Reprocessing of Sintered and Melt High Temperature Superconducting Materials

1994 ◽  
Vol 344 ◽  
Author(s):  
C. Vipulanandan ◽  
B. Martinz
Keyword(s):  
High Temperature ◽  
Past History ◽  
Silver Powder ◽  
Previous History ◽  
High Temperature Superconducting ◽  
Melting Temperatures ◽  
Bulk Ybco ◽  
Barium Copper ◽  
History Of ◽  
The Cost

AbstractIncreasing use of High Temperature Superconducting Ceramics (HTSC) in various applications and the cost of the new superconducting powder dictated the need for evaluating the potential of reusing the old HTSC material (yittrium-barium-copper oxide (YBCO); YBa2Cu3O7-x) with minimum reprocessing. This study examined various methods to reprocess two years old sintered and melt bulk YBCO ceramics. YBCO components were ground and processed with and without adding various amount of silver powder, organic binders and new YBCO powder. The reprocessed YBCO powder was also characterized at every step of processing using X-ray diffraction (XRD) and Differential Thermal Analysis (DTA) to identify impurities.The old YBCO components were first crushed and then ground using automatic grinder and a jet-mill. The ground powder was then mixed with additives and/or binders and compacted uniaxially to 45 ksi. The range of sintereing temperatures from 905 °C to 980 °C were selected based on the past history of sintering/melting temperatures. The reground powder was found to have impurity phases due to its exposure to carbon dioxide and humidity in the atmosphere. Addition of Ag powder resulted in higher relative densities at lower sintering temperatures. The need for re-calcination of used powders was also considered to improve the performance of reprocessed powders. The sintering temperature was selected based on achieving 85% relative density. The results show that the reprocessed powders have to be sintered at higher temperatures than their previous history. The sintered and melt-textured YBCO made from reprocessed powder had similar or better superconducting properties compared to the new powder.

Analysis of the Permanent Magnet Guideway of High Temperature Superconducting Maglev

2013 ◽  
Vol 745-746 ◽  
pp. 197-202 ◽  
Author(s):  
Chang Qing Ye ◽  
Zi Gang Deng ◽  
Jia Su Wang
Keyword(s):  
High Temperature ◽  
Permanent Magnet ◽  
High Speed ◽  
Optimization Design ◽  
Optimization Methods ◽  
High Temperature Superconducting ◽  
Practical Engineering ◽  
Hts Maglev ◽  
Ndfeb Permanent Magnet ◽  
The Cost

t was theoretically and experimentally proved that High Temperature Superconducting (HTS) Maglev had huge potential employment in rail transportation and high speed launch system. This had attracted great research interests in practical engineering. The optimization design was one of the most important works in the application of the HTS Maglev. As the NdFeB permanent magnet and HTS materials prices increased constantly, the design optimization of the permanent guideway (PMG) of HTS maglev became one of the indispensable works to decrease the cost of the application. This paper first reviewed four types of PMGs used by the HTS Maglev, then disucssed their structures and magnetic fields. Finally, the optimization methods of these four PMGs were compared. It was suggested that with better optimization methods, the levitation performance within a limit cost got better. That would be helpful to the future numerical optimization of the PMG of the HTS maglev.

A study of deliberate self-poisoning in a Dublin hospital 1986 – 1990

1994 ◽  
Vol 11 (2) ◽  
pp. 70-72 ◽  
Author(s):  
Fergus Coakley ◽  
Catherine Hayes ◽  
John Fennell ◽  
Zachary Johnson
Keyword(s):  
Past History ◽  
Dublin Hospital ◽  
Psychiatric Inpatient ◽  
Previous History ◽  
Psychiatric Hospitals ◽  
High Rate ◽  
Medical Complication ◽  
Motivating Factors ◽  
History Of ◽  
Low Threshold

