Fishman, Barry; Konstantopoulos, Spyros; Kubitskey, Beth W.; Vath, Richard; Park, Gina; Johnson, Heather; Edelson, Daniel
This article represents a response to the authors' "Journal of Teacher Education" ("JTE") article (Fishman et al., 2013) by Moon, Passmore, Reiser, and Michaels (2013). The authors believe that Moon et al. have properly identified both the value in their study and the importance of moving beyond not only their study, but…
Steven Weinberg visiting the ATLAS cavern accompanied by Peter JenniIt was no surprise that the CERN audience arrived early in the Globe of Science and Innovation for the colloquium on 7 July. Nobel laureate Steven Weinberg is one of the major contributors to the Standard Model of particle physics. He received the Nobel Prize for Physics in 1979 for his work on the unified theory of the electromagnetic and weak interactions, one of the essential pillars of the Standard Model. After lunch at CERN and a visit to ATLAS, Weinberg gave a colloquium on "The Quantum Theory of Fields: Effective or Fundamental" to a packed audience. In his talk, he looked at how the use of quantum field theory in particle physics has fluctuated in popularity since Paul Dirac first introduced the approach to describe the interaction of particles with electromagnetic fields in the late 1920s. In particular, he posed the question: Is quantum field theory fundamental or does it a...
Friedman, Edward A.; Moeller, Joseph J., Jr.
Describes evolution, implementation, and development of a personal computer plan at Stevens Institute of Technology (New Jersey). Although Stevens was the first college to establish a personal computer requirement, the core curriculum could not accommodate additional computing courses. Therefore, computing was integrated throughout the entire…
... Number: 12-014. Applicant: California Institute of Technology, Pasadena, CA 91125. Instrument: Nova Nano... DEPARTMENT OF COMMERCE International Trade Administration Stevens Institute of Technology, et al... Constitution Avenue NW, Washington, DC Docket Number: 12-008. Applicant: Stevens Institute of Technology...
Full Text Available Acyclovir, anti - viral drug rarely causes Stevens - Johnson syndrome (SJS. Steven Johnson syndrome is a rare, life threatening disorder characterized by skin condition with bullous formation, ocular lesions, genital and anal lesions/ulcers. It’s usually a reaction to a medication or an infection. Often Steven Johnson syndrome begins with flu - like symptoms followed by a painful red or purplish rash that spreads and blisters. Then the top layer of the affected skin dies and sheds. This case report is about a 40 year old male patient who came to the medicine out p atient department with blisters on palms and soles and characteristic hemorrhagic crusting of mouth and lips. Initial diagnosis of Steven Johnson Syndrome was made and treated with steroids. Eruption usually healed without sequelae
Pauline Joy F. Santos
Full Text Available History of present illness: 72-year-old female with a history of hypertension and rheumatoid arthritis who presented to the emergency department (ED with a chief complaint of rash for the past ten days. Her primary care provider prescribed azithromycin two weeks prior to her arrival in the ED for a sore throat. The rash started on her bilateral lower extremities and spread cephalad. She also noted a prodrome of subjective fevers and malaise. Significant findings: At presentation to the ED, a macular rash was notable on all four extremities, trunk and face, and involved mucous membranes of the oropharynx and vaginal introitus. The rash was painful, erythematous and purpuric with targetoid lesions. There were also multiple areas of sloughing and desquamation with a positive Nikolsky sign. Denudement totaled approximately 2% of total body surface area. Discussion: Stevens-Johnson syndrome (SJS is a dermatolobullous disease on a spectrum of disease that includes toxic epidermal necrolysis (TEN. The distinguishing characteristic is percentage of body surface area (BSA involvement, with SJS involving less than 10% of BSA while TEN involves greater than 30% of BSA.1 Medications are the most common cause of SJS with sulfonamides and penicillin being the most likely culprits (26%. Other medications include acetaminophen, carbamazepine, non-steroidal anti-inflammatory drugs (NSAIDs, phenytoin, and corticosteroids. Malignancy and immunosuppression are both risk factors for SJS.2 Onset of symptoms typically occurs four to twenty-eight days after starting a new medication, and typically presents with a prodrome that may include fever, upper respiratory infection symptoms, headache, and malaise.2 The rash is usually an atypical target lesion that first appears centrally.3 The rash may be painful and almost always has mucous membrane involvement. A positive Nikolsky sign is also seen, which is the sloughing off of epidermis when a shearing force is applied.1
Inglise disainerist James Stevensist (sünd. 1962) ja tema tegevusest. J. Stevens 2000. a. Amsterdamis tehtud intervjuus koos Jon Bainsi ja Kim Bulliga 1995. a. Londonis avatud Interneti-agentuurist Obsolete, 1996-2000 tegutsenud Interneti-kohvikust Backspace, mittekommertsiaalse juhtmeteta nerworki Consume.net rajamisest Londonis
Steven Hawking is seen meeting with CERN's Director-General, Robert Aymar. Hawking visited CERN between 24 September and 1 October 2006. During his stay he gave two lectures and toured the LHC, which may provide insights into Hawking's most famous area of study, black holes.
ber and Reynolds number which are helpful in appreciating the Classics article by Vogel repro- duced in this issue. Steven Vogel was an eminent American biophysicist. He made seminal contributions which resulted in more than. 100 journal articles and 10 very insightful books that cover a variety of topic in biomechanics.
National Oceanic and Atmospheric Administration, Department of Commerce — The Magnuson-Stevens Fishery Conservation and Management Act (MSA) is the primary law governing marine fisheries management in U.S. federal waters. It has since been...
Luo, Fang Lin
DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.
Howell, W.R.; Knight, A.L.; Scruggs, H.J.
We have reported a case of classic Stevens-Johnson syndrome in association with treatment using a cobalt radiation therapy unit. Previous reports of such an association have been extremely rare. At the time of the reaction, the patient's only medications were methyldopa and trichlormethiazide. Other drugs in the thiazide class have been associated with such a reaction. We feel this is an unlikely association in our patient, however, because she had been on trichlormethiazide for a number of years. This report suggests the role of radiotherapy as a rare cause of Stevens-Johnson syndrome. 14 references
Howell, W.R.; Knight, A.L.; Scruggs, H.J. (Roanoke Memorial Hospitals, VA (USA))
We have reported a case of classic Stevens-Johnson syndrome in association with treatment using a cobalt radiation therapy unit. Previous reports of such an association have been extremely rare. At the time of the reaction, the patient's only medications were methyldopa and trichlormethiazide. Other drugs in the thiazide class have been associated with such a reaction. We feel this is an unlikely association in our patient, however, because she had been on trichlormethiazide for a number of years. This report suggests the role of radiotherapy as a rare cause of Stevens-Johnson syndrome. 14 references.
Steven Spielbergi raskused J.M. Barrie "Peeter Paani" ekraniseerimisel, tulemuseks mängufilm "Hook" : Ameerika Ühendriigid 1991. Järgneb 16. aug. 2004, lk. 38 pealkirja all "Rahulolematu Steven Spielberg"
Caraban Gonzalez, Noemi
Steven William Moffat, OBE is a Scottish television writer and producer, known for his work as showrunner, writer and producer of the British television series Doctor Who and Sherlock. Susan "Sue" Nicola Vertue is an English television producer, mainly of comedy shows, including Mr. Bean and Coupling.
Kaur-Knudsen, Diljit; Zachariae, Claus; Thomsen, Simon Francis
Stevens-Johnson syndrome and toxic epidermal necrolysis are acute mucocutaneous diseases primarily due to drug intake. The diseases are characterised by the separation of epidermis from dermis which can be life-threatening. Mortality is often caused by sepsis and multiple organ failure. The most...
The presented bidirectional DC/DC converter design concept is a further development of an already existing converter used for low battery voltage operation.For low battery voltage operation a high efficient low parts count DC/DC converter was developed, and used in a satellite for the battery charge and battery discharge function.The converter consists in a bidirectional, non regulating DC/DC converter connected to a discharge regulating Buck converter and a charge regulating Buck converter.The Bidirectional non regulating DC/DC converter performs with relatively high efficiency even at relatively high currents, which here means up to 35Amps.This performance was obtained through the use of power MOSFET's with on- resistances of only a few mille Ohms connected to a special transformer allowing paralleling several transistor stages on the low voltage side of the transformer. The design is patent protected. Synchronous rectification leads to high efficiency at the low battery voltages considered, which was in the range 2,7- 4,3 Volt DC.The converter performs with low switching losses as zero voltage zero current switching is implemented in all switching positions of the converter.Now, the drive power needed, to switch a relatively large number of low Ohm , hence high drive capacitance, power MOSFET's using conventional drive techniques would limit the overall conversion efficiency.Therefore a resonant drive consuming considerable less power than a conventional drive circuit was implemented in the converter.To the originally built and patent protected bidirectional non regulating DC/DC converter, is added the functionality of regulation.Hereby the need for additional converter stages in form of a Charge Buck regulator and a Discharge Buck regulator is eliminated.The bidirectional DC/DC converter can be used in connection with batteries, motors, etc, where the bidirectional feature, simple design and high performance may be useful.
Baby, S; Doris, S
Steven Johnson's Syndrome is a serious systemic disorder in which there are vesicobullous lesions involving the skin and mucous membranes. It can result as an immune response to an antigen or as a drug reaction. Most often it is considered as an allergic reaction. It is a self-limiting condition which responds to immediate management or may result in fluid loss, sepsis and death.
Mclyman, C. W.
Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.
Jha, Praveen; Himanshu, D; Jain, Nirdesh; Singh, Ajay Kumar
Imatinib mesylate is a tyrosine kinase inhibitor used widely as the first-line treatment for chronic myeloid leukaemia (CML). The side-effect profile of this drug includes fluid retention, muscle cramps, diarrhoea, myelosuppression and skin rashes. Of these, rashes of the type maculo-papular eruptions and oedema developed most commonly. The cutaneous adverse reactions other than maculo-papular eruptions are rare with imatinib. Severe and life-threatening cutaneous reactions can occur in 5% cases. Here, the author reports a case of newly diagnosed CML that developed Steven-Johnsons syndrome due to imatinib therapy. Patient responded and discharged successfully on withdrawal of the culminating drug.
Full Text Available Stevens Johnson Syndrome (SJS is a life threatening mucocutaneous skin disease that mostlydeveloped after using some drug. SJS mostly appear between 2-4th decades. Mucocutaneouslesions were seen between 1-14 days of drug intake. And these lesions spread diffusely all aroundthe body. First treatment choice is the stopping of drug that cause SJS and giving supportingtreatment. After understanding of underlying cytotoxic and immunological mechanism of SJS,new treatment approaches were developed and mortality of disease was reduced. We hereinreport a short review of drug induced SJS and its treatment.
Castana, O.; Rempelos, G.; Anagiotos, G.; Apostolopoulou, C.; Dimitrouli, A.; Alexakis, D.
Summary The Stevens-Johnson syndrome has the appearance of a partial-thickness burn that may lead to a 100% loss of epidermis, requiring the same resuscitation as a severe burn. A 38-yr-old male patient was admitted to the neurosurgery department of the Evangelismos General Hospital in Athens, where immediately after administration of an antiepileptic drug he developed sloughing of total epidermis, high fever, and the clinical picture of a severe burn patient. He was treated as a burn patient with massive cutaneous injuries and the concomitant systemic effects. Fluid resuscitation was important and the Parkland formula was used, as in a burn patient. Steroid medications were initially administered. Systemic antibiotics were discontinued after signs of sepsis and documented infection had been overcome. Improved treatment techniques and critical burn care have decreased mortality and morbidity in cases of the Stevens-Johnson syndrome. Prompt recognition of the disease and cure of the patient by the appropriate staff of the burns centre contribute to the successful treatment of such patients. PMID:21991171
Shivamurthy, Raghu Prasada M; Kallappa, Ravindra; Reddy, Shashikala G H; Rangappa, Druva Kumar B
Steven-Johnson syndrome may be considered as a cytotoxic immune reaction to drugs, infections etc. This is a case report of Steven-Johnson syndrome due to an ayurvedic preparation which was used in the treatment of mental retardation in a young girl.
Shivamurthy, Raghu Prasada M.; Kallappa, Ravindra; Reddy, Shashikala G. H.; Rangappa, Druva Kumar B.
Steven?Johnson syndrome may be considered as a cytotoxic immune reaction to drugs, infections etc. This is a case report of Steven?Johnson syndrome due to an ayurvedic preparation which was used in the treatment of mental retardation in a young girl.
Stevens-Johnson Syndrome is an uncommon life threatening disease generally induced by drugs. Antibiotics, mainly sulphonamides, are the most involved drugs in Stevens-Johnson Syndrome in children. Co-amoxiclav is a well tolerated antibiotic. It has never been reported to cause, lonely this syndrome in children.
Blanco, N; Gutiérrez, B; Valls, I; Puertas, D; Martín, C; Rivera, M; Hernández, Á; Torrelo, A
Stevens-Johnson syndrome and toxic epidermal necrolysis are two serious immune diseases within the context of bullous mucocutaneous syndrome. These have varying degrees of involvement of the skin and usually at least two mucous membranes. Three clinical cases are presented, two of them with significant ophthalmological sequelae, who had received drug treatment as a possible trigger, and another milder clinical case caused by Mycoplasma pneumoniae. The ophthalmologist plays a crucial role in the outcome and eye care of the patient in order to try to avoid the appearance of sequelae and subsequent loss of vision. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.
Bellakhal, S; Ben Kaab, B; Teyeb, Z; Souissi, A; Derbel, F; Douggui, M-H
Stevens-Johnson syndrome and toxic epidermal necrolysis are life-threatening dermatological conditions. Their most common cause is medication. However, in a small proportion of patients these dermatological conditions could be the first presentation of systemic lupus erythematosus. We now describe a 34-year-old patient who presented with manifestations of Stevens-Johnson as a first feature of systemic lupus erythematosus. Systemic lupus erythematosus reveled by Stevens-Johnson syndrome has been infrequently reviewed in the previous literature. This diagnosis should be considered when cutaneous adverse drug reactions occur without clear drug causality. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Prabhu, Varsha A.; Doddapaneni, Sahiti; Thunga, Girish; Thiyagu, Rajakannan; Prabhu, M. Mukyaprana; Naha, Kushal
Steven Johnson syndrome (SJS) is a rare drug induced mucocutaneous reaction. Here, we present an elaborate report of a 28-year-old female patient who developed Phenytoin induced SJS, which was exacerbated by cefepime.
Prabhu, Varsha A; Doddapaneni, Sahiti; Thunga, Girish; Thiyagu, Rajakannan; Prabhu, M Mukyaprana; Naha, Kushal
Steven Johnson syndrome (SJS) is a rare drug induced mucocutaneous reaction. Here, we present an elaborate report of a 28-year-old female patient who developed Phenytoin induced SJS, which was exacerbated by cefepime.
Steven J. Lindauer
Full Text Available There are so many compliments to Dr. Steven Lindauer that is hard for one to figure where to start from… Well, travelling backwards in time, all the way to the year 2000, I went to Virginia to study English at Virginia Commonwealth University (VCU, in Richmond, Virginia, USA. During my daily walks to the English school, I used to pass by the School of Dentistry, where the Department of Orthodontics was. That was the place where my very first “contact” with the VCU happened. In 2015, 15 years later, I had the pleasure to go back to the VCU and spend two days with Dr. Steven Lindauer. I have to confess that I was anxious and nervous to get to know not only the Chair of the Department, but also the Editor-in-chief of “The Angle Orthodontist”. Since the very first moment I could experience how incredibly positive and pro-active the environment within the Department was. Staff members, Residents and Faculty members used to work very gladly and in perfect synergy. After a quick chat with the residents, I heard from them: “Dr. Lindauer is an unprecedented human being! Besides a brilliant Professor, Researcher and Administrator, he is like a father to all of us!” Besides this touching testimony, I also heard flattering compliments from workmates to the great friend, leader and partner Dr. Lindauer was. Here goes some food for thought, though. Unfortunately, the leader is often compelled to resort to unpopular measures in order to enforce compliance. Dr Lindauer is the living proof that a boss, a leader, can be a light, humble, friendly and highly charismatic human being. In 2016, I was given a second chance to enjoy Dr. Lindauer’s company when he visited Brazil as a guest lecturer in Salvador, at the Federal University of Bahia and the Brazilian Association of Orthodontics (Bahia Chapter. I noticed, once again, that besides an excellent lecturer and careful clinician, he mastered orthodontic mechanics very proficiently. And needless to
Smart, Laura S; Prochaska, James O
Presents an obituary for Mollie Stevens Smart (1916-2012). Mollie attended the University of Toronto, from which she graduated with honors in psychology at age 20 in 1936. She studied and worked at the Merrill-Palmer Institute in Detroit, earning a master's degree in child development from the University of Michigan in 1941. She earned her doctorate in educational psychology at the University of Delhi in 1969. An author, teacher, and mentor, Mollie won Fulbright research grants to India and New Zealand and lectured in the United States, India, New Zealand, Canada, and China. She wrote 26 books, most co-authored with her husband, Russell (Rus) C. Smart. Beginning in the 1940s, when Freudian theory had a strong grip on the popular view of child development, the books placed the developing child in the context of family and community systems. The Smarts' best-selling college textbook Children: Development and Relationships (1967, 1973, 1977, 1982) was based on the theories of Erik Erikson and Jean Piaget. Mollie was a member of the American Psychological Association throughout her professional career and held memberships also in the Society for Research in Child Development, the National Council on Family Relations, the Groves Conference on Marriage and Family, and the Fulbright Association. After moving to Ridgefield, Washington, in 2003 with her daughter Ellen following Rus's death in 1996, she applied her great knowledge to advise a community-based organization that serves the needs of new babies born into destitute families. Mollie died at home in Ridgefield on October 22, 2012, at age 96. © 2013 APA, all rights reserved.
Ma, Xiao; Xiang, Ran; Meng, Xiaoli; Qin, Limin; Wu, Ying; Tain, Lei; Jiang, Yanming; Huang, Yifei; Wang, Liqing
To evaluate the efficacy and safety of Moscow Eye Microsurgery Complex in Russia (MICOF) keratoprosthesis (KPro) implantation in patients with Stevens-Johnson syndrome (SJS). This was a retrospective case series. Fourteen eyes of 13 patients with SJS underwent KPro implantation at the Chinese People's Liberation Army General Hospital between April 1, 2000, and December 24, 2014. The visual outcome, KPro retention rate, and incidence of postoperative complications and their management were recorded and investigated. The mean age and follow-up duration were 61.5 ± 17.3 years (range: 27-87 yrs) and 62 ± 39.1 months (range: 13-144 mo). Thirteen eyes (92.9%) achieved a best-corrected visual acuity of 20/200 or better, and 8 eyes (57.1%) achieved a best-corrected visual acuity of 20/40 or better after surgery. However, 71.4% (10/14) experienced visual decline because of different postoperative complications. Common complications included corneal melting, glaucoma, vitritis, superficial tissue overgrowth, and retroprosthetic membrane, and the incidence of these complications was 71.4%, 28.6%, 35.7%, 14.3%, and 28.6%, respectively. After repair and autoauricular cartilage reinforcement, all cases had stable anatomical retention at the last visit. The MICOF KPro improved vision of patients with SJS, but lifelong surveillance is necessitated because of a high rate of postoperative complications. Corneal melting was the main reason for KPro failure. Infectious endophthalmitis and glaucoma were the main risk factors for visual loss.
Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance
Lukemire, Alan T.
Dc-to-dc power-converter circuits called "forback" resemble circuits of standard configurations called "forward", "flyback", and "Cuk". Circuit employs minor modifications to existing topologies, combines advantages, while eliminating disadvantages, of older circuits.
Ramasamy, Anantharaman; Patel, Chiraush; Conlon, Christopher
Steven-Johnson syndrome is a common condition characterised by erythematous target lesions on the skin and involvement of the oral mucosa, genitals and conjunctivae. It has been documented as one of the extra-pulmonary manifestations of Mycoplasma pneumoniae infection. Recently, there has been several documentation of an incomplete presentation of this syndrome - without the typical rash but with mucosal, conjunctival and genital involvement. Our case illustrates that the incomplete Steven-Johnson syndrome may present with oral mucosal and conjunctival involvement alone without skin or genital involvement. This important clinical diagnosis should not be missed due to its atypical presentation. Treatment of Steven-Johnson syndrome remains supportive along with treating the underlying infection if recognised.
Straight, J. W. (James W.); Osborn, M. A. (Michael A.); Coulter, W. L. (William L.); Mang, J. T. (Joseph T.); Anderson, M. C. (Mark C.); Idar, D. J. (Deanne J.)
Low-velocity mechanical impact leading to unintentional reaction is of concern in accident scenarios involving the handling, transport, and storage of high explosives (HE). These have been investigated using different experimental techniques, from small- to large-scale, including, but not limited to the drop weight impact, Taylor anvil impact, Susan,1 and more recently, the Steven and Modified Steven tests.2-8 Ideally, the data will be used to further advance 3-D finite element analysis predictive capability with improved bulk constitutive HE models for the assessment of HE response to mechanical insult. Our overall objectives for these experiments were to (1) evaluate the HE reaction threshold behavior for two different lots of X-0557, and (2) characterize the degree of reaction violence relative to a detonation. This report summarizes our single impact test results on the two different lots of X-0557 in Modified Steven targets.
Marco-Del Río, José; Domingo-Chiva, Esther; Cuesta-Montero, Pablo; Valladolid-Walsh, Ana; García-Martínez, Eva María
We describe a recent case of Stevens-Johnson Syndrome. A 49-year-old man was admitted to the Intensive Care Unit of an Anaesthesia and Resuscitation Department because of a Fournier gangrene that derived in a sepsis, ventilator-associated pneumonia, and renal failure. He was under treatment with cefepime and suffered a generalized status epilepticus, so started treatment with phenytoin. The next day he developed a "maculous cutaneous eruption in trunk and lower limbs" compatible with a Stevens-Johnson Syndrome. Stevens-Johnson Syndrome is a very severe and potentially fatal multiorganic disease, especially when present in critically ill patients, with a strong drug-related etiology, especially with antiepileptic drugs.
Wang, Qingsong; Cheng, Ming; Jiang, Yunlei
The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi-directio......The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi...... and/or constant discharging for batteries is adopted and four operating modes are analyzed as charging-positive, charging-negative, discharging-positive and discharging-negative modes. An additional mechanism for fast charging or fast discharging is also designed to secure normal operation...... of batteries. With the proposed DCES, the power fluctuations due to intermittent RESs can be passed to non-critical loads (NCLs) and batteries while power on critical loads (CLs) is kept stable. This is possibly the first attempt to design a DCES with only DC/DC converters. The performances of the proposed...
Numerical tables of products of tensor (Racah) operators, Rl,m(J), and Stevens operators Olm(J), working within a J-multiplet are given as a function of X=J(J+1). Examples of the use of the tables, such as the calculation of commutation relations and thermal averages are given.......Numerical tables of products of tensor (Racah) operators, Rl,m(J), and Stevens operators Olm(J), working within a J-multiplet are given as a function of X=J(J+1). Examples of the use of the tables, such as the calculation of commutation relations and thermal averages are given....
Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 5. Steven Vogel and His Theory of Comparative Biomechanics. Book Review Volume 21 Issue 5 May 2016 pp 467-471. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/021/05/0467-0471. Abstract ...
implicated drugs are nevirapine and co-trimoxazole.3. SJS and TEN rarely occur without any prior drug use, and in the .... bacterial infection due to low saliva production and ulceration with fibrinous exudative inflammation which .... PH, Bouchard CS, Dart JK, Gai X, Gomes JA. Stevens-Johnson Syndrome/. Toxic Epidermal ...
Laasik, Andres, 1960-2016
Oscari võitnud dokumentaalfilm "Need viimased päevad" ("The Last Days") : režissöör James Moll : Tootja Steven Spielbergi loodud Survivors of the Shoah Visual History Foundation : Ameerika Ühendriigid 1999. Filmi esitlusest Eesti Vabariigi Välisministeeriumis
Aug 26, 2016 ... Steven Vogel was a pinoneer in applying principles of mechanics to diverse living systems. This article first provides a brief overview of his career. It then reviews the concepts of P´eclet number and Reynolds number which are helpful in appreciating the Classics article by Vogel reproduced in this issue.
Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 5. Steven Vogel and His Theory of Comparative Biomechanics. Book Review Volume 21 Issue 5 May 2016 pp 467-471. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/021/05/0467-0471. Abstract ...
Clayson, D E
Although major firms do not publish their pricing and packaging strategies, an analysis of 83 pairs of boxes of breakfast cereals using Stevens' Law showed that firms price their products on the perception of size rather than by actual size. By contrast, laundry detergents are priced by actual weight and volume.
Mustafa, N; Periyasamy, P; Kamaruddin, N
Cushing's syndrome is a pathological condition associated with excessive cortisol production, the commonest etiology being Cushing's disease. Corticosteroids in high doses have been used in the management of Steven Johnson Syndrome (SJS) with favourable outcome. We describe a patient with Cushing's disease who developed SJS, one week after taking sperulina a product from sea-weed while waiting for transphenoidal surgery.
Background. Stevens-Johnson syndrome (SJS) is an acute life-threatening condition often elicited by drugs. The government's indecisiveness in deciding to stop the use of nevirapine (NVP) in HIV-infected pregnant women owing to the increase of SJS among this population group in South Africa prompted this investigation ...
Steven Vogel was a pinoneer in applying principles of mechanics to diverse living systems. This article first provides a brief overview of his career. It then reviews the concepts of P´eclet number and Reynolds number which are helpful in appreciating the Classics article by Vogel reproduced in this issue.
Stevens-Johnson syndrome (SJS) is a form of toxic epidermal necrolysis (TEN) a rare but life-threatening hypersensitivity reactions that affect the skin and mucous membranes. The most common triggers are drugs, but they can also be triggered by infections. Granulysin has been recently identified as the major molecule ...
Berry, John N., III
This article profiles Steven L. MacCall, winner of "Library Journal's" 2010 Teaching Award. An associate professor at the School of Library and Information Studies (SLIS) at the University of Alabama, Tuscaloosa, MacCall was nominated by Kathie Popadin, known as "Kpop" to the members of her cohort in the online MLIS program at SLIS. Sixteen of…
Neuropsychology professor Steven Petersen describes what scientists are finding out about brain development, synaptic growth and wiring, intentional and incidental learning, the role of emotion in learning, and declarative and implicit memory systems. Neuroscience has only the broadest outline of principles to offer today's educators. (MLH)
Ivo Cavalcanti Pita Neto
Full Text Available Among the severe reactions to medications, immune-mediated Mucocutaneous Disorders are widely represented. Steven-Johnson’s syndrome, or great multiform erythema, appears as a systemic disturbance, involving the skin and mucous membranes, and is related to several factors, such as, viral or bacterial infections and particularly the administration of medicines, in general painkillers and antibiotics. The objective of this article is report the onset of ulcerative vesicle –blister lesions in the regions of the lips, gums, tongue and genital mucosa membrane in a 26 year-old patient, a leukoderm man, being treated with sulfamethoxazole trimethoprim for a respiratory infection, after being diagnosed as having the Steven-Johnson syndrome. SSJ1 558187121279.
Khawaja, Ali; Shahab, Ahmed; Hussain, Syed Ather
Steven Johnson Syndrome and Toxic Epidermal Necrolysis are rare but severe form of hypersensitivity inflammatory reactions to multiple offending agents including drugs. Acetaminophen is extensively used due to its analgesic and anti-pyretic properties. It is rendered to be relatively safe, with hepatotoxicity considered to be the major adverse effect. However, very few cases of Steven Johnson Syndrome and Toxic Epidermal Necrolysis have been reported with acetaminophen usage in the past. We present the case of a 40 years old lady who developed an overlap of the two condition after taking several doses of acetaminophen for fever. She presented with widespread maculopapular rash, stinging in the eyes, oral mucosal ulcerations and high grade fever. She was successfully treated with corticosteroid therapy along with the supportive treatment. This case addresses the fact, that severe hypersensitivity reactions can occur with acetaminophen which can be potentially life threatening.
Sri ram Anne; Sreya Kosanam; Lakshmi Prasanthi N
Toxic epidermal necrolysis (TEN) and Stevens Johnson Syndrome (SJS) are severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes. They are characterized by mucocutaneous tenderness and typically hemorrhagic erosions, erythema and more or less severe epidermal detachment presenting as blisters and areas of denuded skin. Drugs are assumed or identified as the main cause of SJS/TEN in most cases, but Mycoplasma pneumoniae and Herpes simplex virus infection...
... Model DC-10-10, DC- 10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F.... Applicability (c) This AD applies to all The Boeing Company Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10- 40, DC-10-40F, MD-10-10F, MD-10-30F, MD-11, and MD-11F airplanes...
Frequently, it is postulated that the results of a ratio production (resp., ratio estimation) experiment can be summarized by Stevens' power law psi=alphaphi(beta). In the present article, it is argued that the power law parameters depend, among other things, on the standard stimulus presented as a reference point, and the physical stimulus scale by which the physical intensities are measured. To formalize this idea, a new formulation of Stevens' power law is presented. We show that the exponent in Stevens' power law can only be interpreted in a meaningful way if the stimulus scale is a ratio scale. Furthermore, we present empirically testable axioms (termed invertibility and weak multiplicativity) which are both necessary and sufficient for the power law exponent to be invariant under changes of the standard stimulus. Finally, invertibility and weak multiplicativity are evaluated in a ratio production experiment. Ten participants were required to adjust the area of variable circles to prescribed ratio production factors. Both axioms are violated for all participants. The results cast doubts on the well-established practice of comparing power law exponents across different modalities.
Aroke, Desmond; Tchouakam, Diego Nitcheu; Awungia, Alexis Tazinya; Mapoh, Sylvester Yari; Ngassa, Stewart Ndutard; Kadia, Benjamin Momo
Stevens-Johnson syndrome is one of the manifestations of mucocutaneous adverse drug reactions. Although antimicrobials are responsible for greater than 50% of these adverse drug reactions, there is no documented case implicating ivermectin as the culprit. A 38 year old adult Cameroonian male presented to our health facility with facial rash, painful oral sores, black eschars on lips and red tearing eyes 3 days following ingestion of ivermectin received during a nationwide anti-filarial campaign. He had no known chronic illness, no known allergies and was not on any medications prior to the campaign. Physical examination revealed discharging erythematous eyes, crusted and blister-like lesions with cracks on his lips and oral mucosa. His laboratory tests were unremarkable but for a positive Human Immunodeficiency Virus (HIV) test. A diagnosis of Ivermectin induced Stevens-Johnson syndrome in a newly diagnosed HIV patient was made. The patient was managed with supportive therapy and the evolution thereafter was favourable. Stevens-Johnson syndrome is a potential side effect of ivermectin and susceptibility to this adverse effect may be increased in HIV infection.
Reefman, D.; Roozeboom, F.; Notten, P.H.L.; Klootwijk, J.H.
An electronic device is provided which comprises a DC-DC converter. The DC-DC converter comprises at least one solid-state rechargeable battery (B1, B2) for storing energy for the DC-DC conversion and an output capacitor (C2).
Campbell, Jeremy B; Newson, Steve
Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.
...-Stevens Fishery Conservation and Management Act Provisions; Fishing Vessel, Fishing Facility and... the Fisheries Finance Program's programmatic regulations. The proposed rule was published with an...
Full Text Available Wallace Stevens’s “The Man with the Blue Guitar” (1937 is widely recognized as one of the most important and influential poems of the 20th century. Inspired by Picasso’s painting The Old Guitarist, the poem in turn inspired Michael Tippett’s sonata for solo guitar, “The Blue Guitar” (Tippett 1983 and David Hockney’s The Blue Guitar: Etchings by David Hockney who was inspired by Wallace Stevens who was inspired by Pablo Picasso (Hockney and Stevens 1977. Central to “The Man with the Blue Guitar,” the metaphor of the musical instrument as a transformational symbol of the imagination is common in Stevens’s poems. The structure of “The Man with the Blue Guitar,” according to J. Hillis Miller, is the structure of stream-of-consciousness. Stevens’s poem creates what has been called “the deconstructed moment in modern poetry,” “an attempt to project a spatialized time that can be viewed from the privileged position of a timeless, static moment capable of encompassing a life at a glance” (Jackson 1982. This consciousness, which Derrida refers to as the “trace,” Stevens calls “the evasive movement of language.” The trace is the perception of the absence of meaning after the word or perception has passed, the glimpse of a hidden meaning that immediately vanishes. Stevens’s poem influenced not only other poets, artists and composers; references to and echoes of his ideas and techniques can be seen in popular music and culture well into the 21st century.
Kouotou, E-A; Defo, D; Zoung-Kanyi Bissek, A-C; Ndjitoyap Ndam, E-C; Beylot-Barry, M
A cutaneous adverse drug reaction is a skin eruption secondary to the intake of a drug, be it prescribed by a medical practitioner or taken as auto-medication for a given ailment. In this document we present an original case of Stevens-Johnson's syndrome secondary to the ingestion of gunpowder. A 22-year-old female student was hospitalised for diffuse and painful skin eruptions for the previous three days. She had complained six days earlier of an allergic reaction to pineapples, an allergy she had presented for quite a long time. In an attempt to remedy the situation, her mother made her drink a solution made of gunpowder bought at a market mixed with some water. On the third day of this "treatment", the patient noticed eruptions on her skin. These were initially maculopapular, later becoming erosive, and she had a mild fever. Later, a variety of eruptions appeared on the skin, from hyper-pigmented macular papules to blisters and erosive lesions with no Nicolsky sign. These lesions spared the palms of the hands and the soles of the feet. The mucosa of the conjunctivae, nose, buccal cavity, vulva, vagina and anus were severely affected. This clinical presentation was typical of Steven Johnson syndrome. The patient had stopped taking the "treatment" when she noticed the first lesions. On therapy, the outcome was favourable, except for severe complications such as synechiae with diffuse dyschromia. To the best of our knowledge this is the first time gunpowder has been incriminated in Stevens-Johnson's syndrome. Copyright © 2012 Elsevier Masson SAS. All rights reserved.
Emberger, Michael; Lechner, Arno Michael; Zelger, Bernhard
To the best of our knowledge, Stevens-Johnson syndrome (SJS) has not been reported previously as an adverse reaction to Malarone, which is a combination of atovaquone and proguanil hydrochloride used for antimalarial prophylaxis and therapy. We describe a 65-year-old patient who had SJS with typical clinical and histopathological findings associated with the use of Malarone prophylaxis for malaria. This report should alert physicians to this severe cutaneous reaction, and Malarone should be added to the list of drugs that can potentially cause SJS.
Ma, Li; Du, Xusheng; Dong, Yu; Peng, Lirong; Han, Xiaonian; Lyu, Jianhua; Bai, Hehe
We describe the first case of Stevens-Johnson syndrome (SJS) occurring 8 days after the first dose of a three-dose rabies vaccination series. She had no history of vaccine-related rash or other adverse drug reactions, nor had she received any other drug therapy. The temporal relationship between the development of SJS and the vaccination suggests that the rabies vaccination probably was the causal agent. This case serves as a warning of a distinct cutaneous reaction of rabies vaccination. © 2018 The British Pharmacological Society.
Full Text Available Cataract surgery with Stevens-Johnson syndrome (S-J is associated with a high incidence of complications and can worsen the primary disease. We report a case of phacoemulsification of a total, white cataract barely visible through the vascularized, keratinized cornea in the only seeing eye of a patient with S-J syndrome. We describe the intra-operative difficulties encountered during phacoemulsification and the surgical tools and techniques employed to overcome the surgical difficulties. The postoperative course was uneventful and the patient regained useful, navigational vision.
... Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10-40, and DC-10-40F Airplanes AGENCY...-10F, DC-10-30, DC-10-30F (KDC-10), DC-10-40, and DC-10- 40F airplanes, certificated in any category...
Ahmed, Y I; Azeem, S; Khan, O; Majid, T H; Ahmed, D; Amin, A; Mahmood, A; Hameed, K
A pre-tested questionnaire-based, retrospective study to highlight the causative factors, mode of presentation, complications and outcome of patients with Stevens Johnson syndrome. Aga Khan University Hospital over a 10 year period. All case records with a diagnosis of Steven Johnson Syndrome in the period 1990 to 2000 were retrospectively reviewed. Data was retrieved on a comprehensive questionnaire. The demographic variatbles and drugs taken within the previous 21 days were noted. Date analysis was done by Epi-Info Version 6.0. Of the 101 studied patient files, the most common offender was found to be the Penicillins as a group and Sulfadoxine-Pyrimethamine (Fansidar) when considering all drugs individually. Most common complications included electrolyte disturbances (13.9%) and congestive heart failure (6.9%). Mortality rate was high at 10.1%. SJS was found to be a rare condition but having a mortality rate of 10.1%. As it can be induced by a large number of drugs, caution should be practiced while prescribing.
Bocquet, H; Farmer, M; Bressieux, J M; Barzegar, C; Jullien, M; Soto, B; Roujeau, J C; Revuz, J
Lamotrigine is a new anticonvulsant belonging to the triazine family. Several cases of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been described in patients taking this drug. We report 2 cases in children attending the same hospital. Two children, aged 9 and 13 years, developed SJS and TEN respectively, 3 and 28 days after lamotrigine was added to their usual anticonvulsant regimen. In both cases, outcome was favorable despite major decline in psychomotor capacity in one. In the first case, chronological attributability was plausible for lamotrigine and doubtful for sodium valproate, clonazepam and hydrocortisone. In the second case, chronological attributability was probable for amoxicillin, plausible for lamotrigine and doubtful for sodium valproate, but the numerous previous absorptions of amoxicillin made lamotrigine more suspect. The risk of Steven-Johnson syndrome and toxic epidermal necrolysis is high with lamotrigine with an estimated frequency of 1/1000. This risk is probably higher than with other anticonvulsants. Associating lamotrigine with sodium valproate increases the frequency of adverse skin reactions.
The Systems Engineering Program at Stevens Institute of Technology has developed the Open Academic Model (OAM) to guide its strategic planning and operations since its founding in 2001. Guided by OAM, the Stevens Systems Engineering Program (SSEP) has grown from inception in 2001 into one of the largest in the US. The main objectives of the…
Hopwood, J. E.
A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.
A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.
... Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10-40, and DC-10-40F Airplanes AGENCY... propose to adopt a new airworthiness directive (AD) for certain Model DC-10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10- 40, and DC-10-40F airplanes. This proposed AD would require installing a support...
Misra, B.N.; Mohapatra, P.K.; Roy, D.
Very rarely Stevens Johnson Syndrome develops following drug therapy particularly Lithium and Valproate. Worldwide, the reports regarding Lithium and Valproate induced Stevens Johnson Syndrome are very few. Here, we present two cases of Stevens Johnson Syndrome following treatment with Lithium and Valproate for Mood Disorder.
