Design of LLC resonant converter with silicon carbide MOSFET switches and nonlinear adaptive sliding controller for brushless DC motor system

Introduction. The high voltage gain DC-DC converters are increasingly used in many power electronics application systems, due to their benefits of increased voltage output, reduced noise contents, uninterrupted power supply, and ensured system reliability. Most of the existing works are highly concentrated on developing the high voltage DC-DC converter and controller topologies for goal improving the steady state response of brushless DC motor driving system and also obtain the regulated voltage with increased power density and reduced harmonics, the LLC resonant DC-DC converter is implemented with the silicon carbide MOSFET switching devices Problem. Yet, it facing the major problems of increased switching loss, conduction loss, error outputs, time consumption, and reduced efficiency. Also the existing works are mainly concentrating on improving the voltage gain, regulation, and operating performance of the power system with reduced loss of factors by using the different types of converters and controlling techniques. The goal of this work is to obtain the improved voltage gain output with reduced loss factors and harmonic distortions. Method. Because, this type of converter has the ability to generate the high gain DC output voltage fed to the brushless DC motor with reduced harmonics and loss factors. Also, the nonlinear adaptive sliding controller is implemented to generate the controlling pulses for triggering the switching components properly. For this operation, the best gain parameters are selected based on the duty cycle, feedback DC voltage and current, and gain of silicon carbide MOSFET. By using this, the controlling signals are generated and given to the converter, which helps to control the brushless DC motor with steady state error. Practical value. The simulation results of the proposed LLC silicon carbide MOSFET incorporated with nonlinear adaptive sliding controller controlling scheme are validated and compared by using various evaluation indicators. Вступ. Високовольтні перетворювачі постійного струму з високим коефіцієнтом посилення напруги все частіше використовуються в багатьох прикладних системах силової електроніки через їх переваги, пов'язані з підвищеною вихідною напругою, зниженим рівнем шуму, безперебійним живленням і гарантованою надійністю системи. Більшість існуючих робіт значною мірою зосереджені на розробці топологій високовольтного перетворювача постійного струму і контролера з метою поліпшення усталеного відгуку системи приводу безщіткового двигуна постійного струму, а також отримання регульованої напруги з підвищеною щільністю потужності і зменшеними гармоніками; резонансний LLC-перетворювач постійного струму, реалізований на перемикаючих пристроях на основі польових МОП-транзисторах з карбіду кремнію. Проблема. Тим не менш, це стикається з основними проблемами, пов'язаними зі збільшенням втрат при перемиканні, втратами провідності, помилками на виході, витратами часу та зниженням ефективності. Крім того, існуючі роботи в основному зосереджені на покращенні коефіцієнта посилення напруги, регулювання та робочих характеристик енергосистеми із зменшенням факторів втрат за рахунок використання різних типів перетворювачів та методів управління. Метою роботи є отримання покращеного коефіцієнта посилення напруги зі зниженими коефіцієнтами втрат і гармонійних спотворень. Метод. Таким чином, цей тип перетворювача здатний генерувати вихідну постійну напругу з високим коефіцієнтом посилення, що подається на безщітковий двигун постійного струму, зі зменшеними коефіцієнтами гармонік та втрат. Крім того, реалізований нелінійний адаптивний ковзний регулятор для генерування керуючих імпульсів для належного спрацьовування перемикаючих компонентів. Для цієї операції вибираються найкращі параметри посилення на основі робочого циклу, постійної напруги та струму зворотного зв'язку, а також коефіцієнта посилення польового МОП-транзистора з карбіду кремнію. При цьому керуючі сигнали генеруються і передаються на перетворювач, який допомагає керувати безщітковим двигуном постійного струму з помилкою, що встановилася. Практична цінність. Результати моделювання запропонованого LLC-перетворювача на основі польових МОП-транзисторів з карбіду кремнію зі схемою управління нелінійним адаптивним ковзним регулятором перевіряються та порівнюються з використанням різних показників оцінки.&nbsp