AbstractObjective: The study was undertaken to determine the current demographic and clinical features of cases of deliberate self-poisoning (DSP) presenting to an acute general hospital and to compare the findings with previous work in Ireland and elsewhere. Method: Four hundred and sixty seven consecutive admissions for DSP presenting to a Dublin hospital between 1986 and 1990 inclusive were identified retrospectively and the case notes reviewed. Data was collected on age, sex, marital status, past history, date of DSP, drugs used, motivating factors and outcome. Results: The peak age of DSP was 15-24 years. The female:male ratio was 1.5:1. There was an increased incidence of DSP in women in July and August. In 32% there was a previous history of DSP. Benzodiazepines, antidepressants and analgesics/anti-inflammatories were the commonest drugs taken. There was a significant medical complication in 10.5% of cases, but no fatalities. Twenty-five percent of patients were subsequently admitted to psychiatric inpatient care. Conclusions: DSP is an ongoing problem. The summer peak in females may be related to the parenting burden during the summer recess. The high rate of repetition suggests a significant reduction could be achieved with successful strategies for secondary prevention. The high rate of psychiatric in-patient referral may be related to a low threshold for admissions to Irish psychiatric hospitals.

scholarly journals Misdiagnosis and Mistreatment of Post-Kala-Azar Dermal Leishmaniasis

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed Mohamed El Hassan ◽  
Eltahir Awad Gasim Khalil ◽  
Waleed Mohamed Elamin ◽  
Lamyaa Ahmed Mohamed El Hassan ◽  
Mogtaba Elsaman Ahmed ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Past History ◽  
Previous History ◽  
Clinical Appearance ◽  
Kala Azar ◽  
Pcr Diagnosis ◽  
The Face ◽  
History Of ◽  
High Parasite

Post-kala-azar dermal leishmaniasis (PKDL) is a known complication of visceral leishmaniasis (VL) caused byL. donovani. It is rare in VL caused byL. infantumandL. chagasi. In Sudan, it occurs with a frequency of 58% among successfully treated VL patients. In the majority of cases, PKDL can be diagnosed on the basis of clinical appearance, distribution of the lesions, and past history of treated VL. The ideal diagnostic method is to demonstrate the parasite in smears, by culture or PCR. Diagnosis is particularly difficult in patients who develop PKDL in the absence of previous history of visceral leishmaniasis. We describe a case of cutaneous leishmaniasis misdiagnosed as PKDL and 3 cases of PKDL who were either misdiagnosed or mistreated as other dermatoses. This caused exacerbation of their disease leading to high parasite loads in the lesions and dissemination to internal organs in one of the patients, who was also diabetic. The latter patient hadL. majorinfection. A fourth patient with papulonodular lesions on the face and arms of 17-year duration and who was misdiagnosed as having PKDL is also described. He turned out to have cutaneous leishmaniasis due toL. major. Fortunately, he was not treated with steroids. He was cured with intravenous sodium stibogluconate.

scholarly journals ACUTE HEART FAILURE

2018 ◽  
Vol 25 (09) ◽  
pp. 1392-1396
Author(s):  
Jasia Reham Din ◽  
Shahid Maqbool ◽  
Shakeel ur Rehman ◽  
Naeem Hameed
Keyword(s):  
Heart Failure ◽  
Acute Heart Failure ◽  
De Novo ◽  
Past History ◽  
Previous History ◽  
Young Male ◽  
Uncontrolled Hypertension ◽  
Cross Sectional ◽  
History Of ◽  
Emergency Department Patients