Skutt, Glenn; Sable, Dan; Leslie, Leonard; Graham, Shawn
A document discusses power converters suitable for space use that meet the DSCC MIL-PRF-38534 Appendix G radiation hardness level P classification. A method for qualifying commercially produced electronic parts for DC-DC converters per the Defense Supply Center Columbus (DSCC) radiation hardened assurance requirements was developed. Development and compliance testing of standard hybrid converters suitable for space use were completed for missions with total dose radiation requirements of up to 30 kRad. This innovation provides the same overall performance as standard hybrid converters, but includes assurance of radiation- tolerant design through components and design compliance testing. This availability of design-certified radiation-tolerant converters can significantly reduce total cost and delivery time for power converters for space applications that fit the appropriate DSCC classification (30 kRad).
Lukemire, Alan T.
A pulse-width modulated DC-to-DC power converter including a first inductor, i.e. a transformer or an equivalent fixed inductor equal to the inductance of the secondary winding of the transformer, coupled across a source of DC input voltage via a transistor switch which is rendered alternately conductive (ON) and nonconductive (OFF) in accordance with a signal from a feedback control circuit is described. A first capacitor capacitively couples one side of the first inductor to a second inductor which is connected to a second capacitor which is coupled to the other side of the first inductor. A circuit load shunts the second capacitor. A semiconductor diode is additionally coupled from a common circuit connection between the first capacitor and the second inductor to the other side of the first inductor. A current sense transformer generating a current feedback signal for the switch control circuit is directly coupled in series with the other side of the first inductor so that the first capacitor, the second inductor and the current sense transformer are connected in series through the first inductor. The inductance values of the first and second inductors, moreover, are made identical. Such a converter topology results in a simultaneous voltsecond balance in the first inductance and ampere-second balance in the current sense transformer.
Yang, C-Y; Chen, C-H; Wang, H-Y; Hsiao, H-L; Hsiao, Y-H; Chung, W-H
Strontium ranelate is a relatively new medication with good safety profile for the treatment of postmenopausal osteoporosis. However, severe cutaneous adverse drug reactions have been reported, such as drug rash with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). We report the case of a 70-year-old woman who developed multiple itching erythematous macules and plaques about 1 month after beginning strontium ranelate medication. The cutaneous lesions progressed over the entire body with severe oral and ocular mucosa involvement. Probable mild SJS was diagnosed, compatible with the pathology findings, and strontium ranelate was discontinued immediately. Systemic methylprednisolone was administered to suppress the overactive immune system and ameliorate cutaneous symptoms. With early recognition and prompt treatment, the patient's prognosis was good.
Rajput, Rajan; Sagari, Shitalkumar; Durgavanshi, Astha; Kanwar, Alpana
In the contemporary era, use of drugs is the dominant paradigm of health care. The most quotidian drug used for fever and pain is paracetamol. Although adverse reactions to paracetamol in India are rare, at times they can cause life-threatening situations. Stevens-Johnson syndrome (SJS) is one such potentially lethal adverse drug reaction. The most reported cases of analgesic-induced SJS were due to oxicams or propionic acid derivatives. There are very few detailed reports of SJS due to the use of paracetamol. We report a case of SJS, which occurred due to the use of paracetamol. The clinical features of this condition and multidisciplinary management of the patient are described in brief.
Full Text Available Although carbamazepine (CBZ is the most common cause of Stevens-Johnson syndrome (SJS, a new anticonvulsant, oxcarbazepine, which is structurally related to carbamazepine, has been shown to induce SJS, although extremely rarely. Recently, a strong association was found between human leukocyte antigen (HLA B*1502 and CBZ-induced SJS/TEN in a Han Chinese population. Here, we report a case with SJS, which was induced by oxcarbazepine. HLA genotyping in the patient showed HLA-B*1518/B*4001. HLA-B*1518 is a HLA-B15 variant. The genetic significance of HLA-B*1518 in association with oxcarbazepine-induced SJS needs to be further studied.
Drayer, Sara M; Laufer, Larry R; Farrell, Maureen E
Autoimmune progesterone dermatitis is an uncommon disease presenting with cyclical skin eruptions corresponding with the menstrual cycle luteal phase. Because symptoms are precipitated by rising progesterone levels, treatment relies on hormone suppression. A 22-year-old nulligravid woman presented with symptoms mistaken for Stevens-Johnson syndrome. A cyclic recurrence of her symptoms was noted, and the diagnosis of autoimmune progesterone dermatitis was made by an intradermal progesterone challenge. After 48 months, she remained refractory to medical management and definitive surgical treatment with bilateral oophorectomy was performed. Autoimmune progesterone dermatitis is a challenging diagnosis owing to its rarity and variety of clinical presentations. Treatment centers on suppression of endogenous progesterone and avoidance of exogenous triggers. When these modalities fail, surgical management must be undertaken.
Full Text Available In the contemporary era, use of drugs is the dominant paradigm of health care. The most quotidian drug used for fever and pain is paracetamol. Although adverse reactions to paracetamol in India are rare, at times they can cause life-threatening situations. Stevens-Johnson syndrome (SJS is one such potentially lethal adverse drug reaction. The most reported cases of analgesic-induced SJS were due to oxicams or propionic acid derivatives. There are very few detailed reports of SJS due to the use of paracetamol. We report a case of SJS, which occurred due to the use of paracetamol. The clinical features of this condition and multidisciplinary management of the patient are described in brief.
Cocca, Serena; Viviano, Massimo
Stevens-Johnson syndrome (SJS) is characterized by mucocutaneous tenderness and typical hemorrhagic erosions, erythema and epidermal detachment presenting as blisters and areas of denuded skin. SJS is often observed after drug use as well as after bacterial or viral infections. Several drugs are at high risk of inducing SJS, but there are no cases in the English literature regarding anabolic steroid use triggering SJS. In our paper, we describe a case in which use of anabolic androgenic steroids (AAS) was associated with SJS. The patient participated in competitive body-building and regularly took variable doses of AAS. Initial symptoms (headache, weakness, pharyngodynia, and fever) were ignored. After a week he presented to the Emergency Department with a burning sensation on the mouth, lips, and eyes. Painful, erythematous, maculopapular, and vesicular lesions appeared all over the body, including on the genitals. During hospitalization, he also developed a cardiac complication. The patient had not taken any drugs except AAS.
National Aeronautics and Space Administration — The goal of the project was to demonstrate a true direct current (DC) transformer, a new electro-mechanical component with potentially high power applications; in...
The patent describes a synchronous direct current (dc) power supply which has the power supply input drive synchronized with the pulse repetition...frequency (PRF) of the amplifying or load circuit requiring the dc power for operation. This limits the occurrence of ripple components in the power ... supply output to the spectral positions of the PRF lines, eliminating ripple interference with signal processing in the load. An astable multivibrator is
Barry W. Williams
Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.
Ravin, Karen A; Rappaport, Lara D; Zuckerbraun, Noel S; Wadowsky, Robert M; Wald, Ellen R; Michaels, Marian M
Mycoplasma pneumoniae is a common cause of community-acquired respiratory illness in the adolescent population. Stevens-Johnson syndrome is an extrapulmonary manifestation that has been associated with M. pneumoniae infections. Three adolescent males presented within a 1-month period with M. pneumoniae respiratory illnesses and severe mucositis but without the classic rash typical of Stevens-Johnson. Diagnosis was facilitated by the use of a polymerase chain reaction-based assay. This case series highlights the potential for M. pneumoniae-associated Stevens-Johnson syndrome to occur without rash and supports the use of polymerase chain reaction for early diagnosis.
... Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F... to supersede an existing airworthiness directive (AD) that applies to all Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10- 10F, MD-10-30F, MD-11...
... Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F... (AD) for certain Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC- 10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD-10-30F, MD-11, and MD-11F airplanes. This proposed AD would require...
... Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F.... ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD...
... Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F.... ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD...
Amir Hossein Goudarzian
Full Text Available Background Stevens-Johnson syndrome (SJS is one of potentially fatal disorders that often occur after taking certain types of medication. There are reports of this disease after some infections. This paper presents the case of a young boy with idiopathic Stevens-Johnson syndrome. Case Report A six-year-old male patient with complaint of fever and skin lesions was transferred to emergency department of Bu-Ali Sina hospital (Center of Mazandaran province, Iran. After further evaluations (Physical examination and laboratory reports, the patient did not show any common causes of Stevens - Johnson syndrome. Fortunately he was discharged in a good condition after duration of treatment. Conclusion Further studies need to be done in the field of risk factors of Stevens-Johnson syndrome.
Ciralsky, Jessica B; Sippel, Kimberly C
Background Stevens-Johnson syndrome is often associated with blinding ocular surface cicatricial sequelae. Recent reports have described markedly improved clinical outcomes with the application of amniotic membrane to the ocular surface during the acute phase. Here we describe the clinical outcome of a patient with acute Stevens-Johnson syndrome and severe ocular surface involvement in whom the evolving medical condition and family consent resulted in amniotic membrane application to each eye at differing intervals from disease onset. Methods We undertook a retrospective chart review of a woman with Stevens-Johnson syndrome who presented within hours of disease onset. She underwent application of amniotic membrane to the ocular surface of the left eye during the hyperacute phase (Stevens-Johnson syndrome proved superior. Application of amniotic membrane as soon as possible after disease onset, preferably in the hyperacute phase, appears to result in a significantly better clinical outcome than application later in the disease course. PMID:23754867
Full Text Available In this case report, we describe the rare occurrence of bilateral conjunctival retention cysts in a child with Stevens-Johnson syndrome. The case was managed conservatively as there were no functional or cosmetic problems.
Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.
in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...
Kim, M.J.; Lee, K.Y.
About one third of children with Stevens-Johnson syndrome have pulmonary involvement. As a consequence of airway epithelial injury, bronchiolitis obliterans can occur in these patients. Two cases of Stevens-Johnson syndrome-associated bronchiolitis obliterans in children were diagnosed and followed by high resolution CT without open lung biopsy. Serial changes of high resolution CT features of bronchiolitis obliterans are discussed and the literature is reviewed. (orig.)
Narayanan Veena; Mamatha G; Ashok L; Rajashekar N
Steven-Johnson syndrome (SJS) is a rare vesiculobullous disease characterized by an acute cutaneous eruption that ivolves the skin and mucous membranes including those of the oral cavity. A rare case of Steven-Johnson syndrome, an unexpected treatment response, in a 25-year-old female patient due to administration of intravenous Cefriaxone (1 gm), a third generation cephalosporin has been reported and literature reviewed.
Antoon, James W; Goldman, Jennifer L; Lee, Brian; Schwartz, Alan
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening cutaneous reactions, typically to drugs or infection. The incidence and outcomes of these conditions in children are unknown. The objective of this study was to report the overall burden of Stevens-Johnson syndrome and toxic epidermal necrolysis in children in the United States. We performed a retrospective cohort analysis of children and adolescents younger than 18 years of age using the 2009 and 2012 Kids' Inpatient Database. We identified 1486 children and adolescents hospitalized with a diagnosis of Stevens-Johnson syndrome or toxic epidermal necrolysis. The national incidence per 100 000 was 6.3 for Stevens-Johnson syndrome, 0.7 for Stevens-Johnson syndrome/toxic epidermal necrolysis overlap syndrome, and 0.5 for toxic epidermal necrolysis. The highest incidence in children was in those aged 11-15 years (38.4 per 100 000). Toxic epidermal necrolysis and Stevens-Johnson syndrome/toxic epidermal necrolysis overlap syndrome were associated with longer stay, greater mortality, and higher hospital charges than those with Stevens-Johnson syndrome. Hospital mortality was highest in children with toxic epidermal necrolysis and in children aged 0-5 years. The incidence of Stevens-Johnson syndrome and toxic epidermal necrolysis in children is higher than reported in adults, and there are significant age-based variations in incidence and outcomes across the pediatric population. Further study is needed to determine the most effective treatment strategies to reduce costs and improve outcomes in children hospitalized with severe cutaneous reactions. © 2018 Wiley Periodicals, Inc.
Ricchiuto, D.; Mastromauro, R.A.; Liserre, Marco
DC Microgrids have recently received a lot of attention in the last years due to high penetration of renewable energy sources as well as distributed energy storage systems. In the future DC microgrids could be preferable respect to AC microgrids in terms of redundancy since multi-DC-Bus solutions...... could provide a continuative power supply to the loads. An overview of Multi-DC-Bus solutions is presented in this paper. The performances are compared on the basis of possible DC microgrid configurations, redundancy, different DC voltage levels....
Full Text Available SUMMARY Stevens-Johnson syndrome (SJS and toxic epidermal necrolysis (TEN are uncommon, acute and potentially life-threatening adverse cutaneous drug reactions. These pathologies are considered a hypersensitivity reaction and can be triggered by drugs, infections and malignancies. The drugs most often involved are allopurinol, some antibiotics, including sulfonamides, anticonvulsants such as carbamazepine, and some non-steroid anti-inflammatory drugs (NSAIDs. Necrosis of keratinocytes is manifested clinically by epidermal detachment, leading to scalded skin appearance. The rash begins on the trunk with subsequent generalization, usually sparing the palmoplantar areas. Macular lesions become purplish, and epidermal detachment occurs, resulting in flaccid blisters that converge and break, resulting in extensive sloughing of necrotic skin. Nikolsky's sign is positive in perilesional skin. SJS and TEN are considered to be two ends of the spectrum of one disease, differing only by their extent of skin detachment. Management of patients with SJS or TEN requires three measures: removal of the offending drug, particularly drugs known to be high-risk; supportive measures and active interventions. Early diagnosis of the disease, recognition of the causal agent and the immediate withdrawal of the drug are the most important actions, as the course of the disease is often rapid and fatal.
Sri ram Anne
Full Text Available Toxic epidermal necrolysis (TEN and Stevens Johnson Syndrome (SJS are severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes. They are characterized by mucocutaneous tenderness and typically hemorrhagic erosions, erythema and more or less severe epidermal detachment presenting as blisters and areas of denuded skin. Drugs are assumed or identified as the main cause of SJS/TEN in most cases, but Mycoplasma pneumoniae and Herpes simplex virus infections are well documented causes alongside rare cases in which the etiology remains unknown. Several drugs are at "high" risk of inducing TEN/SJS including: Allopurinol, Trimethoprim-sulfamethoxazole and other sulfonamide-antibiotics, aminopenicillins, cephalosporins, quinolones, carbamazepine, phenytoin, phenobarbital and NSAID's of the oxicam-type. Differential diagnosis includes linear IgA dermatosis and paraneoplastic pemphigus, pemphigus vulgaris and bullous pemphigoid, acute generalized exanthematous pustulosis (AGEP, disseminated fixed bullous drug eruption and staphyloccocal scalded skin syndrome (SSSS. Due to the high risk of mortality, management of patients with SJS/TEN requires rapid diagnosis, identification and interruption of the culprit drug, specialized supportive care ideally in an intensive care unit, and consideration of immunomodulating agents such as high-dose intravenous immunoglobulin therapy.
Yoshitake, Tadamasa; Nakamura, Katsumasa; Shioyama, Yoshiyuki
Erythema multiforme (EM) and Stevens-Johnson syndrome (SJS) are thought to be hypersensitivity syndromes with various causes, and radiotherapy might be one of the causes of these syndromes. We herein report two cases of EM/SJS following radiotherapy. The first case was a 63-year-old woman with breast cancer. At the end of postoperative radiotherapy with 60 Gy, severe pruritic erythema appeared in the irradiated area and spread over the whole body. She was diagnosed with EM by a skin biopsy. The second case was a 77-year-old woman with uterine cervical cancer who underwent postoperative radiotherapy. At a dose of 30.6 Gy, pruritic redness appeared in the irradiated area and the precordial region, and it became widespread rapidly with polymorphic transformation. Although without any histological confirmation, SJS was strongly suspected because of her pruritic conjunctivitis. Because both patients were given medicines during irradiation, radiotherapy may not be the only cause of EM/SJS. However, it should be noted that radiotherapy might trigger EM/SJS. (author)
Yoshitake, Tadamasa; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Sasaki, Tomonari; Ooga, Saiji; Abe, Madoka; Urashima, Yusuke; Urabe, Kazunori; Terashima, Hiromi; Honda, Hiroshi
Erythema multiforme (EM) and Stevens-Johnson syndrome (SJS) are thought to be hypersensitivity syndromes with various causes, and radiotherapy might be one of the causes of these syndromes. We herein report two cases of EM/SJS following radiotherapy. The first case was a 63-year-old woman with breast cancer. At the end of postoperative radiotherapy with 60 Gy, severe pruritic erythema appeared in the irradiated area and spread over the whole body. She was diagnosed with EM by a skin biopsy. The second case was a 77-year-old woman with uterine cervical cancer who underwent postoperative radiotherapy. At a dose of 30.6 Gy, pruritic redness appeared in the irradiated area and the precordial region, and it became widespread rapidly with polymorphic transformation. Although without any histological confirmation, SJS was strongly suspected because of her pruritic conjunctivitis. Because both patients were given medicines during irradiation, radiotherapy may not be the only cause of EM/SJS. However, it should be noted that radiotherapy might trigger EM/SJS.
Full Text Available Stevens-Johnson syndrome (SJS and toxic epidermal necrolysis (TEN are rare, life-threatening conditions with a high mortality rate. SJS and TEN are used to denote a group of disorders closely related to each other, characterized by extensive epidermal necrolysis, and usually induced by drugs. Keratinocyte apoptosis is the main reason for widespread epidermal detachment. Drugs or their methobolites can act as a hapten after binding to the keratinocyte surface and initiate cytotoxic immunological attack. Drug-specific CD8+cytotoxic T cells mediate keratinocyte apoptosis by the Fas/FasL pathway and perforin/granzyme pathway. Although numerous drugs have been noted as responsible, sulfonamide class of antibiotics, anticonvulsants, beta-lactam antibiotics, allopurinol, nonsteroidal anti-inflammatory drugs, nevirapine and thiacetazone are the most frequently reported causative ones. Early diagnosis and withdrawal of suspected drug or drugs are one of the most important steps in the treatment. Other diseases resembling SJS/TEN should be excluded as soon as possible. Although various topical and systemic treatments have recently been used, ideal supportive care is still the most important and effective therapeutic approach. SCORTEN, a scoring system used to predict mortality in TEN, has been widely used in recent years. Transfer to a burn unit or intensive care unit is recommended for patients with a SCORTEN 3 (mortality rate; 35.3% or over. In this paper, we aimed to review clinical findings, aetiopathogenesis and treatment of these syndromes in the light of current literature.
Jain, Rajat; Sharma, Namrata; Basu, Sayan; Iyer, Geetha; Ueta, Mayumi; Sotozono, Chie; Kannabiran, Chitra; Rathi, Varsha M; Gupta, Nidhi; Kinoshita, Shigeru; Gomes, José A P; Chodosh, James; Sangwan, Virender S
Stevens-Johnson syndrome (SJS) is an acute blistering disease of the skin and mucous membranes. Acute SJS leads to the acute inflammation of the ocular surface and chronic conjunctivitis. If not properly treated, it causes chronic cicatricial conjunctivitis and cicatricial lid margin abnormalities. Persistent inflammation and ulceration of the ocular surface with cicatricial complications of the lids leads to chronic ocular sequelae, ocular surface damage, and corneal scarring. The destruction of the glands that secrete the tear film leads to a severe form of dry eye that makes the management of chronic SJS difficult. The option that is routinely used for corneal visual rehabilitation, keratoplasty, is best avoided in such cases. We describe the management strategies that are most effective during the acute and chronic stages of SJS. Although treatments for acute SJS involve immunosuppressive and immunomodulatory therapies, amniotic membrane transplantation is also useful. The options for visual rehabilitation in patients with chronic SJS are undergoing radical change. We describe the existing literature regarding the management of SJS and highlight recent advances in the management of this disorder. Copyright © 2016 Elsevier Inc. All rights reserved.
Campiotti, Richard H.; Hopwood, James E.
A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.
The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.
Wang, Bright L.
The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.
... Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD-10-30F, MD-11, and MD-11F Airplanes AGENCY: Federal Aviation... airworthiness directive (AD) for certain Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC- 10A and...
Full Text Available Background and objectives: The genus Colchicum belongs to the family Colchicaceae, which comprises of 19 genera, and 225 species worldwide. They have been recognized for more than 2000 years for their noticeable biological properties. The Colchicum species are well known for presence of tropolonic alkaloids, mainly colchicine. Colchicine, is still the drug of choice for treatment of gout, and is used for the treatment of a number of proinflammatory disorders, such as familial Mediterranean fever, and Behcet’s disease. Clinical studies have proved colchicine to posses potent anti-tumor activity. Colchicum speciosum Steven is an indigenous perennial herbaceous plant widely distributed in northern, central and western regions of Iran. Methods: In the present study, the phytochemical composition of MeOH extract from bulbs of C. speciosum collected fromSavadkouh region, Iranwas investigated by combination of HPLC-PDA-MS spectrometry and NMR specroscopy. The fractionation of MeOH extract was carried out by partitioning on CH2Cl2, EtOAc and water. Results: The isolation and purification of CH2Cl2 portion by combination of reverse and normal phase chromatography resulted in the isolation, purification and identification of two new tropolonic alkaloids, compounds (1 and (2, as well as two known compound colchicine (3 and demecolcine (4. Their structures were established by extensive spectroscopic methods, including 1D (1H NMR and 2D-NMR (COSY, HSQC and HMBC. The absolute configurations of isolated compounds were established by aid of circular dichroism. Conclusion: Phytochemical investigation of CH2Cl2 extract of C. speciosum by combination of HPLC, column chromatography and hyphenated spectroscopic techniques led to identification two new alkaloids with potential as lead compounds.
Low, Yen S; Caster, Ola; Bergvall, Tomas; Fourches, Denis; Zang, Xiaoling; Norén, G Niklas; Rusyn, Ivan; Edwards, Ralph
Objective Quantitative Structure-Activity Relationship (QSAR) models can predict adverse drug reactions (ADRs), and thus provide early warnings of potential hazards. Timely identification of potential safety concerns could protect patients and aid early diagnosis of ADRs among the exposed. Our objective was to determine whether global spontaneous reporting patterns might allow chemical substructures associated with Stevens-Johnson Syndrome (SJS) to be identified and utilized for ADR prediction by QSAR models. Materials and Methods Using a reference set of 364 drugs having positive or negative reporting correlations with SJS in the VigiBase global repository of individual case safety reports (Uppsala Monitoring Center, Uppsala, Sweden), chemical descriptors were computed from drug molecular structures. Random Forest and Support Vector Machines methods were used to develop QSAR models, which were validated by external 5-fold cross validation. Models were employed for virtual screening of DrugBank to predict SJS actives and inactives, which were corroborated using knowledge bases like VigiBase, ChemoText, and MicroMedex (Truven Health Analytics Inc, Ann Arbor, Michigan). Results We developed QSAR models that could accurately predict if drugs were associated with SJS (area under the curve of 75%–81%). Our 10 most active and inactive predictions were substantiated by SJS reports (or lack thereof) in the literature. Discussion Interpretation of QSAR models in terms of significant chemical descriptors suggested novel SJS structural alerts. Conclusions We have demonstrated that QSAR models can accurately identify SJS active and inactive drugs. Requiring chemical structures only, QSAR models provide effective computational means to flag potentially harmful drugs for subsequent targeted surveillance and pharmacoepidemiologic investigations. PMID:26499102
Low, Yen S; Caster, Ola; Bergvall, Tomas; Fourches, Denis; Zang, Xiaoling; Norén, G Niklas; Rusyn, Ivan; Edwards, Ralph; Tropsha, Alexander
Quantitative Structure-Activity Relationship (QSAR) models can predict adverse drug reactions (ADRs), and thus provide early warnings of potential hazards. Timely identification of potential safety concerns could protect patients and aid early diagnosis of ADRs among the exposed. Our objective was to determine whether global spontaneous reporting patterns might allow chemical substructures associated with Stevens-Johnson Syndrome (SJS) to be identified and utilized for ADR prediction by QSAR models. Using a reference set of 364 drugs having positive or negative reporting correlations with SJS in the VigiBase global repository of individual case safety reports (Uppsala Monitoring Center, Uppsala, Sweden), chemical descriptors were computed from drug molecular structures. Random Forest and Support Vector Machines methods were used to develop QSAR models, which were validated by external 5-fold cross validation. Models were employed for virtual screening of DrugBank to predict SJS actives and inactives, which were corroborated using knowledge bases like VigiBase, ChemoText, and MicroMedex (Truven Health Analytics Inc, Ann Arbor, Michigan). We developed QSAR models that could accurately predict if drugs were associated with SJS (area under the curve of 75%-81%). Our 10 most active and inactive predictions were substantiated by SJS reports (or lack thereof) in the literature. Interpretation of QSAR models in terms of significant chemical descriptors suggested novel SJS structural alerts. We have demonstrated that QSAR models can accurately identify SJS active and inactive drugs. Requiring chemical structures only, QSAR models provide effective computational means to flag potentially harmful drugs for subsequent targeted surveillance and pharmacoepidemiologic investigations. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association.
Watkins, Louise K. Francois; Demirjian, Alicia; Lin, Xia; Robinson, Christine C.; Pretty, Kristin; Benitez, Alvaro J.; Winchell, Jonas M.; Diaz, Maureen H.; Miller, Lisa A.; Foo, Teresa A.; Mason, Melanie D.; Lauper, Ursula L.; Kupfer, Oren; Kennedy, Jeffrey; Glodé, Mary P.; Kutty, Preeta K.; Dominguez, Samuel R.
BACKGROUND: Stevens-Johnson syndrome (SJS) is an uncommon, sporadic disease and outbreaks are rare. In November 2013, an outbreak of SJS was identified at Children’s Hospital Colorado. METHODS: Outbreak cases were children aged 5–21 with a discharge diagnosis of SJS admitted from September 1 to November 30, 2013. Medical charts were reviewed using standardized data collection forms. Respiratory specimens were tested for viruses and Mycoplasma pneumoniae (Mp) by polymerase chain reaction (PCR). We conducted a separate 4-year retrospective case-control study comparing hospitalized SJS cases with and without evidence of Mp infection. RESULTS: During the outbreak, 8 children met SJS criteria. Median age was 11.5 years (range 8–16 years); 5 (63%) were boys and 5 (63%) were Mp-PCR–positive. Of the 5 PCR-positive children, none had preceding medication exposure, and all had radiographic pneumonia. All outbreak Mp isolates were macrolide susceptible. The retrospective case-control analysis showed that Mp-associated SJS episodes (n = 17) were more likely to have pneumonia (odds ratio [OR] 10.0, confidence interval [CI] 1.3–5.1), preceding respiratory symptoms (OR 30.0, CI 1.6–72.6), an erythrocyte sedimentation rate ≥35 mg/dL (OR 22.8, CI 2.1–244.9), and ≤3 affected skin sites (OR 4.5, CI 1.2–17.4) than non–Mp-associated SJS episodes (n = 23). CONCLUSIONS: We report the largest outbreak of SJS in children, which was also predominately associated with Mp infection. Mp-associated SJS was associated with a distinct clinical presentation that included less extensive skin disease, an elevated erythrocyte sedimentation rate, and evidence of a preceding respiratory infection. PMID:26216320
V. INDRA GANDHI
Full Text Available DC voltage boost up is essential in numerous applications; especially considering Photovoltaic (PV based renewable power generation system. The conventional DC-DC boost converter is the most admired configuration for this scheme, even if the converter efficiency is restricted at duty cycle near to maximum value. In order to find solution to the problem and improve its conversion capability, many converter configurations have been implemented so far. With this circumstance, this research work proposes to give overview of a few most imperative research works related to DC-DC boost converters. Some configurations are covered and classified basically based on the application. The major benefits and disadvantages related to the available techniques are also briefly conveyed. At last, a proper evaluation is recognized among the important types of DC-DC boost converters in terms of efficiency, number of components, and stability.
Toxic epidermal necrolysis (TEN) and Stevens Johnson Syndrome (SJS) are severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes. Both are rare, with TEN and SJS affecting approximately 1or 2/1,000,000 annually, and are considered medical emergencies as they are potentially fatal. They are characterized by mucocutaneous tenderness and typically hemorrhagic erosions, erythema and more or less severe epidermal detachment presenting as blisters and areas of denuded skin. Currently, TEN and SJS are considered to be two ends of a spectrum of severe epidermolytic adverse cutaneous drug reactions, differing only by their extent of skin detachment. Drugs are assumed or identified as the main cause of SJS/TEN in most cases, but Mycoplasma pneumoniae and Herpes simplex virus infections are well documented causes alongside rare cases in which the aetiology remains unknown. Several drugs are at "high" risk of inducing TEN/SJS including: Allopurinol, Trimethoprim-sulfamethoxazole and other sulfonamide-antibiotics, aminopenicillins, cephalosporins, quinolones, carbamazepine, phenytoin, phenobarbital and NSAID's of the oxicam-type. Genetic susceptibility to SJS and TEN is likely as exemplified by the strong association observed in Han Chinese between a genetic marker, the human leukocyte antigen HLA-B*1502, and SJS induced by carbamazepine. Diagnosis relies mainly on clinical signs together with the histological analysis of a skin biopsy showing typical full-thickness epidermal necrolysis due to extensive keratinocyte apoptosis. Differential diagnosis includes linear IgA dermatosis and paraneoplastic pemphigus, pemphigus vulgaris and bullous pemphigoid, acute generalized exanthematous pustulosis (AGEP), disseminated fixed bullous drug eruption and staphyloccocal scalded skin syndrome (SSSS). Due to the high risk of mortality, management of patients with SJS/TEN requires rapid diagnosis, evaluation of the prognosis using SCORTEN
Martin, L; Hazouard, E; Michalak-Provost, S; Maurage, C; Machet, L
Acute bronchial mucosal sloughing related to Toxic Epidermal Necrolysis (Lyell syndrome) is widely reported in literature. On the contrary severe respiratory involvement is rare in post-infectious or toxic Epitheliolysis (Stevens-Johnson syndrome). There is no well-known predictive sign of bronchial epithelium involvement. An 18-year-old patient was admitted for Stevens-Johnson syndrome related to sulfasalazine (salazosulfapyridine). There were no respiratory signs. An acute respiratory failure occurred 36 hours after from admission due to an obstructive and desquamative necrosis of the tracheobronchial epithelium. We purpose that a fiberoptic laryngoscopy should be performed even in non-dyspneic patients suffering from Stevens-Johnson syndrome if hypersecretion is present. Fiberoptic bronchoscopy can be helpful in these cases.
Booker, Matthew J
This case report describes a 41-year-old Afro-Caribbean lady presenting with a constellation of pyrexia, conjunctivitis, arthralgia, sterile dysuria, apthous ulceration, labial crusting and widespread erythema multiforme. A diagnosis of Stevens-Johnson Syndrome was made. She had taken no medications recently (the most common precipitant of Stevens-Johnson Syndrome) and a full screen for the common and atypical bacterial and viral triggers was negative. The identified trigger was the use of a chemical hair relaxant treatment a few days previously. With supportive measures and a course of oral prednisolone, the patient quickly improved and made a full recovery. This case highlights the importance of considering occupational and recreational precipitants of Stevens-Johnson Syndrome. PMID:19918477
Park, Hyungchul; Ko, Young Bo; Kwon, Hyouk-Soo; Lim, Chae-Man
We report a case of bronchiolitis obliterans associated with Stevens-Johnson syndrome. A 59-year-old man presented with respiratory distress that gradually worsened over 3 months. He had been diagnosed with Stevens-Johnson syndrome 3 months before admission. He had no history of previous airway disease. On physical examination, expiratory breathing sounds were not audible, and a chest X-ray revealed a hyperinflated lung. A pulmonary function test indicated a severe obstructive pattern. Computed tomography scans of inspiratory and expiratory phases of respiration showed oligemia and air trapping, and both were more prominent on expiration view than on inspiration view. The pathogenesis of bronchiolitis obliterans associated with Stevens-Johnson syndrome is largely unknown.
Full Text Available Erythema multiforme (EM is a typically mild, self-limiting and recurring mucocutaneous reaction characterized by target or iris lesions of the skin and mucous membranes. It is most often a recurring phenomenon with great variability in the interval between episodes. It is much more common in persons under 40 years of age. In contrast, Stevens-Johnson syndrome (SJS and toxic epidermal necrolysis (TEN are less common and more severe conditions that typically occur in adults. SJS and TEN are severe variants of EM usually caused by a drug exposure. We report two cases of Stevens-Johnsons syndrome following drug intake. There is an increased incidence of SJS and TEN in the HIV-infected population. 1 Herewith, we report two cases of Stevens-Johnson syndrome in one patient following drug intake and other in a HIV-infected patient.
Gandhi, Roopa P; Klein, Ulrich
Stevens-Johnson syndrome (SJS) is a rare condition, characterized by its dramatic involvement of the skin and various mucosal surfaces including the oral mucosae, that severely impairs the affected patient's ability to speak, chew, or swallow. The purpose of this report was to present two cases with significant variations in the clinical presentation of Stevens-Johnson syndrome. In both situations, the patients' conditions were not immediately recognized. Pediatric dentists should be aware of these variations in the clinical manifestations of SJS, as the signs and symptoms can initially mimic common viral conditions. Appropriate diagnosis can result in timely referral to a hospital environment, optimizing patient management and recovery.
... Railway Service Corporation, Steven C. Hawkins and Cheryl R. Hawkins--Continuance in Control Exemption--Aiken Railway Company, LLC Western Carolina Railway Service Corporation (WCRS) and Steven C. Hawkins and Cheryl R. Hawkins (the Hawkins) (collectively, Applicants) have filed a verified notice of exemption...
Su, Shih-Chi; Mockenhaupt, Maja; Wolkenstein, Pierre; Dunant, Ariane; Le Gouvello, Sabine; Chen, Chun-Bing; Chosidow, Olivier; Valeyrie-Allanore, Laurence; Bellon, Teresa; Sekula, Peggy; Wang, Chuang-Wei; Schumacher, Martin; Kardaun, Sylvia H.; Hung, Shuen-Iu; Roujeau, Jean-Claude; Chung, Wen-Hung
Early diagnosis and prognosis monitoring for Stevens-Johnson syndrome/toxic epidermal necrolysis (TEN) still remain a challenge. This study aims to explore any cytokine/chemokine with prognostic potential in StevensJohnson syndrome/TEN. Through screening a panel of 28 serological factors, IL-6,
Peng, Fang Z.
An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.
Bambang Prio Hartono
Full Text Available Abstract: Using system fuzzy logic as control technology have been used on low load dc-dc converter with combined parallel compiled dc-dc converter can obtain big load. With existence of differrence of component parameter and each parallel compiled converter can obtained different current and voltage output. Function of controller for to do adjustment, so that current which is applied to load by each converter can be obtained difference error as small as possible or same. The object of research is developing design of large signal dc-dc converter which is combined with using FLC so that obtain better performance. To get better performance have been made plant model and simulation with CDE method. The more systematic system and design is needed to overcome bigger load on dc-dc converter, so that parallel compiled current master slave control system on dc-dc converter with using fuzzy logic controller is used. Result of research showed that error or difference of current which is applied to load can handled by fuzzy logic controller. Technic of current and voltage controller co to do adjustment current and voltage distribution equally to load. Distribution of iL1,iL2 and output voltage Vo on dc-dc converter with load 2,25 until 7,875 and voltage 100 until 120 volt, load current beetwen 12 until 48, % relatif error Vo 0,4% until 0,9%.
East-Innis, A D; Thompson, D S
Stevens-Johnson syndrome and toxic epidermal necrolysis are uncommon acute dermatologic disorders. The purpose of this study was to examine the frequency, aetiology and outcome of cases of Stevens-Johnson syndrome and toxic epidermal necrolysis admitted to the dermatology ward at the University Hospital of the West Indies. This was a retrospective study looking at all patients who were admitted with a diagnosis of Stevens-Johnson syndrome, Stevens-Johnson syndrome/toxic epidermal necrolysis overlap syndrome and toxic epidermal necrolysis over a nine-year period. The results showed almost equal numbers of males and females. The drugs most commonly implicated were phenytoin and cotrimoxazole. The most common complications were hepatic impairment and ophthalmic complications. Stevens-Johnson syndrome and toxic epidermal necrolysis contribute significantly to morbidity and mortality of patients on the dermatology ward although mortality was low compared to other studies.
Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav
This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification...
Lee, F.; Mohmoud, M.; Yu, Y.
Two documents aid in design of control modules for dc-to-dc converters. Features of SCM include: Adaptive stability, power component stress limiting, implementation of various control laws, unified design approach. Analysis and quidelines contained in handbooks enable engineer to design SCM circuit and confidently predict resulting overall performance.
Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri
This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can b...
Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.
This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...
... appropriate monitoring levels, costs of those programs, and implementation of electronic monitoring systems... develop electronic monitoring in the Northeast. With respect to the proposed measure, however, NMFS has... Atmospheric Administration 50 CFR Part 648 Magnuson-Stevens Fishery Conservation and Management Act Provisions...
...), acceptable biological catch level (ABC), ACL, annual catch target (ACT), and total allowable landing (TAL... the Magnuson-Stevens Act, and cannot rely upon draft reports, news articles, personal communications... conservatively below the ABC and OFL. Further, the NEFMC and four other commenters also recalled that because the...
Stevens's power law ([Psi][infinity][Phi][beta]) captures the relationship between physical ([Phi]) and perceived ([Psi]) magnitude for many stimulus continua (e.g., luminance and brightness, weight and heaviness, area and size). The exponent ([beta]) indicates whether perceptual magnitude grows more slowly than physical magnitude ([beta] less…
... National Oceanic and Atmospheric Administration 50 CFR Part 600 RIN 0648-AW18 Magnuson-Stevens Fishery... Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Final... meeting announcements in local and national trade magazines and distribution via the vessel monitoring...
30. juunil üheaegselt Jaapanis ja USAs esilinastub Steven Spielbergi "Tehisintellekt" ("A.I. Artificial Intelligence"), mille kohta režissöör Tokyos pressikonverentsil väitis, et see on õieti Stanley Kubricku film, kuna põhineb temast järelejäänud 90-leheküljelisel ideeprojektil
Kellman, Steven G.; Stavans, Ilan
Dialogue might be the most appropriate medium for reflections on translingualism. In a dialogue conducted by email over the course of ten days, Steven G. Kellman and Ilan Stavans consider the validity and implications of linguistic determinism. Their conversation examines whether some words that seem to embody the unique "Weltanschaaung"…
Steven Hou, Ph.D., senior investigator in the Basic Research Laboratory at the Center for Cancer Research describes his latest research that has uncovered potential ways to eliminate cancer stem cells and may offer hope to patients with reoccurring tumors. Learn more...
... National Oceanic and Atmospheric Administration 50 CFR Part 648 RIN 0648-AY01 Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the Northeastern United States; Monkfish Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA...
... National Oceanic and Atmospheric Administration 50 CFR Part 648 RIN 0648-AW30 Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the Northeastern United States; Northeast Skate Complex Fishery; Amendment 3 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...