ASUHAN KEBIDANAN KOMPREHENSIF PADA IBU DENGAN ANEMIA DI PUSKESMAS SEDAYU 1 BANTUL

Latar belakang: Prevalensi ibu hamil dengan anemia menurut rikesdas tahun 2018 di Indonesia yaitu 48,9%, di Puskesmas Sedayu 1 Bantul terdapat ibu hamil dengan anemia pada tahun 2018 sebanyak 50 orang. Anemia pada kehamilan dapat berdampak terhadap proses persalinan dan masa nifas maupun bayi baru lahir. Tujuan: Studi kasus ini bertujuan untuk memberikan Asuhan Kebidanan Komprehensif dengan resiko Anemia Metode: Jenis studi kasus ini yang digunakan metode observasional dan descriptive. Studi kasus ini dilakukan mulai dari bulan Juli-September 2018 di Puskesmas Sedayu I Bantul subyeknya Ny. R dengan anemia. Instrumen yang digunakan baik format askeb rekam medik, kohord, dan buku KIA. Teknik pengambilan data dalam Studi kasus ini dengan metode pengumpulan data dengan cara wawancara, observasi, pemeriksaan fisik, dokumentasi dan studi kepustakaan menggunakan manajemen kebidanan varney. Hasil: Asuhan kebidanan secara komprehensif pada Ny. R umur 40 tahun, selama 3 bulan mulai dari Trimester III sampai nifas, dilakukan perawatan selama 2 kali kunjungan hamil trimester III hasil dari Hb 10.1 gr %, menjadi Hb. 12.0 gr%, persalinan sepontan tanpa penyulit, pada masa nifas dengan nifas normal P3A0AH. Kesimpulan: Setelah dilakukan Asuhan Kebidanan Komprehensif pada ibu hamil dengan anemia teratasi sehingga persalinan normal, nifas normal, bayi sehat dan normal Kata kunci : Asuhan Kebidanan Komprehensif, Anemi

STOK KARBON TUMBUHAN BAWAH DAN IKLIM MIKRO RUANG TERBUKA HIJAU

This study was to determine differences in the percentage of canopy cover on carbon stock in three green oven space (RTH) areas at the Faculty of Forestry Mulawarman University (FFMU) and to determine differences in light intensity, temperature, and humidity at every plot location of understorey plants at the FFMU. The method used in this research was to measure the percentage of canopy cover, plant biomass, and carbon stock in plots of 2 x 2 m, measuring light intensity, temperature, and humidity from 06.00 in the morning to 18.00 in the afternoon. Data was collected at three RTHs, namely, RTH Guest House (Location 1), RTH Workshop (Location 2), and RTH Arboretum LSHK (Location 3). The result found the highest amount of carbon (130,8 tons/ha) and the percentage of crowns (59,42%). Medium green open space RTH Guest House amount of carbon (38,4 tons/ha), percentage of the canopy (55,69%), and the lowest RTH Arboretum LSHK amount of carbon (32 tons/ha) and percentage of the canopy (53.71%). Furthermore, the highest light intensity is in the RTH Guest House because the place is sparse, tenuous, and open so that light can directly enter and get more sunlight; moderate light is in the RTH Arboretum LSHK, and little light is in the RTH Workshop because the place is more closed so that light enters only a few. Then, for each temperature, the humidity values obtained are similar. The findings demonstrated variations in carbon storage due to vegetation density, age, growing place quality, and soil characteristics

Acute and Subchronic Oral Toxicity Assessment of the Ethanolic Extract of the root of Oncoba spinosa (Flacourtiaceae) in Rodents

Purpose: To investigate the toxicological profile of the ethanol extract of Oncoba spinosa (EEOS) after acute and sub-chronic administration to rodents.Methods: In the acute toxicity study, a single administration of the extract at doses of 2000 and 5000 mg/kg, respectively, was given to the mice. Mice were observed for general behavioural changes, adverse effects and mortality up to 14 days post-treatment. In sub-acute toxicity studies, EEOS was given orally to male and female rats at doses of 250 mg/kg, 500 mg/kg and 1000 mg/kg for 28 days. Body weight, food intake and water intake were monitored throughout the experimental period; hematological parameters, biochemical parameters of the blood and histopathology of various organs were also evaluated at the end of the experiment.Results: In the acute toxicity study, both the doses used did not cause any mortality or significant behavioural changes. Daily oral administration of EEOS for 28 days, in the sub-chronic toxicity study, did not show any treatment-related abnormalities with regard to hematological and biochemical parameters. There were no significant differences in body weight and organ weight between the control and treated groups (p < 0.05). Histological analysis did not show any morphological changes in the major vital organs (liver, kidney, stomach, spleen, brain and heart) tested.Conclusion: These results demonstrate that the extract may not have any single dose toxicity. The LD50 value is greater than 5000 mg/kg. The no-observed adverse effects level (NOAEL) was considered to be 1000 mg/kg for male and female rats, respectively.Keywords: Oncoba spinosa, Acute and sub-acute toxicity, Hematological, Biochemical parameter

In vitro hepatoprotective activity of Eichhornia Crassipes flowers against CCl4 induced toxicity in BRL3A cell line

