Journal of Hunan University Natural Sciences

This article outcome is a comparative analysis of Automatic Generation Control (AGC) of a multi-area interconnected hydrothermal gas system in different modes using computational algorithm controllers for the electrical and mechanical governors. Two areas have been implemented. The first area comprises a Thermal and Hydropower station, while the second area consists of a Thermal and Gas power station. The AGC of a multi-area power system is examined to increase frequency stability using improved PID controllers under 1%∆P. The multi-technique is used to tune the gains of PID and its Sine Cosine Algorithms (SCA), Particle Swarm Optimization (PSO), Gray Wolf Optimization (GWO), and Genetic Algorithms (GA). The Implementation determines the validity of the four intelligent techniques for tuning the PID controller parameters to improve the frequency and tie-line deviation difficulties and increase the power system's stability. Finally, the SCA's comparison of dynamic performance to settling time, overshoot, and undershoot in frequency and tie-line power deviations proved to be slightly better than other algorithms with some convergence in results.

Keywords: automatic generation control, PID controller, computational algorithm, power systems.

This study is the first study correlating the effect of the peroxide branching agent with the film blowing stability of polylactic acid (PLA). The peroxide content was varied between 0-0.5 wt%, and the changes in molecular structures, rheological properties, film bubble stability, and mechanical properties were investigated. Our research goal is to improve the processability of PLA blown film and identify key parameters for the good processability of PLA. It was found that the addition of a sufficiently high peroxide content-led not only to higher storage modulus (G') but also to higher melt strength and significant improvement in the film blowing processability, where the blow-up ratio (BUR) increased with increasing peroxide content. However, the peroxide content higher than 0.3 wt% tended to cause stiffer film and a higher amount of gels. Another interesting finding is that the terminal region's G value was strongly correlated with melt strength and film blowing processability.

Keywords: polylactic acid, film blowing, peroxide, processability, rheological properties.

Schizophrenia is a mental disorder affecting almost 1% of the global population. COVID-19 makes schizophrenia patients more vulnerable to poor outcomes because of their immune system disorder. When a patient is diagnosed with COVID-19, they must isolate for at least 14 days. This is where consultation liaison psychiatrists have a great role to play, both in delivering the news and in helping the patients to cope during their illness. The way in which health workers communicate with the patients should also be adjusted during the pandemic to limit the spread of COVID-19. This is a case report of a male paranoid schizophrenia patient who was also diagnosed with COVID-19 during his hospitalization. We used consultation liaison psychiatry techniques to break the news of his COVID-19 diagnosis. The patient refused to be isolated at first, but finally agreed after we had explained the situation further to him. Telepsychiatry could be an alternative way to communicate with an isolated COVID-19 patient as long as both the doctor and the patient were comfortable with the method. We used it to communicate with the patient until his discharge from hospital and he seemed quite comfortable with it. This article aims to raise awareness of the possibility of COVID-19 infection in a schizophrenic patient and highlight the role of consultation liaison psychiatrists in delivering the bad news about COVID-19 infection. The use of telepsychiatry for a psychiatric patient who needs to be isolated due to COVID-19 could also be a safer and more comfortable way to communicate, for both the doctor and the patient.

Keywords: Consultation-Liaison Psychiatry, COVID-19, mental disorder, schizophrenia, telepsychiatry.

An obese person's body suffers from the accumulation of fat, which has a detrimental effect on their health. A person is considered obese when their body weight is at least 20% more than it should be. Overweight is when the Body Mass Index (BMI) is between 25 and 29.9. While a BMI of 30 or more indicates obesity. The research goals are to detect how prevalent obesity is among Kirkuk women and its relation with education level, exercise, and other factors. The type of study is cross sectional study. The area chosen for this study was Kirkuk city, samples taken randomly from schools among teachers, primary health care visitors, and Azadi teaching hospital (mainly relatives of patients). The women were aged between 18-66 years old, and we exclude pregnant females. The data was collected using questionnaires. We measured height by tape-measure and weight by scales, and then we calculated their BMI using the following equation: BMI = weight in Kg/height in meter squared. Our results showed that 40% of the women were overweight, 23% were obese, and 12% were morbidly obese. Only around 25% of the sample was of normal weight. In our study, we found the prevalence of overweight and obesity increases with age. This finding might be related to a decrease in physical activity as people get older. Concerning the type of clothes worn by the women, it was found that those women who wore skirts and trousers quickly noticed changes in their body weight. We found a significant relationship between the increased number of glasses/cups of tea drunk during the day and the prevalence of obesity and overweight. Lactating women were found to be more overweight and obese in this study, but this was not significant. In conclusion, this study mainly has found that normal-weight was less than one-quarter of the sample studied. Type of clothes worn inside the home and older age were the main factors associated with obesity. Despite being a small study in 2 clinics, and the findings cannot be generalized, it still shows there is a problem and should immediately be addressed. More data about this problem needs to be collected and studied. Large studies are required to evaluate the prevalence of obesity in Kirkuk city. Encourage the community to change their eating habits and to exercise as they get older. Educate the community about the negative effects and complications of obesity. The study detected that most of the participants in the study were overweight or obese.

Keywords: obesity, overweight, women, Kirkuk.

The purpose of this study was to determine the most appropriate size of rainwater storage tank for Swinburne University of Technology Sarawak Campus (SUTS) based on the roof area and rainfall data and to compare its cost-effectiveness to a potable water supply. Daily rainfall data used in this study was obtained from meteorological station at Kuching International Airport, located about 6.3Km from SUTS. Water consumption data was obtained by translating the average monthly water bill provided by the SUTS facilities department. The simulation was conducted using a water balance model with yield-before-spillage (YBS) and yield-after-spillage (YAS) operating rules. The results were compared with Tangki Nahrim software. Additionally, cost analysis of rainwater harvesting system (RWHS) from the aspect of reliability, total cost, water-saving amount/year, payback period were further analyzed for choosing the optimum size of rain harvesting tank at different blocks in SUTS. The unit cost of harvested rainwater per m³ was evaluated with the water tariff charged by Kuching Water Board (KWB). Results show the optimal tank size for Block A&B and Block G is 60m³, while the optimal tank size for Block E is 30m³, with a reliability range of 83.5% to 89.5%. The capital cost required for Blocks A&B and G is RM51,310 each, while RM25,655 for Block E. With the installation of RWHS, the total annual water saving cost has amounted to RM8999.32. The payback period for these three blocks ranges from 12.9 years to 15.8 years, with a unit cost of RM1.87/m³ to RM2.29/m³. During the payback period, cost analysis revealed that the unit cost of water is slightly higher than the commercial water tariff rate. However, rainwater was freely supplied after that until the system's life span was reached. Thus, RWHS is the most cost-effective and long-term solution for reducing reliance on potable water supply.

Keywords: rainwater harvesting system, optimum tank size, reliability, yield-after-spillage, yield-before-spillage, Tangki Nahrim.