Avinash, A; Amberkar, V Mohanbabu; Kunder, Sushil Kiran; Madhyastha, Sharath; Meenakumari, K
Stevens-Johnson syndrome is one of the few dermatological emergencies in clinical practice. The syndrome is often secondary to the usage of drugs, of which allopurinol, penicillins, sulfa drugs, ibuprofen, sodium valproate, phenytoin, lamotrigine and carbamazepine are commonly implicated. Agranulocytosis is the existence of a clinically significant reduction in neutrophil count. This condition is a serious threat to the patient, as he/she is at a greater risk of contracting bacterial or fungal infections, which may prove to be fatal. The co-existence of Stevens-Johnson syndrome and agranulocytosis in the same patient further increases the risk of morbidity and mortality. To the best of our knowledge, there are no reports available in the existing literature, of cases that were reported with both these life-threatening conditions in a single patient, at the same point of time. This is a case narrative of a patient who presented with both Stevens-Johnson syndrome and agranulocytosis, following the administration of carbamazepine The patient's differential leucocyte count revealed a neutrophil proportion of 2.33%. A causality assessment done using Naranjo's algorithm showed that carbamazepine "definitely" caused Agranulocytosis and "probably" caused Stevens-Johnson syndrome.
Full Text Available Carbamazepine and other anticonvulsants are commoner cause of severe adverse cutaneous drug reactions such as erythema multiforme, toxic epidermal necrolysis (TEN, and Stevens-Johnson syndrome (SJS. We report a case of SJS rapidly progressing to TEN with a combination of haloperidol and carbamazepine in a patient with bipolar affective disorder. The pathophysiological mechanism underlying this reaction is discussed.
Kawasaki, S.; Nishida, K.; Sotozono, C.; Quantock, A.; Kinoshita, S.
AIMS—To understand the immunopathogenesis of the corneal conjunctivalisation in Stevens-Johnson syndrome. METHODS—Conjunctivalised corneas from five patients with Stevens-Johnson syndrome were studied immunohistochemically for several cell surface antigens and two cytokines. Chemical injury specimens were also studied. RESULTS—In all cases, immunohistochemistry revealed LFA-1, CD4, CD8, and CD68 on subepithelial infiltrating cells. Also, HLA-DR and ICAM-1 were found on the surfaces of epithelial cells, subepithelial infiltrating cells, subepithelial fibroblasts, and endothelial cells in blood vessels. IFN-γ was found in basal epithelial cells; subepithelial cells and subepithelial extracellular matrix CD19 and IL4 were not detected. CONCLUSIONS—The infiltrating cell population in the Stevens-Johnson syndrome samples includes macrophages, CD4 positive T cells, and CD8 positive T cells. The cytokine expression pattern suggests CD4 positive T cells are Th1 cells. The infiltrating cell population is similar in Stevens-Johnson syndrome and chemical injury conjunctivalised corneas. PMID:11004109
Kardaun, Sylvia H.; Jonkman, Marcel F.
Mortality in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) is high. Apart from intensive supportive therapy, no generally accepted specific treatment regimen exists. The role of corticosteroids in SJS/TEN is controversial. It is possible that high-dose pulse therapy with
Sekula, Peggy; Dunant, Ariane; Mockenhaupt, Maja; Naldi, Luigi; Bavinck, Jan Nico Bouwes; Halevy, Sima; Kardaun, Sylvia; Sidoroff, Alexis; Liss, Yvonne; Schumacher, Martin; Roujeau, Jean-Claude
Stevens Johnson syndrome and toxic epidermal necrolysis are severe cutaneous adverse reactions that are of major concern because of high mortality rates. On the basis of data collected in the RegiSCAR study, the aim was to assess risk factors (including modalities of patient management) for
... for Sustainable Fisheries, Northeast Region, NMFS (Assistant Regional Administrator), has made a... University Cooperative Extension of Suffolk County, NY. Regulations under the Magnuson-Stevens Fishery... limits to conduct onboard sampling. This project proposes to evaluate bottom trawl modifications as a...
American Journal of Play, 2010
An authority on the history of American children and families, Steven Mintz is a professor of history at Columbia University, where he also directs the Graduate School of Arts and Sciences Teaching Center. Previously, he was a fellow at the Center for Advanced Study in the Behavioral Sciences at Stanford University and the Moores Professor of…
... Multispecies Fishery Management Plan which was approved on March 8, 2012. This action amends the Northeast Multispecies Fishery Management Plan to explicitly define and facilitate the effective operation of state.... 110901552-20494-02] RIN 0648-BB34 Magnuson-Stevens Fishery Conservation and Management Act Provisions...
... Amendment 17 to the Northeast Multispecies Fishery Management Plan. This action would amend the Northeast Multispecies Fishery Management Plan to explicitly define and facilitate the effective operation of state.... 110901552-1736-01] RIN 0648-BB34 Magnuson-Stevens Fishery Conservation and Management Act Provisions...
Owczarczyk-Saczonek, Agnieszka; Zdanowska, Natalia; Znajewska-Pander, Aleksandra; Placek, Waldemar
Etanercept and other anti-TNF-alpha agents have been indicated as a therapeutic option in severe drug reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis. Etanercept has been shown to quickly reduce the detachment of the epidermis and shorten healing time. Cases of etanercept-induced severe adverse drug reactions were also described. A 27-year-old woman with a 4-year history of etanercept and sulfasalazine treatment for rheumatoid arthritis was admitted with Stevens-Johnson syndrome. The patient received one dose of an OTC drug containing acetaminophen, phenylephrine and pheniramine two days prior to developing fist mucocutaneous symptoms. The most probable causative agent was paracetamol. Throughout the successful routine therapy of Stevens-Johnson syndrome etanercept therapy was continued. Sulfosalazin administration was stopped and administered again after recovery with no recurrence of the skin and mucosal symptoms. This case indicates that there is no justification for discontinuation of long-term anti-TNF-alpha treatment in patients who develop Stevens- Johnson syndrome / toxic epidermal necrolysis.
Deng, Fujin; Chen, Zhe
This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...
Youngquist, Robert C.; Ihlefeld, Curtis M.; Starr, Stanley O.
A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply can be stepped up (or down) with a corresponding step down (or up) in current. The basic theory for this device is developed, performance predictions are made, and the results from a small prototype are presented. Based on demonstrated technology in the literature, this de transformer should be scalable to low megawatt levels, but it is more suited to high current than high voltage applications. Significant development would be required before it could achieve the kilovolt levels needed for de power transmission.
Clarke, J.; Goubau, W.M.; Ketchen, M.B.
Cylindrical thin film dc SQUIDS that make use of resistively shunted Nb-NbOx-Pb tunnel junctions have been constructed and tested. These junctions are very robust: the SQUIDs can be thermally cycled repeatedly and stored at room temperature indefinitely. The weak temperature dependence of the critical current allows SQUID operation at any temperature below about 6K. The resolution is typically 4x10 -5 phi 0 /√Hz above 2x10 -2 Hz; at lower frequencies the noise power spectrum is 1/f. The long-term drift is less than 2x10 -5 phi 0 /hr. The 1/f noise and drift are lower than any values reported for other types of SQUIDs. (Auth.)
Ouyang, Ziwei; Andersen, Michael A. E.
A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling...... between the multiple inputs while the output power is still coupled with all inputs. The energy is accordingly allowed to deliver into the output load simultaneously or at any time-multiplexing scheme. 1-kW experimental prototypes have been built to demonstrate a well-managed power flow for photovoltaic...... (PV) and battery standalone system....
Can, Erol; Sayan, Hasan Hüseyin
This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...
Dragicevic, Tomislav; Anvari-Moghaddam, Amjad; Quintero, Juan Carlos Vasquez
A qualitative overview of different hardware topologies and control systems for DC MGs has been presented in this chapter. Some challenges and design considerations of DC protections systems have also been discussed. Finally, applications of DC MGs in emerging smart grid applications have been su...... in different industries and gradually lead to new ways of rethinking of the future power distribution philosophies, especially with the emergence of SSTs. Research in DC systems, especially in the power electronics-based technologies will be highly attractive in the future.......A qualitative overview of different hardware topologies and control systems for DC MGs has been presented in this chapter. Some challenges and design considerations of DC protections systems have also been discussed. Finally, applications of DC MGs in emerging smart grid applications have been...... summarized. Due to its attractive characteristics in terms of compliance with modern generation, storage and electronic load technologies, high reliability and current carrying capacity, as well as simple control, DC systems are already an indispensable part of power systems. Moreover, the existing...
National Aeronautics and Space Administration — VPT proposes an innovative concept whereby complex, multiple-output, DC-DC converter systems can be configured through use of only 2 standard product hybrid DC-DC...
A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.
Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.
supply (UPS) AC motor drives and other power sup systems, need to step-up the DC input voltage. increase the output voltage level in order requirements, DC-DC boost converter is used provide DC bus voltage for PWM inverters. Hence, conventional design always cascades DC and a separate DC-AC converter.
Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley
We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.
Carlos Andrés Ramos-Paja
Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.
Full Text Available This paper proposes a method for designing fuzzy control of DC-DC converters under actuator saturation. Because linear control design methods do not take into account the nonlinearity of the system, a T-S fuzzy model and a controller design approach is used. The designed control not only handles the external disturbance but also the saturation of duty cycle. The input constraint is first transformed into a symmetric saturation which is represented by a polytopic model. Stabilization conditions for the state feedback system of DC-DC converters under actuator saturation are established using the Lyapunov approach. The proposed method has been compared and verified with a simulation example.
Dragicevic, Tomislav; Lu, Xiaonan; Quintero, Juan Carlos Vasquez
distribution applications such as traction, telecom, vehicular and distributed power systems can be classified under DC MG framework and ongoing development and expansion of the field is largely influenced by concepts used over there. This paper aims firstly to shed light on the practical design aspects of DC...... MG technology concerning typical power hardware topologies and their suitability for different emerging smart grid applications. Then, an overview of the state of the art in DC MG protection and grounding is provided. Owing to the fact that there is no zero current crossing, an arc that appears upon...
Full Text Available Bi-directional buck-boost DC/DC converterfor hybrid battery is described in this paper. The firstpart of the paper is aimed at concept of hybrid battery;main advance compared to conventional accumulatoris explained there. Control circuit with UC3637 andpower circuit of the converter are described in thesecond part of the paper. Experimental results frommeasuring of converter are mentioned in the last part.
This report summarises the results of a study investigating the impact of levels of injected DC current injections on a low voltage AC distribution network systems in order to recommend acceptable limits of DC from microgeneration. Relevant literature is reviewed, and the impact of DC levels in distribution transformers, transformer modelling, and instrumental transformers are discussed. The impact of DC in residual current devices (RCD) and in domestic electricity watt hour meters is examined along with DC enhanced corrosion, corrosion failure, and the measurement of DC current injection. Sources of DC injection outlined include DC from computer power supplies, network faults, geomagnetic phenomena, lighting circuits/dimmers, and embedded generators.
Kukovinets, O. V.; Sidorov, K. M.; Yutt, V. E.
Modern motor-vehicle industrial sector is moving rapidly now towards the electricity-driving cars production, improving their range and efficiency of components, and in particular the step-down DC/DC converter to supply the onboard circuit 12/24V of electric vehicle from the high-voltage battery. The purpose of this article - to identify the best circuitry topology to design an advanced step-down DC/DC converters with the smallest mass, volume, highest efficiency and power. And this will have a positive effect on driving distance of electric vehicle (EV). On the basis of computational research of existing and implemented circuit topologies of step-down DC/DC converters (serial resonant converter, full bridge with phase-shifting converter, LLC resonant converter) a comprehensive analysis was carried out on the following characteristics: specific volume, specific weight, power, efficiency. The data obtained was the basis for the best technical option - LLC resonant converter. The results can serve as a guide material in the process of components design of the traction equipment for electric vehicles, providing for the best technical solutions in the design and manufacturing of converting equipment, self-contained power supply systems and advanced driver assistance systems.
Aznab, Mozaffar; Khazaei, Mansour
Stevens-Johnson syndrome has been an acute, usually self-limiting disease of the skin and mucous membranes. This case report has presented an evidence of the development Stevens - Johnson syndrome associated with combination chemotherapy administration of 5FU, gemcitabin and cisplatin in a patient with biliary tract cancer. Our case was a 54-year-old woman patient, a case of biliary tract cancer who has developed more severe symptoms of Stevens-Johnson syndrome. Diagnosis has confirmed by skin biopsy of an affected area .The patient has improved with supportive care, and during 25 day occurred recovery. Although Stevens-Johnson syndrome has been a rare toxicity, physicians should pay a special attention to the monitoring of biliary tract cancer patients on combination chemotherapy with 5FU, cisplatin and gemcitabin.
Sommervoll, Dag Einar
Artikkelen er gjengitt med tillatelse fra Samfunnsøkonomenes Forening. Bokanmeldelse av: Levitt, Steven D. & Dubner, Stephen J. (2005): "Freakonomics : a rogue economist explores the hidden side of everything", [New York]: Harper Collins Inc.
Ferreira, M. R.; Amado, A.; Jorge, M.; Grillo, I. M.
Background: Stevens Johnson Syndrome and Erythema Multiforme are hypersensitivity skin reactions generally arising in the context of multiple causes. Radiation therapy is considered to be one of these causes, although most reports are hindered by concomitant medications. Aim: The aim of this paper was to present a case of Stevens Johnson Syndrome arising in a patient undergoing gynaecological brachytherapy with an unusual presentation. Case:We describe a case of a 56-year-old woman with endometrial cancer undergoing adjuvant gynaecological radiotherapy. While undergoing a gynaecological brachytherapy boost, she developed bilateral conjunctivitis that progressed to oral mucositis and pruritic erythema with sloughing of the skin on her arms and legs but not the torso or irradiated fields (namely the vaginal mucosa). Conclusion: This case illustrates the association of RT/SJS; however, it also raises the question of patients undergoing RT being more susceptible to SJS as opposed to a direct cause of the disease. (authors)
de Roux Serratrice, C; Serratrice, J; Granel, B; Weiller-Merli, C; Rey, J; Lepidi, H; Disdier, P; Weiller, P J
Sicca syndrome after Stevens-Johnson syndrome is classically described. However, to our knowledge, authentic Sjögren's syndrome following epidermal necrolysis has not been described previously. A 36-year-old woman with Steven-Johnson syndrome developed transient hepatitis and a persistent sicca syndrome. Fourteen years later an authentic Sjögren's syndrome was identified with presence of antinuclear and anti-SSA antibodies and lymphocytes infiltration of the accessory salivary glands, i.e. grade IV disease in the Chisholm classification. The initial mucosal destruction observed in our patients may have laid the ground for Sjögren's syndrome via abnormal antigen presentation in a predisposed dysimmune context.
Chidester, S K; Vandersall, K S; Switzer, L L; Tarver, C M
Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence.
Vandersall, K S; Switzer, L L; Garcia, F
Steven Impact Tests were performed at low velocity on the explosives TNT, Comp B, and C-4 in attempts to obtain a threshold for reaction. A 76 mm helium driven gas gun was used to accelerate the Steven Test projectiles up to approximately 200 m/s in attempts to react (ignite) the explosive samples. Blast overpressure gauges, acoustic microphones, standard video and high-speed photography were used to characterize the level of any high explosive reaction violence. No bulk reactions were observed in the TNT, Composition B, or C-4 explosive samples impacted up to velocities in the range of 190-200 m/s. This work will outline the experimental details and discuss the lack of reaction when compared to the reaction thresholds of other common explosives.
Chidester, Steven K.; Vandersall, Kevin S.; Switzer, Lori L.; Tarver, Craig M.
Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence.
Fallon, Michael J; Heck, Jessica N
Stevens-Johnson syndrome/toxic epidermal necrolysis overlap is an acute hypersensitivity reaction that compromises the integrity of mucous membranes and cutaneous tissue. While the pathophysiology of this syndrome has not been fully elucidated, it is commonly associated with the medication use and carries a significant mortality risk of approximately 30%. No commonalities among causative medications have been identified, and determining the offending agent can be challenging. This case report describes fatal Stevens-Johnson syndrome/toxic epidermal necrolysis overlap in a patient after receiving his first cycle of allopurinol, rituximab, and bendamustine treatment for non-Hodgkin's B-cell lymphoma. An analysis of FDA Medwatch adverse reaction case reports involving allopurinol, rituximab, and bendamustine is also presented. © The Author(s) 2014.
Full Text Available Minocycline is an antibiotic of tetracycline derivatives that is commonly used in the treatment of moderate to severe acne vulgaris. It has been reported to cause rare adverse events from mild cutaneous eruption to severe forms including drug-induced lupus, serum sickness-like reaction, and hypersensitivity reactions, etc. The risks of adverse events attributed to minocycline have not been ascertained reliably and there are concerns about the safety of minocycline which could possibly result in life-threatening events such as the Stevens-Johnson syndrome. Here we demonstrate an unusual case of Stevens-Johnson syndrome in conjunction with bilateral parotitis after the intake of minocycline in a Korean boy suggesting discreet use of the drug.
Çekiç, Şükrü; Canıtez, Yakup; Sapan, Nihat
Stevens Johnson syndrome and toxic epidermal necrolysis are severe acute mucocutaneous diseases. In this study, we evaluated the clinical aspects of Steven Johnson syndrome, toxic epidermal necrolysis and Stevens-Johnson syndrome/toxic epidermal necrolysis overlap patients who admitted to our clinics in the last five years. Eleven patients diagnosed as Stevens-Johnson syndrome, toxic epidermal necrolysis and Stevens-Johnson syndrome/toxic epidermal necrolysis overlap in Department of Pediatric Allergy in Uludağ University School of Medicine were included in this study. Clinical findings, laboratory tests and response to treatments were evaluated via electronic files. Two of the patients had Stevens-Johnson syndrome, four had Stevens-Johnson syndrome/toxic epidermal necrolysis overlap, and five had toxic epidermal necrolysis. The median period for drug usage was 10 days (2-44 days). Herpes simpleks virus IgM antibody was detected two patients. The median healing time was 38 days 26-94 days). Maculopapular eruptions and oral mucositis were seen in all patients. Vesicul or bullae, epidermal detachment and ocular involvement in 10 of patients. Wound care, H1 antihistamine and methyl prednisolon were used in all patients, intravenous immunoglobulin were used in 7 patients and cyclosporine in 1 patient. Sequel lesions developed in 2 of the patients and there was no death. Anticonvulsants, antibiotics and non steroid anti-inflammatory drugs play a major role in the etiology of Stevens-Johnson syndrome and toxic epidermal necrolysis. Anticonvulsants are associated with severe disease. The patients with proper wound care and treatment with immunosuppressive drugs can be recovered without or with minimal sequelae.
Full Text Available Objective: Monnose-Binding lectin (MBL appears to play an important role in the immune system. The genetic polymorphisms in the MBL2 gene can result in a reduction of serum levels, leading to a predisposition to recurrent infection. The aim of this study is to investigate the influence of a polymorphism in codon 54 of the MBL2 gene on the susceptibility to Erythema Multiforme, Stevens-Johnson Syndrome and Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Overlap Syndrome (EM, SJS and SJS/TEN overlap syndrome. Material and Methods: Our study included 64 patients who were clinically and/or histopathologically diagnosed with EM, SJS, and SJS/TEN overlap syndrome and 66 healthy control subjects who were genotyped for the MBL2 gene codon 54 polymorphism using the PCR-RFLP method. For all statistical analyses, the level of significance was set at p<0.05. Results: The prevalence of the B allele was 18% in the EM, SJS and SJS/TEN patient groups and 13% in the control group. No significant differences in allele frequencies of any polymorphism were observed between the patient and control groups, although the B allele was more frequent in the patient groups (p=0.328.Conclusion: Our results provide no evidence of a relationship between MBL2 gene codon 54 polymorphism and the susceptibility to EM, SJS and SJS/TEN overlap syndrome. However, these findings should be confirmed in studies with a larger sample size.
Balasundaram, S; Ranganathan, K; Umadevi, K; Gunaseelan, R; Kumaraswamy, N; Solomon, Sunithi; Devaleenol, Bella; Ambrose, Pradeep
Nevirapine is a non-nucleoside reverse transcriptase inhibitor, widely used in combination with other antiretroviral agents for treatment of HIV infection. Steven Johnson syndrome (SJS) is the major toxicity of nevirapine. We describe here four cases of SJS in HIV seropositive patients following nevirapine therapy. In all four cases cutaneous hypersensitivity reaction was seen with extreme oral lesions, three patients presented clinically with elevated liver enzymes and hepatitis, and two patients had ocular involvement.
Havva Yildiz Seckin
Full Text Available Fox-Fordyce Disease (FFD is a rare, chronic disorder of the apocrin sweat glands and characterized by pruritic papules. The disease primarily affects females and the etiology is unclear. A 19-year-old male patient developed FFD in his lips with a history of Steven-Johnson Syndrome is presented in this report. [J Contemp Med 2016; 6(3.000: 214-217
Avinash, A.; Amberkar, V. Mohanbabu; Kunder, Sushil Kiran; Madhyastha, Sharath; Meenakumari, K.
Stevens-Johnson syndrome is one of the few dermatological emergencies in clinical practice. The syndrome is often secondary to the usage of drugs, of which allopurinol, penicillins, sulfa drugs, ibuprofen, sodium valproate, phenytoin, lamotrigine and carbamazepine are commonly implicated. Agranulocytosis is the existence of a clinically significant reduction in neutrophil count. This condition is a serious threat to the patient, as he/she is at a greater risk of contracting bacterial or funga...
Trivedi, Bhavi S.; Darji, Nishita H.; Malhotra, Supriya D.; Patel, Pankaj R.
Stevens?Johnson syndrome (SJS) is an acute life-threatening mucocutaneous reaction, characterized by extensive necrosis and detachment of the epidermis from the skin. The overall incidence of SJS is seen in five cases per million people per year. SJS is typically caused by drugs and is a kind of idiosyncratic reaction. Adverse drug reactions such an SJS have a remarkable effect on patient's safety issues. We encountered nine cases of antiepileptic drug (AED)-induced SJS, specifically with car...
Gavigan, Geneviève M; Kanigsberg, Nordau D; Ramien, Michele L
We report a case of an 11-year-old female with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) overlap, most likely triggered by sulfamethoxazole-trimethoprim, who was treated with the combination of methylprednisolone, cyclosporine, and etanercept. Her condition stabilized and her skin involvement did not progress after the addition of etanercept. To our knowledge, this is the first report of etanercept for pediatric SJS/TEN.
Full Text Available The Stevens-Johnson syndrome (SJS classically involves a targetoid skin rash and the association of the oral mucosa, genitals, and conjunctivae. Recently, there have been several documentations of an incomplete presentation of this syndrome, without the typical rash, usually associated with the mycoplasma pneumoniae infection. Our case illustrates that this important clinical diagnosis should not be missed due to its atypical presentation.
Luisa María Pacheco Álvarez
Full Text Available El síndrome de Stevens-Johnson, es una enfermedad inflamatoria aguda, originada por una hipersensibilidad, que incluye la piel y las membranas mucosas; en una forma mayor pone en peligro la vida del paciente. Puede ser inducida por muchos factores precipitantes, desde los medicamentos hasta una infección. La afección se caracteriza por una súbita erupción morfológicamente variable, acompañada de estomatitis y oftalmia. En este trabajo se presenta un niño de 8 años de edad, con la entidad clínica en forma muy severa, el síndrome de Stevens-Johnson, que involucra manifestaciones cutáneas, oculares y de la mucosa oral, acompañada de otras complicaciones graves, por lo que requirió terapéutica en cuidados intensivos, y se logró una evolución satisfactoria del paciente.Stevens-Johnson syndrome is an acute inflammatory disease caused by a hypersensibility that includes the skin and the mucous membranes and that in a severe form endangers the patient’s life. It may be induced by many precipitating factors, from drugs to infection. The affection is characterized by a sudden morphologically variable rash, accompanied with stomatitis and ophthalmia. An 8-year-old boy suffering from this clinical entity in a very severe form, Stevens-Johnson syndrome, with skin , ocular and oral mucosa manifestations and with other serious complications, is presented in this paper. He had to be treated at the ICU and a satisfactory evolution was attained.
Burkhart, Keith K.; Abernethy, Darrell; Jackson, David
Drug features that are associated with Stevens-Johnson syndrome (SJS) have not been fully characterized. A molecular target analysis of the drugs associated with SJS in the FDA Adverse Event Reporting System (FAERS) may contribute to mechanistic insights into SJS pathophysiology. The publicly available version of FAERS was analyzed to identify disproportionality among the molecular targets, metabolizing enzymes, and transporters for drugs associated with SJS. The FAERS in-house version was al...
Siqueira, Ana Carolina Punzi de; Santos, Myrna Serapião dos; Farias, Charles Costa de; Barreiro, Telma Regina Maria Pereira; Gomes, José Álvaro Pereira
To evaluate the efficacy of scleral contact lenses use on the management of ocular sequelae from Stevens-Johnson syndrome patients. In a retrospective study, patients who suffered sequelae of Stevens-Johnson syndrome and started the use of scleral contact lenses were followed. Patients were submitted to an evaluation of symptoms through a questionnaire; ophthalmologic exam (visual acuity measurement, biomicroscopy, ocular surface staining with fluorescein drops, Schirmer test). Ten eyes of seven patients were analyzed. Visual acuity varied from hand movements to 20/25. All patients presented some degree of corneal opacity and slight symblepharon. In patients whose adaptation to scleral contact lenses was successful (90%), they all refered improvement of symptoms and sight. As for the biomicroscopic findings it was observed an improvement of conjunctival hyperemia and keratitis and a reduction of the mucous secretion in 90% the cases. A successful adaptation to scleral contact lenses was feasible on most patients, with relief of symptoms and better visual acuity, probably due to regularization of the surface. Scleral contact lenses represent an important and accessible alternative to reduce the limitations inferred by the damages from Stevens-Johnson syndrome.
Mochitomi, Y; Inoue, A; Kawabata, H; Ishida, S; Kanzaki, T
Stevens-Johnson syndrome is considered to be a severe type of erythema exsudativum multiforme. It is characterized by erythema with bullous and eroded lesions of skin and mucous membranes. We report a case of Steven-Johnson syndrome following consumption of a health drink containing ophiopogonis tuber. A 66-year-old female took an O.T.C. health drink for fever. The next morning, she noted erythema and swelling of her face, neck, and chest. She started to develop bullous and eroded lesions on the skin of her entire body and the mucous membranes of her oral cavity, conjunctiva, and cornea, and she became feverish. She had high degrees of corneal erosion and liver dysfunction. Skin biopsy showed diffuse necrosis of the epidermis. After admission to the hospital, steroid pulse therapy (1000 mg/day of methylprednisolone sodium succinate) was continued for 5 days. The health drink induced a positive drug lymphocyte stimulation test (DLST) and patch test. A challenge test was done with a one hundredth dose, and it was positive. We did patch tests with all components of the drink and found that Mai-Meu-Dong-Tang (ophiopogonis) alone was positive at 72 hours. There is no previous report of Stevens-Johnson syndrome caused by a health drink or Mai-Meu-Dong-Tang. Even though it is a health drink, we should be aware of the possibility of a severe reaction.
Arantes, Luana Bernardes; Reis, Carmélia Santiago; Novaes, Alice Garbi; de Carvalho, Marta Rodrigues; Göttems, Leila Bernarda Donato; Novaes, Maria Rita Carvalho Garbi
Background Adverse drug reactions are harmful and involuntary responses to drugs that occur at doses normally used for a given condition. Among them are Stevens-Johnson syndrome and toxic epidermal necrolysis, both rare and potentially fatal conditions. Objectives To analyze the epidemiological and clinical characteristics related to patients diagnosed with Stevens-Johnson syndrome and toxic epidermal necrolysis in public hospitals in the Federal District - Brazil. Methods Retrospective, cross-sectional and descriptive study, in which data were collected referring to patients hospitalized in the public healthcare system of the Federal District from 1999 to 2014. Results: Between 1999 and 2014, 86 cases of hospitalized patients with diagnosis of Stevens-Johnson syndrome and toxic epidermal necrolysis in the Federal District were reported. The majority of patients were women; the most affected age group was 0 to 10 years. Patients older than 60 years (elderly) represent 6.98% of the cases. Most patients admitted to the referral hospital were discharged. However, occurrence of deaths exceeded that of discharge in elderly patients. Limitations of the study There is fragility in the registry of hospitalization of patients, both in the hospital information system and in the medical records of the reference hospital. Conclusion There is a need for greater production and better dissemination of information on the incidence of adverse drug reactions. PMID:29166503
Arantes, Luana Bernardes; Reis, Carmélia Santiago; Novaes, Alice Garbi; Carvalho, Marta Rodrigues de; Göttems, Leila Bernarda Donato; Novaes, Maria Rita Carvalho Garbi
Adverse drug reactions are harmful and involuntary responses to drugs that occur at doses normally used for a given condition. Among them are Stevens-Johnson syndrome and toxic epidermal necrolysis, both rare and potentially fatal conditions. To analyze the epidemiological and clinical characteristics related to patients diagnosed with Stevens-Johnson syndrome and toxic epidermal necrolysis in public hospitals in the Federal District - Brazil. Retrospective, cross-sectional and descriptive study, in which data were collected referring to patients hospitalized in the public healthcare system of the Federal District from 1999 to 2014. Results: Between 1999 and 2014, 86 cases of hospitalized patients with diagnosis of Stevens-Johnson syndrome and toxic epidermal necrolysis in the Federal District were reported. The majority of patients were women; the most affected age group was 0 to 10 years. Patients older than 60 years (elderly) represent 6.98% of the cases. Most patients admitted to the referral hospital were discharged. However, occurrence of deaths exceeded that of discharge in elderly patients. There is fragility in the registry of hospitalization of patients, both in the hospital information system and in the medical records of the reference hospital. There is a need for greater production and better dissemination of information on the incidence of adverse drug reactions.
Schoeffler, A; Levy, E; Weinborn, M; Cuny, J-F; Schmutz, J-L; Barbaud, A; Cribier, B; Bursztejn, A-C
Hodgkin's disease has been associated with a variety of cutaneous symptoms. We report two cases of Stevens-Johnson syndrome (SJS) associated with Hodgkin's disease. Case 1: a 22-year-old man was hospitalized for a second erythematous vesicular eruption with intense mucosal involvement. Histopathological examination confirmed the diagnosis of Stevens-Johnson syndrome. He also developed enlarged cervical lymph nodes that revealed Hodgkin's disease. The latter diagnosis was followed by two recurrent rashes. Treatment consisted of systemic chemotherapy. Complete remission was obtained with no signs of cutaneous recurrence after 24 months of regular follow-up. Case 2: a 29-year-old man was admitted for a generalized erythematous and bullous rash with intense mucosal involvement. Histopathological examination confirmed the diagnosis of Stevens-Johnson syndrome. He then developed muco-cutaneous icterus that was secondary to Hodgkin's disease. Under specific hematologic treatment, no cutaneous relapse was noticed. These cases illustrate the rare association of SSJ revealing Hodgkin's disease. In these cases, no evidence was found of infectious disease or drug-induced cutaneous effects. Only one case of toxic epidermal necrolysis associated with Hodgkin's disease had previously been reported. The link between both diseases may be immunosuppression induced by Hodgkin's disease, which could favor infection inducing SJS or secretion by tumor cells granulysin, a mediator responsible for damage to keratinocytes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Liu, Dong; Deng, Fujin; Wang, Yanbo
T-type isolated DC/DC converters have recently attracted attention due to their numerous advantages, including few components, low cost, and symmetrical operation of transformers. This study proposes an improved control strategy for increasing the efficiency of T-type isolated DC/DC converters....../DC converters. The operation principles and performances of T-type isolated DC/DC converters under the proposed control strategy are analyzed in detail and verified through the simulation and experimental results....
Full Text Available Choppers are widely used in order to get smooth speed characteristics of DC motors. If the load or input voltage is changed, a feedback control technique is used to get the constant speed. To design the proper feedback control, the transfer function of the chopper-motor combination should be kno\\vn. ln this study, the effort was given to obtain the general black diagram, inciurling the field current and aı1na ture current of chopper-fed DC motor. It can be seen from the black diagram that the chopper circuit modifies the transfer function of the DC motor. DC-DC DARBEL E YİCİ iLE YABANCI UYARTIMLI DC KÜÇÜK SİNY AL ANALİZİ ÖZET BESLENEN MOT O RUN DC motorlardan düzgün bir hız karakteristiği elde etmek için darbeleyiciler çok kullamlır. Eğer yük ya da giriş gerilimi de ği şirse, sabit hız elde etmek için geribeslemeli kontrol tekniği kuJlanılır. Uygun bir geribesleme kontrolu tasarlamak iç� darbeliyici-motor kombinasy onunun transfer fonksiyonu bilinmelidir. -Bu çalışma da, darbeleyici ile beslenen DC motorun alan akımı ve endüvi akımını da kapsayan genel blok diyağraınını elde etıııek için çaba gösterilmiştir. Blok diyagramından görülebilec eği gibi, darbeleyici devresi DC motorun tra nsfer fonksiyonunu değiştirmektedir. I. INTRODUCTI ON Choppers are widely used for speed control of DC separately excited motors as they offer high efficiency, quick response, wide speed control range and regeneration down to very low speeds [ 1] . All chopper circuits can be classified into two groups. (a Load ind ependent choppers� in which the output voltage waveform is either a square wave or can be approximated by a square \\vave. (b Load dependent choppers, in which charging of the commutating capacitor is govemed by load current. In such cases, the output voltage wavefoım is neither a square wave nor can be approximated by a square wave. Various methods of analyzing of DC motors fed by a chopper with
Wahid Ibrahim, Arifin; Wahyu Widodo, Triyogatama; Wahyu Supardi, Tri
The use of a DC motor in the industrialized world is very important. Speed of DC motor and torque of DC motor greatly affects quality and quantity of product. Therefore, we need control system of a DC motor that can be set speed and torque. The number of industry players complained about damage to the DC motor because transported load torque of motor exceeds capabilities of torque of DC motor. Based on these problem, we should make torque control system in DC motor.Torque control system made ...
Park, Kiwoo; Chen, Zhe
This study presents a control strategy and its dynamic analysis of a high-power dc-dc converter, which is constructed with the parallel-connected single active bridge (SAB) dc-dc converters for dc-grid wind farm applications. The structural and operational characteristics of the SAB dc-dc converter...
This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to
SHESHIDHAR REDDY ADDULA
Full Text Available In this paper, a novel soft-switched interleaved DC-DC converter which provides a high voltage gain of 12 is proposed. Voltage gain of the basic interleaved boost converter is extended by using diode-capacitor multiplier (DCM cells. The switches are operated at a nominal duty ratio of 0.5. The voltage stress on the power switches and diodes is only a fraction of the output voltage. To enhance the operating power conversion efficiency, the switches are turned ON at zero voltage condition. Experimental results of 18-216V, 100W prototype converter validate the operating principle and the advantageous features of the presented converter.
Druce, R.L.; Kirbie, H.C.; Newton, M.A.
A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.
Kazimierczuk, Marian K
This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,
Lehman, J.; Yui, C.; Rax, B. G.; Miyahira, T. F.; Weideman, M.; Schrick, P.; Swift, G. M.; Johnston, A. H.
Box-level total dose testing of the FOG (Fiber Optic Gyro) by IXSEA at ESA's GammabeamFacility were abruptly terminated at 8krad (Si) due to catastrophic failure (complete shutdown). This was unexpected because all components within the gyro were supposedly radiation tolerant. Further testing showed that the components responsible for the failure were two DC-DC converters, manufactured by Interpoint, that stopped regulating shortly before shutdown. This paper summarizes diagnostic test results for the converters to determine the underlying cause of the unexpected failure at low levels of radiation.
Elangovan, D.; Archana, R.; Jayadeep, V. J.; Nithin, M.; Arunkumar, G.
More than fifty percent Indian population do not have access to electricity in daily lives. The distance between the power generating stations and the distribution centers forms one of the main reasons for lack of electrification in rural and remote areas. Here lies the importance of decentralization of power generation through renewable energy resources. In the present world, electricity is predominantly powered by alternating current, but most day to day devices like LED lamps, computers and electrical vehicles, all run on DC power. By directly supplying DC to these loads, the number of power conversion stages was reduced, and overall system efficiency increases. Replacing existing AC network with DC is a humongous task, but with power electronic techniques, this project intends to implement DC grid at a household level in remote and rural areas. Proposed work was designed and simulated successfully for various loads amounting to 250 W through appropriate power electronic convertors. Maximum utilization of the renewable sources for domestic and commercial application was achieved with the proposed DC topology.
Haxthausen, Anne Elisabeth; Yong, X.
Duration Calculus (DC) is an interval-based real-time logic, which can be used in capturing and eliciting users' real-time requirements. The Timed RAISE Specification Language (TRSL) is an extension of the RAISE Specification Language with real-time features. This paper links DC and TRSL together...... in a method for real-time developments. An operational semantics with behavior is specified for TRSL. It is defined what its means for a TRSL process to satisfy a DC requirement, and a method for verifying whether the satisfaction relation holds or not is provided. Our contribution also demonstrates a general...... approach for linking state-based real-time logics together with event-based, timed process algebra languages....
S. Rekarte García; C. Montalvo Ávalos; A. López Martínez; L. Mantecón Fernández; P. Fernández González
Introducción. El síndrome de Stevens-Johnson es una reacción idiosincrásica mucocutánea secundaria mayoritariamente a fármacos y a ciertos agentes infecciosos. En algunas ocasiones, como los dos casos que aquí se presentan, cursa con mínima afectación cutánea, predominando el compromiso mucoso en forma de ampollas, erosiones y costras. Caso clínico 1. Niño de 8 años con lesiones aftosas, vesículo-ampollosas y costrosas en mucosa oral, labial y endonasal; eritema violáceo periocular bilateral,...
Tomas Gudmundsson, Jon; Hecimovic, Ante
A typical dc discharge is configured with the negative cathode at one end and a positive anode at the other end, separated by a gas filled gap, placed inside a long glass cylinder. A few hundred volts between the cathode and anode is required to maintain the discharge. The type of discharge that is formed between the two electrodes depends upon the pressure of the working gas, the nature of the working gas, the applied voltage and the geometry of the discharge. We discuss the current–voltage characteristics of the discharge as well as the distinct structure that develops in the glow discharge region. The dc glow discharge appears in the discharge current range from μA to mA at 0.5–300 Pa pressure. We discuss the various phenomena observed in the dc glow discharge, including the cathode region, the positive column, and striations. The dc glow discharge is maintained by the emission of secondary electrons from the cathode target due to the bombardment of ions. For decades, the dc glow discharge has been used as a sputter source. Then it is often operated as an obstructed abnormal glow discharge and the required applied voltage is in the range 2–5 kV. Typically, the cathode target (the material to be deposited) is connected to a negative voltage supply (dc or rf) and the substrate holder faces the target. The relatively high operating pressure, in the range from 2 to 4 Pa, high applied voltages, and the necessity to have a conductive target limit the application of dc glow discharge as a sputter source. In order to lower the discharge voltage and expand the operation pressure range, the lifetime of the electrons in target vicinity is increased through applying magnetic field, by adding permanent magnets behind the cathode target. This arrangement is coined the magnetron sputtering discharge. The various configurations of the magnetron sputtering discharge and its applications are described. Furthermore, the use of dc discharges for chemical analysis, the
Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja
A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.
