and MWCNT characteristic peaks. Since interactions between the filler and the epoxy cause a shift in the peak location of 1wt%. Due to the homogeneity of the nanofillers entire epoxy matrix, there may be changes in the intensity or location of the peaks at 1% for 2θ= 20.13°, which corresponds to an interlayer distance of d=0.461nm.
This study compares two different sockets, traditional and smart. It includes designs, manufacturing, and testing to evaluate the influence of the socket designs on gait symmetry. The proposed materials are locally available in the prosthetics center where traditional sockets are manufactured. and smart socket designs with the same materials as traditional additions. A simple electronic system programmed to control the movement of the stump by pneumatic pads and prevent slipping during movement is considered an advanced suspension system. A gait cycle test was carried out to evaluate the sockets. it was performed on a patient with AK amputation in two cases: the first when the patient was wearing the traditional and the second when wearing the smart. Where the difference in (gait cycle time, step velocity, heel contact, and mid-stance) between the left and right leg is equal to (0.54, 4.3, 0.19, and 0.34) respectively, when the patient uses the traditional, while these values reduce to (0.09, 0.7, 0.07, and 0.27) respectively when the patient used the smart, it improves comfort by modifying pressure distribution, relieving pressure points, and enhancing functionality through gait analysis. They adjust to the volume of the residual limb, ensuring an effective fit. Real-time monitoring and remote modifications decrease the need for in-person meetings and enhance user confidence. The smart socket, designed to fit user requirements, provides enhanced comfort, functionality, and independence. The studies will explore its long-term benefits and broader applications, focusing on its originality, practical implications, and outcome measurement.
Nowadays, robotic exoskeletons demonstrated great abilities to replace traditional rehabilitation processes for activating neural abilities performed by physiotherapists. The main aim of this review study is to determine a state-of-the-art robotic exoskeleton that can be used for the rehabilitation of the lower limb of people who have mobile disabilities as a result of stroke and musculoskeletal conditions. The study presented the anatomy of the lower limb and the biomechanics of human gait to explain the mechanism of the limb, which helps in constructing a robotic exoskeleton. A state-of-the-art review of more than 100 articles related to robotic exoskeletons and their constructions, functionality, and rehabilitation capabilities are accurately implemented. Moreover, the study included a review of upper limb rehabilitation that has been studied locally and successfully applied to patients who exhibited significant improvements. Results of recent studies herald an abundant future for robotic exoskeletons used in the rehabilitation of the lower extremity. Significant improvement in the mechanism and design, as well as the quality, were observed. Also, impressive results were obtained from the performance when used by patients. This study concludes that working and improving the robotic devices continuously in accordance with the cases are necessary to be treated with the best results and the lowest cost.
The recent progress in integrated photonics has promoted microwave photonic filter (MPF) technologies to a supreme level to develop wireless, radar, and internet communication systems. Therefore, the specifications that distinguish the MPF chip include small size, low power, and inexpensive. The MPF that utilized these technologies has demonstrated the merit of wide frequency tuning and reconfiguring by selecting the desired spectral content and rejecting the sideband signals furthermore the immunity to electromagnetic interference. This paper reviews recent techniques involved in microwave filter design on multiple platforms, which involve cascaded micro-ring resonator (MRR), ring-assisted Mach-Zehender-Interferometer (MZI) coupler, Brillion-active waveguide, reflector-type MRR, and Bragg grating with phase shifts. In particular, we demonstrated the output characteristics of the microring integrated with a Mach–Zehnder interferometer coupler technique.
In the field of engineering, 3D printers are indispensable due to their high precision. This study focuses on the construction and optimization of a 3D printer using aluminum T-slotted bars for the frame, Raspberry Pi 4 for control, and Lightburn software for image printing and machine control. After assembling the main components and programming with Marlin firmware, the machine was tested for vibration and noise reduction. The research compared the vibration of a diode laser and spindle during printing, revealing significantly lower vibration with the laser compared to the spindle. These findings demonstrate the effectiveness of the constructed 3D printer in reducing vibration and noise during operation.
A substantial amount of research has been dedicated to improving the efficiency of heat exchangers, which are extensively utilized in electronic equipment, heating and air conditioning systems, space vehicles, thermal power systems, industrial applications, and transportation. Enhancing the efficiency of these devices can lead to significant reductions in materials, cost, and space. Constructal design offers a promising approach to optimizing various heat transfer systems, including electronic packages, by applying the constructal law to achieve optimal configurations. This review aims to examine recent advancements in the application of constructal design theory to heat exchangers and its potential for enhancing thermal performance. The most recent state-of-the-art developments are thoroughly described, along with their evaluating parameters, and recommendations for further research in this field are provided.
In this paper, we suppose a method for reducing the dispersion in the plastic optical fiber (POF) Bragg gratings based on optimizing the grating coupling-strength (?) using genetic algorithms. The effects of average refractive index (?n) and temperature (T) change on the dispersion properties are investigated numerically. It is found that the amplitude of the ?n for low dispersion performance needs to be reduced at the cost of the design complexity of the POF Bragg gratings. Owing to the unusually large and negative thermo-optic coefficient of the POF, the dispersion due to the wavelength shift induced by the temperature variation will be reduced by operating at high ? value. Results showed that by optimizing the ? value a very large dispersion reduction range has been obtained, from 1178 to 11.5 ps/nm at 30 mm grating length.
This paper provides a comprehensive overview of microfluidic device (MFD) manufacturing processes. The review starts with an introduction elucidating the significance and advantages of MFDs. Subsequently, a brief description of the materials employed in MFD fabrication is presented. The manufacturing process used to create MFDs is then thoroughly examined, with a focus on the application of laser technology.
The robot manipulator output feedback problem points out to the controlled system in which the measurements of the joint position are available. In this study, all kinematic and dynamic parameters of robot manipulator are supposed unknown and the manipulator have to follow the desired trajectory. Therefore, the adaptive control problem for robot manipulators based on velocity estimation is investigated. According to the practical robot actuator power limitation, the bounded torque input is also considered in this study. The control algorithm is applied for 2-link manipulator to evaluate controller effectiveness. The design parameters that guaranteed the control performance of closed loop system are chosen by using optimization output constrained method. The proposed controller performances are provided by numerical simulations.
Türkiye possesses abundant geothermal resources. It is ranked seventh globally for this particular energy resources and grade among the first 5 in utilizing geothermal and thermal springs for various purposes such as electricity generation, residential cooling and heating, greenhouse operations, desiccating processes, thermal recreation, therapeutic applications, mining, agricultural uses, and aquaculture. The government's endorsement from renewable power sources is fueling growing interest on this particular energy sector. This article provides a comprehensive analysis of geothermal energy in select locations of Türkiye, including an assessment of its potential and various applications. The study seeks to provide a valuable involvement to the future advancements of a geothermal technology on Türkiye.