Stray inductance effects and protection in GTO thyristor circuits

The recently developed gate turn-off thyristor is now becoming well established as the first choice switching device in high power converters for applications such as uninterruptible power supplies, frequency changers, and AC and some DC variable speed motor drives. The special operating features of these devices in conventional circuit configurations are investigated. The GTO thyristor physical behaviour and operating characteristics are first described and supported by measurements made at turn-off currents of up to 600A on a specially constructed test circuit. From this, it is shown that, owing to the extremely fast rates of fall of anode current at turn-off, voltage overshoot effects caused by the stray circuit inductances are highly dangerous to the device, and effective snubbing is essential. A detailed study of these stray inductance effects in constructed DC chopper and H-bridge inverter circuits follows. The circuits are modelled to include these strays, with appropriate mathematical analysis and computer simulation, to determine which stray inductances are the most influential in causing GTO thyristor voltage stress. The different switching patterns are considered for the H-bridge to provide quasi-square and various pulse width modulated (PWM) output voltage waveforms, and the detailed current transfer paths in the various circuit devices and snubber components defined and mathematically analysed in each case. Practical switching effects of diode reverse recovery and GTO mismatched switching times are demonstrated and possible damaging conditions revealed. All analytical and computed results are supported by experimental measurements. A GTO thyristor will be damaged by attempting to turn-off an over-current, and satisfactory protection against this is essential. Conventional fusing is usually inadequate, and a better method is to use a fast active system utilising either a crowbar and fuse, or rapid direct gate turn-off. Both methods are investigated and experimental results provided. It is concluded that, with appropriate circuit layout and component choice, the unavoidable stray inductance effects can be limited to manageable levels. The most severe effects are caused by the DC source inductance which is the most difficult to minimise. Others within the power circuit, if kept small, will have a marginal effect. Fast over-current protection is achievabl

Nurses' Roles towards Patient undergoing Cardiac Catheterization at Al- Najaf Governorate: Patient Perspective

The study objectives to evaluate nurses’ roles toward patient undergoing cardiac catheterization and to find out the relationship between the patient perspective and demographic data (age, gender, level of education, social status, occupation, economic status, and residence). a descriptive cross-sectional design (patient perspective) was carried out through the present study in order to achieve the early stated objectives for period January 4th 2017 to August  6th 2017. The study conducted at AL-Najaf cardiac center, A convenient sample of (100) patients undergoing to cardiac catheterization patients that admitted to cardiac catheterization unites. The data were collected through the use of questionnaire, which consists of two parts, socio-demographic data, and question related to nurses' roles toward patient undergoing cardiac catheterization. The data were described statistically and analyzed though use of the descriptive and inferential statistical analysis procedures. The results of present study indicate that the nurses' roles toward patient undergoing cardiac catheterization was good more than 89% of patient agree with this role. The study confirms that the nurses have a good practice toward patient undergoing cardiac catheterization according to patient perspective. Nurses, who working in cardiac center, should be hired with certain qualification, which are related to the performance of such high quality practices. Special training programs should be designed and constructed for nurses in this area to reinforce their skills and promote their experience. The standards for such practices bill should be created and presented to all ties in which such practices are performed

Pengaruh Bentuk Profile Kemudi Terhadap Aliran Fluida Pada Kapal Ikan Tradisional Km. Surya Andalan Berbasis Cfd

Teknik pembuatan kapal ikan tradisional oleh para nelayan masih dilakukan secarakonvensional dimana kapal tradisional pada umunya menggunakan daun kemudi hanya berupapelat tunggal, penelitian ini dilakukan untuk mengetahui pengaruh penggunaan profile daunkemudi dengan memodifikasi pelat tunggal yang ada pada sebuah kapal ikan tradisionalsehingga dapat dibandingkan gaya angkat yang dihasilkan oleh pelat tunggal dengan daunkemudi yang menggunakan bentuk foil (modifikasi) melalui simulasi CFD.Penelitian ini mengkaji pengaruh bentuk profile kemudi terhadap aliran fluida dantahanan yang disebabkan oleh daun kemudi pada kapal ikan tradisional KM. Surya Andalanyang mempunyai bentuk buritan cembung (cruiser) dengan menggunakan paket programCAD (Computer Aided Design) serta CFD (Computational Fluid Dynamics). Dengan menjagaluasan total pada daun kemudi agar diketahui dampak penambahan profile daun kemudi,sementara modifikasi modifikasi dengan mengubah sudut serang daun kemudi.Hasil perhitungan dan analisa dengan menggunakan metode free surface modelmodifikasi pada sudut 00 dengan kecepatan 7 knot tahanan yang tereduksi sebesar 45.71%.Hasil simulasi daun kemudi dengan menggunakan foil mempunyai gaya angkat yang lebihbesar namun bekerja secara optimum pada sudut 200 pada kecepatan 7 knot terjadipeningkatan gaya angkat 37.59 % dari gaya angkat yang diperoleh model daun kemuditunggal