In a typical residential, commercial or utility grade photovoltaic (PV) system, PV modules are connected in series and in parallel to form an array that is connected to a standard DC/AC inverter, which is then connected directly to the grid. This type of standard installation; however, does very little to maximize the energy output of the solar array if certain conditions exist. These conditions could include age, temperature, irradiance and other factors that can cause mismatch between PV modules in an array that severely cripple the output power of the system. Since PV modules are typically connected in series to form a string, the output of the entire string is limited by the efficiency of the weakest module. With PV module efficiencies already relatively low, it is critical to extract the maximum power out of each module in order to make solar energy an economically viable competitor to oil and gas. Module level DC/DC electronics with maximum power point (MPP) tracking solves this issue by decoupling each module from the string in order for the module to operate independently of the geometry and complexity of the surrounding system. This allows each PV module to work at its maximum power point by transferring the maximum power the module is able to deliver directly to the load by either boosting (stepping up) the voltage or bucking (stepping down) the voltage. The goal of this thesis is to discuss the development of a per-module DC/DC converter in order to maximize the energy output of a PV module and reduce the overall cost of the system by increasing the energy harvest.
Norwich's Entropy Theory of Perception (1975-present) is a general theory of perception, based on Shannon's Information Theory. Among many bold claims, the Entropy Theory presents a truly astounding result: that Stevens' Law with an Index of 1, an empirical power relation of direct proportionality between perceived taste intensity and stimulus concentration, arises from theory alone. Norwich's theorizing starts with several extraordinary hypotheses. First, 'multiple, parallel receptor-neuron units' without collaterals 'carry essentially the same message to the brain', i.e. the rate-level curves are identical. Second, sensation is proportional to firing rate. Third, firing rate is proportional to the taste receptor's 'resolvable uncertainty'. Fourth, the 'resolvable uncertainty' is obtained from Shannon's Information Theory. Finally, 'resolvable uncertainty' also depends upon the microscopic thermodynamic density fluctuation of the tasted solute. Norwich proves that density fluctuation is density variance, which is proportional to solute concentration, all based on the theory of fluctuations in fluid composition from Tolman's classic physics text, 'The Principles of Statistical Mechanics'. Altogether, according to Norwich, perceived taste intensity is theoretically proportional to solute concentration. Such a universal rule for taste, one that is independent of solute identity, personal physiological differences, and psychophysical task, is truly remarkable and is well-deserving of scrutiny. Norwich's crucial step was the derivation of density variance. That step was meticulously reconstructed here. It transpires that the appropriate fluctuation is Tolman's mean-square fractional density fluctuation, not density variance as used by Norwich. Tolman's algebra yields a 'Stevens Index' of -1 rather than 1. As 'Stevens Index' empirically always exceeds zero, the Index of -1 suggests that it is risky to infer psychophysical laws of sensory response from information theory
Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.
This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of
Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the…
Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 10. Electricity - AC versus DC. D P Sen Gupta. General Article Volume 2 Issue 10 October 1997 pp 46-53. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/10/0046-0053. Author Affiliations.
Manolio, Teri A; Hutter, Carolyn M; Avigan, Mark; Cibotti, Ricardo; Davis, Robert L; Denny, Joshua C; Grenade, Lois La; Wheatley, Lisa M; Carrington, Mary N; Chantratita, Wasun; Chung, Wen-Hung; Dalton, Andrea D; Hung, Shuen-Iu; Lee, Ming Ta Michael; Leeder, J Steven; Lertora, Juan J L; Mahasirimongkol, Surakameth; McLeod, Howard L; Mockenhaupt, Maja; Pacanowski, Michael; Phillips, Elizabeth J; Pinheiro, Simone; Pirmohamed, Munir; Sung, Cynthia; Suwankesawong, Wimon; Trepanier, Lauren; Tumminia, Santa J; Veenstra, David; Yuliwulandari, Rika; Shear, Neil H
Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is one of the most devastating of adverse drug reactions (ADRs) and was, until recently, essentially unpredictable. With the discovery of several risk alleles for drug-induced SJS/TEN and the demonstration of effectiveness of screening in reducing incidence, the stage is set for implementation of preventive strategies in populations at risk. Yet much remains to be learned about this potentially fatal complication of commonly used drugs. © 2017 American Society for Clinical Pharmacology and Therapeutics.
In 3 patients with status after Fuchs-Steven-Johnson syndrome highly hydrophilic contact lenses (72% H2O-up take) were adapted and worn permanently. 2 patients had worn already for a long time usual HEMA-lenses. The lenses showed themselves to be favorable against mechanical irritation from cilia and accessory eyelashes and from scarring conjunctival conditions, and they affected favorably the signs of dessication of the cornea. Corneal defects healed, and the patients had subjectively no complaints. It is sometimes necessary to replace the tears. An increase in the corneal vascularisation already present could not be observed during the 18 months observation time.
Idar, D.J.; Lucht, R.A.; Straight, J.W. [and others
Low-velocity mechanical impact and subsequent high explosive (HE) reaction are of concern in credible accident scenarios involving the handling, transport, and storage of nuclear weapons. Using modified Steven spigot gun tests, the authors have investigated the high-explosive violent-reaction (HEVR) potential of PBX 9501 to low-amplitude insult. Reliable modeling predictions require that one identify the relevant parameters and behavioral responses that are key to the reaction mechanism(s) in PBX 9501. Additional efforts have been targeted at identifying relevant differences in the response between baseline and stockpile-aged PBX 9501 to low-velocity impacts.
Gupta, Lalit Kumar; Martin, Abhay Mani; Agarwal, Nidheesh; D'Souza, Paschal; Das, Sudip; Kumar, Rajesh; Pande, Sushil; Das, Nilay Kanti; Kumaresan, Muthuvel; Kumar, Piyush; Garg, Anubhav; Singh, Saurabh
Stevens-Johnson syndrome and toxic epidermal necrolysis are severe, life-threatening mucocutaneous adverse drug reactions with a high morbidity and mortality that require immediate medical care. The various immunomodulatory treatments include systemic corticosteroids, cyclosporine, intravenous immunoglobulin, cyclophosphamide, plasmapheresis and tumor necrosis factor-α inhibitors. The ideal therapy of Stevens-Johnson syndrome/toxic epidermal necrolysis still remains a matter of debate as there are only a limited number of studies of good quality comparing the usefulness of different specific treatments. The aim of this article is to comprehensively review the published medical literature and frame management guidelines suitable in the Indian perspective. The Indian Association of Dermatologists, Venereologists and Leprologists (IADVL) assigned the task of preparing these guidelines to its special interest group on cutaneous adverse drug reactions. The group performed a comprehensive English language literature search for management options in Stevens-Johnson syndrome/toxic epidermal necrolysis across multiple databases (PubMed, EMBASE, MEDLINE and Cochrane) for keywords (alone and in combination) and MeSH items such as "guidelines," "Stevens-Johnson syndrome," "toxic epidermal necrolysis," "corticosteroids," "intravenous immunoglobulin," "cyclosporine" and "management." The available evidence was evaluated using the strength of recommendation taxonomy and graded using a three-point scale. A draft of clinical recommendations was developed on the best available evidence which was also scrutinized and critically evaluated by the IADVL Academy of Dermatology. Based on the inputs received, this final consensus statement was prepared. A total of 104 articles (meta-analyses, prospective and retrospective studies, reviews [including chapters in books], previous guidelines [including Indian guidelines of 2006] and case series) were critically evaluated and the evidence
Full Text Available Stevens-Johnson syndrome (SJS is an uncommon occurrence in Mycoplasma pneumoniae (M. pneumoniae infection (1–5% and has been mainly reported in children and young adults. We present a case of SJS in a 32-year-old male induced by M. pneumoniae infection. This patient presented with fever, cough, and massive occupation of mucus membranes with swelling, erythema, and necrosis accompanied by a generalized cutaneous rash. He clinically responded after treatment with antibiotics and IVIG. SJS is usually a drug-induced condition; however, M. pneumoniae is the commonest infectious cause and should be considered in the differential diagnosis.
Stevens-Johnson syndrome and toxic epidermal necrolysis are rare, life-threatening, cutaneous drug reactions. Medications are the most common cause, although an infection may be responsible. A link between genetics and certain medications has been established. Clinical diagnosis should be confirmed with biopsy. When the area of epidermal detachment approaches 30%, burn center care is advisable. An ophthalmologist should be consulted to optimize ocular care. Pharmacologic interruption has been sought but there is little consensus on the most appropriate agent and no high-quality studies have been conducted to demonstrate if any of these agents lead to improved survival. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.
... Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes AGENCY: Federal Aviation Administration (FAA... DC-9-30, DC-9-40, and DC-9-50 series airplanes. This AD requires inspecting to determine the part...-30, DC-9-40, and DC-9-50 series airplanes. That NPRM was published in the Federal Register on August...
Stefanov, Goce; Kukuseva, Maja; Citkuseva Dimitrovska, Biljana
In this paper pulse mode of operation of DC motor controlled by DC/DC power converter is analyzed. DC motor operation with time intervals in which the motor operates without output load is of interest. In this mode it is possible the motor to restore energy. Also, in the paper are represented calculations for the amount of the restored energy in the pulse mode operation of the motor for different duty cycles.
Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed
A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.
Rakan Kh Antar
Full Text Available This paper describes the application of ac/ac/dc and ac/dc converters to control the speed of a separately excited DC motor. Artificial neural network and PI controller are trained to select the desired values of firing angles for triggering thyristors of the ac/ac/dc and ac/dc bridge converters in order to control the speed of the dc motor at a desired value with constant and different load torques in order to obtain the best speed response. Simulation results show that the rising time for ac/dc and ac/ac/dc converters at 250rpm are reduced about 79% and 89% respectively, while delay time it reduced about 69% and 64% respectively. Therefore, speed response of the dc motor is more efficient for closed loop system compared with open loop also the response of ac/ac/dc converter is better than ac/dc converter.
Sun, Xiaofeng; Wu, Xiaoying; Shen, Yanfeng
This paper proposes a current-fed isolated bidirectional DC-DC converter (CF-IBDC) which has the advantages of wide input voltage range, low input current ripple, low conduction losses, and soft switching over the full operating range. Compared with conventional CF-IBDCs, the voltage spikes...... of the low-voltage (LV) side switches in the proposed converter can be eliminated without additional clamp circuits. The converter adopts the pulse width modulation (PWM) plus hybrid phase-shift control scheme such that the bus voltage can match the output voltage by means of the transformer. Thus......, the current stresses and conduction losses of the converter become lower. In addition, the practical ZVS of the secondary-side switches can be realized by adjusting the phase-shift angle within the secondary side when in light load or no load condition. The operating principles and characteristics including...
charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier by a semiconductor switch arrangement in accordance with a switch control signal to produce the converter output voltage. The resonant step-down DC-DC power converter comprises an electrical short...... and an input capacitor coupled between the positive and negative input terminals and the secondary side circuit comprises an output capacitor chargeable to a converter output voltage between a first positive electrode and a second negative electrode. A resonant network is con- figured for alternatingly being......-circuit connection across the galvanic isolation barrier connecting, in a first case, the second negative electrode of the output capacitor to the positive input terminal of the primary side circuit or, in a second case, connecting the second positive electrode of the output capacitor to the negative input terminal...
being charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier in accordance with a switch control signal to produce the converter output voltage. The step-up DC-DC power converter comprises an electrical short-circuit connection across the galvanic...... capacitor coupled between the positive and negative input terminals and the secondary side circuit comprises an output capacitor chargeable to a converter output voltage between a first positive electrode and a second negative electrode. A switched energy storage network is configured for alternatingly...... isolation barrier connecting, in a first case, the second negative electrode of the output capacitor to the positive input terminal of the primary side circuit or, in a second case, connecting the second positive electrode of the output capacitor to the negative input terminal of the primary side circuit...
National Aeronautics and Space Administration — The NAMMA DC-8 Dropsonde dataset were collected by the DC-8 dropsonde system, which uses an integrated, highly accurate, GPS-located atmospheric profiling dropsonde...
Miliszewski, Monica A; Kirchhof, Mark G; Sikora, Sheena; Papp, Anthony; Dutz, Jan P
Stevens-Johnson syndrome and toxic epidermal necrolysis are severe mucocutaneous adverse drug reactions characterized by extensive epidermal detachment. The mortality rates have been reported to vary between 1% and 5% for Stevens-Johnson syndrome and 25% and 35% for patients with toxic epidermal necrolysis. Studies have shown that early recognition and prompt withdrawal of the causative agent leads to increased patient survival. A retrospective chart review was conducted on 64 patients admitted to Vancouver General Hospital with a diagnosis of Stevens-Johnson syndrome or toxic epidermal necrolysis from 2001 to 2011. The aim of this study was to identify the medications most often implicated in triggering Stevens-Johnson syndrome and toxic epidermal necrolysis, as well as to delineate the timeline of identification and removal of these triggers. A trigger was identified in 75% of cases. Allopurinol was the single most common offending agent (20% of cases). Anticonvulsants and antibiotics were common triggers. The offending agent was often removed at time of hospital admission/diagnosis but not at onset of symptoms. A history of prior culprit drug exposure with previous mucocutaneous adverse reaction was noted in 19% of cases with identified triggers. Asians and Native North Americans had a higher mortality than whites, and Asians more frequently had allopurinol as a trigger. The onset and high mortality rate of Stevens-Johnson syndrome/toxic epidermal necrolysis may be related to unawareness of the early signs and symptoms of Stevens-Johnson syndrome and toxic epidermal necrolysis, the common drug triggers that cause it, and what investigations (human leukocyte antigen typing in Asians) can be done to prevent it. Copyright © 2016. Published by Elsevier Inc.
di Carlo, Leonardo
Since the inception of mesoscopic electronics in the 1980's, direct current (dc) measurements have underpinned experiments in quantum transport. Novel techniques complementing dc transport are becoming paramount to new developments in mesoscopic electronics, particularly as the road is paved toward quantum information processing. This thesis describes seven experiments on GaAs/AlGaAs and graphene nanostructures unified by experimental techniques going beyond traditional dc transport. Firstly, dc current induced by microwave radiation applied to an open chaotic quantum dot is investigated. Asymmetry of mesoscopic fluctuations of induced current in perpendicular magnetic field is established as a tool for separating the quantum photovoltaic effect from classical rectification. A differential charge sensing technique is next developed using integrated quantum point contacts to resolve the spatial distribution of charge inside a double quantum clot. An accurate method for determining interdot tunnel coupling and electron temperature using charge sensing is demonstrated. A two-channel system for detecting current noise in mesoscopic conductors is developed, enabling four experiments where shot noise probes transmission properties not available in dc transport and Johnson noise serves as an electron thermometer. Suppressed shot noise is observed in quantum point contacts at zero parallel magnetic field, associated with the 0.7 structure in conductance. This suppression evolves with increasing field into the shot-noise signature of spin-lifted mode degeneracy. Quantitative agreement is found with a phenomenological model for density-dependent mode splitting. Shot noise measurements of multi-lead quantum-dot structures in the Coulomb blockade regime distill the mechanisms by which Coulomb interaction and quantum indistinguishability correlate electron flow. Gate-controlled sign reversal of noise cross correlation in two capacitively-coupled dots is observed, and shown to
Graham, Laurie A; Finnigan, Gregory C; Kane, Patricia M
Tom Stevens' lab has explored the subunit composition and assembly of the yeast V-ATPase for more than 30 years. Early studies helped establish yeast as the predominant model system for study of V-ATPase proton pumps and led to the discovery of protein splicing of the V-ATPase catalytic subunit. The Vma - phenotype, characteristic of loss-of-V-ATPase activity in yeast was key in determining the enzyme's subunit composition via yeast genetics. V-ATPase subunit composition proved to be highly conserved among eukaryotes. Genetic screens for new vma mutants led to identification of a set of dedicated V-ATPase assembly factors and helped unravel the complex pathways for V-ATPase assembly. In later years, exploration of the evolutionary history of several V-ATPase subunits provided new information about the enzyme's structure and function. This review highlights V-ATPase work in the Stevens' lab between 1987 and 2017. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Vandersall, K S; Switzer, L L; Garcia, F
Steven Impact Tests were performed at low velocity on the explosives TNT (trinitrotolulene), Composition B (63% RDX, 36% TNT, and 1% wax by weight), C-4 (91% RDX, 5.3% Di (2-ethylhexyl) sebacate, 2.1% Polyisobutylene, and 1.6% motor oil by weight) and ANFO (94% ammonium Nitrate with 6% Fuel Oil) in attempts to obtain a threshold for reaction. A 76 mm helium driven gas gun was used to accelerate the Steven Test projectiles up to approximately 200 m/s in attempts to react (ignite) the explosive samples. Blast overpressure gauges, acoustic microphones, standard video and high-speed photography were used to characterize the level of any high explosive reaction violence. No bulk reactions were observed in the TNT, Composition B, C-4 or ANFO explosive samples impacted up to velocities in the range of 190-200 m/s. This work will outline the experimental details and discuss the lack of reaction when compared to the reaction thresholds of other common explosives. These results will also be compared to that of the Susan Test and reaction thresholds observed in the common small-scale safety tests such as the drop hammer and friction tests in hopes of drawing a correlation.
Chidester, Steven K.
Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 150-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence. This work was performed under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.
Saeed, Hajirah; Mantagos, Iason S; Chodosh, James
Ocular and cutaneous disease are common chronic sequelae of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and have been well described in the literature. Long-term complications affecting other organ systems have not been so well described. The purpose of this review article is to highlight non-ocular and non-cutaneous chronic complications of SJS/TEN. The PubMed database was searched for the keywords "Stevens-Johnson syndrome" and "toxic epidermal necrolysis" through September 1, 2014. Relevant articles were then reviewed in full. 138 articles in the English language were found that described chronic sequelae of SJS/TEN. Our search revealed six affected organ systems other than the eyes and integument, with chronic sequelae from SJS/TEN: respiratory, gastrointestinal/hepatic, oral, otorhinolaryngologic, gynecologic/genitourinary, and renal. Complications involving these organs systems appeared likely to reduce the quality of life for SJS/TEN survivors. SJS/TEN is a multi-organ disease requiring multidisciplinary care from a variety of specialists. Affected patients have complex hospital stays, and their quality of life may be severely impacted by multiple long-term complications. We believe that preventative care in the acute setting might limit the development and progression of many of the sequelae described above. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.
Full Text Available Resumen La necrólisis epidérmica tóxica y el síndrome de Stevens-Johnson son reacciones cutáneas adversas graves a medicamentos e infecciones. Los corticoides se describen como una alternativa terapéutica, sin embargo, su uso es aún controvertido. Utilizando la base de datos Epistemonikos, la cual es mantenida mediante búsquedas en múltiples bases de datos, identificamos cuatro revisiones sistemáticas que en conjunto incluyen once estudios primarios que responden la pregunta de interés. Extrajimos los datos y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Concluimos que no está claro si los corticoides disminuyen la mortalidad o la estadía hospitalaria en la necrólisis epidérmica tóxica y el síndrome de Stevens-Johnson porque la certeza de la evidencia es muy baja.
Full Text Available Part I of the literature review provides modern terminology and classification of Stevens-Johnson syndrome (SJS and toxic epidermal necrolysis (TEN, which is now considered different ways of treating the single pathological process induced in children by infections, drugs, malignant and autoimmune diseases. It illustrates in detail the latest data on pathogenesis, describes clinical manifestations of both scenarios and their transition forms. Special emphasis is made on the organisation of care for patients with SJS and TEN. It details various aspects of systemic therapy.Key words: Stevens-Johnson syndrome, toxic epidermal necrolysis, systemic treatment, children.
Jin, Chi; Wang, Peng; Xiao, Jianfang
DC microgrids are becoming popular in low-voltage distribution systems due to the better compatibility with photovoltaic panels, electric vehicles, and dc loads. This paper presents a practical dc microgrid developed in the Water and Energy Research Laboratory (WERL) in the Nanyang University...
Liu, Dong; Deng, Fujin; Chen, Zhe
/dt, reduce voltage stress on the transformer, and thus reduce the electromagnetic interference (EMI) and increase reliability. An elimination method for the dead time effect is also proposed along with the proposed modulation strategy by employing a switch in series with the flying capacitor, which can......This paper proposes a five-level active-neutralpoint- clamped (5L-ANPC) dc/dc converter for applications in medium voltage dc (MVDC) grids. A modulation strategy is proposed for the 5L-ANPC dc/dc converter to generate multilevel voltage waveforms, which can effectively reduce voltage change rate dv...
Mostaan, Ali; Soltani, Mohsen
A family of four quadrant DC/DC converters is presented in this paper. Compare with existing four quadrant DC/DC converters that have been introduced in literature, the proposed converters have lower number of components. There are two bidirectional switches, two coupled inductors and one capacitor...
Forouzesh, Mojtaba; Siwakoti, Yam Prasad; Gorji, Saman Asghari
Step-up dc-dc converters are used to boost the voltage level of the input to a higher output level. Despite of its features such as simplicity of implementation, the fundamental boost dc-dc converter has shortcomings such as low boost ability and low power density. With these limitations, researc...
Shen, Yanfeng; Wang, Huai; Blaabjerg, Frede
This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant DC-DC converters, and meanwhile achieves high efficiency. It i...
Feld, Lutz Werner; Marcel Friedrichs; Richard Hensch; Karpinski, Waclaw; Klein, Katja; Sammet, Jan Domenik; Wlochal, Michael
The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking betwe...
Dragicevic, Tomislav; Lu, Xiaonan; Quintero, Juan Carlos Vasquez
This paper presents a review of control strategies, stability analysis and stabilization techniques for DC microgrids (MGs). Overall control is systematically classified into local and coordinated control levels according to respective functionalities in each level. As opposed to local control...... strategies to achieve various control objectives are reviewed in the paper. Moreover, properties of DC MG dynamics and stability are discussed. The paper illustrates that tightly regulated point-of-load (POL) converters tend to reduce the stability margins of the system since they introduce negative...... which relies only on local measurements, some line of communication between units needs to be made available in order to achieve coordinated control. Depending on the communication method, three basic coordinated control strategies can be distinguished, i.e. decentralized, centralized and distributed...
Haxthausen, Anne; Yong, Xia
(parts of) the history of the observables of the system,and then define a satisfaction relation in terms of behaviours. DC has previously been linked together with subsets of other event-based process algebra languages, but using another approach:the event-based languages were given a denotational...... of constraints on the durations of states of the system, i.e. at a high level of abstraction.However, as a state-based logic, it lacks the ability to specifysequential programs and communicating concurrent processes at a concrete level. The Timed RAISE Specification Language (TRSL) [XG99] has this ability.......TRSL is a real-time extension of the RAISE Specification Language (RSL) [Rlg92] which together with its associated method [Rmg95]and tools has shown to be very useful in the industrial development of software systems. Therefore, a promising approach for the development of real-time systemscould be to use DC...
Full Text Available It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC is proposed for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control.
Moh. Zaenal Efendi
Full Text Available This paper presents a combination of power factor correction converter using Flyback converter and Full-bridge dc-dc converter in series connection. Flyback converter is operated in discontinuous conduction mode so that it can serve as a power factor correction converter and meanwhile Full-bridge dc-dc converter is used for dc regulator. This converter system is designed to produce a 86 Volt of output voltage and 2 A of output current. Both simulation and experiment results show that the power factor of this converter achieves up to 0.99 and meets harmonic standard of IEC61000-3-2. Keywords: Flyback Converter, Full-bridge DC-DC Converter, Power Factor Correction.
... Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, and MD-10-30F...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain Model DC-10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10), DC- 10-40, DC10-40F, and MD-10-30F airplanes. This proposed AD would...
... Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, and MD-10-30F... new airworthiness directive (AD) for certain Model DC-10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC- 10-40F, and MD-10-30F airplanes. This AD requires doing a one-time inspection of the...
Full Text Available There are difficulties in analyzing the stability of microgrids since they are located on various network structures. However, considering that the network often consists of passive elements, the passivity theory is applied in this paper to solve the above-mentioned problem. It has been formerly shown that when the network is weakly strictly positive real (WSPR, the DC microgrid is stable if all interfaces between the microgrid and converters are made to be passive, which is called interface passivity. Then, the feedback passivation method is proposed for the controller design of various DC–DC converters to achieve the interface passivity. The interface passivity is different from the passivity of closed-loop systems on which the passivity based control (PBC concentrates. The feedback passivation design is detailed for typical buck converters and boost converters in terms of conditions that the controller parameters should satisfy. The theoretical results are verified by a hardware-in-loop real-time labotray (RTLab simulation of a DC microgrid with four generators.
... DEPARTMENT OF COMMERCE Bureau of Industry and Security In the Matter of: Steven Neal Greenoe, Currently Incarcerated at: Inmate 54450-056, USP Atlanta, U.S. Penitentiary, P.O. Box 1150160, Atlanta, GA...: Currently incarcerated at: Inmate 54450-056, USP Atlanta, U.S. Penitentiary, P.O. Box 1150160, Atlanta, GA...
Haddad, Cynthia; Sidoroff, Alexis; Kardaun, Sylvia H.; Mockenhaupt, Maja; Creamer, Daniel; Dunant, Ariane; Roujeau, Jean-Claude
Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) are severe drug reactions associated with high mortality and multiple incapacitating sequelae. In the past 20 years, two large multinational case control studies, published in 1995 and 2008, had identified different degrees of drug
Khafaga, Y.M.; Jamshed, A.; Allam, A.A.K.; Ezzat, A.; Gray, A.J.; Schultz, H.; Mourad, W.A.; Al Eisa, A.
The use of phenytoin as a prophylactic anticonvulsant after brain surgery, particularly for brain tumors, is a common practice, regardless of whether the patient has a previous history of convulsions. This treatment policy assumes that the benefits exceed the risks. Four cases are described of adverse reactions of phenytoin during the cocomitant use of cranial radiotherapy. In one patient this proved fatal. There is increasing anecdotal support in the literature for a synergistic effect between phenytoin therapy and cranial radiotherapy that can result in the life-threatening Stevens-Johnson syndrome. While the association is uncommon, four cases within 24 months in one department suggest that the routine use of postoperative phenytoin as a prophylactic anticonvulsant in the absence of a history of seizures may not be warranted, particularly if the patient is to receive cranial radiotherapy. (orig.)
Full Text Available Toxic epidermal necrolysis and Stevens-Johnson syndrome are severe cutaneous adverse drug reactions. Intravenous immunoglobulin is described as a therapeutic option, however its use is still controversial. Using Epistemonikos database, which is maintained by screening over 20 databases, we identified six systematic reviews, including 39 primary studies. We combined the evidence using tables for summary of findings, following the GRADE approach, and concluded there is uncertainty about the effects of intravenous immunoglobulin because the certainty of the evidence is very low; it probably leads to important adverse effects; and has high cost. Intravenous immunoglobulin should not be used outside the context of a clinical trial, or only in cases where other treatments have failed and there are no resource constraints.
Saeed, Hajirah N; Kohanim, Sahar; Le, Hong-Gam; Chodosh, James; Jacobs, Deborah S
To report the occurrence of corneal ectasia (ECT) in patients with history of Stevens-Johnson syndrome (SJS), and to make the case for an association between these 2 diagnoses. We also report the impact of prosthetic replacement of the ocular surface ecosystem (PROSE) treatment on visual acuity (VA) in these patients. Retrospective cohort study. A manufacturing database of PROSE patients from 2002 to 2014 at Boston Foundation for Sight (BFS), a single-center clinical practice, was reviewed to identify patients with diagnoses of both SJS and ECT. Nine patients were identified with diagnoses of both SJS and ECT. In each case, review of the medical record revealed that diagnosis of SJS preceded that of ECT. The prevalence of ECT in this population exceeded that in the general population (P corneal microtrauma and matrix metalloproteinases. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
Jha, Kunal Kishor; Chaudhary, Durgesh Prasad; Rijal, Tshristi; Dahal, Semanta
Lamotrigine is a mood-stabilizing drug used in maintenance treatment of bipolar I disease. There are adverse effects with lamotrigine such as a headache, blurred vision, diplopia, somnolence, ataxia, dizziness, rash, Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis. SJS is a life-threatening, blistering mucocutaneous disease. SJS is characterized by the presence of flat, diffuse erythematous maculopapular rashes with the involvement of <10% of the body surface area. Standard trigger is drugs including anticonvulsants, antibiotics, and Mycoplasma pneumoniae infection. We report a case where a patient developed SJS secondary to delayed-type hypersensitivity reaction after 6 months of the use of lamotrigine, while his initial response during the first 6 months did not show any sign of SJS.
Maggini, Valentina; Lombardi, Niccolò; Lenti, Maria Carmela; Masi, Stefano; Trapani, Sandra; Pugi, Alessandra; Mugelli, Alessandro; Vannacci, Alfredo
We describe a case of Steven-Johnson Syndrome (SJS) associated with albuterol exposure in a 6-year-old male. A possible contributing role of albuterol in SJS occurrence in the present case is strongly suggested by the temporal relationship between the event and the initiation of drug therapy as well as by the positive rechallenge. To the best of our knowledge, albuterol had not been previously associated with SJS in medical literature. It can be therefore possible that physicians, pediatricians in particular, probably not aware of the possible risk of albuterol-induced SJS, might underestimate skin reactions in children taking the drug, thus underreporting this kind of severe adverse drug reaction. Copyright © 2015 Elsevier B.V. All rights reserved.
Sharma, Bhawna; Sannegowda, Raghavendra Bakki; Gandhi, Pankaj; Dubey, Parul; Panagariya, Ashok
Stevens-Johnson syndrome (SJS) is a severe, episodic, acute mucocutaneous reaction that is most often elicited by drugs and occasionally by infections. The drugs commonly implicated as the cause of SJS are anticonvulsants, sulfonamides, non-steroidal anti-inflammatory drugs and antibiotics. Carbamazepine (CBZ) has been commonly implicated in SJS. Neuroleptic malignant syndrome (NMS) is a rare, life-threatening but potentially treatable condition. Among the neuroleptics, haloperidol (parenteral) is implicated as a most common drug for NMS. Though rare, association of NMS with CBZ and association of NMS with toxic epidermal necrolysis (TEN) in a single patient after administration of neuroleptics has been reported in the literature before. However, a combination of NMS and SJS in a single patient after administration of CBZ has not been reported so far. We present a patient with seizure who developed SJS and NMS following administration of CBZ.
Taqi, Syed Ahmed; Zaki, Syed Ahmed; Nilofer, Angadi Rajasab; Sami, Lateef Begum
Trimethoprim-sulfamethoxazole (TMP/SMX) is a widely prescribed antimicrobial for the management of several uncomplicated infections. It is commonly used for the treatment and prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in the HIV-infected population. The adverse reaction to TMP/SMX is more frequent and severe in HIV-infected patients as compared to the general population. Here, we report a case of Stevens-Johnson syndrome (SJS) secondary to TMP/SMX. The patient had a generalized cutaneous reaction with involvement of the eyes, oral cavity, and genitals. He had elevated hepatic alanine aminotransferase and aspartate aminotransferase enzyme. TMP/SMX therapy was stopped and supportive treatment was started. His condition improved after eight days of stopping TMP/SMX therapy.
Gravante, G; Delogu, D; Marianetti, M; Trombetta, M; Esposito, G; Montone, A
Toxic epidermal necrolysis and Steven Johnson syndrome are rare diseases that usually follow drug-exposures. The authors present one retrospective study with their management and focus their retrospective analysis on finding prognostic factors. We reviewed charts of admitted patients from January 1995 to December 2005. Only those with an histologic-proved diagnosis were included in the study. Causative drugs, symptoms, management and outcome were recorded and analysed. We found 32 patients that met inclusion criteria. Mortality rate was 34.4% (11/32). Age, delay of referral, Total Burn Surface Area, white blood cells, creatinine, blood sodium, immunoglobulins therapy and more than two different types of blood bacterial species isolated were significantly correlated with death (p < 0.05). These data confirm prognostic factors already present in literature and find that the number of different bacterial species isolated from blood increase mortality. Further prospective studies are necessary to confirm these findings.
Full Text Available Bronchiolitis obliterans (BO was defined as a nonreversible obstructive lung disease in which the bronchioles are always compressed and narrowed by fibrosis or inflammation. In the severe event of lung collapse after BO, surgical intervention is often recommended, and conservative therapy is thought to be ineffective. Here, we report the case of a 9-year old girl clinically diagnosed as having bronchiolitis obliterans with abrupt occlusion of the right B4b bronchus. After a lamotrigine-induced Stevens-Johnson syndrome (SJS occurred, she presented with total collapse of the right lung on admission, which was subsequently complicated by a pneumothorax during conservative treatment, but with the re-expansion of the right upper lobe after intervention. The case indicates the possibility of reversing pulmonary atelectasis in BO. Thus, surgery may not be necessary.
Trivedi, Bhavi S; Darji, Nishita H; Malhotra, Supriya D; Patel, Pankaj R
Stevens-Johnson syndrome (SJS) is an acute life-threatening mucocutaneous reaction, characterized by extensive necrosis and detachment of the epidermis from the skin. The overall incidence of SJS is seen in five cases per million people per year. SJS is typically caused by drugs and is a kind of idiosyncratic reaction. Adverse drug reactions such an SJS have a remarkable effect on patient's safety issues. We encountered nine cases of antiepileptic drug (AED)-induced SJS, specifically with carbamazepine, oxcarbazepine, and phenytoin. To manage the reaction, the clinician withdrew the drug in all 8 cases, and in 1 case, the patient was shifted to valproate and symptomatic treatment was provided. There is still a controversy whether or not all AEDs can cause SJS. Recent studies have investigated the role of genetic factors - HLAB*502 allele in the development of AED-induced SJS in patients of Asian ancestry.
Stevens-Johnson syndrome (SJS) is an acute life-threatening mucocutaneous reaction caused by excessive necrosis and detachment of the epidermis. It is commonly drug induced and phenytoin is a common precipitant. Phenytoin, an antiepileptic drug, is also known to cause myocarditis. Phenytoin causing both myocarditis and SJS in the same patient is very rare and can lead to increased morbidity and mortality. Here, we describe the case of a 43-year-old male who developed SJS and myocarditis secondary to phenytoin. In spite of aggressive resuscitative efforts, the patient could not be revived. Thus, a combination of myocarditis with SJS increases the mortality and should be considered in patients with SJS secondary to phenytoin and associated shock.
Yang, Che-Wen; Cho, Yung-Tsu; Chen, Kai-Lung; Chen, Yi-Chun; Song, Hsiang-Lin; Chu, Chia-Yu
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse drug reactions characterized by different extents of epidermal necrosis and mucosal breakdown. A limited number of studies have reported the long-term patterns of SJS and TEN complications in patient populations over long follow-up periods. The aim of this retrospective study was to collect data on long-term sequelae in patients admitted for SJS, SJS/TEN overlap, or TEN between 1998 and 2012. Among all 102 patients eligible for analysis, the 2 most common sequelae were cutaneous and ocular problems, both with incidences of 44.1%. Visceral organ involvement was observed in 2 patients with irreversible deterioration of chronic kidney disease and in one patient with interstitial lung disease. Autoimmune disease was present in 6 patients: Sjögren's syndrome or Sjögren-like syndrome in 5 patients and concomitant systemic lupus erythematosus and Hashimoto thyroiditis in one patient.
Zaidi, Maheen; Zaidi, Syeda Kashaf; Bhutto, Moomal; Umer, Mohammad Yasir
Stevens-Johnson syndrome (SJS) is an immune mediated hypersensitivity reaction. Significant involvement of oral, nasal, eye, vaginal, urethral, GI and lower respiratory tract mucous membrane may develop. It is usually a reaction due to a medication or due to an infection. In 95 % of case reports, drugs were found to be an important cause for the development of SJS. In this case report, a 32 year old female reported chief complaint of itch skin eruptions all over the body along with erosive lesions on tongue, lips, buccal mucosa and genital mucosa. The reaction occurred after administration of augmentin (containing amoxycillin and clavulanic acid). She was treated with antimicrobials, antiallergics and conservative management. The patient improved and was discharged from the hospital. Causality assessment using Naranjo Adverse Drug Reaction Probability Scale revealed that amoxycillin and clavulanic acid combination was a possible cause for the adverse reaction with a score of 4.
Chong, Ian; Chao, Alice
Introduction One of the most dangerous dermatologic emergencies is Stevens-Johnson Syndrome (SJS)/toxic epidermal necrolysis (TEN). Although a rare disease, it can often lead to significant mortality. Case Presentation In this case report, we present a 77-year-old man who developed a sloughing rash that was secondary to a nonsteroidal anti-inflammatory drug. In addition to the recommended supportive care, the patient was treated with etanercept, a new, less commonly used intervention. Discussion We provide a brief review of SJS/TEN. Nonsteroidal anti-inflammatory drugs are a rare cause of SJS/TEN, and additionally, the use of biologics is a novel treatment modality for SJS/TEN. PMID:28488978
Khafaga, Y.M.; Jamshed, A.; Allam, A.A.K.; Ezzat, A.; Gray, A.J.; Schultz, H. [King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Oncology; Mourad, W.A. [King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Pathology; Al Eisa, A. [King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Medicine
The use of phenytoin as a prophylactic anticonvulsant after brain surgery, particularly for brain tumors, is a common practice, regardless of whether the patient has a previous history of convulsions. This treatment policy assumes that the benefits exceed the risks. Four cases are described of adverse reactions of phenytoin during the cocomitant use of cranial radiotherapy. In one patient this proved fatal. There is increasing anecdotal support in the literature for a synergistic effect between phenytoin therapy and cranial radiotherapy that can result in the life-threatening Stevens-Johnson syndrome. While the association is uncommon, four cases within 24 months in one department suggest that the routine use of postoperative phenytoin as a prophylactic anticonvulsant in the absence of a history of seizures may not be warranted, particularly if the patient is to receive cranial radiotherapy. (orig.)
Delattre, J.Y.; Safai, B.; Posner, J.B.
In 15 months we encountered eight patients with intracranial tumors who developed erythema multiforme (EM) or erythema multiforme bullosa (Stevens-Johnson syndrome). All occurred shortly after use of phenytoin (DPH) and brain radiation therapy (WBRT). The clinical picture differed from the classic form of EM in that the erythema began on the scalp and spread to the extremities, progressing in three cases to extensive bullous formation. There were no cases of EM among patients who received either DPH or radiotherapy alone. The combination of DPH, WBRT, and tapering of steroids seems to predispose to EM. The pathogenesis of the disorder is probably immunologic. In the absence of seizures, anticonvulsants should not be given routinely to patients with brain tumors. When anticonvulsants are necessary in patients scheduled for WBRT, DPH may not be the drug of choice.
Le, Hong-Gam; Saeed, Hajirah; Mantagos, Iason S; Mitchell, Caroline M; Goverman, Jeremy; Chodosh, James
Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a systemic disease that can be associated with debilitating acute and chronic complications across multiple organ systems. As patients with acute SJS/TEN are often treated in a burn intensive care unit (BICU), we surveyed burn centers across the United States to determine their approach to the care of these patients. The goal of our study was to identify best practices and possible variations in the care of patients with acute SJS/TEN. We demonstrate that the method of diagnosis, use of systemic therapies, and involvement of subspecialists varied significantly between burn centers. Beyond supportive care provided to every patient, our data highlights a lack of standardization in the acute care of patients with SJS/TEN. A comprehensive guideline for the care of patients with acute SJS/TEN is indicated. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.
