Design and implementation of PSO/ABC tunned PID controller for Buck converters

In the recent years, Buck converters have been widely involved in a variety of the everyday applications such as smartphones and PCs. Buck converters can provide better and steadier performance when integrating a control system in the design. Therefore, it is interesting to work on this integration and gain the required efficiency in term of the gained voltage. In this paper, PID controller is adopted to control the output voltage of the Buck converter. An optimization is achieved on the performance of the Buck converter using two bio-inspired algorithms namely, Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC). The voltage controlled Buck converter system is simulated using MATLAB environment to validate the proposed PID controller system. In this study, the voltage regulation process of Buck converter is investigated based on many working disturbances such as the change in the supply voltage, reference voltage, and load resistance in order to verify the robustness of the proposed PID controller. Finally, the feedabck voltage control system of the Buck converter is implemented experimentaly in real-time to validatde the simulated PID controller

High-Rate Space-Time Coded Large MIMO Systems: Low-Complexity Detection and Channel Estimation

In this paper, we present a low-complexity algorithm for detection in high-rate, non-orthogonal space-time block coded (STBC) large-MIMO systems that achieve high spectral efficiencies of the order of tens of bps/Hz. We also present a training-based iterative detection/channel estimation scheme for such large STBC MIMO systems. Our simulation results show that excellent bit error rate and nearness-to-capacity performance are achieved by the proposed multistage likelihood ascent search (M-LAS) detector in conjunction with the proposed iterative detection/channel estimation scheme at low complexities. The fact that we could show such good results for large STBCs like 16x16 and 32x32 STBCs from Cyclic Division Algebras (CDA) operating at spectral efficiencies in excess of 20 bps/Hz (even after accounting for the overheads meant for pilot based training for channel estimation and turbo coding) establishes the effectiveness of the proposed detector and channel estimator. We decode perfect codes of large dimensions using the proposed detector. With the feasibility of such a low-complexity detection/channel estimation scheme, large-MIMO systems with tens of antennas operating at several tens of bps/Hz spectral efficiencies can become practical, enabling interesting high data rate wireless applications.Comment: v3: Performance/complexity comparison of the proposed scheme with other large-MIMO architectures/detectors has been added (Sec. IV-D). The paper has been accepted for publication in IEEE Journal of Selected Topics in Signal Processing (JSTSP): Spl. Iss. on Managing Complexity in Multiuser MIMO Systems. v2: Section V on Channel Estimation is update

Exercise as a treatment modality for depression: A narrative review

Depression is a major health burden associated with poor quality of life and impaired functioning. Depression is a leading cause of disability worldwide and is associated with profound economic costs. Depression is usually treated with antidepressant medications and psychological therapy or combination of both. However, there are lot of limitations associated with these therapies and as a result, a number of alternative or adjunctive therapies have been sought for. Exercise is one such option with a lot of substantial supportive research. The objective of the article was to review the beneficial effects of exercise in depression. An electronic search of literature from inception till 06/2017 highlighting the effects of exercise on depression and the possible mechanistic pathways involved was conducted using PubMed/ Medline, Google scholar and Scopus and relevant articles were utilized for this review. The results of this review confirmed the beneficial role of exercise in depression as evidenced by the improvement in the outcomes and the various psychobiological parameters measured. Thus exercise can be considered as a treatment option for the management of depression.Keywords: Depression, Exercise, Physical activity, Mechanistic pathways, BDN

Saudi SCD patients’ symptoms and quality of life relative to the number of ED visits

Background Individuals living with sickle cell disease (SCD) have significantly increased emergency department (ED) use compared to the general population. In Saudi Arabia, health care is free for all individuals and therefore has no bearing on increased ED visits. However, little is known about the relationship between quality of life (QoL) and frequency of acute care utilization in this patient population. Methods A cross-sectional study was conducted on 366 patients with SCD who attended the outpatient department at King Fahad Hospital, Hofuf, Saudi Arabia. Data were collected through self-administered surveys, which included: demographics, SCD-related ED visits, clinical issues, and QoL levels. We assessed the ED use by asking for the number of SCD-related ED visits within a 6-month period. Results The self-report survey of ED visits was completed by 308 SCD patients. The median number of SCD-related ED visits within a 6-month time period (IQR) was four (2-7 visits). According to the unadjusted negative binomial model, the rate of SCD-related ED visits increased by (46, 39.3, 40, and 53.5 %) for patients with fever, skin redness with itching, swelling, and blood transfusion, respectively. Poor QoL tends to increase the rate of SCD-related ED visits. Well education and poor general health positively influenced the rate of SCD-related ED visits. Well education tends to increase the rate of SCD-related ED visits by 50.2 %. The rate of SCD-related ED visits decreased by 1.4 % for every point increase in general health. Conclusion Saudi patients with sickle cell disease reported a wide range of SCD-related ED visits. It was estimated that six of 10 SCD patients had at least three ED visits within a 6-month period. Well education and poor general health resulted in an increase in the rate of SCD-related ED visits

Study the effect of the adding of Ash of Palm Fronds on the Mechanical Properties for High Density Polyethylene (HDPE).