316-319The present study was carried out to determine the in vitro hepatoprotective activity of ethanolic extract from Eichhornia crassipes (EEEC) flowers using the CCl4-challenged BRL3A cell model. Hepatoprotective activity of EEEC (at concentrations of 50, 100 and 200 μg/mL) and standard drug silymarin (200 μg/mL) was evaluated against CCl4 induced toxicity using BRL3A cell line by measuring the cell viability, aspartate aminotransferase (AST), alanine aminotransaminase (ALT), lactate dehydrogenase (LDH) leakage, lipid peroxidation (LPO) and glutathione level (GSH). Treatment with CCl4 produced a significant decrease in cell viability. In addition, hepatotoxicity was revealed by increased hepatic marker enzymes like AST, ALT and LDH paralleled with elevated lipid peroxidation and decline in GSH levels. The toxicity induced by CCl4 in the BRL3A cells was significantly recovered by treatment with EEEC. The tested doses (100 and 200 μg/mL) significantly (P <0.01) reduced the CCl4 induced elevation of AST, ALT and LDH and also restored the altered biochemical parameters. These findings provide a basis for confirming the traditional uses of E. crassipes in treating liver ailments

In vitro hepatoprotective activity of Eichhornia Crassipes flowers against CCl4 induced toxicity in BRL3A cell line

The present study was carried out to determine the in vitro hepatoprotective activity of ethanolic extract from Eichhornia crassipes (EEEC) flowers using the CCl4-challenged BRL3A cell model. Hepatoprotective activity of EEEC (at concentrations of 50, 100 and 200 μg/mL) and standard drug silymarin (200 μg/mL) was evaluated against CCl4 induced toxicity using BRL3A cell line by measuring the cell viability, aspartate aminotransferase (AST), alanine aminotransaminase (ALT), lactate dehydrogenase (LDH) leakage, lipid peroxidation (LPO) and glutathione level (GSH). Treatment with CCl4 produced a significant decrease in cell viability. In addition, hepatotoxicity was revealed by increased hepatic marker enzymes like AST, ALT and LDH paralleled with elevated lipid peroxidation and decline in GSH levels. The toxicity induced by CCl4 in the BRL3A cells was significantly recovered by treatment with EEEC. The tested doses (100 and 200 μg/mL) significantly (P &lt;0.01) reduced the CCl4 induced elevation of AST, ALT and LDH and also restored the altered biochemical parameters. These findings provide a basis for confirming the traditional uses of E. crassipes in treating liver ailments

Effects of Probiotics on Colitis-Induced Exacerbation of Alzheimer\u27s Disease in

Alzheimer’s disease (AD) is characterized by progressive cognitive decline and is a leading cause of death in the United States. Neuroinflammation has been implicated in the progression of AD, and several recent studies suggest that peripheral immune dysfunction may influence the disease. Continuing evidence indicates that intestinal dysbiosis is an attribute of AD, and inflammatory bowel disease (IBD) has been shown to aggravate cognitive impairment. Previously, we separately demonstrated that an IBD-like condition exacerbates AD-related changes in the brains of the AppNL-G-F mouse model of AD, while probiotic intervention has an attenuating effect. In this study, we investigated the combination of a dietary probiotic and an IBD-like condition for effects on the brains of mice. Male C57BL/6 wild type (WT) and AppNL-G-F mice were randomly divided into four groups: vehicle control, oral probiotic, dextran sulfate sodium (DSS), and DSS given with probiotics. As anticipated, probiotic treatment attenuated the DSS-induced colitis disease activity index in WT and AppNL-G-F mice. Although probiotic feeding significantly attenuated the DSS-mediated increase in WT colonic lipocalin levels, it was less protective in the AppNL-G-F DSS-treated group. In parallel with the intestinal changes, combined probiotic and DSS treatment increased microglial, neutrophil elastase, and 5hmC immunoreactivity while decreasing c-Fos staining compared to DSS treatment alone in the brains of WT mice. Although less abundant, probiotic combined with DSS treatment demonstrated a few similar changes in AppNL-G-F brains with increased microglial and decreased c-Fos immunoreactivity in addition to a slight increase in Aβ plaque staining. Both probiotic and DSS treatment also altered the levels of several cytokines in WT and AppNL-G-F brains, with a unique increase in the levels of TNFα and IL-2 being observed in only AppNL-G-F mice following combined DSS and probiotic treatment. Our data indicate that, while dietary probiotic intervention provides protection against the colitis-like condition, it also influences numerous glial, cytokine, and neuronal changes in the brain that may regulate brain function and the progression of AD

A Fibreoptic Endoscopic Study of Upper Gastrointestinal Bleeding at Bugando Medical Centre in Northwestern Tanzania: a Retrospective Review of 240 Cases.