Wang, Wu-ping; Ni, Yun-feng; Wei, Yao-ning; Li, Xiao-fei; Cheng, Qing-shu; Lu, Qiang
Bronchiolitis obliterans (BO) was defined as a nonreversible obstructive lung disease in which the bronchioles are always compressed and narrowed by fibrosis or inflammation. In the severe event of lung collapse after BO, surgical intervention is often recommended, and conservative therapy is thought to be ineffective. Here, we report the case of a 9-year old girl clinically diagnosed as having bronchiolitis obliterans with abrupt occlusion of the right B4b bronchus. After a lamotrigine-induced Stevens-Johnson syndrome (SJS) occurred, she presented with total collapse of the right lung on admission, which was subsequently complicated by a pneumothorax during conservative treatment, but with the re-expansion of the right upper lobe after intervention. The case indicates the possibility of reversing pulmonary atelectasis in BO. Thus, surgery may not be necessary. Copyright © 2012. Published by Elsevier B.V.
Carvalho, Evanilda Souza de Santana; Araújo, Edna Maria de; Santos, Silvone Santa Bárbara da Silva; Santos, Alexandro Gesner Gomes Dos
Objectives To analyze the representations of the nurse and individual in mental suffering portrayed in the photographic work by Steven Klein, in the USAnatomy exhibit held at the Museum of Sculpture (Museu da escultura) in São Paulo, in 2011. Methods Qualitative study carried out in 2012. Three photographs were submitted to iconographic analysis. The interpretation of the findings was based on theoretical frameworks of Foucault and Bourdieu on power relations. Results The nurse is represented as a sensual, insensitive person, with the power to control and torture while the person in psychological distress is represented as dirty, imprisoned and subjected to an asymmetrical relationship of power with the nurse. Final considerations Relationships of submission and symbolic dominance, in which the person in psychological distress has their body molded by discipline imposed by the nurse. Stereotypes of the image of the nurse oppose the ideology of the profession, which is to ensure the integrity of those being cared for.
Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the mechanical and electrical parameters of the motor is clearly seen. The measurements are carried out with the ScienceWorkshop data-acquisition system and the DataStudio software from PASCO scientific. The experiments are well related to university courses of electricity and magnetism and can be used in undergraduate laboratories or for lecture demonstrations.
Iyer, Geetha; Srinivasan, Bhaskar; Agarwal, Shweta; Kamala Muralidharan, Seema; Arumugam, Sumathi
Stevens Johnson Syndrome (SJS) can lead to end stage corneal blindness. This study describes the comprehensive treatment measures and their outcomes in the management of ocular sequelae and complications of SJS. Four hundred sixty-four eyes of 232 patients of SJS who underwent surgical intervention (punctal cautery, mucus membrane grafting for lid margin keratinisation, fornix reconstructive procedures, tectonic procedures, keratoplasty and keratoprosthesis) were studied. It was a non-comparative, retrospective, interventional case series. The primary outcome was the change in the best corrected visual acuity (BCVA). Secondary outcome measures included an improvement in the ocular surface status as indicated by corneal epithelial fluorescein staining and Schirmer's I strip wetting. The BCVA and the ocular surface status improved and/or stabilized in > 70 % of eyes following punctal cautery (n = 160) and > 80 % of eyes following lid margin mucus membrane grafting (n = 238). BCVA improved in 50 % of eyes following fornix reconstructive procedures (n = 24) with COMET (n = 6), in 63.9 % eyes with the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) lens (n = 36), in 81.8 % of eyes after cataract surgery (n = 22). A BCVA of ≥20/200 was achieved in 72.34 % of eyes following keratoprostheses procedures (n = 47). The mean duration of follow up was 53.3 ± 15.2 months. The ocular sequelae of Stevens Johnson Syndrome can be blinding. They need to be identified and addressed early to retard the continued deterioration of the ocular surface. Our study aims to highlight the problem as well as the importance of comprehensive measures in the management of this potentially blinding disorder.
Martinez-Rodrigo, Fernando; Herrero-De Lucas, Luis Carlos; de Pablo, Santiago; Rey-Boue, Alexis B.
This paper examines the question of how to use project-based learning to increase student performance and satisfaction in a power electronics course addressing the topics of dc/dc and dc/ac converters, the assembly of a dc/dc converter, and the use of a commercial speed drive. A detailed presentation of the methodology is shown, and the results…
Introduces chaos theory, its analytical methods and the means to apply chaos to the switching power supply design DC-DC converters are typical switching systems which have plenty of nonlinear behaviors, such as bifurcation and chaos. The nonlinear behaviors of DC-DC converters have been studied heavily over the past 20 years, yet researchers are still unsure of the practical application of bifurcations and chaos in switching converters. The electromagnetic interference (EMI), which resulted from the high rates of changes of voltage and current, has become a major design criterion in DC-DC co
Sreenivasappa Veeranna Bhupasandra
Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.
Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.
Shubaly, M.R.; de Jong, M.S.
Development of high-current cw accelerators such as ZEBRA and FMIT, use of high current dc ion beams in industry for sputtering and material treatment, and scientific applications such as heavy-ion fusion and plasma physics diagnostics have provided the impetus for ion source development programs at many laboratories. At Chalk River, development of efficient plasma generators and reliable extraction columns to provide high quality beams of hydrogen, nitrogen, argon and xenon is underway. DC beams of up to 850 mA (limited by available power supplies) of hydrogen, 200 mA of nitrogen, 155 mA of argon and 100 mA of xenon have been produced with good reliability. DuoPIGatrons, with and without magnetic cusps, are used to generate a high density, reasonably quiescent plasma. Multi-aperture accel-decel columns are used for extraction with shaped apertures and beamlet steering to improve beam quality. This paper describes the performance of these sources and identifies some of the remaining problems. Guidelines for extraction column design, and experience with transporting high current beams are also presented
Low voltage power sources have played an important role in applications such as automotive system, renewable energy power generation and so on, where require a high gain DC-DC step-up converter. The converter is going to sustain a very high input current which can bring many design challenges in the existing topologies, such as high component current stress and power loss, complex and costly design for magnetic components, high input current ripple, etc. A new topology of high gain DCDC step-up converter proposed in this dissertation. The topology has many merits such as high gain capability, high efficiency, low components stress and requirement of the transformer, simple topology with less number of active switching devices, and easy to control. The dissertation carries out theoretical analysis of the proposed topology under different operating modes and the voltage gain has been deduced for each mode. The design of circuit components has been well studied, including the power devices current stress and power, the selection of transformer turns-ratio, the design method of the resonant tank and input current ripple. System dynamic state-space models are acquired by using generalized averaging method. Small signal model of the converter is achieved by linearization of the dynamic model around the operating points. The stability study indicates that the open loop system is stable at all operating points, except some operating points containing RHP zeros which can cause closed loop system unstable. The parameter sensitivity study shows that the system transfer function is not greatly affected by the variation of the leakage inductance and load resistance. A design of PI controller is implemented to achieve the output voltage regulation. Simulations have been carried out to validate the circuit operation and support the design analysis. A 2kW prototype has been built for experimental testing. The experimental results are in a good agreement with the theoretical
Prabhala, Venkata Anand Kishore
Distributing the electric power in dc form is an appealing solution in many applications such as telecommunications, data centers, commercial buildings, and microgrids. A high gain dc-dc power electronic converter can be used to individually link low-voltage elements such as solar panels, fuel cells, and batteries to the dc voltage bus which is usually 400 volts. This way, it is not required to put such elements in a series string to build up their voltages. Consequently, each element can function at it optimal operating point regardless of the other elements in the system. In this dissertation, first a comparative study of dc microgrid architectures and their advantages over their ac counterparts is presented. Voltage level selection of dc distribution systems is discussed from the cost, reliability, efficiency, and safety standpoints. Next, a new family of non-isolated high-voltage-gain dc-dc power electronic converters with unidirectional power flow is introduced. This family of converters benefits from a low voltage stress across its switches. The proposed topologies are versatile as they can be utilized as single-input or double-input power converters. In either case, they draw continuous currents from their sources. Lastly, a bidirectional high-voltage-gain dc-dc power electronic converter is proposed. This converter is comprised of a bidirectional boost converter which feeds a switched-capacitor architecture. The switched-capacitor stage suggested here has several advantages over the existing approaches. For example, it benefits from a higher voltage gain while it uses less number of capacitors. The proposed converters are highly efficient and modular. The operating modes, dc voltage gain, and design procedure for each converter are discussed in details. Hardware prototypes have been developed in the lab. The results obtained from the hardware agree with those of the simulation models.
Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored.
Brush DC motor is being replaced by brushless DC motors on every area of application. My diploma thesis is a presentation of brushless DC motor, how it works and its application. Within first part we describe various electric motors and their application. There are several types of electric motors division. Last to be added is a brushless motor. Within second part of thesis we look into a brushless DC motor, how it works, its application and control. In the third part of thesis we construct a...
Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored
Polese, Luigi Gentile
A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.
National Aeronautics and Space Administration — Studying and analyzing the ageing mechanisms of electronic components avionics in systems such as the GPS and INAV are of critical importance. In DC-DC power...
National Aeronautics and Space Administration — VPT proposes an innovative concept whereby complex NASA space power electronic systems can be configured using a small number of qualified hybrid DC-DC converter and...
National Aeronautics and Space Administration — This proposal is aimed at demonstrating the feasibility of a Decentralized Control based SiC Parallel DC-DC Converter Unit (DDCU) with targeted application for...
National Aeronautics and Space Administration — The Space Micro Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...
National Aeronautics and Space Administration — The Space Micro-Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...
National Aeronautics and Space Administration — We shall develop wide temperature range DC-DC boost converters that can be fabricated using commercial CMOS foundries. The boost converters will increase the low...
Vilberger, M. E.; Vislogusov, D. P.; Kotin, D. A.; Kulekina, A. V.
The paper considers questions of energy storage devices used in electric transport, especially in the electric traction drive of a trolley bus, in order to provide an autonomous motion, overhead system’s load leveling and energy recovering. For efficiency of the proposed system, a bidirectional DC-DC converter is used. During the simulation, regulation characteristics of the bidirectional DC-DC converters were obtained.
Miah, Mohammad Alam; Bae, Yong-Soo
Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.
Miah, Mohammad Alam; Bae, Yong-Soo
Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.
Droege, Thomas F.
A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively.
Wu, Weimin; Wang, Houqing; Liu, Yuan
Due to the widely used dc characterized loads and more distributed power generation sources, the dc nanogrid becomes more and more popular, and it is seen as an alternative to the ac grid. For safety considerations, the dc nanogrid should provide reliable grounding for the residential loads...
Full Text Available This paper presents fuzzy logic controlled dc-dc boost converter based Dynamic Voltage Restorer (DVR to compensate severe voltage sag problems in an electrical system. DVR absorbs real power from battery to compensate voltage sags in the system. This condition causes reduction in voltage magnitude of dc-link capacitor. Additionally, DVR requires large dc capacitors to compensate long and severe voltage sags in the system. In this study, dc-dc boost converter is connected to DVR for keeping dc link voltage constant. For this propose, a control algorithm based on Fuzzy Logic (FL control is developed for dc-dc boost converter. The main contribution of this study is that Fuzzy Logic (FL is firstly used to generate reference signal for PWM signals of dc-dc converter applied in DVR. FL is a very flexible controller which keeps the dc link voltage constant during voltage sag. The performance results of proposed study are verified with PSCAD/EMDTC.
Full Text Available This paper presents the topology of operating DC-DC buck converter in boost mode for extra-high-voltage applications. Traditional DC-DC boost converters are used in high-voltage applications, but they are not economical due to the limited output voltage, efficiency and they require two sensors with complex control algorithm. Moreover, due to the effect of parasitic elements the output voltage and power transfer efficiency of DC-DC converters are limited. These limitations are overcome by using the voltage lift technique, opens a good way to improve the performance characteristics of DC-DC converter. The technique is applied to DC-DC converter and a simplified control algorithm in this paper. The performance of the controller is studied for both line and load disturbances. These converters perform positive DC-DC voltage increasing conversion with high power density, high efficiency, low cost in simple structure, small ripples, and wide range of control. Simulation results along theoretical analysis are provided to verify its performance.
Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an
Henson, Barrie W.
The design requirements, the design, development tests and problems, the qualification and life test and the findings of the strip examination of a dual wound DC brushed motor gearhead are described. It is the only space qualified dual wound dc brushed motor gearhead in Europe.
Duong, Alan; Corke, Thomas; Thomas, Flint
A power system for dielectric barrier discharge (DBD) plasma actuators that utilizes a pulsed-DC waveform is presented. The plasma actuator arrangement is identical to most typical AC-DBD designs with staggered electrodes that are separated by a dielectric insulator. A key difference is that the pulsed-DC actuator utilizes a DC voltage source to drive the actuator instead of an AC voltage input. The DC source is supplied to both electrodes. The exposed electrode remains constant in time while the encapsulated electrode is periodically grounded for short instances then is allowed to rise to the source DC level. Further investigation of the pulsed-DC plasma actuator was conducted. Time-resolved velocity measurements were done to characterize the induced velocity field generated by the pulsed-DC plasma actuator. A model of the pulsed-DC plasma actuator is developed in LTspice for further study. The work presented are intended in developing a model to be used in CFD flow control simulations. NASA SBIR NNX14CC12C.
This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components
Full Text Available The traditional controllable saturation reactor (CSR consists of single toroidal core, DC (direct current controlled loop (including DC controlled winding and DC biasing source and AC (alternating current excitation loop (including excitation winding and AC source. A detection winding and secondary winding are added up to the CSR configuration and form a hybrid DC comparator. The excitation current is asymmetric waveform when the CSR core is commonly stimulated by both AC and DC biasing sources, which just is the fundamental characteristic for the proposed comparator. Research shows the terminal voltage of the detection winding is asymmetric waveform when the secondary winding of the comparator is open and the CSR core is stimulated both by AC and DC biasing sources. Both theory analysis and experiment verify the feasibility of the differential RMS (root-mean-square between positive and negative half waves of the terminal voltage from the detection winding fitting for the feedback variance to balance DC biasing magnetic potential and form a self-balancing comparator. The zero-flux technique that the primary ampere-turn is equal to the secondary is the function base for the comparator. The operation details of the comparator including the control characteristics both of open-loop and close loop, the satiability judgment criterion, static error property and test range are introduced. The experimental results testify to the truth of the principle of the proposed DC comparator.
The paper discusses DC/DC converters for integration of double layer condensers into the onboard power system. First, requirements on DC/DC converters are listed and compared on the basis of three exemplary applications. A DC/DC converter concept is developed for decoupling transient high-power loads like electric steering systems. Three different topologies are compared using a specially developed method in order to find the best solution for the given application. In order to establish adequate criteria for selecting the switching frequency and inductivities of storage throttles, the influence of the trottle power change on the switching characteristics of the MOSFETs and on certain ranges of EMP interference emissions is investigated. As methods of optimising the operation of the synchronous rectifiers, parallel connection of Schottky diodes and synchronous rectifiers as well as the variation of the shut-off dead times of synchronous rectifiers were investigated. Further, a concept for converter control was developed in consideration of the intended application and topology. Finally, selected aspects for implementation of the DC/DC converter concept are presented as well as the results of experimental investigations.
Kotter, Dale K.; Rankin, Richard A.; Morgan, John P,.
A magnetic field controller for laboratory devices and in particular to dc operated magnetic field controllers for mass spectrometers, comprising a dc power supply in combination with improvements to a hall probe subsystem, display subsystem, preamplifier, field control subsystem, and an output stage.
... 125 airplanes of the affected design in the worldwide fleet. The following table provides the... 30-1 ``DC-8 Pneumatic System Decay Check'' in Appendix C of Boeing DC-8 Special Compliance Item... contained in Table 1 of this AD to do the actions required by this AD, unless the AD specifies otherwise...
DC Action for Children, 2012
This report presents indicators that are included in DC Action for Children's 2012 KIDS COUNT e-databook, their definitions and sources and the rationale for their selection. The indicators for DC KIDS COUNT represent a mix of traditional KIDS COUNT indicators of child well-being, such as the number of children living in poverty, and indicators of…
Adegbenro Omotuyi John Fakoya
Full Text Available Stevens - Johnson Syndrome and Toxic Epidermal Necrolysis are adverse hypersensitivity reactions that affect the skin and mucous membranes. They are characterised by erythematous macules and hemorrhagic erosions of the mucous membranes. Epidermal detachments of varying degrees of severity also occur in these conditions. Various aetiologies are associated with these conditions, with adverse drug reaction being the most common. Though the worldwide incidence of these conditions is recorded as low, diverse types of medication are being observed to lead to these conditions. This review compiles information on the details of Stevens-Johnson syndrome and Toxic Epidermal Necrolysis, the pathophysiology, therapeutic management, and largely considers the drug-induced etiologies associated with these conditions.
Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede
Because of the advances in power electronics, DC-based power systems, have been used in industrial applications such as data centers , space applications , aircraft , offshore wind farms, electric vehicles , DC home systems [5, 20], and high-voltage DC transmission systems....... To provide such sensitive loads with more reliability, efficiency, and controllability for future power systems, AC microgrid and more recently DC microgrid and smart-grid technologies have been employed [ , , , and ]. To obtain stable and optimal operation in DC power systems (microgrids), proper load...... sharing among different energy units and acceptable voltage regulation across the microgrid is required. This can be achieved by use of a hierarchical power management structure. The highest level in this hierarchy (tertiary) is responsible for the power flow control between the microgrid and the utility...
Akhter, F.; Macpherson, D.E.; Harrison, G.P.
of operational flexibility, as more than one VSC station controls the DC link voltage of the MTDC system. This model enables the study of the effects of DC droop control on the power flows of the combined AC/DC system for steady state studies after VSC station outages or transient conditions without needing...... to use its complete dynamic model. Further, the proposed approach can be extended to include multiple AC and DC grids for combined AC/DC power flow analysis. The algorithm is implemented by modifying the MATPOWER based MATACDC program and the results shows that the algorithm works efficiently....
Su, Shih-Chi; Mockenhaupt, Maja; Wolkenstein, Pierre; Dunant, Ariane; Le Gouvello, Sabine; Chen, Chun-Bing; Chosidow, Olivier; Valeyrie-Allanore, Laurence; Bellon, Teresa; Sekula, Peggy; Wang, Chuang-Wei; Schumacher, Martin; Kardaun, Sylvia H; Hung, Shuen-Iu; Roujeau, Jean-Claude; Chung, Wen-Hung
Early diagnosis and prognosis monitoring for Stevens-Johnson syndrome/toxic epidermal necrolysis (TEN) still remain a challenge. This study aims to explore any cytokine/chemokine with prognostic potential in Stevens-Johnson syndrome/TEN. Through screening a panel of 28 serological factors, IL-6, IL-8, IL-15, tumor necrosis factor-α, and granulysin were upregulated in patients with Stevens-Johnson syndrome/TEN and selected for the further validation in total 155 patients with Stevens-Johnson syndrome/TEN, including 77 from Taiwan and 78 from the Registry of Severe Cutaneous Adverse Reactions. Among these factors evaluated, the levels of IL-15 (r = 0.401; P < 0.001) and granulysin (r = 0.223; P = 0.026) were significantly correlated with the disease severity in 112 samples after excluding patients with insufficient data to calculate the score of TEN. In addition, IL-15 was also associated with mortality (P = 0.002; odds ratio, 1.09; 95% confidence interval, 1.03-1.14; P = 0.001; adjusted odds ratio, 1.10; 95% confidence interval, 1.04-1.16). Consistent results were obtained after the exclusion of Taiwanese patients with sepsis to rule out possible confounders. Moreover, IL-15 was shown to enhance cytotoxicity of cultured natural killer cells and blister cells from patients with TEN. Our findings highlight a usefulness of IL-15 in prognosis monitoring and therapeutic intervention of this devastating condition. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Paulmann, Maren; Mockenhaupt, Maja
Fever is a symptom that often accompanies skin eruptions, especially in children. It can be a sign of an infectious condition presenting with exanthems or it may precede an exanthematous eruption. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe reactions affecting skin and mucosa with blisters and erosions. High fever occurs in these conditions, frequently before the skin and/or mucosa is affected.
Wetter, David A.; Camilleri, Michael J.
OBJECTIVE: To examine clinical, etiologic, and histologic features of Stevens-Johnson syndrome and to identify possible correlates of clinical disease severity related to etiologic and histopathologic findings. PATIENTS AND METHODS: This is a retrospective review of patients seen at Mayo Clinic between January 1, 2000, and December 31, 2007. RESULTS: Of 27 patients (mean age, 28.1 years), 22 (81%) had involvement of 2 or more mucous membranes, and 19 (70%) had ocular involvement. Medications, most commonly antibiotics and anticonvulsants, were causative in 20 patients. Mycoplasma pneumoniae infection caused 6 of the 27 cases. Corticosteroids were the most common systemic therapy. No patients with mycoplasma-induced Stevens-Johnson syndrome had internal organ involvement or required treatment in the intensive care unit, in contrast to 4 patients each in the drug-induced group. Three patients had chronic ocular sequelae, and 1 died of complications. Biopsy specimens from 13 patients (48%) showed epidermal necrosis (8 patients), basal vacuolar change (10 patients), and subepidermal bullae (10 patients). Biopsy specimens from 11 patients displayed moderate or dense dermal infiltrate. Histologic features in drug-induced cases included individual necrotic keratinocytes, dense dermal infiltrate, red blood cell extravasation, pigment incontinence, parakeratosis, and substantial eosinophils or neutrophils. CONCLUSION: Our clinical and etiologic findings corroborate those in previous reports. M pneumoniae—induced Stevens-Johnson syndrome manifested less severely than its drug-induced counterpart. The limited number of biopsies precludes unequivocal demonstration of histopathologic differences between drug-induced and M pneumoniae—induced Stevens-Johnson syndrome. PMID:20118388
Creamer, D; Walsh, S A; Dziewulski, P; Exton, L S; Lee, H Y; Dart, J K G; Setterfield, J; Bunker, C B; Ardern-Jones, M R; Watson, K M T; Wong, G A E; Philippidou, M; Vercueil, A; Martin, R V; Williams, G; Shah, M; Brown, D; Williams, P; Mohd Mustapa, M F; Smith, C H
The overall objective of the guideline is to provide up-to-date, evidence-based recommendations for the diagnosis and management of the full spectrum of Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and SJS-TEN overlap in adults during the acute phase of the disease. The document aims to. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Bae, Hyun Min; Park, Yoo Jung; Kim, Young Hoon; Moon, Dong Eon
Stevens-Johnson syndrome (SJS) is a rare but life-threatening skin reaction disease and carbamazepine is one of its most common causes. We report a case of SJS secondary to carbamazepine in a patient with previous pruritus due to carbamazepine which was given for treatment of trigeminal neuralgia. We would like to caution all providers that carbamazepine readministration should be avoided in the patient with a previous history of SJS or adverse skin reaction. In addition, we strongly recommen...
We describe the case history of a 9-year-old boy who developed Stevens-Johnson syndrome (SJS) following concomitant use of valproic acid and lamotrigine. He presented with rash and fever several weeks after introduction of lamotrigine, having been on valproic acid for seizure disorder. SJS happens to be one of the rare adverse reactions of antiepilepsy drugs (AED). Management is mainly supportive with care escalation when necessary because of the significant morbidity.
Kiser, S.C.; Chenot, D.W.
Waste-water disposal is a major concern of the petroleum business, especially because of complications associated with many produced-water surface-impoundment percolation facilities. In the San Joaquin Valley, California, the current environmental regulations protecting the potentially usable groundwaters are stringent. the Stevens has significant potential as a disposal zone that may offer considerable capacity when the project is designed using proper geologic and engineering studies. The Stevens sands are well known for their oil-producing capabilities, however, not much has been published regarding its suitability as a zone for deep well injection. Conditions that make the Stevens potentially suitable include (1) adequate confinement providing geologic separation from the groundwater sources in the basin, (2) storage capacity, and (3) large areal extent. Because the search for acceptable disposal options is becoming critical, the current class II disposal options is becoming critical, the current class II disposal activities in the Stevens sands were reviewed and the areas offering the greatest future potential were identified. The authors then discuss class II disposal projects in Stevens sands in the West Bellevue and Midway Sunset oil fields and estimate the ultimate basin-wide disposal capacity of the Stevens
Garg, Taru; Sanke, Sarita; Ahmed, Riaz; Chander, Ram; Basu, Srikanta
Chikungunya fever is a benign, self-limiting, acute viral illness. An epidemic occurred in New Delhi, India, in August and September 2016. We observed many cases with atypical cutaneous features mimicking Stevens-Johnson syndrome and toxic epidermal necrolysis during this epidemic, especially in infants and children. Twenty-one children (13 [61.9%] boys, 8 [38%] girls) presenting with vesico-bullous and necrotic lesions were reviewed. Cutaneous presentation included vesicles and bullae with purpuric macules and necrosis, seen in 16 (76%) patients. Skin lesions resolved in 5-7 days, leaving behind hyperpigmentation in seven (33.3%) patients and hypopigmentation in three (14.2%). Minor oral erosions were observed in three (14.2%) patients, and palmoplantar erythema was seen in four (19.04%). It is essential for dermatologists to understand the Stevens-Johnson syndrome and toxic epidermal necrolysis-like presentation of chikungunya and not to misinterpret it as true Stevens-Johnson syndrome and toxic epidermal necrolysis, which will lead to unnecessary intervention and management. © 2018 Wiley Periodicals, Inc.
Pannu, Bibek S; Egan, Ashley M; Iyer, Vivek N
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are both rare but serious idiosyncratic drug reactions characterized by diffuse muco-epidermoid injury and high mortality. Keratinocytes in both skin and mucous membranes (including eyes, mouth and genitalia) are injured resulting in a diffuse maculopapular rash, blistering lesions and epithelial detachment with minimal force (Nikolsky's sign). SJS is typically diagnosed when less than 10% of the skin surface is involved and the term TEN is used in cases with more than 30% involvement. Respiratory involvement in SJS-TEN is common with 30-50% of cases demonstrating respiratory epithelial sloughing with severe short and long term complications. Patients who survive SJS-TEN are often left with impaired respiratory function and bronchiolitis obliterans. Cases of bronchiolitis obliterans with SJS/TEN have been very rarely reported. We report a case of phenytoin induced SJS/TEN followed by severe bronchiolitis obliterans in an adult patient. The presentation, pathophysiology and management of SJS/TEN related bronchiolitis obliterans is also reviewed.
Jayanta Kumar Das
Full Text Available An 18-year-old woman was referred with late sequelae of chloroquine-induced Steven-Johnson syndrome. At the time of presentation, the symblepharon was involving the upper lids to almost the whole of the cornea, and part of the lower bulbar conjunctiva with the lower lid bilaterally. Other ocular examinations were not possible due to the symblepharon. B-scan ultrasonography revealed acoustically clear vitreous, normal chorioretinal thickness, and normal optic nerve head, with an attached retina. Conjunctivo-corneal adhesion released by superficial lamellar dissection of the cornea. Ocular surface reconstruction was carried out with a buccal mucous membrane. A bandage contact lens was placed over the cornea followed by the symblepharon ring to prevent further adhesion. The mucosal graft was well taken up along with corneal re-epithelization. Best corrected visual acuity of 20/120 in both sides after 1 month and 20/80 after 3 months was achieved and maintained till the 2.5-year follow-up.
Kang, Byeong Soo; Kim, Mee Kum; Wee, Won Ryang; Oh, Joo Youn
To investigate the incidence, clinical and microbiological characteristics, risk factors, and therapeutic outcome of infectious keratitis in patients with limbal stem cell deficiency (LSCD) related to Stevens-Johnson syndrome (SJS) and corneal chemical burn. Medical records of 90 eyes of 59 patients who were diagnosed with LSCD resulting from SJS (52 eyes of 29 patients) or corneal chemical burn (38 eyes of 30 patients) were reviewed. Infectious keratitis developed in 35% of LSCD patients with SJS (18 eyes, 14 patients) and in 18% of those with chemical burn (7 eyes, 7 patients). The development of infectious keratitis in SJS was significantly associated with the severity of chronic ocular surface complications in the cornea, conjunctiva, and eyelids and with the use of topical corticosteroids during the disease course. All cases of infectious keratitis following chemical burn occurred in patients with grade III or IV burn by Roper-Hall classification. Approximately 83% of culture-proven cases of infectious keratitis were bacterial infection, most of which (80%) were caused by Gram-positive bacteria. For resolution of infection, 17 eyes (68%) received surgery in addition to medical treatment, whereas 8 eyes (32%) received medical treatment alone. After infection resolution, the final visual acuity was decreased in 10 eyes (40%) compared with before infection. Infectious keratitis is a common complication of LSCD associated with SJS or severe chemical burn to the cornea. Despite medical and surgical treatments, the visual outcome is poor.
Full Text Available In Steven Spielberg's cinema the flight is a recurring theme. Flying scenes can be sorted into two classes: those involving a realistic flight – by aircraft – and those involving a magical flight – by supernatural powers. The realistic flight is influenced by the war stories of Spielberg's father – a radio man in U.S. Air-force during WWII – and it is featured in such films as Empire of the Sun (1987, Always (1989, and 1941 (1979. The magical flight is influenced by James M. Barries' character Peter Pan (Peter and Wendy, 1911, which is quoted directly in E.T. the Extraterrestrial (1982 and, above all, in Hook (1991, which is a sequel to Barrie's story. These two types of flying scenes are analysed as to their meanings, compared to the models that influenced them, and surveyed as to their evolution across Spielberg's films. A central case study is the episode The Mission from Amazing Stories (1985, in which the realistic and the magical flights overlap.
Weinberg, Steven [Texas Univ., Austin, TX (United States). Dept. fuer Physik und Astronomie
Quantum mechanics represents the central revolution of modern natural science and reaches in its importance farely beyond physics. Neither chemistry nor biology on the molecular scale would be understandable without it. Modern information technology from the laptop over the mobile telephone and the flat screen until the supercomputer would be unthinkable without quantum-mechanical effects. It desribes the world on the atomic and subatomic scale and is by this the starting point of our modern worldview. The Nobel-prize carrier Steven Weinberg has done ever among others by his theory of the unification of the weak and the electromagnetic interaction one of the most important contributions to this revolution. In this book he reproduces his personal view of quantum mechanics, which captivates by its strictly logic construction, precise linguistic representation, and mathematical clearness and completeness. This book appeals to studyings of natural sciences, especially of physics. Accompanied is the test by exercise problems, which allow the studying to apply immediately the knowledge, but also test their understanding. Because of its precision and clearness ''Lectures on Quantum Mechanics'' by Weinberg is also essentially suited for the self-study.
Rathi, Varsha M; Taneja, Mukesh; Dumpati, Srikanth; Mandathara, Preeji S; Sangwan, Virender S
To report the rare coexistence of keratoconus and Stevens-Johnson syndrome (SJS) managed with scleral contact lenses (ScCLs). This is a retrospective case series. Five patients (9 eyes) who had coexisting SJS and corneal ectasia were identified from the database during the 2-year period. Diagnosis of SJS was based on a positive history of drug reactions, signs of ocular surface disease, and the presence of keratinization of lid margins. Keratoconus was diagnosed by slit-lamp biomicroscopy. Five eyes of 3 patients had coexisting SJS and keratoconus and were dispensed with ScCLs (PROSE, prosthetic replacement of the ocular surface ecosystem; Boston Foundation for Sight, Needham Heights, MA). All these patients had photophobia. Visual acuity improved in all these patients with ScCL wear. Two patients (4 eyes) were excluded from this study because they had SJS with generalized corneal thinning from limbus to limbus, corneal opacification, and pannus. One patient developed deep vessels in the cornea on prolonged ScCL wear. Reduction in the ScCL wear schedule and change of material with a higher Dk resulted in regression of vascularization. Case 3 developed conjunctival congestion and was uncomfortable wearing ScCLs, although visual acuity was 20/40. He discontinued using ScCL wear. Keratoconus, a noninflammatory condition of the cornea coexisted with inflammatory SJS. Managing such patients with ScCLs may improve vision and comfort.
Das, Jayanta Kumar; Medhi, Jnanankar; Chakravarty, Ranjay; Soibam, Ronel
An 18-year-old woman was referred with late sequelae of chloroquine-induced Steven-Johnson syndrome. At the time of presentation, the symblepharon was involving the upper lids to almost the whole of the cornea, and part of the lower bulbar conjunctiva with the lower lid bilaterally. Other ocular examinations were not possible due to the symblepharon. B-scan ultrasonography revealed acoustically clear vitreous, normal chorioretinal thickness, and normal optic nerve head, with an attached retina. Conjunctivo-corneal adhesion released by superficial lamellar dissection of the cornea. Ocular surface reconstruction was carried out with a buccal mucous membrane. A bandage contact lens was placed over the cornea followed by the symblepharon ring to prevent further adhesion. The mucosal graft was well taken up along with corneal re-epithelization. Best corrected visual acuity of 20/120 in both sides after 1 month and 20/80 after 3 months was achieved and maintained till the 2.5-year follow-up.
Reyes, Cesar V
Chlamydophila psittaci causes psittacosis, an ornithosis acquired usually from infected birds. The disease is often focal and pneumonic but on rare instances can be protean and fatal. Diagnosis is by Chlamydophila serology, which may take as long as 21 days or more. The recovery of the organisms from mice, eggs or tissue culture inoculated with the patient's blood or sputum is tedious and dangerous for laboratory personnel. On occasion, C psittaci inclusion bodies have also been detected in infected cells by fluorescent antibody, Giemsa or Gimenez staining. This report describes heretofore not previously reported recognition of the causative organisms in Diff-Quik-stained clinical cytologic materials. A 17-year-old man presented with fever and sore throat, associated with Steven-Johnson syndrome, of 6 days' duration. In the touch and scrape smears of the orolabial mucosal lesions, C psittaci inclusion bodies were recognizable in Diff-Quik-stained but not with Papanicolaou-stained smears and Gram stain. There were few to numerous organisms per macrophage, which were enlarged or bloated and usually collared by polymorphonuclear leukocytes. The diagnosis was supported by a therapeutic trial with doxycycline and confirmed by a positive third serological tests for C psittaci 3 weeks after discharge. In a suspected or probable case of ornithosis, a rapid diagnosis of C psittaci inclusion bodies is possible in clinical cytology materials using Diff-Quik.
Full Text Available Stevens-Johnson syndrome (SJS and toxic epidermal necrolysis (TEN are life-threatening adverse reactions, which could be induced by a variety of drugs. It was proposed that human leukocyte antigen (HLA-restricted presentation of antigens (drugs or their metabolites to T lymphocytes initiates the immune reactions of SJS/ TEN. However, the genetic susceptibility and the exact pathogenesis were not clear until the recent studies. We first identified that HLA-B*1502 is strongly associated with carbamazepine (CBZ-induced SJS/TEN and HLA-B*5801 with allopurinol-SJS/TEN in Han Chinese. The same associations had been validated across different human populations. For the downstream danger signals, Fas-Fas ligand (FasL and perforin/granzyme B had been advocated as cytotoxic mediators for keratinocyte death in SJS/TEN. However, expression levels of these cytotoxic proteins from the skin lesions were too low to explain the distinct and extensive epidermal necrosis. Our recent study identified that the granulysin, a cytotoxic protein released from cytotoxic T cells or natural killer (NK cells, is a key mediator for disseminated keratinocyte death in SJS/TEN. This article aims to provide an overview of both of the genomic and immunologic perspectives of SJS/TEN. These studies give us a better understanding of the immune mechanisms, biomarkers for disease prevention and early diagnosis, as well as providing the therapeutic targets for the treatments of SJS/TEN.
Eralp, Y; Aydiner, A; Taş, F; Saip, P; Topuz, E
A 28-year-old female patient with a recent history of breast carcinoma was referred to our clinic with generalized necrotic skin eruptions and severe mucosal erosions, which developed right after the completion of cranial radiotherapy for brain metastases. She had been receiving prophylactic diphenylhydantoin treatment 100 mg three times daily during radiation therapy. The extensive involvement of the oral mucosa with conjunctivitis and synechiae of the eyelids, facial swelling, and extension of the rash over the trunk and shoulders with bullous detachment of less than 10% of the total body surface strongly suggested Stevens-Johnson syndrome caused by phenytoin treatment in our patient. There has been conflicting evidence on the role of radiotherapy in the increased risk of severe drug reactions. Although various authors have emphasized the augmented rate of severe mucocutaneous reactions caused by anticonvulsants given during radiotherapy and suggested discontinuing the prophylactic use of such drugs in patients with no history of seizures, others have argued in favor of prophylactic anticonvulsants. Given the high risk of seizures, reaching 20% in patients with brain tumors, and the low incidence of drug reactions, the suggestion of refraining from prophylactic anticonvulsants in the setting of primary or metastatic brain tumors is controversial.
Okamoto-Uchida, Yoshimi; Nakamura, Ryosuke; Sai, Kimie; Imatoh, Takuya; Matsunaga, Kayoko; Aihara, Michiko; Saito, Yoshiro
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse drug reactions. Recent studies have revealed that the prevalence of SJS/TEN is associated with genetic backgrounds, such as polymorphisms in human leukocyte antigens (HLAs). However, non-genetic factors contributing to the etiology of SJS/TEN are largely unknown. This study aimed to assess the involvement of concurrent infection on the pathological states of SJS/TEN, examining the severity of cutaneous symptoms and ocular involvement as well as the time to onset in drug-induced SJS/TEN patients. We recruited 257 Japanese SJS/TEN patients from June 2006 to September 2013 through a nationwide case collection network and participating hospitals and reviewed the clinical information including patient backgrounds, primary disease and medication status. Association between infection and pathological states of SJS/TEN was assessed using univariate and multivariate analyses. The concurrent infectious group of SJS/TEN patients showed a significantly higher rate of exhibiting severer dermatological and ophthalmological phenotypes and an earlier onset of SJS/TEN than the non-infectious group. Our results suggest that the infection could be a risk factor to cause severer symptoms and earlier onset of SJS/TEN.