Objectives: To determine the frequency of the major precipitating factorsamong the patients presenting with acute heart failure. Study Design: Cross sectional study.Setting: Faisalabad Institute of Cardiology, Faisalabad. Period: July 2014 to January 2015.Materials and Methods: 190 patients of acute heart failure were included after obtaininginformed consent from emergency department. Patients from age of 25 years to 80 years andof either sex either diabetic or non-diabetic were enrolled in study. ECG and CXR were takenin emergency with baseline investigations. Precipitating cause was identified from collectedhistory, clinical examination and ECG, CXR and lab results. Results: Mean age of these patientswere 54.4 + 8.92, 100 (52.6%) were male, 90 (47.4%) were females, 88 patients (46.3%) werediabetic, 102 patients (53.68%) were non-diabetic and 124 (65.3%) had previous history of heartfailure and 66 (34.7%) had no past history of heart failure. ACS was the common precipitatingfactor of Acute Heart Failure ( 31.57% ) among all the patients of the study with non-complianceof drugs 27.9% , arrhythmias 17.9% uncontrolled hypertension 17.36% and infections 5.3%.Conclusion: Young, male, diabetics and patients with history of chronic HF suffered more fromAHF. ACS was the most common precipitating factor while in patients with de novo Acute HeartFailure; it was ACS and non-compliance with drugs.

scholarly journals Problem-Based Review: Paracetamol Overdose

2011 ◽  
Vol 10 (4) ◽  
pp. 212-215
Author(s):  
Tom Heaps ◽  
Keyword(s):  
Emergency Department ◽  
Glasgow Coma Scale ◽  
Past History ◽  
Previous History ◽  
Past Medical History ◽  
Minute Period ◽  
Normal Diameter ◽  
History Of ◽  
Self Harm ◽  
History Of Depression

A 29-year old male presents to the emergency department 1h after an overdose of cocodamol. He admits to taking approximately 60 x 8/500mg tablets, with alcohol, over a 20 minute period. He has a past history of depression, treated by his GP with citalopram 20mg OD. He has no previous history of deliberate self-harm. His past medical history is otherwise unremarkable and he is not on any additional medications. He drinks approximately 40 units of alcohol per week. Physical examination is unremarkable, his pupils are normal diameter and his Glasgow Coma Scale is 15. He weighs 82kg.

Exergy Costing in Exergoeconomics

1993 ◽  
Vol 115 (1) ◽  
pp. 9-16 ◽  
Author(s):  
G. Tsatsaronis ◽  
L. Lin ◽  
J. Pisa
Keyword(s):  
Previous History ◽  
Energy Systems ◽  
Process Step ◽  
New Approach ◽  
Chemical Exergy ◽  
Recent Developments ◽  
History Of ◽  
Exergoeconomic Analysis ◽  
The Cost ◽  
Objective Methodology

Existing methods of exergoeconomic analysis and optimization of energy systems operate with single average or marginal cost values per exergy unit for each material stream in the system being considered. These costs do not contain detailed information on (a) how much exergy, and (b) at what cost each exergy unit was supplied to the stream in the upstream processes. The cost of supplying exergy, however, might vary significantly from one process step to the other. Knowledge of the exergy addition and the corresponding cost at each previous step can be used to improve the costing process. This paper presents a new approach to exergy costing in exergoeconomics. The monetary flow rate associated with the thermal, mechanical and chemical exergy of a material stream at a given state is calculated by considering the complete previous history of supplying and removing units of the corresponding exergy form to and from the stream being considered. When exergy is supplied to a stream, the cost of adding each exergy unit to the stream is calculated using the cost of product exergy unit for the process or device in which the exergy addition occurs. When the stream being considered supplies exergy to another exergy carrier, the last-in-first-out (LIFO) principle of accounting is used for the spent exergy units to calculate the cost of exergy supply to the carrier. The new approach eliminates the need for auxiliary assumptions in the exergoeconomic analysis of energy systems and improves the fairness of the costing process by taking a closer look at both the cost-formation and the monetary-value-use processes. This closer look mainly includes the simultaneous consideration of the exergy and the corresponding monetary values added to or removed from a material stream in each process step. In general, the analysis becomes more complex when the new approach is used instead of the previous exergoeconomic methods. The benefits of using the new approach, however, significantly outweigh the increased efforts. The new approach, combined with some other recent developments, makes exergoeconomics an objective methodology for analyzing and optimizing energy systems.

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