Upper gastrointestinal (GI) bleeding is recognized as a common and potentially life-threatening abdominal emergency that needs a prompt assessment and aggressive emergency treatment. A retrospective study was undertaken at Bugando Medical Centre in northwestern Tanzania between March 2010 and September 2011 to describe our own experiences with fibreoptic upper GI endoscopy in the management of patients with upper gastrointestinal bleeding in our setting and compare our results with those from other centers in the world. A total of 240 patients representing 18.7% of all patients (i.e. 1292) who had fibreoptic upper GI endoscopy during the study period were studied. Males outnumbered female by a ratio of 2.1:1. Their median age was 37 years and most of patients (60.0%) were aged 40 years and below. The vast majority of the patients (80.4%) presented with haematemesis alone followed by malaena alone in 9.2% of cases. The use of non-steroidal anti-inflammatory drugs, alcohol and smoking prior to the onset of bleeding was recorded in 7.9%, 51.7% and 38.3% of cases respectively. Previous history of peptic ulcer disease was reported in 22(9.2%) patients. Nine (3.8%) patients were HIV positive. The source of bleeding was accurately identified in 97.7% of patients. Diagnostic accuracy was greater within the first 24 h of the bleeding onset, and in the presence of haematemesis. Oesophageal varices were the most frequent cause of upper GI bleeding (51.3%) followed by peptic ulcers in 25.0% of cases. The majority of patients (60.8%) were treated conservatively. Endoscopic and surgical treatments were performed in 30.8% and 5.8% of cases respectively. 140 (58.3%) patients received blood transfusion. The median length of hospitalization was 8 days and it was significantly longer in patients who underwent surgical treatment and those with higher Rockall scores (P < 0.001). Rebleeding was reported in 3.3% of the patients. The overall mortality rate of 11.7% was significantly higher in patients with variceal bleeding, shock, hepatic decompensation, HIV infection, comorbidities, malignancy, age > 60 years and in patients with higher Rockall scores and those who underwent surgery (P < 0.001). Oesophageal varices are the commonest cause of upper gastrointestinal bleeding in our environment and it is associated with high morbidity and mortality. The diagnostic accuracy of fibreoptic endoscopy was related to the time interval between the onset of bleeding and endoscopy. Therefore, it is recommended that early endoscopy should be performed within 24 h of the onset of bleeding

Reconstructive periodontal therapy with simultaneous ridge augmentation. A clinical and histological case series report

Treatment of intrabony periodontal defects with a combination of a natural bone mineral (NBM) and guided tissue regeneration (GTR) has been shown to promote periodontal regeneration in intrabony defects. In certain clinical situations, the teeth presenting intrabony defects are located at close vicinity of the resorbed alveolar ridge. In these particular cases, it is of clinical interest to simultaneously reconstruct both the intrabony periodontal defect and the resorbed alveolar ridge, thus allowing insertion of endosseous dental implants. The aim of the present study was to present the clinical and histological results obtained with a new surgical technique designed to simultaneously reconstruct the intrabony defect and the adjacently located resorbed alveolar ridge. Eight patients with chronic advanced periodontitis displaying intrabony defects located in the close vicinity of resorbed alveolar ridges were consecutively enrolled in the study. After local anesthesia, mucoperiosteal flaps were raised, the granulation tissue removed, and the roots meticulously scaled and planed. A subepithelial connective tissue graft was harvested from the palate and sutured to the oral flap. The intrabony defect and the adjacent alveolar ridge were filled with a NBM and subsequently covered with a bioresorbable collagen membrane (GTR). At 11–20 months (mean, 13.9 ± 3.9 months) after surgery, implants were placed, core biopsies retrieved, and histologically evaluated. Mean pocket depth reduction measured 3.8 ± 1.7 mm and mean clinical attachment level gain 4.3 ± 2.2 mm, respectively. Reentry revealed in all cases a complete fill of the intrabony component and a mean additional vertical hard tissue gain of 1.8 ± 1.8 mm. The histologic evaluation indicated that most NBM particles were surrounded by bone. Mean new bone and mean graft area measured 17.8 ± 2.8% and 32.1 ± 8.3%, respectively. Within their limits, the present findings indicate that the described surgical approach may be successfully used in certain clinical cases to simultaneously treat intrabony defects and to reconstruct the resorbed alveolar ridge