Frey, Noel; Jossi, Janine; Bodmer, Michael; Bircher, Andreas; Jick, Susan S; Meier, Christoph R; Spoendlin, Julia
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening mucocutaneous diseases. SJS/TEN mostly manifest as a reaction to new drug use, but little is known about their incidence and epidemiology. We conducted a large observational study on the epidemiology of SJS/TEN using data from the UK-based Clinical Practice Research Datalink. Among 551 validated SJS/TEN patients, we calculated an incidence rate of 5.76 SJS/TEN cases per million person-years between 1995 and 2013, which was consistent throughout the study period and was highest in patients aged 1-10 years and 80 years or older. Within a 1:4 matched case-control analysis, black and Asian patients were at a 2-fold risk of SJS/TEN when compared with white patients. Among patients with epilepsy and gout, odds ratios for SJS/TEN were significantly increased only in the presence of recent new drug treatment with antiepileptics or allopurinol, respectively. We observed statistically significant associations between SJS/TEN and pre-existing depression, lupus erythematosus, recent pneumonia, chronic kidney disease, and active cancer, but confounding by drug use needs to be followed up. This large and longitudinal observational study on the epidemiology of SJS/TEN contributes to the understanding of this still underinvestigated severe skin disease in a European and largely white study population. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions (SCAR) to drugs which are associated with significant morbidity and mortality. High risk drugs in Asia are similar to those reported worldwide. Human leukocyte antigen (HLA)-related risk alleles for carbamazepine and allopurinol SCAR are unique to Asians. Although prognostic scoring systems like the SCORTEN have been used for more than a decade, pitfalls and caveats need to be recognized, in particular in patients with multiple medical co-morbidities and systemic features in SJS/TEN. In centres without a tertiary Burns Centre, SJS/TEN patients can still be managed successfully in general and dermatology wards with well-executed supportive/nursing care. Controversy remains regarding the effectiveness of immunomodulation in reducing SJS/TEN morbidity, mortality and hastening re-epithelialization. Despite paucity of robust evidence, intravenous immunoglobulins and ciclosporin remain the most commonly used modalities worldwide. Acute and long-term ocular effects are an important source of morbidity for which emerging ophthalmic therapies appear promising. Quality of life issues have now become an important outcome in patients with SJS/TEN as they often impact survivors' future attitudes towards pharmacotherapy. Even though pharmacogenetic testing for high-risk drugs appears to be the panacea for preventing carbamazepine- and allopurinol-induced SJS/TEN in ethnic Asians, many issues remain before health regulators in our region can conclusively determine whether testing should be made mandatory or highly recommended as standard of care. PMID:24260726
Robert, Marie-Claude; Črnej, Alja; Shen, Lucy Q; Papaliodis, George N; Dana, Reza; Foster, C Stephen; Chodosh, James; Dohlman, Claes H
To report our experience using intravenous infliximab for the treatment of tissue melt after Boston keratoprosthesis (B-KPro) types I and II in patients with autoimmune disease. Case series. We identified four patients who were treated with intravenous infliximab in the context of tissue melt after B-KPro. Stevens-Johnson syndrome-associated corneal blindness was the primary surgical indication for B-KPro implantation in all patients. Two patients received a B-KPro type I and two patients received a B-KPro type II. The patients received intravenous infliximab for skin retraction around B-KPro type II, melting of the carrier graft or leak. Treatment resulted in a dramatic decrease in inflammation and, in some cases, arrest of the melting process. Cost and patient adherence were limiting factors to pursuing infliximab therapy. In addition, one patient developed infusion reactions. Intravenous infliximab may be considered as globe- and sight-saving therapy for tissue melt after B-KPro.
Full Text Available Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN are life-threatening disease. However, there are only few epidemiologic studies of SJS/TEN from China. To analyze the clinical characteristics, causality, and outcome of treatment for SJS/TEN in China, we reviewed case reports of patients with SJS/TEN from the China National Knowledge Infrastructure (CNKI and Wanfang database from 2006 to 2016 and patients with SJS/TEN who were admitted to the First Affiliated Hospital of Fujian Medical University during the same period. There were 166 patients enrolled, including 70 SJS, 2 SJS/TEN overlap, and 94 TEN. The most common offending drugs were antibiotics (29.5% and anticonvulsants (24.1%. Carbamazepine, allopurinol, and penicillins were the most common single offending drugs (17.5%, 9.6%, and 7.2%. Chinese patent medicines accounted for 5.4%. There were 76 (45.8% patients receiving systemic steroid and intravenous immunoglobulin (IVIG in combination therapy, especially for TEN (80.3%, and others were treated with systemic steroids alone. Mortality rate of combination treatment comparing with steroid alone in TEN patients had no statistical significance. In conclusion, carbamazepine and allopurinol were the leading causative drugs for SJS/TEN in China. Combination of IVIG and steroids is a common treatment for TEN, but its efficacy in improving mortality needs further investigation.
Full Text Available Drug-induced severe cutaneous adverse reactions (SCARs include acute generalized exanthematous pustulosis, drug reaction with eosinophilia and systemic symptoms (DRESS, and epidermal necrolysis (Stevens-Johnson syndrome [SJS], toxic epidermal necrolysis. The identification of the causal drug is crucial in order to avoid further exposure, but making the right differential diagnosis of the type of SCAR is equally important since treatment, follow-up, and prognosis of different SCARs are not the same. These syndromes are distinct entities with different clinical, biological, and histological patterns, but sometimes the early distinction between 2 SCARs can be extremely challenging, and overlapping conditions could therefore be taken into consideration, although true overlapping SCARs are very rare when using strict diagnostic criteria (described by the RegiSCAR group. Only a better understanding of the physiopathology of the SCARs could possibly explain these ambiguities and overlaps. We report a case of SCAR in an 86-year-old patient probably induced by allopurinol and simultaneously fulfilling the diagnostic criteria for DRESS and SJS, thus considered as an overlapping case of SCARs.
Casagranda, Aneline; Suppa, Mariano; Dehavay, Florence; Del Marmol, Véronique
Drug-induced severe cutaneous adverse reactions (SCARs) include acute generalized exanthematous pustulosis, drug reaction with eosinophilia and systemic symptoms (DRESS), and epidermal necrolysis (Stevens-Johnson syndrome [SJS], toxic epidermal necrolysis). The identification of the causal drug is crucial in order to avoid further exposure, but making the right differential diagnosis of the type of SCAR is equally important since treatment, follow-up, and prognosis of different SCARs are not the same. These syndromes are distinct entities with different clinical, biological, and histological patterns, but sometimes the early distinction between 2 SCARs can be extremely challenging, and overlapping conditions could therefore be taken into consideration, although true overlapping SCARs are very rare when using strict diagnostic criteria (described by the RegiSCAR group). Only a better understanding of the physiopathology of the SCARs could possibly explain these ambiguities and overlaps. We report a case of SCAR in an 86-year-old patient probably induced by allopurinol and simultaneously fulfilling the diagnostic criteria for DRESS and SJS, thus considered as an overlapping case of SCARs.
Full Text Available This article interprets the work of cultural theorists Steven Connor and Sianne Ngai in terms of their efforts to reevaluate certain key presumptions of aesthetic theory that inherits the surprisingly resilient biases of the 18th century, in particular the work of Immanuel Kant and Edmund Burke. Focusing on the work of Ngai and Connor, I think through the implications this recent theory has for the previously peripheral position occupied by gustatory taste and the cultural objects and experiences it implicates. I discuss the possibility that ideas and examples drawn from the work of Connor and Ngai might form the basis for an alternative area of analysis that is better adapted to the peculiarities of gustatory taste and the culinary. In particular, I argue that the visceral element, which tends to accompany gustatory taste, ought to be interpreted in terms of its generative contribution to the creation of concepts through metaphor, rather than as a muddying influence that prevents clarity of discrimination. Similarly, the close relationship between the edible and the domestic is deserving of a more generous reading than is commonly found in aesthetic theory underwritten by the categories of the sublime and the beautiful.
Taylor, A. B.
Results of a flight evaluation of winglets on a DC-10 Series 10 aircraft are presented. For sensitive areas of comparison, effects of winglets were determined back-to-back with and without winglets. Basic and reduced-span winglet configurations were tested. After initial encounter with low-speed buffet, a number of acceptable configurations were developed. For maximum drag reduction at both cruise and low speeds, lower winglets were required, having leading edge devices on upper and lower winglets for the latter regime. The cruise benefits were enhanced by adding outboard aileron droop to the reduced-span winglet aircraft. Winglets had no significant impact on stall speeds, high-speed buffet boundary, and stability and control. Flutter test results agreed with predictions and ground vibration data. Flight loads measurement, provided in a concurrent program, also agreed with predictions. It was estimated that a production version of the aircraft, using the reduced-span winglet and aileron droop, would yield a 3-percent reduction in fuel burned with capacity payload. This range was 2% greater than with winglets. A 5% reduction in takeoff distance at maximum takeoff weight would also result.
Wiatrowski, A; Posadowski, W M; Radzimski, Z J
At standard magnetron sputtering conditions (argon pressure ∼0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (∼550W/cm 2 ). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%
Full Text Available Background. Human dendritic cell-specific intracellular adhesion molecule-3 (ICAM3-grabbing non-integrin (DC-SIGN is a mannose-binding lectin that initiates interaction between dendritic cells and resting T-lymphocytes. DC-SIGN is highly expressed in placental tissue on dendritic cells and Hofbauer cells, and it is suggested that HIV may become adsorbed to DC-SIGN on Hofbauer cells as part of the mechanism of mother-to-child HIV transmission. A possible mechanism of transfer of the virus from the Hofbauer cells to the fetus is the subsequent adsorption to DC-SIGN-related molecules (DC-SIGNRs, present on immediately adjacent capillary vascular endothelium. However, data on DC-SIGN and DC-SIGNR expression in the placenta are few. Methods. Forty term placentas from HIV-positive mothers and 21 term placentas from HIV-negative mothers underwent immunohistochemistry staining for DC-SIGN and DC-SIGNR expression. Five random sets of 10 villi were assessed, and the average number of positive cells were counted in each case. In addition, where possible, maternal and cord blood viral loads and maternal CD4+ counts were performed in the HIV-positive group only. Results. The median maternal CD4+ count was 377 cells/µl and 27% of participants had undetectable viral loads; the median detectable viral load was 3.72 log. Most (97% of the cord bloods tested in infants from HIV-positive mothers had lower than detectable viral loads. HIV-positive cases had significantly greater expression of both DC-SIGNRs (median values in HIV-positive cases, 14.5 positive cells/10 villi (pc/10villi, compared with 11 pc/10villi in HIV-negative cases, p=0.020 and DC-SIGN (median value in HIV-positive cases, 26.5 pc/10villi, compared with 23 pc/10villi in HIV-negative cases, p=0.037. DC-SIGNR expression was also noted in Hofbauer cells and decidual macrophages in addition to endothelium (reported currently. There was no difference in expression of DC-SIGN and DC-SIGNRs in patients
Ripka, Pavel; Draxler, Karel; Styblíková, Renata
Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830
In the recent decades, shortage of fossil fuels and global warming have increased the demand for renewable energy resources. Dc-dc converters are widely used in renewable energy systems, electric vehicles, and battery chargers. In practical applications, dc-dc converters are required to be regula......In the recent decades, shortage of fossil fuels and global warming have increased the demand for renewable energy resources. Dc-dc converters are widely used in renewable energy systems, electric vehicles, and battery chargers. In practical applications, dc-dc converters are required...... to be regulated by a closed-loop controller. The Peak Current Mode Control (PCMC) is one of the most promising control methods for dc-dc converters. It has been known for high bandwidth (speed), and inherent current protection. Increasing the controller bandwidth decreases the output filter size and cost. Analog...... controllers (including PCMC) are sensitive to temperature drift, component aging and noise. Digital controllers do not have the aforementioned drawbacks of analog controllers; but they have lower bandwidth than analog controllers due to the sampling and calculation delays. Generally, analog controllers have...
Miah, Mohammad Alam; Yoon, Cheol-Hee; Kim, Joonoh; Jang, Jinah; Seong, Young-Rim; Bae, Yong-Soo
The cytokine inducible SH2-domain protein (CISH) is a well-known STAT5 target gene, but its role in the immune system remains uncertain. In this study, we found that CISH is predominantly induced during dendritic cell (DC) development from mouse bone marrow (BM) cells and plays a crucial role in type 1 DC development and DC-mediated CTL activation. CISH knockdown reduced the expression of MHC class I, co-stimulatory molecules and pro-inflammatory cytokines in BMDCs. Meanwhile, the DC yield was markedly enhanced by CISH knockdown via cell-cycle activation and reduction of cell apoptosis. Down-regulation of cell proliferation at the later stage of DC development was found to be associated with CISH-mediated negative feedback regulation of STAT5 activation. In T-cell immunity, OT-1 T-cell proliferation was significantly reduced by CISH knockdown in DCs, whereas OT-2 T-cell proliferation was not affected by CISH knockdown. CTLs generated by DC vaccination were also markedly reduced by CISH knockdown, followed by significant impairment of DC-based tumor immunotherapy. Taken together, our data suggest that CISH expression at the later stage of DC development triggers the shutdown of DC progenitor cell proliferation and facilitates DC differentiation into a potent stimulator of CTLs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.
Full Text Available Bidirectional DC-DC converter is needed in the energy storage system. The converter topology used in this paper was a non-isolated bidirectional DC-DC buck-boost converter. This converter worked in two ways, which the charging mode stored energy into battery when load current was less than nominal main DC current (set point and discharging mode transferred energy from battery to the load when its current exceeded set point value. Both of these modes worked automatically according to the load current. The charging and discharging currents were controlled by fuzzy logic controller which was implemented on microcontroller ARM Cortex-M4F STM32F407VG. This paper compares two types of fuzzy membership function (triangular and sigmoid in controlling bidirectional DC-DC converter. The results showed that fuzzy logic controller with triangle membership function and sigmoid as control bidirectional DC-DC converter had no significant different response, both had an average error for charging and discharging process under 4% with ripple current on the main DC bus around 0.5%. The computing time of program for fuzzy logic controller with triangular membership functions had 19.01% faster than sigmoid, and fuzzy logic computation time on a microcontroller with hardware floating point was 60% faster than software floating point.
National Aeronautics and Space Administration — The DC-8 dropsonde system uses an integrated, highly accurate, GPS-located atmospheric profiling dropsonde, which measures and records current atmospheric conditions...
Creek, K.O.; Liska, D.J.
The Fusion Materials Irradiation Test (FMIT) Facility dc power system provides excitation current for all linac and High-Energy Beam Transport (HEBT) quadrupole and bending magnets, excitation for horizontal and vertical beam steering, and current-bypass shunts.
National Aeronautics and Space Administration — The DC-8 dropsonde system uses an integrated, highly accurate, GPS-located atmospheric profiling dropsonde, which measures and records current atmospheric conditions...
National Aeronautics and Space Administration — The GRIP DC-8 Dropsonde V3 dataset consists of atmospheric pressure, dry-bulb temperature, dew point temperature, relative humidity, wind direction, wind speed, and...
Lee, F. C.; Mahmoud, M. F.; Yu, Y.
The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.
for many decades. However, the rate of improvement slowed as the silicon power materials asymptotically approached its theoretical bounds. Compared to Si, wideband gap materials such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are promising semiconductors for power devices due to their superior...... properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga...... in this thesis. Efficiency measurements from the hardware prototype of both the topologies are also presented in this thesis. Finally, the bidirectional operation of an optimized isolated dc-dc converter is presented. The optimized converter has achieved an ultra-high efficiency of 98.8% in both directions...
Wang, Bright L.
This paper describes a novel fault detection technique for hybrid DC/DC converter oscillation diagnosis. The technique is based on principles of feedback control loop oscillation and RF signal modulations, and Is realized by using signal spectral analysis. Real-circuit simulation and analytical study reveal critical factors of the oscillation and indicate significant correlations between the spectral analysis method and the gain/phase margin method. A stability diagnosis index (SDI) is developed as a quantitative measure to accurately assign a degree of stability to the DC/DC converter. This technique Is capable of detecting oscillation at an early stage without interfering with DC/DC converter's normal operation and without limitations of probing to the converter.
Garcia-Valverde, R.; Miguel, C.; Urbina, A. [Universidad Politecnica de Cartagena, Departamento de Electronica, Tecnologia de Computadoras y Proyectos, Plaza del Hospital, 1, Cartagena, 30203 Murcia (Spain); Martinez-Bejar, R. [Universidad de Murcia, Departamento de Ingenieria de la Informacion y las Comunicaciones, Facultad de Informatica, Campus de Espinardo, 30071 Murcia (Spain)
The coupling of a photovoltaic generator and an electrolyser is one of the most promising options for obtaining hydrogen from a renewable energy source. Both are well known technologies, however, since the high variability of the solar radiation, an efficient coupling still presents some challenges. Direct or through a DC-DC converter couplings are the options in isolated applications. In this work, three models, respectively, for a photovoltaic (PV) generator, a controlled DC-DC converter and a complete proton exchange membrane (PEM) electrolyser have been designed by using Matlab/Simulink. A PV-electrolyser specific algorithm to search for the optimum and safe working point for both elements is presented. Simulation results demonstrate that the use of a controlled DC-DC converter with the proposed algorithm shows better adaptability to the variable radiation conditions than the other coupling options. Therefore, it leads to a better compliance between the electrolyser and the sizing of the PV generator. (author)
Patterson, Richard; Hammoud, Ahmad
DC/DC converters are widely used in space power systems in the areas of power management and distribution, signal conditioning, and motor control. Design of DC/DC converters to survive cryogenic temperatures will improve the power system performance, simplify design, and reduce development and launch costs. In this work, the performance of nine COTS modular, low-tomedium power DC/DC converters was investigated under cryogenic temperatures. The converters were evaluated in terms of their output regulation, efficiency, and input and output currents. At a given temperature, these properties were obtained at various input voltages and at different load levels. A summary on the performance of the tested converters was given. More comprehensive testing and in-depth analysis of performance under long-term exposure to extreme temperatures are deemed necessary to establish the suitability of these and other devices for use in the harsh environment of space exploration missions.
Zhang, Qi; Zhang, Yongping; Sun, Xiangdong
A soft-switching solution implemented to the traditional bidirectional DC/DC converter is developed. The soft-switching cell, which composed of three auxiliary switches, one resonant capacitor and one resonant inductor, is equipped in the traditional bidirectional DC/DC converter to realize circuit...... from a hard turning off process in one of the auxiliary switches, while the others experience the soft operation. As for the other method, the zero voltage or zero current transmissions in all switches are realized, however, the relative higher but fixed conduction losses are introduced by the resonant...... circle. And the proposed topology of bidirectional soft-switching dc-dc converter(TASBC) performs ideal soft switching at boost operations. The characteristics of the proposed converter has been verified by MATLAB simulations and experimental results....
The DC to DC converters built by the US SynQor company use a dual stage conversion technique. One stage is devoted to regulation and the other to insulation. This technique allows to combine a high efficiency (up to 90%) with small dimensions. Instead of the classical Schottky diodes, a synchronous MOSFET is used for the rectification of the low voltage current. A simple air flow is required for the cooling of these converters. Short paper. (J.S.)
Liu, Min; Lei Mei, Zhong; Ma, Xiang; Cui, Tie Jun
Based on the transformation optics method, we propose a dc illusion device, which can transform a metallic object into a magnified dielectric object using anisotropic conducting materials. Utilizing the analogy between electric conductivities and resistor networks, we design and fabricate the device using metal film resistors. The practical measurement data agree very well with simulation results. The proposed dc illusion device is easy to process and measure, and thus has potential applications in various sectors.
Mathe, Laszlo; Rosendahl Andersen, Henrik; Lazar, Radu
Slim DC-link PWM (AC) drives for lowperformance applications are emerging on the market. Such drives equipped with a small DC-link capacitance exhibit instability tendencies, if installed on a soft line, giving a degraded performance. The total harmonic distortion (THD) and the partially weighted...... method, which ensures the stability of the slim DC-link on a soft grid. The proposed compensation method may be used for open- and closedloop control schemes, requiring a small overhead in the digital implementation....
Full Text Available OBJETIVO: Avaliar a qualidade de vida dos pacientes portadores de síndrome de Stevens-Johnson. MÉTODOS: Foram avaliados 14 pacientes com SSJ no período de 1998 e 1999 no Setor de Córnea do Departamento de Oftalmologia da UNIFESP. Empregou-se o questionário S. F. 36 - pesquisa em saúde. A pontuação indica melhor condição de saúde. A mesma avaliação foi repetida quatro vezes em intervalo de três meses. RESULTADOS: As médias das médias das 4 avaliações dos 14 pacientes apresentaram importante redução dos seus valores em todos os subitens do S.F. 36 (41,04±22,38 para aspectos físicos, 53,82±22,82 para aspectos sociais, 26,24±22,46 para aspectos emocionais, 34,95±25,45 para capacidade funcional, 42,03±31,85 para dor, 46,33±18,37 para vitalidade, 46,18±24,83 para saúde mental e 50,26±16,29 para saúde geral. CONCLUSÃO: O questionário S.F. 36 representa método adequado de avaliação de aspectos físicos e emocionais em pacientes com baixa de acuidade visual, que nos permitiu detectar comprometimento importante nas funções básicas dos pacientes com SSJ. Mais pacientes com maior tempo de seguimento são necessários para aprimorar a análise de qualidade de vida nesses pacientes e avaliar os efeitos do acompanhamento psicológico.
Macke, D.L.; Johnson, S.Y.; Otton, J.K.
Surficial accumulations of uranium (up to 0.2 wt. % U/sub 3/O/sub 8/, dry basis) are currently forming in organic-rich, poorly drained sediments deposited in fluvial-lacustrine environments. Known occurrences are in northeastern Washington, northern Idaho, the Sierra Nevada, the Colorado Front Range, New Hampshire, and several areas in Canada. The first accumulation of this type to be mined is in postglacial sediments of a 10-acre boggy meadow along North Flodelle Creek in Stevens County, Washington. The meadow is flanked by hills of fine- to medium-grained two-mica quartz monzonite that are mantled by glacial drift of late Wisconsin age (about 18,000 to 11,500 yr B.P.). Relatively thick, hummocky deposits of this same glacial drift impede drainage at the lower end of the meadow. Following ice retreat, glacial sediments on the meadow floor were reworked by fluvial processes, and patches of organic-rich sediment may have formed in ice-melt depressions. About 6700 yr B.P., a blanket of Mazama ash from the Crater Lake eruption was deposited in the meadow. Shortly thereafter, a beaver dam across the lower end of the meadow further restricted drainage, and peat and organic mud accumulated in the pond behind the dam. The dam is preserved in the stratigraphic record as a sheet-like body of woody peat (with beaver-gnawed sticks) about 100m wide and 60 cm thick. After the gradual influx of sand and coarse silt had filled the pond, and the beavers had abandoned the site, fluvial deposition was reestablished
Full Text Available Background: Stevens - Johnson syndrome (SJS and Toxic Epidermal Necrolysis (TEN are currently regarded to be same disease entity which differs only in the extent and severity of epidermal sloughing. Both are potentially life-threatening mucocutaneous immunologic reaction, which are most frequently induced by drug consumption. The epithelial destruction of skin and mucosal membrane can cause both acute as well as chronic/ long term outcomes in term of late sequelae during the course of the disease. Sequelae often occur during the late phase of SJS/TEN and become a significant problem due its chronicity and severe degree of impairment, which leads to deterioration of quality of life for the patients. This may prevented or decreased in terms of intensity if the patient’s received prompt and sufficient topical therapy, particularly in managing lesions on the mucosa of the eye, oral, and genital. Objective : This review underlines topical therapies which could be delivered for management of mucocutaneous lesions from SJS/ TEN, aimed to prevent late sequelae due to SJS – TEN in order to improve the life quality of SJS – TEN survivors. Conclusion: SJS/ TEN frequently lead to late sequeale which includes skin, ocular, oral, and genital involvement. These sequelaes are often severe and chonic. Thus, may cause significant decrease in quality of life of SJS/TEN survivors. It is therefore most important to detect them early in order to manage them adequately. To date, we still have an impression that the specific sequelae of SJS – TEN are often late diagnosed and insufficiently treated. Finally, we want to emphasize that for mucosal involvement in particular, such as ocular, genital and oral involvement, a careful topical treatment have to be taken into special consideration in order to prevent severe late sequelae.
Verma, Nipun; Singh, Shreya; Sawatkar, Gitesh; Singh, Virendra
Sofosbuvir is an imperative drug used in treatment regimens for hepatitis C virus (HCV). It is considered relatively safe with fewer adverse effects than other treatments. Here, we report a rare and potentially serious, dermatologic, adverse effect following the use of sofosbuvir. A 35-year-old man with genotype 3-related HCV cirrhosis presented with decompensated ascites and jaundice following 7 weeks of therapy with peginterferon alpha-2a and oral ribavirin. After peginterferon withdrawal and stabilization, oral sofosbuvir and ribavirin were started; 10 days later, he developed itching over the trunk and legs, followed by multiple papules and vesicles over an erythematous base. Over the next 15 days, the rash progressed with the formation of blisters and peeling skin. Simultaneously, the oral mucosa and lips developed crusting and painful erosions. Considering drug-induced Steven John Syndrome (SJS), sofosbuvir and ribavirin were withdrawn and the patient was treated with topical emollients, steroids, and supportive care. The lesions improved over the next 4 weeks, with some residual hyperpigmentation. Rechallenge with sofosbuvir alone at one eighth the dose resulted in similar skin and mucosal lesions after 2 months; these lesions also improved after sofosbuvir withdrawal. The Algorithm of Drug Causality for Epidermal Necrolysis score was 7, which suggested sofosbuvir as the very probable drug resulting in SJS in our patient. Conclusion: The appearance of SJS following sofosbuvir use is an important and potentially fatal complication from a drug that serves as the backbone of several HCV treatment regimens. Treating physicians must use sofosbuvir with caution and consider withholding or discontinuing this drug in patients with such severe dermatologic manifestations. ( Hepatology Communications 2018;2:16-20).
Micozzi, Sarah; Perez-Ezquerra, Patricia Rojas; Morales-Cabeza, Cristina; Diez, Cristina; De Barrio, Manuel
HIV positive patients can suffer many complications due to infectious diseases. A sever drug reaction to some of the drugs involved in the treatment can overlap the symptoms of the infections, making the diagnosis very difficult. We present the case of a 28-year-old-man, HIV positive, with secondary syphilis, who developed a Stevens Johnson Syndrome (SJS) caused by one of the many drugs he received. The SJS was overlapped with a possible Jarisch Herxheimer Reaction, which complicated the diagnosis of the skin reaction. In HIV+ patients, the overlapping of severe drug reactions and infectious diseases could be fatal, thus an accurate diagnosis is mandatory. A Rapid Plasma Reagin Test (RPR), an ELISA test, a blood laboratory test, chest radiography and a skin biopsy were realized in order to diagnose the infectious disease and the cause of skin lesions. Intradermal tests and double blind challenge tests were realized in the allergy study. The laboratory tests confirmed the diagnosis of syphilis; the skin biopsy confirmed the cause of lesions, a severe allergic reaction as a SJS. The allergy study discharged all the drugs involved, except dypirone which wasn't proved in the study because of the severity of reaction, the high possibility to be the causative drug and the alternative of other similar drugs available. For the inflammatory response, HIV+ patients are especially susceptible to severe reaction, both infectious and allergic, as in this case. Thus, recent patents emphasize the interest in inflammatory molecules that cause inflammatory symptoms. Although the diagnose of SJS has established criteria, the possibility of overlapping with infectious illness and/or with its treatment, may complicate the diagnosis. Copyright© Bentham Science Publishers; For any queries, please email at email@example.com.
CHANTAPHAKUL, HIROSHI; SANON, THANOMSAK; KLAEWSONGKRAM, JETTANONG
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are erythematous skin lesions with blister formation accompanied by mucosal involvement. These conditions are considered to be life-threatening illnesses. Understanding the clinical presentation, risk factors, treatment options and results will be advantageous for physicians in the management of patients in the future. The aim of the present study was to review and analyze the clinical manifestations, drug implications, treatment and outcome of patients with SJS and/or TEN who had been hospitalized in a tertiary care center. All hospitalized patients with SJS and/or TEN during a 5-year period were retrospectively reviewed. The clinical severity was graded according to the score of toxic epidermal necrolysis (SCORTEN) scale. Clinical symptoms, diagnosis, possible precipitating factors, management and outcome data were collected for analysis. A total of 43 patients (mean age, 49.5 years) were hospitalized and classified into the SJS group (55.8%), SJS/TEN overlap group (20.9%) and TEN group (23.3%). The majority of the patients (90.7%) had mucocutaneous eruptions associated with oral drug administration. Allopurinol, anticonvulsants and antibiotics were the most common causative agents for the mucocutaneous eruption. Twenty-eight patients (65.1%) were treated with corticosteroids. The mortality rate was 6.9%. Comparison between the survival group and the non-survival group revealed that patient age >70 years (P=0.014) and body surface area involvement >20% (P<0.01) were the significant factors associated with mortality. The use of systemic steroids was higher in the survival group in comparison with the non-survival group (65.1 vs. 0%, respectively; P=0.014). The mucocutaneous eruptions in SJS and TEN are mostly caused by medication. With early recognition and treatment, the mortality rate in this study was lower than that in previous reports. Patient age and the area of mucocutaneous involvement
Wang, Li; Mei, Xue-Ling
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening diseases with high mortality rates. This study was designed to analyze the pathogenic factors, clinical manifestations, complications, treatment, and prognosis of SJS/TEN and to explore the differences between surviving and deceased patients. SJS/TEN patients admitted to Beijing Friendship Hospital from January 2006 to December 2015 were included in the study. Patients' data were retrospectively analyzed. Comparative studies were performed on the survival group and the deceased group, and Fisher's exact probability test was used for statistical analysis. Among the 88 patients included, 40 (45.5%) were male with a mean age of 45 ± 18 years. Forty-eight (54.5%) had SJS, 34 (38.6%) had SJS/TEN, and 6 (6.8%) had TEN. Fifty-three (60.2%) cases were caused by medications, mainly antibiotics (n = 24) followed by traditional Chinese medicines (n = 7). Forty-two cases (47.7%) developed visceral damage. Eighty-two patients improved or recovered and were discharged from hospital, and six patients died. Comparative studies on the survival group and the deceased group showed that the presence of malignant tumor ( χ2 = 27.969,P 100 times/min ( χ2 = 6.347, P= 0.012), detached skin area >20% ( χ2 = 5.594, P= 0.018), concurrent mucosal involvement at the mouth, eyes, and external genitals ( χ2 = 4.945, P= 0.026), subsequent accompanying liver/kidney damage ( χ2 = 11.839, P= 0.001, and χ2 = 36.302,P 2 ( χ2 = 37.148,P < 0.001) increased the risk of death. SJS/TEN is mainly caused by medications, and nearly half of patients develop visceral damage. Multiple factors increase the mortality risk.
Catt, Caroline J; Hamilton, Gavin M; Fish, Joel; Mireskandari, Kamiar; Ali, Asim
To describe the acute and chronic ocular manifestations of Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and SJS/TEN Overlap syndrome (Overlap syndrome) in children. Retrospective case series. Medical records of children admitted to the Hospital for Sick Children between 2001 and 2011 with SJS, TEN, and Overlap syndrome were reviewed. Demographic information, all abnormal ophthalmic findings (and median time to first diagnosis), visual acuities, and ophthalmic treatments prescribed were collected for each eye for every patient. Thirty-six children were identified for inclusion in the study. Twenty-nine (81%) had acute ocular involvement, including all patients with TEN (n = 7). Conjunctivitis was the most common (78%) clinical sign. This, together with conjunctival membranes and subconjunctival hemorrhage, were the earliest signs, presenting by a median of 1 day. The percentage of patients and median time to occurrence of complications were as follows: for lid margin ulceration and corneal epithelial defects, 25%, 3 days; conjunctival ulceration, 39%, 3.5 days; symblepharon, 28%, 4 weeks; corneal opacification, 11%, 4 months; limbal stem cell failure, 8%, 7 months; and corneal vascularisation, 8%, 10 months after admission. Over 90% of children maintain a visual acuity of 20/40 or better in each eye at a mean follow-up of 1.4 years. Ocular involvement in SJS, TEN, and Overlap syndrome is common and the ocular manifestations may develop many months after the initial presentation, mandating the need for long-term follow-up of these children. Despite the high frequency of sight-threatening disease, most children maintain good vision in the long term. Copyright © 2016 Elsevier Inc. All rights reserved.
Gregory, Darren G
To describe a new grading system and associated treatment guidelines for the acute ocular manifestations of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Prospective case series. Seventy-nine consecutive patients (158 eyes) evaluated and treated for acute ocular involvement in SJS or TEN during hospitalization. Photographic and chart review of acute ocular findings, interventions received, and outcomes with regard to visual acuity, dry eye symptoms, and scarring sequelae at least 3 months after the acute illness. Visual acuity, dry eye severity, and scarring of the ocular surface and eyelids were assessed after follow-up of at least 3 months. Cases graded as mild or moderate were managed medically. All had best-corrected visual acuity (BCVA) of 20/20, no dry eye symptoms, and no scarring sequelae. Cases graded as severe or extremely severe were treated with urgent amniotic membrane transplantation (AMT) in addition to medical management. Severe cases all had BCVA of 20/20 and mild or no dry eye problems. Five of 28 patients had mild tarsal conjunctival scarring. No other scarring sequelae occurred. Nine of the 10 extremely severe cases had BCVA of 20/20 (1 was 20/30). Three of 10 had moderate scarring of the tarsal conjunctiva and lid margins and also moderate dry eyes with severe photophobia. Seven of 10 had only mild or no dry eye symptoms and scarring sequelae. This grading system facilitates decision making in the evaluation and management of the acute ocular manifestations of SJS and TEN. Mild and moderate cases have a low risk of significant scarring or visual sequelae and may be monitored and treated medically if not worsening. Severe and extremely severe cases should receive urgent AMT to decrease the risk of scarring and visual sequelae. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
Liu, Wenmin; Nie, Xiaojuan; Zhang, Li
Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are severe mucocutaneous reactions that incur high mortality, and in which the systemic application of corticosteroids remains controversial. This study aimed to determine the optimal protocols for the use of corticosteroids and treatment measures. We performed a retrospective analysis of 70 patients with SJS/TEN who were hospitalized between January 2008 and May 2015 in the Department of Dermatology, Shandong Provincial Hospital, and treated with corticosteroids. Expected and actual mortality rates in patients treated with different doses of corticosteroids, according to SCORTEN, were compared. The diagnoses associated with initial corticosteroid use differed significantly between the low- and high-dose groups (P = 0.041). There were significant differences between expected and actual mortality rates according to the use of corticosteroid therapy (P = 0.0168, standardized mortality ratio [SMR] = 0.30). There was a statistical difference between expected and actual mortality rates in the low-dose group (P = 0.0145, SMR = 0.20). Serum albumin levels were significantly lower in patients administered corticosteroids additive therapy (31.12 ± 8.32 g/l vs. 35.54 ± 5.82 g/l; P = 0.016), and the rate of use of antibiotics was higher among patients in the additive therapy group than in the non-additive group (94.7% vs. 60.8%). Our research supports the use of corticosteroids for the systemic treatment of SJS/TEN. Corticosteroids should be used in a timely manner and in accordance with disease severity, age, underlying diseases, serum albumin level, and concurrent treatment with antimicrobial therapy. © 2016 The International Society of Dermatology.
Full Text Available OBJECTIVE: Stevens-Johnson Syndrome (SJS is one of the most severe muco-cutaneous diseases and its occurrence is often attributed to drug use. The aim of the present study is to quantify the risk of SJS in association with drug and vaccine use in children. METHODS: A multicenter surveillance of children hospitalized through the emergency departments for acute conditions of interest is currently ongoing in Italy. Cases with a diagnosis of SJS were retrieved from all admissions. Parents were interviewed on child's use of drugs and vaccines preceding the onset of symptoms that led to the hospitalization. We compared the use of drugs and vaccines in cases with the corresponding use in a control group of children hospitalized for acute neurological conditions. RESULTS: Twenty-nine children with a diagnosis of SJS and 1,362 with neurological disorders were hospitalized between 1(st November 1999 and 31(st October 2012. Cases were more frequently exposed to drugs (79% vs 58% in the control group; adjusted OR 2.4; 95% CI 1.0-6.1. Anticonvulsants presented the highest adjusted OR: 26.8 (95% CI 8.4-86.0. Significantly elevated risks were also estimated for antibiotics use (adjusted OR 3.3; 95% CI 1.5-7.2, corticosteroids (adjusted OR 4.2; 95% CI 1.8-9.9 and paracetamol (adjusted OR 3.2; 95% CI 1.5-6.9. No increased risk was estimated for vaccines (adjusted OR: 0.9; 95% CI 0.3-2.8. DISCUSSION: Our study provides additional evidence on the etiologic role of drugs and vaccines in the occurrence of SJS in children.
Andersen, Karsten Holm; Nymand, Morten
This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic...... performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical...
Yu, Y.; Biess, J. J.; Schoenfeld, A. D.; Lalli, V. R.
Standardized control and interface circuits were applied to the three most commonly used dc to dc converters: the buck-boost converter, the series-switching buck regulator, and the pulse-modulated parallel inverter. The two-loop ASDTIC regulation control concept was implemented by using a common analog control signal processor and a novel digital control signal processor. This resulted in control circuit standardization and superior static and dynamic performance of the three dc-to-dc converters. Power components stress control, through active peak current limiting and recovery of switching losses, was applied to enhance reliability and converter efficiency.
Miah, Mohammad Alam; Byeon, Se Eun; Ahmed, Md Selim; Yoon, Cheol-Hee; Ha, Sang-Jun; Bae, Yong-Soo
Early growth response gene 2 (Egr2), which encodes a zinc finger transcription factor, is rapidly and transiently induced in various cell types independently of de novo protein synthesis. Although a role for Egr2 is well established in T-cell development, Egr2 expression and its biological function in dendritic cells (DCs) have not yet been described. Here, we demonstrate Egr2 expression during DC development, and its role in DC-mediated immune responses. Egr2 is expressed in the later stage of DC development from BM precursor cells. Even at steady state, Egr2 is highly expressed in mouse splenic DCs. Egr2-knockdown (Egr2-KD) DCs showed increased levels of major histocompatability complex (MHC) class I and II and co-stimulatory molecules, and enhanced antigen uptake and migratory capacities. Furthermore, Egr2-KD abolished SOCS1 expression and signal transducer and activator of transcription 5 (STAT5) activation during DC development, probably resulting in the enhancement of IL-12 expression and Th1 immunogenicity of a DC vaccine. DC-mediated cytotoxic T lymphocyte (CTL) activation and antitumor immunity were significantly enhanced by Egr2-KD, and impaired by Egr2 overexpression in antigen-pulsed DC vaccines. These data suggest that Egr2 acts as an intrinsic negative regulator of DC immunogenicity and can be an attractive molecular target for DC vaccine development. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Wei, J.; Lefeuvre, E.; Mathias, H.; Costa, F.
This paper presents an interface circuit with power control features for electrostatic vibration energy harvesting. A DC-DC convertor is used to control the output voltage of a diode-based charge pump circuit. Therefore, the maximum and minimum voltage across the variable capacitor of the energy harvester may be adjusted to track the maximum power point of the system. The power conversion function of the DC-DC convertor depends on the switches configuration. An example of Maximum Power Point Tracking (MPPT) for different conversion function is presented in this paper. Simulation results show that at least 10 μW is generated.