Life Cycle Assessment pada Pembibitan Kelapa Sawit untuk Menghitung Emisi Gas Rumah Kaca

Palm oil plantations in Indonesia is growing every year due to increased consumption of vegetable oil in line with the increase in the population of the world that are used as food , cosmetics , renewable sources , etc. Challenges in the development of palm oil plantations are problems and negative issues; land conflicts, damage to biodiversity, and environmental damage issues. Environmental damage caused by palm oil plantations became the object of attack developed countries and Non Governmental Organization (NGO), with the pretext to cause an increase in Greenhouse Gas (GHG) emissions that cause global warming. This research aimed to determine the Greenhouse Gas (GHG) emissions in palm oil seedling production. Methods carried out were studying the environmental aspects of a product by Life Cycle Assessment (LCA) in which all environmental aspects were analyzed and evaluated throughout its life cycle. Steps in LCA were goal and scope definition, life cycle inventory, life cycle impact assessment, and life cycle interpretation. The result showed that in the palm oil seedling sources of Greenhouse Gas (GHG) emissions derived from the use of diesel fuel, NPK fertilizer, pesticides, and fungicides. Total emissions of Greenhouse Gases (GHG) is 0.50685 kg CO2 eq / seed. Diesel fuel became the biggest emissions is 0,332 kg CO2 eq / seed or 65.5 % and emissions from the use of NPK fertilizers is 0.1703 kg CO2 eq / seed or 33.6 % of total Greenhouse Gas ( GHG ) emissions in palm oil seedling

Aktor Pelaksana Pengelolaan Transportasi Publik Perkotaan (Studi Kasus Bus Trans Metro di Kota Pekanbaru)

Modernisasi dalam bidang transportasi merupakan suatu terobosan bagi pemerintah untuk memperbaiki sistem pelayanan dalam bidang angkutan umum. Pertumbuhan ekonomi suatu negara atau bangsa tergantung tersedianya pengangkutan dalam negara atau bangsa yang bersangkutan. Agar hal tersebut bisa terwujud, maka dalam pengelolaannya diperlukan aktor lain diluar pemerintah agar pelaksanaan kebijakan dapat disinergikan sehingga dapat memperoleh hasil yang maksimal dalam pencapaian tujuan dari kebijakan. Penelitian yang digunakan adalah penelitian deskriptif kualitatif, yakni jenis penelitian yang menggambarkan suatu fenomena atau kejadian secara apa adanya. Hasil yang diperoleh dalam penelitian ini bahwa aktor utama dalam kegiatan pengelolaan transportasi publik perkotaan yaitu pemerintah (Dinas Perhubungan Komunikasi dan Informatika Kota Pekanbaru). Diperlukan keterlibatan aktor diluar pemerintah dalam melakukan kegiatan pengelolaan transportasi publik perkotaan (Bus Trans Metro Pekanbaru) agar hasil yang dicapai terlaksana secara optimal

An update on VEXAS syndrome

Introduction VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently described, late-onset, acquired autoinflammatory disorder caused by mutations in the UBA1 gene. The various clinical manifestations of VEXAS broadly divided into inflammatory or haematological. VEXAS defines a new disease category – the hematoinflammatory disorders triggered by somatic mutations restricted to blood but causing systemic inflammation with multi-organ involvement and associated with aberrant bone marrow status. VEXAS causes significant morbidity and reduced life expectancy, but the optimum standard of care remains undefined Areas covered This review describes the discovery of VEXAS, relevant genetic causes and immunopathology of the disease. A detailed account of its various clinical manifestations and disease mimics is provided. Current treatment and management options are discussed. Expert opinion New rare variants in UBA1 and VEXAS-like UBA1 negative cases are reported. Consensus diagnostic criteria might be required to define VEXAS and its related disorders. Investigation of sporadic, VEXAS-like cases will require the application of deep sequencing using DNA obtained from various cellular or tissue locations. Prospective studies are needed to define the optimal supportive and treatment options for patients with varying disease severity and prognosis. VEXAS-specific hematopoietic stem cell transplant selection criteria also require development

Improving Diagnosis and Clinical Management of Acquired Systemic Autoinflammatory Diseases

Systemic autoinflammatory diseases (SAID) are conditions caused by dysregulation or disturbance of the innate immune system, with neutrophils and macrophages the main effector cells. Although there are now more than 40 distinct, genetically defined SAIDs, the genetic/molecular diagnosis remains unknown for a significant proportion of patients with the disease onset in adulthood. This review focuses on new developments related to acquired/late onset SAID, including phenocopies of monogenic disorders, Schnitzler’s syndrome, Adult onset Still’s disease, VEXAS syndrome, and autoinflammatory complications associated with myelodysplastic syndrome

