Investigation of brake squeal/self induced vibrations.

kebisingan brek hingar persatuan dengan ketidakstabilan dinamik dari sistem dan dikategorikan bergantung pada frekuensi untuk hingar quality (menjerit) dan rendah kebisingan (Mengerang). Pada frekuensi rendah (0-500kHz) model tongkat-slip digunakan untuk menyediakan disc-pad sistem yang diselesaikan dengan menggunakan kaedah ODE45 berangka dengan MATLAB perisian. Brake noise associates with the dynamic instability of the system and is categorized depending on the frequency to high noise (squeal) and low noise (groan). At low frequencies (0-500kHz) a stick-slip model was used to present the disc-pad system which is solved by using a numerical method ODE45 with MATLAB software

Management of hemorrhagic complications associated with antithrombotic therapy

Anticoagulants are used for the prevention and treatment of arterial and venous thromboembolism. Such therapy is always associated with an increased risk of bleeding. Intracranial hemorrhage is the most serious form of anticoagulantsrelated bleeding and caries a high mortality rate. Many treating physicians and patients are reluctant to restart anticoagulation after such an event. For patients with continued increased risk of cardioembolism, the decision of when to restart anticoagulation is challenging and few small, single-center studies and case reports are the only available source of information. Prothrombin complex concentrates (PCC) have been shown to rapidly correct the prolonged prothrombin time associated with vitamin K antagonist (VKA) therapy. The clinical efficacy of such treatment for controlling bleeding or preventing post-operative hemorrhage in patients treated with VKA is uncertain. Thromboembolism is a potential side effect of PCC and there are limited data on the risk of such complications. New direct oral anticoagulants are approved as alternatives for VKA. These agents lack antidote and the management and outcome of patients with major bleeding on these agents is uncertain. In this thesis different aspects of the management of anticoagulants-associated bleeding complications are studied and discussed. A cohort of 234 patients from Sweden and Canada with VKA-related intracranial hemorrhage was analyzed to establish the optimal time point for resumption of anticoagulation. Early resumption carries a high risk of recurrent bleeding, whereas the risk of thromboembolism increases with delayed start. According to the result of our study, the optimal timing of resuming iii anticoagulation after VKA-associated intracranial hemorrhage seems to be between week 10 and 30 after the event. A subgroup of the above-mentioned cohort was combined with another cohort from the Netherlands. A total of 135 patients were investigated to assess the effect of PCC - compared to plasma - on survival after VKA-related intracerebral hemorrhage. Unadjusted analysis showed a benefit for PCC treatment in reducing the 30-day all-cause mortality. After adjustment for differences in prognostic factors between the two treatment groups, especially the volume of intracerebral hematoma, the beneficial effect of PCC was attenuated and became non-significant. The safety of reversal of VKA with PCC was assessed in a third cohort of 160 Swedish patients with a major bleeding event or before emergency surgery. Six patients (3.8%) developed thromboembolic events (5 arterial and 1 venous) within a week after the administration of PCC. In these patients, the unmasking of the increased risk for thromboembolism by the reversal of anticoagulation and the activation of the coagulation system by the bleeding or surgery, seem to be important contributing factors, while PCC seem to increase the risk only minimally, if any. A cohort of 1121 patients with major bleeding on dabigatran or warfarin, derived from 5 phase III trials, was used to study the management and outcomes of these bleeding events in the absence of an antidote to dabigatran. The patients who suffered major bleeding on dabigatran were older, had more renal impairment and were more frequently treated with antiplatelet agents or non-steroidal antiinflammatory drugs compared to those on warfarin, yet the outcome of dabigatran bleeding was better as reflected by a shorter stay by 1 day in the iv intensive care unit and lower 30-day all-cause mortality compared to the warfarin group. In summary, PCC seem to be safe for the treatment of VKA-associated bleeding, but their beneficial effect over plasma in case of intracerebral hemorrhage is questionable. The absence of a reversal agent for dabigatran does not seem to impact negatively on the outcome after major bleeding. When intracranial hemorrhage occurs on VKA resumption of anticoagulation should be delayed for 10-30 weeks

Pilonidal Sinus Management Using 980 nm Diode Laser

Background: Pilonidal sinus is a chronic, debilitating disease of the natal cleft. It mainly involves the sacrococcygeal region and the presentation varies from asymptomatic pits to painful abscesses or sinuses. Treatment options vary from observation to wide excision. Unfortunately, surgical treatment may result in recurrence. Many conservative methods had being described for treatment of pilonidal sinus, photocoagulation using laser is one of them.The aim of study: To assess the efficacy of laser (diode) as a therapy to the pilonidal sinus.Design: A cohort of five patients with a provisional diagnosis of  pilonidal sinus (unbranched) were treated by photocoagulation of sinus tract by diode laser 980 nm, between 17 and 25 year old (20.6±2.58), were diagnosed clinically and by sinogram to know the exact length of the tract and to exclude branching tract. The average length of the tracts were (5 cm) ranging (3-7) cm. Only one patient had recurrent sinus after surgical excision.Result: The mean operative time was (10.10) min. (range of 6.10-14.10 min.). All patient were seen the day after the procedure and then weekly, only one patient had pus discharge at day nine and was treated with ciprofloxacin and metronidazole for ten days and tract closed after 21 days of the procedure. The average time for closure was (10.4) day ranging (6-21).conclusion: Diode laser as a surgical tools in the treatment of pilonidal sinus offers the following benefits: Reducing hospital stay, minimizing tissue assault by avoiding unduly extensive procedures with the attendant complications, early resumption of work by the patient and preventing recurrence of the disease. Keywords: pilonidal, diode 980nm, diode lase