Mohanty, Swosti; Das, Anupam; Ghosh, Anupama; Sil, Amrita; Gharami, Ramesh Chandra; Bandyopadhyay, Debabrata; Das, Nilay Kanti
Toxic epidermal necrolysis and Stevens-Johnson syndrome comprise life-threatening, drug-induced mucocutaneous disease spectrum. Interest in cyclosporine, a calcineurin inhibitor that can block the function of T-cells, has increased with the discovery of the importance of granulysin in apoptosis in toxic epidermal necrolysis. In our hospital, cyclosporine is given to Stevens-Johnson syndrome/toxic epidermal necrolysis patients as an adjunctive therapy. This study is an observational, record-based study comparing the effectiveness and safety of patients receiving cyclosporine versus only supportive therapy. Medical records as bed-head tickets and laboratory investigation reports of Stevens-Johnson syndrome/toxic epidermal necrolysis patients admitted in the hospital over a period of 1 year were collected. Data regarding clinico-demographic profile, suspected drug causing Stevens-Johnson's syndrome/toxic epidermal necrolysis, SCORTEN, body surface area involved, treatment received and outcome were obtained. Twenty-eight patients were analyzed. Nineteen belonged to the cyclosporine group (supportive treatment + cyclosporine), nine to supportive treatment only group. Among the suspected drugs, antiepileptics formed the major group (28.6%). Five patients in the supportive only group and one in the cyclosporine group died. Time for stabilization and reepithelialization and duration of recovery were significantly lower in the cyclosporine group (P Stevens-Johnson syndrome/toxic epidermal necrolysis may decrease the risk of dying, may provide faster healing of lesions and might lead to early discharge from hospital.
The winners for 2011 of the Department of Energy's Ernest Orlando Lawrence Award were recognized in a ceremony held May 21, 2012. Dr. Steven Chu and others spoke of the importance of the accomplishments and the prestigious history of the award. The recipients of the Ernest Orlando Lawrence Award for 2011 are: Riccardo Betti (University of Rochester); Paul C. Canfield (Ames Laboratory); Mark B. Chadwick (Los Alamos National Laboratory); David E. Chavez (Los Alamos National Laboratory); Amit Goyal (Oak Ridge National Laboratory); Thomas P. Guilderson (Lawrence Livermore National Laboratory); Lois Curfman McInnes (Argonne National Laboratory); Bernard Matthew Poelker (Thomas Jeffereson National Accelerator Facility); and Barry F. Smith (Argonne National Laboratory).
Full Text Available The Russian military largely went below the radar of Western interest after the disintegration of the Soviet Union. More than a decade after the creation of the Armed Forces of the Russian Federation, they have become again the object of interest for scholars – this time, both Western and Russian, as demonstrated by the reviewed volume, whose editors assembled a group of extraordinarily knowledgeable experts from Russia and the West. In his introduction, Steven Miller explains that the purp...
Teo, L; Tay, Y K; Liu, T T; Kwok, C
Toxic epidermal necrolysis (TEN) is a rare, severe adverse drug reaction. Steven-Johnson syndrome (SJS) represents the milder end of the spectrum. The exact pathogenesis of TEN and SJS is still unknown and many drugs, including prednisolone, cyclosporin and intravenous immunoglobulin (IVIG), have been used in an attempt to halt the disease process. The use of IVIG in particular is controversial. We share our experience with the use of IVIG in six patients with TEN. We will also review the various proposed mechanisms underlying TEN, the mechanism of action of IVIG in TEN and summarise useful treatment options.
Reddy, Ramana Bv; Shekar, P Chandra; Chandra, K Lalith Prakash; Aravind, Rs
Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are closely related severe, acute mucocutaneous reactions usually caused by drugs. They are acute life-threatening conditions and cause widespread necrosis of the epithelium. There is persistence of a high risk of SJS or TEN in relation to human immunodeficiency virus (HIV) infection associated with exposure to nevirapine (NVP). In this article, we present nine cases of SJS and one case of TEN in HIV-seropositive individuals who developed cutaneous, oral, ocular and genital lesions while being treated with NVP.
Zhi, Wang; Maotao, Yang; Jing, Yang
With the implementation of energy saving and emission reduction policies, DC energy metering has been widely used in many fields. In view of the lack of a DC energy measurementtraceability system, in combination with the process of downward measurement transfer in relation to the DC charger-based field calibration technology and DC energy meter and shunt calibration technologies, the paper proposed DC fast charging, high DC, small DC voltage output and measuring technologies, and built a time-based plan by converting high DC voltage into low voltage and high current into low current and then into low voltage, leaving DC energy traceable to national standards in terms of voltage, current and time and thus filling in the gap in DC energy measurement traceability.
Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen
A novel buck-boost dc-dc converter with high voltage step-up and step-down ability has been introduced in this paper. There are two switches in this converter, of which the sources are connected together and also connected to the ground of the input voltage source. Hence, there is no need for flo...
Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen
A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...
Kovacevic, Milovan; Knott, Arnold; Andersen, Michael A. E.
A new method for achieving self-oscillating, self-interleaved operation of class E derived resonant DC/DC converters is presented. The proposed method is suitable for operation at frequencies in the Very High Frequency (VHF) band. Interleaved and self-oscillating modes of operation are achieved......% in continuous operation....
Sanders, Anthony B.; Chen, Dakai; Kim, Hak S.; Phan, Anthony M.
This study was undertaken to determine the single event effect and transient susceptibility of the Crane Interpoint Maximum Flexible Power (MFP) Single Output Point of Load DC/DC Converters for transient interruptions in the output signal and for destructive and non destructive events induced by exposing it to a heavy ion beam..
Vinnikov, Dmitri; Chub, Andrii; Liivik, Elizaveta
In this paper magnetically integrated resonant single-switch quasi-Z-source DC-DC converter is evaluated as a candidate topology for the low-cost photovoltaic microconverter. The derivation of the topology and its basic operation principle are explained. Generalized design guidelines...
Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.
This paper presents a very high frequency DC/DC converter for LED lighting. Several resonant topologies are compared and their usability discussed. At the end the resonant SEPIC converter is chosen based on the achievable power density and total bill of material. Simulations of a 51 MHz converter...
Kruse, Kristian; Zhang, Zhe; Elbo, Mads
-isolated bidirectional DC-DC converter equipped with Gallium Nitride (GaN) semiconductor transistors is presented. The converter’s operation principles, zero-voltage switching (ZVS) constraints and dead-time effects are studied. Moreover, the optimization and tradeoffs on the adopted high-frequency inductor...
Spliid, Frederik Monrad; Larsen, Dennis Øland; Knott, Arnold
This paper analyzes the relationship between efficiency and chip area in a fully integrated switched capacitor voltage divider dc-dc converter implemented in 180nm-technology and a 1/2 topology. A numerical algorithm for choosing the optimal sizes of individual components, in terms of power loss,...
This thesis investigated the possibility of increasing the efficiency of a DC-DC converter over a wide load range and a wide input-voltage range based on the Single Active Bridge (SAB) topology with two approaches. The first approach involved making changes to the topology whereas the second made
Silva-Ortigoza, R; Marciano-Melchor, M; Silva-Ortigoza, G; Hernández-Guzmán, V M; Saldaña-González, G; Marcelino-Aranda, M
We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories. (paper)
Xu, Z Q [Research Institutes, University of Electronic Science and Technology of China, Chengdu (China); Shi, Y; Guo, H P; Yang, B C, E-mail: firstname.lastname@example.org [State key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu (China)
A compact DC-DC convertor is proposed and fabricated in multilayer ferrite substrate using LTCC technology. The spiral conductors are buried into the ferrite substrate with a multilayer 3-D structure to reduce the volume of convertor. The passive integration of magnetic components and surface circuitry are achieved in a whole substrate and the size of module can be reduced markedly. The whole height of module is only 3mm, 1/3 of the height of conventional modules. Testing results indicate that the performance of the module is excellent in Point-of-Load (POL) field. The step-down DC-DC converter converts input voltage of 5V to output voltage of 3.3V. It is confirmed that the maximum conversion efficiency of 93.2% is sufficient for actual DC-DC converter application. Such a compact DC-DC convertor provides a compact, low cost and high reliability approach for power supply and magnetic integration application.
Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing
Four DC/DC converters are analyzed and compared with respects to availability, efficiency, ratings, repair costs and power density. Intended application is offshore wind farms with MVDC power collection. The selected topology is a new series resonant converter, which offers 99% efficiency across...... the entire operational range, but needs components designed for high voltage stress....
Full Text Available DC/DC converters are widely used in many industrial and electrical systems. As DC/DC converters are nonlinear and time-variant systems, the application of linear control techniques for the control of these converters is not suitable. In this paper, a new sliding mode controller is proposed as the indirect control method and compared to a simple direct control method in order to control a buck converter in photovoltaic applications. The solar arrays are dependent power sources with nonlinear voltage-current characteristics under different environmental conditions (insolation and temperature. From this point of view, the DC/DC converter is particularly suitable for the application of the sliding mode control in photovoltaic application, because of its controllable states. Simulations are performed in Matlab/Simulink software. The simulation results are presented for a step change in reference voltage and input voltage as well as step load variations. The simulations results of proposed method are compared with the conventional PID controller. The results show the good performance of the proposed sliding mode controller. The proposed method can be used for the other DC/DC converter.
ICAM3)-grabbing non-integrin (DC-SIGN) is a mannose-binding lectin that initiates interaction between dendritic cells and resting T-lymphocytes. DC-SIGN is highly expressed in placental tissue on dendritic cells and Hofbauer cells, and it is ...
Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.
In this paper, a novel push-pull-forward half-bridge (PPFHB) bi-directional DC-DC converter with coupled inductors is proposed. All switches can operate under zero-voltage-switching (ZVS). The operation principle with phase-shift modulation scheme, characteristics of coupled inductors, the steady...
Siwakoti, Yam Prasad; N. Soltani, Mohsen; Blaabjerg, Frede
This paper proposes a modified coupled-inductor SEPIC dc-dc converter for low power and high voltage gain applications such as for piezoelectric drive systems. The converter uses the same components as of SEPIC converter with an additional diode. Compared to conventional topologies with similar...
Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede
This paper introduces a versatile Y-source boost dc/dc converter intended for distributed power generation, where high gain is often demanded. The proposed converter uses a Y-source impedance network realized with a tightly coupled three-winding inductor for high voltage boosting that is presently...
Chen, Jianfei; Hou, Shiying; Deng, Fujin
A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized...
Liu, Dong; Deng, Fujin; Chen, Zhe
Multi-level converters are getting more and more attentions because of their obvious merits such as lower voltage stress and harmonic, smaller size of output filters, and so on. In this paper, a five-level active-neutral-point-clamped (5L-ANPC) dc/dc converter is proposed for power transfer...
Brouzes, H.; Geurts, S.; Besselink, M.; Telli, A.; Hek, A.P. de; Bent, G. van der; Vliet, F.E. van
A highly integrated high-power transmitter has been designed in a high breakdown GaAs MMIC technology. The transmitter includes, on top of an S-Band 10 W class-F HPA, a DC/DC converter and its associated gate driver, the full voltage regulation control loop, which provides a significant step for
Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede
A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...
Andreiciks, A.; Steiks, I.; Krievs, O.
of a DC/DC converter and an inverter. In this paper a detailed simulation study of such interfacing converter system comprising a double inductor push-pull step-up DC/DC converter and a cascaded H-bridge inverter has been carried out and further confirmed with experimental results. The power converter...
Liu, Dong; Deng, Fujin; Gong, Zheng
In this paper, a double phase-shift control strategy is proposed for the full-bridge three-level (FBTL) DC/DC converter applied into DC distribution systems with the medium DC bus voltage. By utilizing the proposed control strategy, the voltage change rate dv/dt and voltage stress of the transfor...
Yang, Xi-jun; Qu, Hao; Yao, Chen
As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...
Guerrero, Josep M.; Tan, Don F. D.
With the development of dc coupled devices, such as photovoltaic generations, batteries, supercapacitors, LEDs, computers, and electronics equipment, low-voltage dc distribution networks, structured dc microgrids are emerging as a natural platform to integrate renewable energy sources. However...... in either series/parallel, forming a number of dc busses with different voltage levels. Recently, with the advance of new dc power technologies, several ongoing standards, alliances, and initiatives are bringing the possibility of developing future homes, offices, buildings, campuses, datacenters, ships...
Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.
The magnetron sputtering has become one of the commonly used techniques for industrial deposition of thin films and coatings due to its simplicity and reliability. At standard magnetron sputtering conditions (argon pressure of ∼0.5 Pa) inert gas particles (necessary to sustain discharge) are often entrapped in the deposited films. Inert gas contamination can be eliminated during the self-sustained magnetron sputtering (SSS) process, where the presence of the inert gas is not a necessary requirement. Moreover the SSS process that is possible due to the high degree of ionization of the sputtered material also gives a unique condition during the transport of sputtered particles to the substrate. So far it has been shown that the self-sustained mode of magnetron operation can be obtained using dc powering (dc-SSS) only. The main disadvantage of the dc-SSS process is its instability related to random arc formation. In such case the discharge has to be temporarily extinguished to prevent damaging both the magnetron source and power supply. The authors postulate that pulsed powering could protect the SSS process against arcs, similarly to reactive pulsed magnetron deposition processes of insulating thin films. To put this concept into practice, (i) the high enough plasma density has to be achieved and (ii) the type of pulsed powering has to be chosen taking plasma dynamics into account. In this article results of pulsed dc self-sustained magnetron sputtering (pulsed dc-SSS) are presented. The planar magnetron equipped with a 50 mm diameter and 6 mm thick copper target was used during the experiments. The maximum target power was about 11 kW, which corresponded to the target power density of ∼560 W/cm 2 . The magnetron operation was investigated as a function of pulse frequency (20-100 kHz) and pulse duty factor (50%-90%). The discharge (argon) extinction pressure level was determined for these conditions. The plasma emission spectra (400-410 nm range) and deposition
Orlandi, S; Buso, S; Michelis, S; Fuentes, C A; Kayal, M; Faccio, F; Spiazzi, G
The paper describes the design of optimized printed circuit board (PCB) air-core toroids for high-frequency dc-dc converters with strict requirements in terms of volume and noise. The effect of several design parameters on the overall inductor volume, on dc and ac winding resistance, and on the radiated noise will be investigated. PCB toroids are compared to standard air-core solenoids and other state-of-the-art air-core toroids both theoretically and experimentally: at first, using ANSOFT Maxwell and ANSOFT Q3D simulation tools, and subsequently, with laboratory measurements (irradiated noise, efficiency, and frequency response) on several prototypes. These very flexible and rather easy to manufacture inductors appear very attractive for compact high-frequency dc-dc converters where high efficiency, low volume, and low noise are of primary concern.
Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)
In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)
Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.
interface to the grid. In power electronics, the converter efficiency is characterized at fixed operating voltage for various output power. This type of characterization is not suitable for fuel cells, since as the power from the fuel cell increases, the cell voltage decreases. This paper analyses how......Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...... the fuel cell I-V characteristics influences the power electronics converter efficiency and their consequence on the overall system. A loaddependent efficiency curve is presented based on experimental results from a 6 kW dc-dc converter prototype including the most suitable control strategy which maximizes...
Deng, Fujin; Chen, Zhe
. Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....
McCullough, M; Burg, M; Lin, E; Peng, D; Garner, W
The diffuse epidermal exfoliation seen in Steven Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) is similar to skin loss in second degree burns, and many of these patients are referred for treatment at burn centers. Treatment can differ markedly from center to center, and mortality can range from 25% to 70%, including a considerable morbidity. However, our experience over a 15-year period from 2000 to 2015 with 40 patients found a mortality rate of only 10% (4/40). The purpose of this paper is to discuss our treatment algorithm as a model for other centers treating SJS/TENs patients. Records were reviewed for all patients admitted to the LAC+USC burn unit between 2000 and 2015 and 40 patients were identified with biopsy-proven SJS or TENS. These cases were reviewed for age, gender, initial and greatest TBSA, causative drug, pre-existing medical conditions, and morbidity and mortality. All data were entered into the SPSS statistical software package and all statistical analyses were performed using this program. Our treatment algorithm focused on early referral to a specialty burn unit, immediate discontinuation of the offending drug, fluid resuscitation, nutritional supplementation, and meticulous wound care. Average time to transfer to a burn unit was 3.36 days. Silver-releasing antimicrobial dressings were applied to the affected skin surface and changed every 3 days. Mupirocin coated petroleum gauze was used for facial involvement. Steroids were tapered and discontinued if initiated at an outside facility (58% of patients), and starting after 2001, all patients received a course of IVIG. All patients received fluid resuscitation and the majority received supplemental tube feedings (69%). Average length of total stay was 17.1 days and length of ICU stay 15.9 days. While 44% were transferred to another facility for further rehabilitative care, 37% of patients discharge to home. In patients discharged home with complete resolution of skin lesions, time
Lerch, Marianne; Mainetti, Carlo; Terziroli Beretta-Piccoli, Benedetta; Harr, Thomas
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered a delayed-type hypersensitivity reaction to drugs. They represent true medical emergencies and an early recognition and appropriate management is decisive for the survival. SJS/TEN manifest with an "influenza-like" prodromal phase (malaise, fever), followed by painful cutaneous and mucous membrane (ocular, oral, and genital) lesions, and other systemic symptoms. The difference between SJS, SJS/TEN overlap, and TEN is defined by the degree of skin detachment: SJS is defined as skin involvement of 30%, and SJS/TEN overlap as 10-30% skin involvement. The diagnosis of different degrees of epidermal necrolysis is based on the clinical assessment in conjunction with the corresponding histopathology. The mortality rates for SJS and TEN have decreased in the last decades. Today, the severity-of-illness score for toxic epidermal necrolysis (SCORTEN) is available for SJS/TEN severity assessment. Drugs with a high risk of causing SJS/TEN are anti-infective sulfonamides, anti-epileptic drugs, non-steroidal anti-inflammatory drugs of the oxicam type, allopurinol, nevirapine, and chlormezanone. Besides conventional drugs, herbal remedies and new biologicals should be considered as causative agents. The increased risk of hypersensitivity reactions to certain drugs may be linked to specific HLA antigens. Our understanding of the pathogenesis of SJS/TEN has improved: drug-specific T cell-mediated cytotoxicity, genetic linkage with HLA- and non-HLA-genes, TCR restriction, and cytotoxicity mechanisms were clarified. However, many factors contributing to epidermal necrolysis still have to be identified, especially in virus-induced and autoimmune forms of epidermal necrolysis not related to drugs. In SJS/TEN, the most common complications are ocular, cutaneous, or renal. Nasopharyngeal, esophageal, and genital mucosal involvement with blisters, erosions as well as secondary development of strictures
Hsu, Derek Y; Brieva, Joaquin; Silverberg, Nanette B; Paller, Amy S; Silverberg, Jonathan I
Little is known about the epidemiology of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in children. We sought to determine the morbidity, mortality, and comorbid health conditions of SJS and TEN in US children. This was a cross-sectional study of the 2009 to 2012 Nationwide Inpatient Sample, which contains a representative 20% sample of all US hospitalizations. Sociodemographics, inflation-adjusted cost, length of stay, comorbidities, and mortality were analyzed using descriptive statistics and multivariate regression analyses. The incidences of SJS, SJS-TEN, and TEN were a mean 5.3, 0.8, and 0.4 cases per million children per year in the US, respectively. Prolonged length of stay and higher costs of care (SJS: 9.4 ± 0.6 days, $24,947 ± $3171; SJS-TEN: 15.7 ± 1.5 days, $63,787 ± $8014; TEN: 20.4 ± 6.3 days, $102,243 ± $37,588) were observed compared with all other admissions (4.6 ± 0.1 days, $10,496 ± $424). Mortality was 0% for SJS, 4% for SJS-TEN, and 16% for TEN. In regression models, predictors of mortality included renal failure (adjusted OR [aOR] 300.28, 95% confidence interval [CI] 48.59->999.99), malignancy (aOR 54.33, 95% CI 9.40-314.22), septicemia (aOR 30.45, 95% CI 7.91-117.19), bacterial infection (aOR 20.38, 95% CI 5.44-76.36), and epilepsy (aOR 5.56, 95% CI 1.37-26.2). Data regarding treatment were not available. Date of diagnosis of comorbidities was not present, precluding temporal analysis. Pediatric SJS/TEN poses a substantial health burden in the United States. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.
Van Batavia, J P; Chu, D I; Long, C J; Jen, M; Canning, D A; Weiss, D A
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are devastating hypersensitivity disorders that cause epidermal cell death and can affect all epidermal surfaces, including the urethra, vagina, labial and scrotal skin. Despite the well-described ocular and orofacial manifestations of SJS/TEN, there is a paucity of reports on the genitourinary (GU) symptoms and their management. Specifically, consulting services often ask the pediatric urology team if it is safe to place a urethral catheter, but there is no data in the literature to help guide management. The present study sought to review all pediatric cases of SJS/TEN in a tertiary care hospital to determine the incidence and optimal management of GU manifestations, including the use of urethral catheters. With IRB approval, cases of SJS and TEN that were managed as an inpatient between January 2008 and June 2015 were retrospectively reviewed in order to identify the extent of GU involvement/manifestations, the treatment provided, use of urethral catheterization and long-term follow-up or complications. Thirty-one patients (15 female, 16 male; age range 2-18 years) presented with SJS or TEN over the study period. Etiologies for SJS/TEN included mycoplasma infection (48%) and medications (45%). Incidences of GU manifestations at presentation and their management are shown in Summary Table. Overall, 74% of patients had genital involvement of skin lesions. In 12 cases (39%), urology consultation was obtained. Twenty patients (61%) complained of dysuria and one child had gross hematuria in the setting of meatal lesion. Petroleum jelly was used in the majority of patients. A urethral catheter was placed in eight patients (25.8%, four female, four male) with a range of duration of 7-23 days. No patient developed hematuria or any other complications (i.e. strictures or urinary symptoms) after catheter removal. One boy required lysis of penile adhesions in the short-term. One of each gender developed
Bloom, Romi; Amber, Kyle T
Lamotrigine is an antiepileptic drug used for the treatment of epilepsy, bipolar disorder and numerous off-label uses. The development of rash significantly affects its use. The most concerning of these adverse reactions is Stevens-Johnson syndrome/toxic epidermal necrolysis. We performed a systematic review of randomized controlled trials using lamotrigine as a monotherapy to quantify the incidence of cutaneous reactions, particularly Stevens-Johnson syndrome/toxic epidermal necrolysis. Of a total of 4,364 papers regarding lamotrigine, 122 studies met our inclusion and exclusion criteria. In total, 18,698 patients were included with 1,570 (8.3%) of patients experiencing an adverse dermatologic reaction. The incidence of Stevens-Johnson syndrome/toxic epidermal necrolysis was 0.04%.
This report is an environmental evaluation of the impacts of proposed borehole drilling activities at the Hanford Site, northwest of Richland, Washington. The proposed action is to drill six research boreholes ranging in depth from 137 to 1372 meters (m) [250 to 4500 +- feet (ft)]. In addition, an existing borehole (DC-7) will be extended from 1249 to 1524 m (4099 to 5000 +- ft). The purpose of the US Department of Energy's (DOE) borehole drilling activities is to collect data on in situ rock formations that are considered potentialy suitable for nuclear waste repositories. The technical program efforts necessary to identify and qualify specific underground waste facility sites in candidate rock formations include geologic and hydrologic studies (seismicity and tectonics, rock structure and stratigraphy, lithology, etc.). Borehole drilling is an integral part of the geological studies and is essential to a thorough understanding of potentially suitable geologic formations. The purpose of the proposed drilling activities is to obtain data for evaluating Columbia River basalts that are being evaluated by the National Waste Terminal Storage (NWTS) Program to determine their suitability potential for nuclear waste repositories. Unavoidable impact to the environment is limited primarily to the clearing of land needed for access and drilling operations. Considerations exercised during site preparation, drilling, and subsequent site restoration will limit modification of the natural environment to the minimum required for accomplishment of test objectives
Ortiz-Acosta, Denisse [Los Alamos National Laboratory; Cady, Carl [Los Alamos National Laboratory; Densmore, Crystal [Los Alamos National Laboratory
The objectives of this project are: (1) study the molecular and mechanical properties of DC745U - (a) DC745U is a silicone elastomer used in several weapons systems, (b) depending on their chemistry and formulation, polymers can be susceptible to damage and failures due to weak chemical linkages and physical interactions, (c) inefficient production processes can generate heterogeneities throughout the material that can contribute negatively to the overall performance and lifetime of the polyer, (d) aging, long-term thermal and radioactive conditions, and mechanical strains can affect the materials network structure and contribute to the degradation of the production; (2) characterization of DC745U materials cured under different conditions to determine possible differences to the polymer structure; and (3) this work is relevant to mission-critical programs and for supporting programmatic work for weapon research.
This investigation was initiated by the apparent rivalry between Fechner-law and Stevens-power function. We used the pupil reaction as on objective measure for the excitation of the visual system within both the threshold and the suprathreshold region. The course of the threshold as a function of adaptation light shows important differences at different field areas. The Weber-law is valid only in the case of large fields (30 degrees) as had been used by Weber himself. At smaller fields the threshold may be described as a power function with exponents of 0.5 at the smallest (0.5 degrees) and about 0.75 at medium sized (5 degrees) fields. In all these experiments the Fechner-hypothesis is suitable automatically because of the constant increment of pupil constriction at the threshold. The validity of the Fechner-hypothesis together with the approximation of the threshold course by power functions lead to Stevens-power functions for the suprathreshold region. The Fechner-law - a logarithmic function - is valid at large fields only. This consideration has been confirmed by our measurements in the suprathreshold sphere.
Michael T. Catalano
Full Text Available Strogatz, Steven. The Joy of x: A Guided Tour of Math, from One to Infinity, (New York, NY, Houghton Mifflin Harcourt, 2012. 316 pp. ISBN 978-0-547-51765-0 The Joy of x: A Guided Tour of Math, from One to Infinity, by Steven Strogatz, is an engaging and example-filled argument for mathematics as a valuable and enjoyable activity. The thirty chapters are divided into six parts, entitled Numbers, Relationships, Shapes, Change, Data, and Frontiers. The discussion ranges from intuitive explanations of basic concepts such as place value, the four arithmetic operations, percentage increase and decrease, and solving equations, to “higher” levels of mathematics such as calculus, probability and statistics, group theory, and the nature of infinity. As in John Allen Paulos’ work, Beyond Numeracy, the chapters are short and punchy, and they can be read independently. While the book is not specifically devoted to numeracy, several chapters, especially those in Part Five on Data, address ideas and examples relevant to quantitative literacy.
Stern, Robert S; Divito, Sherrie J
Although rare, Stevens-Johnson syndrome and toxic epidermal necrolysis remain among the most devastating of acute conditions involving the skin. In the past 30 years, tremendous progress has been made in understanding the causes and pathobiology of this often life-threatening condition. Su et al demonstrate associations between IL 15 serum levels and the outcome of patients with Stevens-Johnson syndrome and toxic epidermal necrolysis. Their findings provide ideas for further investigations that may help us better understand the role of cytokines in this T-cell mediate disease and provides clues to possible new therapies. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Jeras, Matjaž; Švajger, Urban; Obermajer, Nataša; Anderluh, Marko
The dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC SIGN) is a type II C-type lectin whose expression is restricted to the most potent antigen-presenting cells (APCs), the dendritic cells (DCs). In recent years, DC-SIGN has gained an exponential increase in attention because of its involvement in multiple aspects of immune function. Besides being an adhesion molecule, particularly in binding ICAM-2 and ICAM-3,it is also crucial in recognizing several endoge...
Studer, P. A. (Inventor)
A three phase decoder for dc motors is disclosed which employs an extremely simple six transistor circuit to derive six properly phased output signals for fullwave operation of dc motors. Six decoding transistors are coupled at their base-emitter junctions across a resistor network arranged in a delta configuration. Each point of the delta configuration is coupled to one of three position sensors which sense the rotational position of the motor. A second embodiment of the invention is disclosed in which photo-optical isolators are used in place of the decoding transistors.
Full Text Available The goal of this work is to study theperformances of a hybrid controller used to controlDC Motor drive with a single-phase power factorcorrection rectifier. This study is made usingcomputer simulation (Simulink. The first part isdevoted to the control system of the DC Motors. Inthe second part, the design of the hybrid controllerwill be presented. The third part is the design ofthe fast response single-phase boost power factorcorrection rectifier. The last parts are devoted tosimulation and experimental results.
Krainiak, John W.; Speaks, Paul D.; Cornett, Michael S.
This patent application relates to electroexplosive devices (EEDs) such as detonators, blasting caps and squibs, in particular to a method and device for desensitizing EEDs to electromagnetic radiation and electrostatic charges with the added ability to desensitize the device to essentially dc currents. An insensitive electroexplosive device to electrically ignite explosive is disclosed. This device is inherently immune to radio frequency (RF) radiation, and also provides protection against dc or very low frequency RF induced by arcing. A central feature is use of zeners and capacitors to form a reactively balanced bridge circuit. When constructed in semiconductor form, as described in this application, the device is capable of incorporation in small caliber ordnance.
Wang, Haojie; Han, Minxiao; Yan, Wenli
for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load...
Crapo, Alan D.; Lloyd, Jerry D.
Two motors have been designed and built for use with high-temperature superconductor (HTSC) materials. They are a homopolar dc motor that uses HTSC field windings and a brushless dc motor that uses bulk HTSC materials to trap flux in steel rotor poles. The HTSC field windings of the homopolar dc motor are designed to operate at 1000 A/sq cm in a 0.010-T field. In order to maximize torque in the homopolar dc motor, an iron magnetic circuit with small air gaps gives maximum flux for minimum Ampere turns in the field. A copper field winding version of the homopolar dc motor has been tested while waiting for 575 A turn HTSC coils. The trapped flux brushless dc motor has been built and is ready to test melt textured bulk HTSC rings that are currently being prepared. The stator of the trapped flux motor will impress a magnetic field in the steel rotor poles with warm HTSC bulk rings. The rings are then cooled to 77 K to trap the flux in the rotor. The motor can then operate as a brushless dc motor.
Elangovan, D.; Karthigeyan, V.; Subhanu, B.; Ashwin, M.; Arunkumar, G.
Transportation (Diesel and petrol internal combustion engine vehicles) approximately contributes to 25.5% of total CO2 emission. Thus diesel and petrol engine vehicles are the most dominant contributors of CO2 emission which leads global warming which causes climate change. The problem of CO2 emission and global warming can be reduced by focusing on renewable energy vehicles. Out of the available renewable energy sources fuel cell is the only source which has reasonable efficiency and can be used in vehicles. But the main disadvantage of fuel cell is its slow response time. So energy storage systems like batteries and super capacitors are used in parallel with the fuel cell. Fuel cell is used during steady state vehicle operation while during transient conditions like starting, acceleration and braking batteries and super capacitors can supply or absorb energy. In this paper a unidirectional fuel cell DC-DC converter and bidirectional energy storage system DC-DC converter is proposed, which can interface dc sources at different voltage levels to the dc bus and also it can independently control the power flow from each energy source to the dc bus and vice versa. The proposed converters are designed and simulated using PSIM version 9.1.1 and gate pulse pattern, input and output voltage waveforms of the converters for steady state operation are studied.
Irwan, Y M; Leow, W Z; Irwanto, M; M, Fareq; Hassan, S I S; Amelia, A R; Safwati, I
The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer. (paper)
Irwan, Y. M.; Leow, W. Z.; Irwanto, M.; M, Fareq; Hassan, S. I. S.; Safwati, I.; Amelia, A. R.
The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.
Full Text Available Our electricity is predominantly powered by alternating current (AC, ever since the War of Currents ended in the favor of Nicola Tesla at the end of the 19th century. However, lots of the appliances we use, such as electronics and lights with light-emitting diode (LED technology, work internally on direct current (DC and it is projected that the number of these appliances will increase in the near future. Another contributor to the increase in DC consumption is the ongoing electrification of mobility (Electric Vehicles (EVs. At the same time, photovoltaics (PV generate DC voltages, while the most common storage technologies also use DC. In order to integrate all these appliances and technologies to the existing AC grid, there is a need for converters which introduce power losses. By distributing DC power to DC devices instead of converting it to AC first, it is possible to avoid substantial energy losses that occur every time electricity is converted. This situation initiated the concept for the implementation of the DC-Flexhouse project. A prototype DC installation will be developed and tested in one of the buildings of the developing living lab area called the District of Tomorrow (De Wijk van Morgen which is located in Heerlen, the Netherlands. A neighborhood cooperative (Vrieheide cooperatie is also part of the consortium in order to address the aspect of social acceptance. Although DC seems to be a promising solution for a more sustainable energy system, the business case is still debatable due to both technology- and market-related challenges. The current energy infrastructure is predominantly based on AC, manufacturers produce devices based on AC standards and people are using many AC products across a long life span. This Smart Energy Buildings & Cities (SEB&C PDEng project is a contribution to the DC-Flexhouse project. The aim is to analyze the challenges in the transition to DC micro grids, assess the market potential of DC
Zavaleyev, V.; Walkowicz, J.; Aksyonov, D.S.; Luchaninov, A.A.; Reshetnyak, E.N.; Strel'nitskij, V.E.
Comparative studies of the structure, mechanical and tribological properties of DLC coatings deposited in DC and DC with superimposed high current pulse modes of operation vacuum-arc plasma source with the graphite cathode are presented. Imposition the pulses of high current on DC vacuum-arc discharge allows both increase the deposition rate of DLC coating and reduce the residual compressive stress in the coatings what promotes substantial improvement the adhesion to the substrate. Effect of vacuum arc plasma filtration with Venetian blind filter on the deposition rate and tribological characteristics of the coatings analyzed.
Full Text Available This review paper discusses power quality considerations for direct current (DC electric power distribution systems, particularly DC microgrids. First, four selected sample DC architectures are discussed to provide motivation for the consideration of power quality in DC systems. Second, a brief overview of power quality challenges in conventional alternating current (AC distribution systems is given to establish the field of power quality. Finally, a survey of literature addressing power quality issues in DC systems is presented, and necessary power quality considerations in DC distribution system design and operation are discussed.
Shen, Hanxin; Lei, Qiao; Chen, Wenxiang
The micro DC motor has a large market demand but there is a lack of theoretical research for it. Through detailed analysis of the commutation process of micro DC motor commutator, based on micro DC motor electromagnetic torque equation and mechanical torque equation, with the help of Simulink toolkit, a triangle connection micro DC motor simulation model is established. By using the model, a sample micro DC motor are simulated, and an experimental measurements has been carried on the sample micro DC motor. It is found that the simulation results are consistent with theoretical analysis and experimental results.
Shafiee, Qobad; Dragicevic, Tomislav; Vasquez, Juan Carlos
DC microgrids (MGs) have gained research interest during the recent years because of many potential advantages as compared to the ac system. To ensure reliable operation of a low-voltage dc MG as well as its intelligent operation with the other DC MGs, a hierarchical control is proposed in this p......DC microgrids (MGs) have gained research interest during the recent years because of many potential advantages as compared to the ac system. To ensure reliable operation of a low-voltage dc MG as well as its intelligent operation with the other DC MGs, a hierarchical control is proposed...
Sugahara, Masanori; Kaneda, Hisayoshi
It is shown that dc parametric excitation is possible in a circuit named JUDO, which is composed of two resistively-connected Josephson junctions. Simulation study proves that the circuit has large gain and properties suitable for the construction of small, high-speed logic circuits.
Hajizadeh, Amin; N. Soltani, Mohsen; Norum, Lars
In this paper, an intelligent power management strategy is proposed for hybrid DC microgrid, including wind turbine, fuel cell and battery energy storage. The considered wind turbine has a permanent magnet synchronous generator (PMSG). In the considered structure, wind turbine operates as the main...
Beheshtaein, Siavash; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez
and DC microgrids, and then investigates the existing and promising solutions for the corresponding challenges. To the authors’ knowledge, three parts of smart grids are required to be developed to facilitate implementation of protection scheme in microgrids. The main requirements and open issues...
Small dc servomotor powered by simple constant-current source and with suitable gearing used to cancel effect of gravity upon load. Lead-screw positioning system has load counterbalanced by small supplementary motor powered by constant current source. Motor lighter and more compact alternative to counterbalance. Used in variety of mechanical systems where load positioned or accelerated in vertical plane.
Willett, Richard M.; Carroll, Michael J.; Geiger, Ronald V.
Speed and torque ranges in generator mode extended. System of shunt resistors, electronic switches, and pulse-width modulation controls torque exerted by large, three-phase, electronically commutated dc motor. Particularly useful for motor operating in generator mode because it extends operating range to low torque and high speed.
Merritt, Bernard T.; Dreifuerst, Gary R.; Post, Richard F.
A new configuration of DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An "inside-out" design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then "switched" or "commutated" to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives.
Full Text Available Most of organizations today use information-communication technologies (ICT for building an information system (IS. IS is assembled of hardware, software, network resources, organizational and human resources. In IS development process, complexity is crucial for evaluating quantities of resources needed (time, people, money, equipment. Complexity of an IS can be evaluated and/or measured in different phases of development. There are many methods for measuring complexity, but mostly used and thoroughly described method is Function Point Analysis (FP. The opposite method, Database Complexity (DC, does not measure all the aspects of IS, but it could evaluate system complexity depending on the database complexity. DC method is intended to be used for measuring semantic complexity of the IS database, and can be shown by counting attributes A and foreign keys F. This paper describes a very high correlation between FP and DC methods, and defines a function which can in 95% of accuracy express FP values from measured DC values.
... Dilation and Curettage (D&C) Page Navigation ▼ ACOG Pregnancy Book Patient Education FAQs Patient Education Pamphlets - Spanish FAQ062, February 2016 ... written permission from the publisher. Related FAQs Early Pregnancy Loss (Miscarriage) (FAQ090) Abnormal Uterine Bleeding ... Committee Opinions Practice Bulletins Patient ...
The design, manufacture, and ground test activities during development of production methods for an advanced composite rudder for the DC-10 transport aircraft are described. The advanced composite aft rudder is satisfactory for airline service and a cost saving in a full production manufacturing mode is anticipated.
As reported, most DC pension scheme participants simply follow proposed defaults, even though they have the freedom to choose. Consequently, default designs have dramatic impacts on individuals’retirement saving outcomes. Given the fact that the default design matters, this paper evaluates
Hamzeh, Mohsen; Ghafouri, Mohsen; Karimi, Houshang
impedance loop is determined using small signal analysis and pole placement method. The Mesh analysis is employed to further study the stability of low-frequency modes of the overall dc microgrid. Moreover, based on the guardian map theorem, a robust stability analysis is carried out to determine...
Sinclair, Charles K.