SAPONINS, GLYCOSIDES AND FLAVONOIDS IN CELLS AND TISSUES OF BALANITES AEGYPTIACA CULTURED ON SOLID AND LIQUID CULTURE MEDIA

Objectives: The main objective of the present study is to obtain callus and cell suspension culture from Balanitesa egyptiaca sterile plantlets grown in vitro and to compare growth and the biosynthetic potential of saponins, flavonoids and glycosides by callus and cell suspension culture Balanitisa egyptiaca. Methods: Callus was induced from the mother plants on MS culture media supplemented with  2.0 mg/l  BA + 2.0 mg/l  2,4-D with and without agar gelling. Total saponins, glycosides and flavonoids were estimated in both types of cultures over a period extending from 1 to 5 weeks to compare the productivity of such secondary metabolites in callus and cell suspension cultures. Results: The results obtained indicated that both calli and cell suspension cultures were able to synthesize the target active ingredients and that cell suspension culture was superior to the callus culture in the biosynthesis and accumulation processes. By the end of the incubation period, the amount of total saponins in cell suspension culture reached up 51.97±0.26 dry biomass compared to 35.02 ±0.06 mg/g in callus culture. The amount of total flavonoids in cell suspension culture reached up 10.88±0.24 dry biomass compared to 6.40±0.02 mg/g in callus culture and of total glycosides reached up 6.11±0.25 dry biomass compared to 5.06 ±0.05 mg/g in callus culture. Conclusions: The results obtained in this study may indicate the promising role that plant cell culture will play in the future in phytopharmaceutical industry.                          Peer Review History: Received 16 July 2020; Revised 12 August; Accepted 26 August, Available online 15 September 2020 Academic Editor: Dr. Iman Muhammad Higazy, National Research Center, Egypt, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Dr. Gehan Fawzy Abdel Raoof Kandeel, Researcher at pharmacognosy Department, National Research Centre, Egypt, [email protected] Ahmad Najib, Department of Pharmacognosy-Phytochemystry Universitas Muslim Indonesia-Indonesia, [email protected] Similar Articles: PHYTOCHEMICAL ANALYSIS AND ANTIMICROBIAL ACTIVITY OF COLOCASIA ESCULENTA (TARO) MEDICINAL PLANT LEAVES USED IN FOLK MEDICINE FOR TREATMENT OF WOUNDS AND BURNS IN HUFASH DISTRICT AL MAHWEET GOVERNORATE–YEMEN PHYTOCHEMICAL SCREENING AND THIN LAYER CHROMATOGRAPHIC OF PRUNUS DULCIS (ALMOND) MEDICINAL PLANT LEAVES USED IN FOLK MEDICINE FOR TREATMENT OF WOUNDS AND BURNS IN HUFASH DISTRICT AL MAHWEET GOVERNORATE–YEME

Identifying leaf rust resistance gene Lr19 in durum wheat using simple sequence repeat (SSR) marker

Leaf rust, caused by Puccinia triticina Eriks., is an important disease affecting durum wheat (Triticum turgidum ssp. durum) worldwide, particularly in the Mediterranean region. The disease can be controlled through the use of plant host resistance. Based on seedling resistance tests of 103 durum genotypes against a bulk of P. triticina, urediniospores were previously collected from Syria and Lebanon during 2007/08 and 2008/09 growing seasons. Percentage of resistance in the durum set tested was up to 52%. The resistant genotypes might have one of the following resistance gene(s): Lr15, Lr 19, Lr 24, Lr 25, Lr 27 +31, Lr 28 and Lr 29. Results revealed that the Gb/130-bp polymorphic band was linked to Lr19 and Sr25. In this study, twelve genotypes carrying resistance to Lr19 and Sr25 have been identified (Azeghar2, Rutucha1, Ammar9/Azeghar2, Ammar9/Terbol97-4, T.polonicum9/Ch1//Icamor-TA04-68/3/Icamor-TA04-69//(Lahn/ Ch1)2519, Arislahn5//Icamor-TA04- 63/Icasyr1, T.dicoccum1/Ch1//Ammar8/3/Bonadur/Icamor-TA04-63, Mrb3/ T. urartu500651/4/Icamor- TA04-63/3/Bcr/Gro1// Mgnl1, SwAlg/Gd1-81 //Ch1-48, Icamor-TA04-1//Mgnl3/Ainzen1, 319-ADDO/5/D68-1- 93A-1A//Ruff/Fg/3/Mtl5/4/Lahn, and Mrf1/Stj2/3/1718/BT24//Karim). Promising results on Gb/130-bp and genotypes carrying Lr19 and Sr25 will be used in a marker assisted selection of the durum breeding programs in the Mediterranean region.Key words: Puccinia triticina, durum genotypes, Syria, Lebanon, Lr19, Sr25, Gb primer