The mechanical properties of (HDPE - ash of palm fronds) composites were studied. The range of added powder of ash of palm fronds has the values (0%, 1%, 2%, 3%, 4%, 5%, 7.5% and 10%) of polyethylene weight and the best ratio was (10 %). The mechanical properties of (HDPE / ash of palm fronds) composites were analyzed as a function of the added powder amount. All prepared composites showed improved powder dispersion in the high density polyethylene matrix. More composites displayed lower elongation of break compared to pure HDPE. The results lead to that the strength at breaks will be affected little till the percentage (3%) is (6.8 Mpa), and increased after that with increasing the percentages, also indicate a lowered in young's modules (Young modulus) which at the percentage (3%). The highest value of the proportional limit was when the proportion of the added polymer (2%) is (431.2 N) while the less proportion limit of which (372 N) at the percentage is (4%). Keywords: polymer, Mechanical properties, Ash of palm fronds; Polymer composites; high density polyethylene, Fillers

Kinematic Modelling of FES Induced Sit-to-stand Movement in Paraplegia

FES induced movements from indication is promising due to encouraging results being obtained by scholars. The kinematic model usually constitute the initial phase towards achieving the segmental dynamics of any rigid body system. It can be used to ascertain that the model is capable of achieving the desired goal. The dynamic model builds on the kinematic model and is usually mathematically cumbersome depending on the number of degrees-of-freedom. This paper presents a kinematic model applicable for human sit-to-stand movement scenario that will be used to obtain the dynamic model the FES induced movement in a later study. The study shows that the 6 DOF conceptualized sit-to-stand movement can be achieved conveniently using 4 DOF. The 4 DOF has an additional joint compared to similar earlier works which makes more it accurate and flexible. It is more accurate in the sense that it accommodates additional joint i.e. the neck joint whose dynamics could be captured. And more flexible in the sense that if future research uncover more contributions by the segments it can be easily incorporated including that of other segments e.g. the trunk, neck and upper limbs

“Clinical Management of an Epigenetic Enamel Hypoplasia- A Case Report”

    Enamel hypoplasia is quantitative enamel defect, having reduced thickness of enamel. Dental enamel defects have been associated with a broad spectrum of etiologies including genetic and epigenetic factors such as systemic (bronchial asthma), local and environmental factors. Partial anodontia can be caused due to environmental and genetic factors which can cause failure of tooth development.  The purpose of the case report is to emphasize the possible correlation between bronchial asthma and enamel hypoplasia and the clinical management of the same

Evolution of second trimester low implanted placenta to previa at term: a prospective cohort study

Background: The objective of this study is to identify the percentage of low implanted placenta (LIP) at second trimester of pregnancy and identify the risk factors of its persistence to placenta previa (PP) at term.Methods: Through a registered prospective cohort study conducted at tertiary hospital in Upper Egypt, authors screened all pregnant ladies comes to present facility for antenatal second trimester USG between 18-24 weeks gestation. All participants interviewed for detailed risk factors of placenta previa. Those diagnosed to have a LIP (≤1.5 cm from the internal os) had had TVS to confirm the exact distance between the lower edge of the placenta and the internal os. Serial USG had been done every 4 weeks up to delivery to measure the same distance. The primary outcome was the percentage of LIP at 18-24 weeks. Logistic regression analysis was performed to predict the risk factors for PP at term.Results: Through screening of 1000 pregnant lady, LIP had been identified in (52 cases) 5.2% of pregnant women between 18-24 weeks. This percentage dropped gradually to reach 1.3% at 36 weeks of gestation and at time of delivery. The logistic regression analysis demonstrated that the distance between the internal os and the lower edge of the placenta between 18-24 weeks was the single significant variable associated with PP at term (p<0.001, odds ratio 0.319, 95% CI 0.20-0.50). However, excluding the distance from the regression model demonstrated other risk factors as previous miscarriage, previous cesarean section (CS), and history of multiple pregnancies and history of previous PP.Conclusions: About 5.0% of pregnant women have LIP at the second trimester of pregnancy (18-24 weeks) and only 25.0 % of them remain placenta previa at term. A cut-off value of 10 mm between the internal os and the lower edge of the placenta is the most important predictor of development of PP

Computational studies on the effect of geometric parameters on the performance of a solar chimney power plant

A solar chimney power plant (SCPP) is a renewable-energy power plant that transforms solar energy into electricity. The SCPP consists of three essential elements – solar air collector, chimney tower, and wind turbine(s). The present work is aimed at optimizing the geometry of the major components of the SCPP using a computational fluid dynamics (CFD) software ANSYS-CFX to study and improve the flow characteristics inside the SCPP. The overall chimney height and the collector diameter of the SCPP were kept constant at 10 m and 8 m respectively. The collector inlet opening was varied from 0.05 m to 0.2 m. The collector outlet diameter was also varied from 0.6 m to 1 m. These modified collectors were tested with chimneys of different divergence angles (0�–3�) and also different chimney inlet openings of 0.6 m to 1 m. The diameter of the chimney was also varied from 0.25 m to 0.3 m. Based on the CFX computational results, the best configuration was achieved using the chimney with a divergence angle of 2� and chimney diameter of 0.25 m together with the collector opening of 0.05 m and collector outlet diameter of 1 m. The temperature inside the collector is higher for the lower opening resulting in a higher flow rate and power

The nutritional, hormonal and vitamin status in overweight and obesity

Background: Obesity is a global epidemic which is increasing dramatically in overwhelming rates among males and females of all age categories in developing and developed countries.Methods: The first phase of the project involves the questionnaires which apply to all the Participants in research. We also use the lab investigation to determine the abnormality in overweight and obese people. Then we will analysis and combine the results to others research and give output and recommendation that we hope helping us to limiting of increase incidence of obesity.Results: sample show that high cholesterol above normal average approximately in 31.05% of the participants while the triglyceride rate increased in 31.67%. A lack of vitamin D, as the rate did not exceed 18±6.8, in individuals with the BMI 25-29, and to be 13±8.82, in individuals with the BMI>30. Vitamin B12 rate became borderline in individuals with BMI 25-29, and deficient in individuals with BMI>30.Conclusions: Obese Saudi individuals have several nutritional deficiencies specifically in vitamins D and B12 despite their overweight. Efforts should be focused to increase awareness of healthy and weight control