Very-high-voltage DC electron guns, delivering moderate duration bunches from photoemission cathodes, and followed by conventional drift bunching and acceleration, offer a practical solution for an ERL injector. In a variant of this scheme, a DC gun is placed in close proximity to a superconducting RF accelerator cavity, with few or no active elements between the gun and cavity. The principal technical challenge with such electron guns arises from field emission from the cathode electrode and its support structure. Field emission may result in voltage breakdown across the cathode-anode gap, or a punch-through failure of the insulator holding off the cathode potential, as well as lesser though still serious problems. Various means to mitigate these problems are described. The operational lifetime of high quantum efficiency photocathodes in these guns is determined by the vacuum conditions, through phenomena such as chemical poisoning and ion back-bombardment. Minimization of the field strength on electrode structures pushes high-voltage DC guns toward large dimensions and, correspondingly, large outgassing loads, but it is also true that these guns offer many opportunities for achieving excellent vacuum conditions. Good solutions to vacuum problems that had previously limited cathode lifetime have been demonstrated in recent years. Designs for DC guns presently in use and planned for the near future will be described. The parameters necessary for a 100 mA average current, very-high-voltage DC gun with a photocathode operational lifetime greater than 100 h appear to be within reach, but have yet to be demonstrated. A 1 A average current source with good cathode operational lifetime will require developments beyond the present state-of-the-art
Bochenek, M; Faccio, F; Michelis, S
The High Luminosity Upgrade of the ATLAS Inner Tracker puts demanding requirements on the powering system of the silicon strip detector modules due to 10-fold increase of the channel count compared to the existing SemiConductor Tracker. Therefore, new solutions for the powering scheme must be elaborated. Currently two possible approaches, the serial powering and the parallel powering scheme using the DC-DC conversion technique, are under development. This paper describes two switched capacitor DC-DC converters designed in a 130 nm technology. For the optimized step-down converter, foreseen for the parallel powering scheme, power efficiency of 97% has been achieved, while for the charge pump, designed for the serial powering scheme, power efficiency of 85% has been achieved
A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.
Meng, Lexuan; Dragicevic, Tomislav; Guerrero, Josep M.
Paralleled dc converter systems are widely used in distribution systems and uninterruptable power supplies. This paper implements a hierarchical control in a droop-controlled dc-dc conversion system with special focus on improving system efficiency which is dealt within the tertiary regulation....... As the efficiency of each converter changes with output power, virtual resistances (VRs) are set as decision variables for adjusting power sharing proportion among converters. It is noteworthy that apart from restoring the voltage deviation, secondary control plays an important role to stabilize dc bus voltage when...... implementing tertiary regulation. Moreover, system dynamic is affected when shifting VRs. Therefore, the stability is considered in optimization by constraining the eigenvalues arising from dynamic state space model of the system. Genetic algorithm is used in searching for global efficiency optimum while...
Makda, Ishtiyaq Ahmed; Nymand, Morten
A Differential Mode EMI filter for a low input voltage high-current isolated dc-dc boost converter is designed and presented in this paper. The primary side Differential Mode noise voltage is low due to the high transformer turn ratio, however, the input current is very high and since the EMI limit...... also does not change for such converters, it requires greatly optimized design approach for the filter including the correct sizing of the filter components. A complete analytical filter design process is carried out such a way that the Differential Mode noise voltage source in the converter...... is identified first. The DM noise model is then established and based on the harmonic analysis of the noise source voltage waveform, the complete Differential Mode EMI filter, including the filter resonance damping branch, is designed for a 3kW isolated dc-dc boost converter. The noise model and its theoretical...
U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...
Marlino, Laura D [ORNL; Zhu, Lizhi [Ballard Power Systems/Siemens VDO
The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.
U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...
Full Text Available The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable.
This paper describes the control, interlock, and power circuits for 680 unipolar switch mode DC-to-DC converters used to regulate the Advanced Photon Sources (APS's) storage ring quadrupole and sextupole magnet currents. Quadrupole current stability is ± 6x10 -5 and the sextupole current stability is ±3x10 -4 . The stability is obtained with pulse width modulation, operating at a switching frequency of 20kHz with full current switching. The converters are housed in 200 cabinets located on top of the storage ring tunnel. Raw DC power is distributed from 80 AC-to-DC power supplies, four at each of 20 locations around the storage ring. Voltages, currents, and temperatures are computer monitored and logged for the converters and magnets. All converters and magnets are water cooled with the flow and pressure monitored at the inlet and outlet of groups. Water is interlocked with the raw power supplies and not the individual converters
Full Text Available Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a new current mode control scheme which could consistently provide good closed-loop performance for LLC resonant converters for the entire operational range. The proposed control scheme employs an additional feedback from the current of the resonant tank network to overcome the limitation of the existing voltage mode control. The superiority of the proposed current mode control over the conventional voltage mode control is verified using an experimental 150 W LLC series resonant DC-to-DC converter.
Allongue, B; Blanchot, G; Faccio, F; Fuentes, C; Mattavelli, P; Michelis, S; Orlandis, S; Spiazzi, G
A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficiently distribute power to the on-detector electronics of SLHC trackers. A comparative analysis of different promising converter topologies is presented, leading to the choice of a magneticbased buck converter as a first conversion stage followed by an on-chip switched capacitors converter. An overall efficiency above 80% is estimated for the practical implementation proposed.
Sitompul, Fuad Rahim
Motor listrik merupakan perangkat elekromagnetis yang mengubah energi listrik menjadi energi mekanik. Motor DC memerlukan tegangan searah pada kumparan medan untuk diubah menjadi energi mekanik. Energi mekanik ini digunakan sebagai penggerak peralatan listrik seperti pompa,penggerak kipas angin, lift dan lain-lain. Karena penggunaannya yang cukup luas maka kinerjanya harus baik. Kinerja suatu motor DC dikatakan baik jika efisiensi motor tersebut tinggi. Hal itu dapat dicapai dengan mengatur b...
Carlos Andrés Ramos-Paja
Full Text Available Se propone una estructura de desvío activo para maximizar la producción de potencia en sistemas fotovoltaicos bajo condiciones irregulares de operación, comparando su eficiencia con soluciones individuales y distribuidas basadas en convertidores DC/DC convencionales. Los análisis y simulaciones realistas demuestran las ventajas del nuevo convertidor de desvío activo sobre soluciones basadas en convertidores Boost, Buck y Buck-Boost.
proliferated due to the recent advances in electric cars. Yilmaz and Krein’s overview of battery charger topologies for electric and hybrid vehicles ...7] M. Yilmaz and P. T. Krein, “Review of Battery Charger Topologies, Charging Power Levels, and Infrastructure for Plug-In Electric and Hybrid...thesis meets the needs of an efficient, sensor integrated, and galvanically isolated trickle charger . The SLR DC- DC converter was successfully
Pelan, Ovidiu; Cornea, Octavian; Muntean, Nicolae
This paper presents and discusses design considerations and efficiency investigation of a conventional step-down and a hybrid switched-capacitor DC-DC converter. Three MOSFETs with low on-resistance have been tested for each converter in order to find the most adequate switch for this application....... The experimental results and comparative efficiency graphs were obtained with a 1kW laboratory prototype dedicated for a 42/14V dual voltage automotive system....
Full Text Available Extended Conducted Electromagnetic Interference in Densely Packed DC- DC Converter I Grobler1 and MN Gitau2 Department of Electrical, Electronic and Computer Engineering, University of Pretoria, South Africa. email@example.com, mgitau.... This will improve the overall design efficiency and shorten the crucial time to market period . It is of utmost importance to try and model the electromagnetic compatibility concurrent with the power processor design stage. The marketplace is in need...
Spassova, MI; Prins, M; Stevens, MR; Hille, J; Goldbach, RW; Spassova, Mariana I.; Stevens, Mikel R.; Goldbach, Rob W.
The Sw-5 gene is a dominantly inherited resistance gene in tomato and functional against a number of tospovirus species. The gene has been mapped on chromosome 9, tightly linked to RFLP markers CT220 and SCAR421. To analyse the Sw-5 locus, a BAC genomic library was constructed of tomato cv. Stevens,
Sekula, Peggy; Liss, Yvonne; Davidovici, Batya; Dunant, Ariane; Roujeau, Jean-Claude; Kardaun, Sylvia; Naldi, Luigi; Schumacher, Martin; Mockenhaupt, Maja
The purpose of this study was to evaluate the severity-of-illness score called SCORTEN with respect to its predictive ability and by using data obtained in the RegiSCAR study, the most comprehensive European registry of patients with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis
Ziemer, M.; Kardaun, S. H.; Liss, Y.; Mockenhaupt, M.
Background Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions with high morbidity and mortality. Some expressions of lupus erythematosus (LE) may cause enormous difficulties in differentiating them from SJS and TEN by showing large areas of
Smith, Dane; Carroll, Carol; Marschall, Jochen; Pallix, Joan
Flight testing of thermal protection materials has been carried out over a two year period on the base heat shield of the Delta Clipper (DC-X and DC-XA), as well on a body flap. The purpose was to use the vehicle as a test bed for materials and more efficient repair or maintenance processes which would be potentially useful for application on new entry vehicles (i.e., X-33, RLV, planetary probes), as well as on the existing space shuttle orbiters. Panels containing Thermal Protection Systems (TPS) and/or structural materials were constructed either at NASA Ames Research Center or at McDonnell Douglas Aerospace (MDA) and attached between two of the four thrusters in the base heat shield of the DC-X or DC-XA. Three different panels were flown on DC-X flights 6, 7, and 8. A total of 7 panels were flown on DC-XA flights 1, 2, and 3. The panels constructed at Ames contained a variety of ceramic TPS including flexible blankets, tiles with high emissivity coatings, lightweight ceramic ablators and other ceramic composites. The MDS test panels consisted primarily of a variety of metallic composites. This report focuses on the ceramic TPS test results.
Denzinger, Wolfgang; Hintze, Thomas
A commercial-of-the-shelf (COTS) DC/DC converter for digital space equipment has been developed by ASP under ESA contract with special emphasis on low cost, no use of ITAR listed EEE parts like Mosfets, minimum number of rad-hard digital IC's and a design tolerance against single event effects by appropriate filtering. However, the intention to qualify this discrete converter design for a low cost FM series production was difficult due to the high up-sceening cost of EEE-parts with one lot guarantee and minimum-by. To overcome this problem, in a next step a redesign of the DC/DC converter was performed with all semiconductors like bipolar transistors, rectifiers and zener diodes packaged into hybrids. With this approach it was possible to buy a high number of less expensive wafers or dies from one lot, to perform a lot acceptance test and to integrate the dies into hybrid packages with further up- screening for FM use. The semiconductors have been packaged into three signal hybrids with 44 pins and one power hybrid with 24 pins for the dissipating transistors and rectifiers. The design of the hybrids is such, that all integrated semiconductors can be tested individually. The qualification of four EQM DC/DC converters with different combinations of output voltages has been successfully performed and two FM's have been manufactured and tested.
Milind Metha, Manish; Tutki, Sanjay; Rajan, Aju; Elangovan, D.; Arunkumar, G.
As the fossil fuels are depleting day by day, the use of renewable energy sources came into existence and they evolved a lot lately. To increase efficiency and productivity in the hybrid vehicles, the existence less efficient petroleum and diesel IC engines need to be replaced with the new and efficient converters with renewable energy sources. This has to be done in such a way that impacts three factors mainly: cost, efficiency and reliability. The PHEVs that have been launched and the upcoming PHEVs using converters with voltage range around 380V to 400V generated with power ranges between 2.4KW to 2.8KW. The basic motto of this paper is to design a prolific converter while considering the factor such as cost and size. In this paper, a two stage DC-DC converter is proposed and the proposed DC-DC converter is utilized to endeavour voltage from 24V (photovoltaic source) to a yield voltage of 400V and to meet the power demand of 250W, since only one panel is being used for this proposed paper. This paper discuss in detail about why and how the current fed DC-DC converter is utilized along with a voltage doubler, thus reducing transformer turns and thereby reducing overall size of the product. Simulation and hardware results have been presented along with calculations for duty cycle required for firing sequence for different values of transformer turns.
Mohamed Abdualla Shrud
Full Text Available The paper presents a model for a dc-dc centralised based architecture using Matlab/Simulink for load dump analysis. As the electrical load varies for various driving conditions such as day or night, summer or winter; and city or country side, the analysis of load change is a very important parameter for system behaviour. In order to study the 42V power generation dynamic performance under load variations, step change in loads have been investigated. A detailed mathematical model for a 3-phase, 4 kW and 42V Lundell alternator average electrical equivalent circuit along with the DC/DC converter based architectures for dual-voltage systems has been covered in previous publications. Aspects of the steady-state output current capabilities, transient behaviour due to load dump on the 14/42V buses and the behaviour of the system model under different loads are assessed and results discussed. The performance of the 42V Lundell alternator with the interleaved six-phase buck dc-to-dc converter system is modelled using Simulink software to assess the effectiveness of the model and its transient behaviour. The simulated results are presented for the transient characteristics of the system for load dumps.
Benton H. Calhoun
Full Text Available This paper presents a model of inductor based DC-DC converters that can be used to study the impact of power management techniques such as dynamic voltage and frequency scaling (DVFS. System level power models of low power systems on chip (SoCs and power management strategies cannot be correctly established without accounting for the associated overhead related to the DC-DC converters that provide regulated power to the system. The proposed model accurately predicts the efficiency of inductor based DC-DC converters with varying topologies and control schemes across a range of output voltage and current loads. It also accounts for the energy and timing overhead associated with the change in the operating condition of the regulator. Since modern SoCs employ power management techniques that vary the voltage and current loads seen by the converter, accurate modeling of the impact on the converter efficiency becomes critical. We use this model to compute the overall cost of two power distribution strategies for a SoC with multiple voltage islands. The proposed model helps us to obtain the energy benefits of a power management technique and can also be used as a basis for comparison between power management techniques or as a tool for design space exploration early in a SoC design cycle.
Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.
The DC Circulator is a local transit system designed to facilitate travel to and within the central business area in the District of Columbia. Since its inception in 2005, the Downtown DC Business Improvement District (DCBID) and the District Departm...
National Aeronautics and Space Administration — The CAMEX-4 DC-8 Forward and NADIR Video dataset consists of DVDs which capture the forward and nadir views from the NASA DC-8 aircraft during CAMEX-4 flights. These...
National Aeronautics and Space Administration — The CAMEX-4 DC-8 Dropsonde System dataset was collected by the DC-8 Dropsonde System (D8D) uses dropwindsonde and Global Positioning System (GPS) receivers to...
This report analyzes cycling trends, policies, and commuting in the Washington, DC area. The analysis is divided into two parts. : Part 1 focuses on cycling trends and policies in Washington (DC), Alexandria (VA), Arlington County (VA), Fairfax Count...
Wang, Huai; Blaabjerg, Frede
DC-link capacitors are an important part in the majority of power electronic converters which contribute to cost, size and failure rate on a considerable scale. From capacitor users' viewpoint, this paper presents a review on the improvement of reliability of DC-link in power electronic converters from two aspects: 1) reliability-oriented DC-link design solutions; 2) conditioning monitoring of DC-link capacitors during operation. Failure mechanisms, failure modes and lifetime models of capaci...
Juan, Y. L.; Chen, T. R.; Chang, H. M.; Wei, S. E.
Compared with the centralized power system, the distributed modularized power system is composed of several power modules with lower power capacity to provide a totally enough power capacity for the load demand. Therefore, the current stress of the power components in each module can then be reduced, and the flexibility of system setup is also enhanced. However, the parallel-connected power modules in the conventional system are usually controlled to equally share the power flow which would result in lower efficiency in low loading condition. In this study, a modular power conversion system for DC micro grid is developed with 48 V dc low voltage input and 380 V dc high voltage output. However, in the developed system control strategy, the numbers of power modules enabled to share the power flow is decided according to the output power at lower load demand. Finally, three 350 W power modules are constructed and parallel-connected to setup a modular power conversion system. From the experimental results, compared with the conventional system, the efficiency of the developed power system in the light loading condition is greatly improved. The modularized design of the power system can also decrease the power loss ratio to the system capacity.
Jairo Antonio Melo Flórez
Full Text Available Aunque ya es una tesis bastante aceptada por los historiadores y sociólogos, la posibilidad de que, al contrario de la creencia popular, vivamos en tal vez una de las épocas más pacíficas de la historia es aún controvertida, más aún cuando llega un trabajo de una de las figuras públicas de la academia como es el profesor de Harvard Steven Pinker. Sin embargo, Pinker se había dedicado a psicología cognitiva y ganó fama al presentar al lenguaje como un instinto de la humanidad, y más aún al presentar sus resultados en libros dirigidos al público en general, algo bastante común entre los científicos norteamericanos.
Jarrett, Benjamin; Ghazala, Sehem; Chao, Joseph; Chaudhary, Sachin
The mortality rate for Stevens-Johnson syndrome (SJS) is estimated to be ∼12% and for toxic epidermal necrolysis (TEN) it is around 30%. It continues to be a severe life-threatening drug reaction. We present a 60-year-old Caucasian man with a medical history significant for breast cancer status post mastectomy and chemotherapy with docetaxel and cyclophosphamide who presented with severe mucositis and a progressing skin rash consistent with SJS. He was started on high-dose corticosteroids and IVIG but continued to have worsening mucosal ulcerations and severe bleeding from the oral, conjunctival and genital mucosa. He underwent several rounds of plasmapheresis and additional high-dose steroids with mild improvement in the mucocutaneous manifestations. He subsequently developed respiratory failure, which required mechanical ventilation, as well as disseminated intravascular coagulation, diffuse alveolar haemorrhage, with Pneumocystis jirovecii pneumonia which led to his demise on hospital day 15. 2016 BMJ Publishing Group Ltd.
Naveen, Kikkeri Narayanasetty; Pai, Varadraj V; Rai, Vijetha; Athanikar, Sharatchandra B
Cutaneous drug reactions are the most common type of adverse drug reactions. Adverse cutaneous drug reactions form 2-3% of the hospitalized patients. 2% of these are potentially serious. This study aims to detect the drugs commonly implicated in Steven Johnson Syndrome-Toxic Epidermal Necrosis (SJS-TEN). A retrospective analysis was done in all patients admitted in the last five years in SDM hospital with the diagnosis of SJS-TEN. A total of 22 patients with SJS-TEN were studied. In 11 patients anti-epileptics was the causal drug and in 7, anti-microbials was the causal drug. Recovery was much faster in case of anti epileptics induced SJS-TEN as compared to that induced by ofloxacin. SJS-TEN induced by ofloxacin has a higher morbidity and mortality compared to anti convulsants.
Full Text Available Background and Aims: Stevens Johnson syndrome (SJS, toxic epidermal necrolysis (TEN and SJS-TEN overlap are serious adverse cutaneous drug reactions. Drugs are often implicated in these reactions. Methods: A retrospective analysis of inpatients′ data with these dermatological diagnoses were carried out for three years, to study the causative drugs, clinical outcome, and mortality in these conditions. Results: Thirty patients (15 TEN, nine SJS-TEN overlap, and six SJS were admitted. In 21 cases, multiple drugs were implicated whereas single drugs were responsible in nine. Anticonvulsants (35.08% were the most commonly implicated drugs followed by antibiotics (33.33% and NSAIDS (24.56%. Twenty-five patients recovered whereas five died (four TEN, one SJS-TEN overlap. Conclusion: Anticonvulsants, antibiotics and NSAIDs were the most frequently implicated drugs. TEN causes higher mortality than both SJS and SJS-TEN overlap.
Smith, Saxon D; Dodds, Annabel; Dixit, Shreya; Cooper, Alan
Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are severe mucocutaneous eruptions. There is currently no defined optimal approach to wound care. The objective of this study was to evaluate silver dressings in the wound-care management of TEN and SJS/TEN syndrome overlap with a retrospective case review of nine patients with TEN and SJS/TEN overlap presenting to our institution. Nanocrystalline silver dressings appear to be useful in the rapid commencement of healing in these patients. TEN and SJS/TEN overlap are rare conditions. This contributed to a relatively small number of cases included in the study. The ease of application, antimicrobial properties and low frequency of change make nanocrystalline silver dressings ideal in TEN/SJS. © 2014 The Australasian College of Dermatologists.
Full Text Available Background: Stevens-Johnson Syndrome (SJS and toxic epidermal necrolysis are severe cutaneous reactions caused by certain drugs, including antiepileptic carbamazepine. A strong association has been reported between human leucocyte antigen (HLA-BFNx011502 and carbamazepine-induced SJS in Han Chinese patients. European studies suggested that HLA-BFNx011502 is not a universal marker but is ethnicity-specific for Asians. Aim: To study the association between HLA-BFNx011502 and carbamazepine-induced SJS in Indian patients. Methods: Eight individuals who fulfilled the diagnostic criteria of SJS induced by carbamazepine were identified and HLA-B molecular typing was performed. HLA-B genotyping was carried out by polymerase chain reaction using sequence-specific primers. Results: Out of eight patients studied for genotype, six patients were found to have the HLA-BFNx011502 allele. Conclusion: This study suggests an association between HLA-BFNx011502 and carbamazepine-induced SJS in Indian patients.
D.C. conductivity measurements are conducted on the graded composites by using an Electrometer in the temperature range from 26°C to 150°C. D.C. conductivity increases with the increase of distance in the direction of centrifugal force, which shows the formation of graded structure with the composites. D.C. conductivity ...
Shi Jing; Tang Yuejin; Wang, Chen; Zhou Yusheng; Li Jingdong; Ren Li; Chen Shijie
With the extensive application of DC power systems, suppression of DC fault current is an important subject that guarantees system security. This paper presents an active superconducting DC fault current limiter (DC-SFCL) based on flux compensation. The DC-SFCL is composed of two superconducting windings wound on a single iron core, the primary winding is in series with DC power system, and the second winding is connected with AC power system through a PWM converter. In normal operating state, the flux in the iron core is compensated to zero, and the SFCL has no influence on DC power system. In the case of DC system accident, through regulating the active power exchange between the SFCL's second winding and the AC power system, the current on the DC side can be limited to different level complying with the system demand. Moreover, the PWM converter that interface the DC system and AC system can be controlled as a reactive power source to supply voltage support for the AC side, which has little influence on the performance of SFCL. Using MATLAB SIMULINK, the mathematic model of the DC-SFCL is created, simulation results validate the dynamics of system, and the performance of DC-SFCL is confirmed
Birkl, Josef; Zahlmann, Peter [Dehn + Soehne GmbH + Co.KG, Neumarkt (Germany)
The utilisation of DC power systems has increased dramatically in the recent years. In addition to traditional DC applications such as in telecommunications and railway engineering a variety of DC applications arise due to a rapid spread of photovoltaic systems. Current projects for the e-mobility expand the scope of application.
Smith, Tracy T.; Kleykamp, Bethea A.; Fant, Reginald V.; Donny, Eric C.
Background and rationale Steven R. Goldberg was a pioneering behavioral pharmacologist whose intravenous drug self-administration studies advanced the understanding of conditioned stimuli and schedules of reinforcement as determinants of pattern and persistence of drug-seeking behavior, and in particular, the importance of nicotine in tobacco use. His passing in 2014 led to invitations to contribute articles to psychopharmacology dedicated to his work. Objectives The objectives of this review are to summarize and put into historical perspective Goldberg’s contributions to elucidate the reinforcing effects of nicotine and to summarize the implications of his research for medication development, tobacco regulation, and potential tobacco control policy options. This includes a review of intravenous nicotine self-administration research from the 1960s to 2016. Results Goldberg’s application of behavioral pharmacology methods to investigate nicotine reinforcement and the influence of schedule of reinforcement and conditioned stimuli on nicotine administration contributed to the conclusions of the US National Institute on Drug Abuse, and the Surgeon General, that nicotine met the criteria as a dependence-producing drug and cigarette smoking as a prototypic drug dependency or “addiction.” Equally important, this work has been systematically extended to other species and applied to address a range of factors relevant to tobacco use, medication development, regulation, and public health policy. Conclusions Steven R. Goldberg was a pioneering scientist whose systematic application of the science of behavioral pharmacology advanced the understanding of tobacco and nicotine use and contributed to the scientific foundation for tobacco product regulation and potential public health tobacco control policy development. PMID:27766371
Martínez-García, Herminio; García-Vílchez, Encarna
This paper shows the modelling of linear-assisted or hybrid (linear & switching) DC/DC voltage regulators. In this kind of regulators, an auxiliary linear regulator is used, which objective is to cancel the ripple at the output voltage and provide fast responses for load variations. On the other hand, a switching DC/DC converter, connected in parallel with the linear regulator, allows to supply almost the whole output current demanded by the load. The objective of this topology is to take advantage of the suitable regulation characteristics that series linear voltage regulators have, but almost achieving the high efficiency that switching DC/DC converters provide. Linear-assisted DC/DC regulators are feedback systems with potential instability. Therefore, their modelling is mandatory in order to obtain design guidelines and assure stability of the implemented power supply system.
Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Pauls, Alexander Josef; Preuten, Marius; Rauch, Max Philip; Wangelik, Frederik; Wlochal, Michael
The 2S silicon strip modules for the CMS Phase-2 tracker upgrade will require two operating voltages. These will be provided via a two-step DC-DC conversion powering scheme, in which one DC-DC converter delivers 2.5\\,V while the second DC-DC converter receives 2.5\\,V at its input and converts it to 1.2\\,V. The DC-DC converters will be mounted on a flex PCB, the service hybrid, together with an opto-electrical converter module (VTRx+) and a serializer (LP-GBT). The service hybrid will be mounted directly on the 2S module. A prototype service hybrid has been developed and its performance has been evaluated, including radiative and conductive noise emissions, and efficiency. In addition system tests with a prototype module have been performed. In this report the service hybrid will be described and the test results will be summarized.
National Aeronautics and Space Administration — The Space Micro Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...
Descoeudres, Antoine; Nordlund, Kai
RF accelerating structures of the Compact Linear Collider (CLIC) require a material capable of sustaining high electric field with a low breakdown rate and low induced damage. Because of the similarity of many aspects of DC and RF breakdown, a DC breakdown study is underway at CERN in order to test candidate materials and surface preparations, and have a better understanding of the breakdown mechanism under ultra-high vacuum in a simple setup. The conditioning speed, breakdown field and field enhancement factor of cobalt have been measured. The average breakdown field after conditioning reaches 615 MV/m, which places cobalt amongst the best materials tested so far. By comparison with results and properties of other metals, the high breakdown field of Co could be due to its high work function and maybe also to its hexagonal crystal structure. Geneva, Switzerland (June 2009) CLIC – Note – 875
The current distribution in a DC railway and the resulting magnetic effects have been modelled using the parameters of the DC railway networks in Italy. The results show that the magnetic perturbations are substantially high in the vicinity of electrified railway lines. The order of magnitude of the induced field can be as significant as ∼ 40nT at a distance of ≅ 2km from the railway line indicating that geophysical techniques that employ natural magnetic anomalies can be badly effected, within this range. The magnetic effects rapidly decay with increasing distance, but the noise level could be significant even at a range of ∼ 10km. Also, these induced anomalies vary significantly with the conductivity of the ground. When the conductivity is high it is possible that the railway currents dispersed through the ground interact with those induced in the earth, causing a severe disruption to the telluric measurements. (author). 11 refs, 10 figs, 1 tab
Ge, Xian-Hui, E-mail: firstname.lastname@example.org [Shanghai Key Laboratory of High Temperature Superconductors, Department of Physics, Shanghai University, Shanghai, 200444 (China); Department of Physics, University of California, San Diego, CA92122 (United States); Sin, Sang-Jin, E-mail: email@example.com [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Wu, Shao-Feng, E-mail: firstname.lastname@example.org [Department of Physics, Shanghai University, Shanghai, 200444 (China)
We propose a universal formula of dc electrical conductivity in rotational- and translational-symmetries breaking systems via the holographic duality. This formula states that the ratio of the determinant of the dc electrical conductivities along any spatial directions to the black hole area density in zero-charge limit has a universal value. As explicit illustrations, we give several examples elucidating the validation of this formula: We construct an anisotropic black brane solution, which yields linear in temperature for the in-plane resistivity and insulating behavior for the out-of-plane resistivity; We also construct a spatially isotropic black brane solution that both the linear-T and quadratic-T contributions to the resistivity can be realized.
Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.
Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.
Newman, W. H.; Viele, M. R.
An 0.8 percent fuel savings was achieved by a reduction in engine bleed air through the use of cabin air recirculation. The recirculation system was evaluated in revenue service on a DC-10. The cabin remained comfortable with reductions in cabin fresh air (engine bleed air) as much as 50 percent. Flight test verified the predicted fuel saving of 0.8 percent.
BAYRAKTAR, H. C.; BALIK, H. H.
In this paper, about brushless DC motors and their structures, working principles, types, control logic and control methods commonly used are given general information. Nowadays, using BLDC motors are increased because of their advantages. For example, simple structure, easy control, small size and high effiency etc. Therefore, BLDC motors and their controls has become increasingly important in recently. The result of this paper, most common control techniques are also discussed
Dalimunthe, Amty Ma’rufah Ardhiyah; Mindara, Jajat Yuda; Panatarani, Camellia; Joni, I. Made, E-mail: email@example.com [Lab. of Instrumentation System and Functional Material Processing, Physics Department, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang KM21, Jatinangor 45363, Jawa Barat (Indonesia)
Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for a renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become ‘smart’. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.
Dalimunthe, Amty Ma'rufah Ardhiyah; Mindara, Jajat Yuda; Panatarani, Camellia; Joni, I. Made
Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for a renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become `smart'. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.
Elidiomar Ribeiro Da-Silva
Full Text Available This article compares arachnid-based Marvel and DC comics characters. The composition of a comic book character often has interesting ‘real-life’ influences. Given the strong connection between arachnids (especially spiders, scorpions and mites, all belonging to the zoological class 'Arachnida' and human beings it is not surprising that they have inspired many fictional characters. We recorded 84 Marvel Comics characters and 40 DC Comics characters, detailed in the dataset that accompanies the article (Da-Silva 2014. Most characters have been created recently, since the 1990s. Marvel has significantly more arachnid characters than DC. As for taxonomic classification, the characters were based mostly on spiders (zoological order 'Araneae'. Of the total characters, the majority are human beings, but an overwhelming number have at least some typical arachnid features. Villains (60.91% of total are significantly more numerous, considering the sum of the two publishers. Arachnids have bad reputation for being dangerous (Thorp and Woodson 1976; Ruppert and Barnes 1996. Since the public usually considers spiders, scorpions and mites “harmful” in general, we expected a larger contingent of villains. However, there was no statistical difference between the amount of villains and heroes in Marvel characters. It did not happen probably due to the success of one character: the Amazing Spider-Man.
Schwab, J. R.
Performance data obtained through experimental testing of a 22.4 kW traction motor using two types of excitation are presented. Ripple free dc from a motor-generator set for baseline data and pulse width modulated dc as supplied by a battery pack and chopper controller were used for excitation. For the same average values of input voltage and current, the motor power output was independent of the type of excitation. However, at the same speeds, the motor efficiency at low power output (corresponding to low duty cycle of the controller) was 5 to 10 percentage points lower on chopped dc than on ripple free dc. The chopped dc locked-rotor torque was approximately 1 to 3 percent greater than the ripple free dc torque for the same average current.
Siwakoti, Yam Prasad; Blaabjerg, Frede; Loh, Poh Chiang
In this letter, a new topology called “quasi-Y-source dc-dc converter” is presented. It inherits all the advantages of the original Y-source converter. In addition, the new topology draws a continuous current from the source, which is definitely more appropriate for most renewable sources. It als...... has dc-current-blocking capacitors, which will definitely help to prevent the coupled inductor core from saturation. Experimental testing has proven the validity of the proposed network and its application as a high boost dc-dc converter....
Xiong Liang; Yin Chongxian; Liu Ming; Chen Jianfeng
Both DC current transformer (DCCT) and integrating current transformer (ICT) can be used in DC beam current measurement. The ICT has strong capability of resisting electromagnetic interference, but its measurement accuracy cannot satisfy the DC beam current measurement requirement when using traditional high speed A/D. With high resolution A/D and equivalent sampling system, DC beam current measuring system based on ICT can reach high accuracy compared with DCCT system. In this paper, the ICT-based DC beam current measurement, equivalent sampling method and testing results at Shanghai Synchrotron Radiation Facility(SSRF) is described. (authors)
Kanhu Charan Bhuyan
Full Text Available Fuel cells are an attractive option for alternative power and of use in a variety of applications. This paper proposes a state space model for the solid oxide fuel cell (SOFC based power system that comprises fuel cell, DC-DC buck converter, and load. In this investigation we have taken up a case study for SOFC feeding a DC load where a DC-DC buck converter acts as the interface between the load and the source. A proportional-integral (PI controller is used in conjunction with pulse width modulation (PWM that computes the pulse width and switches the MOSFET at the right instant so that the desired voltage is obtained. The proposed model is validated through extensive simulation using MATLAB/SIMULINK. Controller for the fuel cell power system (FCPS is prototyped using XC3S500E development board containing a SPARTAN 3E Xilinx FPGA that simplifies the entire control circuit besides providing additional flexibility for further improvement. The results clearly indicate improved performance and validate our proposed model.
Full Text Available This paper studies and presents a series-connected high frequency DC/DC converter connected to a DC microgrid system to provide auxiliary power for lighting, control and communication in a DC light rail vehicle. Three converters with low voltage and current stresses of power devices are series-connected with single transformers to convert a high voltage input to a low voltage output for a DC light rail vehicle. Thus, Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs with a low voltage rating and a turn-on resistance are adopted in the proposed circuit topology in order to decrease power losses on power switches and copper losses on transformer windings. A duty cycle control with an asymmetric pulse-width modulation is adopted to control the output voltage at the desired voltage level. It is also adopted to reduce switching losses on MOSFETs due to the resonant behavior from a leakage inductor of an isolated transformer and output capacitor of MOSFETs at the turn-on instant. The feasibility and effectiveness of the proposed circuit have been verified by a laboratory prototype with a 760 V input and a 24 V/60 A output.
Nami, A.; Zare, F.; Ghosh, A.
for a diode-clamed inverter in the grid connection systems, where boosting low rectified output-voltage and series DC link capacitors is required. To verify the proposed topology, steady-state and dynamic analyses of a MOB converter are examined. A simple control strategy has been proposed to demonstrate......This study presents a new DC DC multi-output boost (MOB) converter which can share its total output between different series of output voltages for low- and high-power applications. This configuration can be utilised instead of several single output power supplies. This is a compatible topology...... the performance of the proposed topology for a double-output boost converter. The topology and its control strategy can easily be extended to offer multiple outputs. Simulation and experimental results are presented to show the validity of the control strategy for the proposed converter....
Huang, Peter Jen-Hung
This research first proposes a method to merge photovoltaic (PV) cells or PV panels within the internal components DC-DC converters. The purpose of this merged structure is to reconfigure the PV modules between series and parallel connections using high switching frequencies (hundreds of kHz). This leads to multi-levels of voltages and currents that become applied to the output filter of the converter. Further, this research introduces a concept of a switching cell that utilizes the reconfiguration of series and parallel connections in DC-DC converters. The switching occurs at high switching frequency and the switches can be integrated to be within the solar panels or in between the solar cells. The concept is generalized and applied to basic buck and boost topologies. As examples of the new types of converters: reconfigurable PV-buck and PV-boost converter topologies are presented. It is also possible to create other reconfigurable power converters: non-isolated and isolated topologies. Analysis, simulation and experimental verification for the reconfigurable PV-buck and PV-boost converters are presented extensively to illustrate proof of concept. Benefits and drawbacks of the new approach are discussed. The second part of this research proposes to utilize the internal solar cell capacitance and internal solar module wire parasitic inductances to replace the input capacitor and filter inductor in boost derived DC-DC converters for energy harvesting applications. High switching frequency (MHz) hard switched and resonant boost converters are proposed. Their analysis, simulation and experimental prototypes are presented. A specific proof-of-concept application is especially tested for foldable PV panels, which are known for their high internal wire inductance. The experimental converters successfully boost solar module voltage without adding any external input capacitance or filter inductor. Benefits and drawbacks of new proposed PV submodule integrated boost
Khan, U.A.; Shin, W.J.; Seong, J.K.; Oh, S.H.; Lee, S.H.; Lee, B.W.
We modeled DC SFCL by use of SimPowerSystem blocks. We examine the DC fault current limitation in low voltage DC distribution networks. SFCL's affects at critical points were measured. SFCL installed at the substation rectifier branch resulted in abnormal increase of fault current. The strategic location of SFCL is the point of integration of the PV plant with the power grid. DC fault current limitation in DC distribution network is one of the critical issues which need to be taken care of before they can be practically implemented. High temperature superconductors could be efficiently installed to cope with the problem of DC fault currents. In this paper, a generalized DC high temperature superconducting fault current limiter (SFCL) is modeled by integrating Simulink and SimPowerSystem blocks. This model is designed for limiting DC fault currents in low voltage DC distribution networks. A DC microgrid having a low voltage DC distribution network, an integrated photovoltaic plant and domestic customer load is modeled. Transient analysis of the DC microgrid is performed by generating fault and measuring DC fault currents at critical points. The designed DC SFCL is placed at different strategic locations in DC microgrid and fault current limitation performance of DC SFCL in DC microgrid has been analyzed. Moreover, the affects of rapid impedance changing in the distribution network due to the fault followed by DC SFCL activation is investigated. Finally, the best suitable position and affects of DC SFCL in a DC microgrid along with suggestions for implementation have been proposed.
Allongue, B; Faccio, F; Fuentes, c; Michelisa, S; Orlandia, S
The upgrade of the trackers at the sLHC experiments requires implementing new powering schemes that will provide an increased power density with reduced losses and material budget. A scheme based on buck and switched capacitors DC to DC converters has been proposed as an optimal solution. The buck converter is based on a power ASIC, connected to a custom made air core inductor. The arrangement of the parts and the board layout of the power module are designed to minimize the emissions of EMI in a compact volume, enabling its integration on the tracker modules and staves.
Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Wheeler, Patrick
The proposed exertion represents the modified high voltage conversion Cuk converter for renewable energy application. The proposed Cuk converter is a combination of the conventional boost converter and Cuk converter. The arrangement of the proposed converter make, such as, it becomes the single...... controlled device DC-DC topology. The voltage conversion ratio of proposed converter has increased by ten times of the conventional Cuk converterat a duty ratio of 90%. The detailed analysis of the voltage conversion ratio and losses occur due to internal resistance of components is done in the paper...
Siwakoti, Yam Prasad; Blaabjerg, Frede; Loh, Poh Chiang
In this paper, a new magnetically coupled single-switch non-isolated dc-dc converter with a high voltage gain is proposed. The new topology utilizes a transformer to boost the output voltage. However, unlike other converter topologies with transformer or coupled magnetics, the voltage gain...... in the proposed topology is increased by reducing the turns ratio of the transformer. Hence the name Trans-inverse (Tx−1) is given to represent the inverse transformer principle of operation of the proposed converter. The new topology draws a continuous current from the source, which is required for many...
Ouyang, Ziwei; Thomsen, Ole Cornelius; Andersen, Michael A. E.
A planar magnetic is a low profile transformer or inductor utilizing planar windings instead of the traditional windings made of Cu-wires. In this paper, the important factors for planar transformer design including winding loss, core loss, leakage inductance and stray capacitance have been.......2-kW full-bridge DC-DC converter prototype employing the improved planar transformer structure has been constructed, over 96% efficiency is achieved and a 2.7% improvement compared to the non-interleaving structure is obtained....
Hamasaki, Shin-ichi; Mukai, Ryosuke; Yano, Yoshihiro; Tsuji, Mineo
As a distributed generation system increases, a stable power supply becomes difficult. Thus control of power leveling (PL) unit is required to maintain the balance of power flow for irregular power generation. The unit is required to respond to change of voltage and bidirectional power flow. So the bidirectional buck/boost DC/DC converter is applied for the control of PL unit in this research. The PL unit with Electric double-layer capacitor (EDLC) is able to absorb change of power, and it is...