MOBILE ROBOT MOTION CONTROL BASED ON CHAOTIC TRAJECTORY GENERATION

This paper introduces chaotic motion control of autonomous differential drive wheeled mobile robot to cover a certain surrounded area completely and as fast as possible. The suggested method was based on utilization of chaotic logistic map to accomplish a complete coverage of entire area. The trajectory is created by a microcontroller and fed to the designed robot using the proposed chaotic trajectory generator. The designed robot was occupied with infrared sensors to avoid the unforeseen obstacles during the navigation. The mathematical model of the designed robot and the motion control strategy were described in details. Computer simulation tests as well as the practical tests by using the designed robot show satisfactory results and confirm the success of the proposed method

AI-Based Q-Learning Approach for Performance Optimization in MIMO-NOMA Wireless Communication Systems

In this paper, we investigate the performance enhancement of Multiple Input, Multiple Output, and Non-Orthogonal Multiple Access (MIMO-NOMA) wireless communication systems using an Artificial Intelligence (AI) based Q-Learning reinforcement learning approach. The primary challenge addressed is the optimization of power allocation in a MIMO-NOMA system, a complex task given the non-convex nature of the problem. Our proposed Q-Learning approach adaptively adjusts power allocation strategy for proximal and distant users, optimizing the trade-off between various conflicting metrics and significantly improving the system’s performance. Compared to traditional power allocation strategies, our approach showed superior performance across three principal parameters: spectral efficiency, achievable sum rate, and energy efficiency. Specifically, our methodology achieved approximately a 140% increase in the achievable sum rate and about 93% improvement in energy efficiency at a transmitted power of 20 dB while also enhancing spectral efficiency by approximately 88.6% at 30 dB transmitted Power. These results underscore the potential of reinforcement learning techniques, particularly Q-Learning, as practical solutions for complex optimization problems in wireless communication systems. Future research may investigate the inclusion of enhanced channel simulations and network limitations into the machine learning framework to assess the feasibility and resilience of such intelligent approaches

Reconfigurable intelligent surface passive beamforming enhancement using unsupervised learning

Reconfigurable intelligent surfaces (RIS) is a wireless technology that has the potential to improve cellular communication systems significantly. This paper considers enhancing the RIS beamforming in a RIS-aided multiuser multi-input multi-output (MIMO) system to enhance user throughput in cellular networks. The study offers an unsupervised/deep neural network (U/DNN) that simultaneously optimizes the intelligent surface beamforming with less complexity to overcome the non-convex sum-rate problem difficulty. The numerical outcomes comparing the suggested approach to the near-optimal iterative semi-definite programming strategy indicate that the proposed method retains most performance (more than 95% of optimal throughput value when the number of antennas is 4 and RIS’s elements are 30) while drastically reducing system computing complexity

Effect of proper oral rehabilitation on general health of mandibulectomy patients

Introduction Reduced oral aperture and mandibular opening are relatively common problems, which have a wide variety of causes [1]. Limited access to the oral cavity can be problematic for patients and dental professionals [2]. According to Glossary of Prosthodontics terms GPT [3], reduced oral aperture is defined as microstomia, which is a term used to describe any congenital or acquired reduction in the size of the oral opening that is severe enough to compromise esthetic, deglutition, nutrition, and quality of life [4]. The mandible is the key bone involved in face esthetic, mastication, and speech. Surgical resection of the mandible (known as a mandibulectomy) is often performed for tumors of the head and neck area, which should be followed by oral rehabilitation (i.e., occlusal adjustments and replacement of missing teeth and/or soft tissues, if involved) [5]. The treatment of oral tumors such as squamous cell carcinomas may require mandibular resection to secure adequate margins [6]. Segmental resection of the mandible leads to significant patient illness if not properly managed. Mandibulectomy can lead to loss of mandibular support to the teeth, inadequate mastication, impaired speech and disfigurement of the face [7]

Design and fabrication of power generating treadmill

This paper aims to take advantage of treadmill’s wasted electrical energy during a person’s workout and utilize the energy for charging electrical appliances. The energy expended on a treadmill during the exercise is all wasted. In order to take advantage of the wasted energy, it could be harnessed by a power generator and stored in a battery bank. The electrical energy generated during the exercise on the treadmill could be utilized to power electronic devices and appliances. The attached power generation machine will not interrupt a person’s workout flow and it can be attached to any treadmill due to its friendly design. Wasted energy is harnessed in this research by a non-traditional manner of using shaft and wheel method. A multi-meter is used to measure the voltage and current and power is then calculated from the readings recorded. Tests have shown that the prototype machine is able to fully charge a 3096 mAh smartphone in 135 minutes and the phone could be fully charged for 2 charging cycles. This power generating machine is showing a good implementation for the Sustainable development Goals (SDG’s)

Solar powered outdoor air purifier with air quality monitoring

This paper has documented the detailed design, fabrication and test of a solar powered air purifier prototypee with a High Efficiency Particulate Air Filter (HEPA) and Carbon Filters which can achieve air purification with selfsustainable ability. Besides. Several tests have been conducted to assess the performance of the proposed solar operated air purifier. In the first test, a 67.37% efficiency is achieved for the solar panel. Second test of air purifier test has shown the efficiency of cleaning ammonia pollutant in the air as 43.55% for burning cigarettes and 35.33% for floor detergent using the equipped two MQ135 sensors. The findings are showing that the floor detergent might have higher rate of diffusion than ammonia molecule found in cigarette smoke