Thermal Control in Solids With Rapid Relaxation

2003 ◽  
Vol 125 (4) ◽  
pp. 563-568 ◽  
Author(s):  
D. Y. Tzou
Keyword(s):  
Feedback Control ◽  
Wide Spectrum ◽  
Thermal Relaxation ◽  
Thermal Control ◽  
Heat Propagation ◽  
High Rate ◽  
Neutral Stability ◽  
Heating Rates ◽  
Effective Feedback ◽  
Short Time

Feedback control of temperature in solids with a finite speed of heat propagation is investigated in this work. The emphases are placed on the effect of rapid thermal relaxation in high-rate heating and the possible delay during the short-time operations. Fundamental characteristics and dominating parameters are identified for effective feedback control in proportional heating. Transient instability, including the intrinsic transition from the desirable stability, neutral stability, to the ultimate unstable response are investigated in a wide spectrum of heating rates. Delayed heating is found to have a destabilizing effect during the short-time transient.

Description of short time phase transformations during the heating of steels based on high-rate experimental data

2004 ◽  
Vol 120 ◽  
pp. 591-598
Author(s):  
T. Mioković ◽  
J. Schwarzer ◽  
V. Schulze ◽  
O. Vöhringer ◽  
D. Löhe
Keyword(s):  
Phase Transformations ◽  
High Rate ◽  
Temperature Fields ◽  
Continuous Heating ◽  
Heating Rates ◽  
Temperature Changes ◽  
Steel Aisi ◽  
Temperature Transformation ◽  
Transformation Diagrams ◽  
Short Time

During surface hardening of steels like laser hardening, rapid thermal changes are imposed to the material. The modelling of these hardening processes allows the determination of time-dependent temperature fields and phase transformations within the affected zones. While there are many investigations on the transformation behaviour during cooling, there is a lack of data concerning the transformation during heating at very high heating rates. Therefore, experiments simulating the fast temperature changes are necessary to implement the effects of short time phase transformation during hardening into simulation. In this paper the effect of heating rates up to 10000 K/s on the austenitizing behaviour of the steel AISI 4140 (German grade 42CrMo4) are presented and described using an Avrami-function. The results obtained are summarized in time-temperature-transformation diagrams for continuous heating and isothermal time-temperature-transformation diagrams which may be used as input data for the simulation.

Guest is God

2019 ◽  
Author(s):  
Drew Thomases
Keyword(s):  
Everyday Life ◽  
Sacred Space ◽  
Wide Spectrum ◽  
Daily Basis ◽  
Economic Changes ◽  
Ethnographic Fieldwork ◽  
Northwestern India ◽  
Gathering Place ◽  
Short Time ◽  
The Town

This book is based on ethnographic fieldwork in Pushkar, a Hindu pilgrimage site in northwestern India whose population of 20,000 sees an influx of two million visitors each year. Since the 1970s, the town has also received considerable attention from international tourists, a group with distinctly hippie beginnings but that now includes visitors from a wide spectrum of social positions and religious affiliations. To locals, though, Pushkar is more than just a gathering place for pilgrims and tourists: it is where Brahma, the creator god, made his home; it is where pilgrims feel blessed to stay, if only for a short time; and it is where Hindus would feel lucky to be reborn, if only as an insect. In short, it is their paradise. But even paradise needs upkeep. Thus, on a daily basis the town’s locals, and especially those engaged in pilgrimage and tourism, work to make Pushkar paradise. The book explores this massive enterprise to build “heaven on earth,” paying particular attention to how the articulation of sacred space becomes entangled with economic changes brought on by globalization and tourism. As such, the author not only attends to how tourism affects everyday life in Pushkar but also to how Hindu ideas determine the nature of tourism there; the goal, then, is to show how religion and tourism can be mutually constitutive.

scholarly journals Fanconi Bickel syndrome: clinical phenotypes and genetics in a cohort of Sudanese children

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Salwa A. Musa ◽  
Areej A. Ibrahim ◽  
Samar S. Hassan ◽  
Matthew B Johnson ◽  
Asmahan T. Basheer ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Novel Mutation ◽  
Wide Spectrum ◽  
Rare Condition ◽  
Neonatal Diabetes ◽  
Abdominal Ultrasound ◽  
Sub Saharan Africa ◽  
High Rate ◽  
Genetic Characteristics ◽  
Sub Saharan

Abstract Background Fanconi-Bickel syndrome (FBS) is a rare condition of carbohydrate metabolism, caused by a recessive defect in the facilitative glucose transporter GLUT2 encoded by the SLC2A2 gene and characterized by a wide spectrum of phenotypical features. There is a paucity of reported data on FBS from Sub-Saharan Africa. Here, we describe the clinical, biochemical and genetic characteristics of our patients with FBS from Sudan, a country with a high consanguinity rate. Patients & methods Eleven patients from ten unrelated Sudanese families were included. Clinical & biochemical data were documented and imaging studies done including bone survey and abdominal ultrasound. Liver biopsy was done to confirm the pathological diagnosis in 45% of cases and molecular genetics was performed through contribution with the Exeter genomics laboratory for ten patients. Results Reported consanguinity was 70% among our patients. Growth was significantly impaired at presentation with mean weights of (-5.3 ± 1.8) SD and heights (-5.4 ± 2.5) SD. Severe chest deformity was present in (27%) and all patients showed features of rickets at presentation. Three patients had neonatal diabetes requiring insulin therapy of which one has been reported before. Six families lost undiagnosed siblings with similar clinical presentations. We identified a total of four homozygous pathogenic SLC2A2 variants in our patients, one of whom had a novel mutation. Conclusions FBS is not uncommon in Sudan where there is a high rate of consanguinity. Many cases are likely missed because of variable presentation and lack of public and professionals’ awareness. This is the first series to describe this condition from Sub-Saharan Africa.

scholarly journals Molecular Characteristics of Streptococcus pyogenes Isolated From Chinese Children With Different Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Dingle Yu ◽  
Yunmei Liang ◽  
Qinghua Lu ◽  
Qing Meng ◽  
Wenjian Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Streptococcus Pyogenes ◽  
Wide Spectrum ◽  
Expression Patterns ◽  
Virulence Gene ◽  
High Rate ◽  
Molecular Characteristics ◽  
Virulence Gene Expression ◽  
Obstructive Sleep

Streptococcus pyogenes is a bacterial pathogen that causes a wide spectrum of clinical diseases exclusively in humans. The distribution of emm type, antibiotic resistance and virulence gene expression for S. pyogenes varies temporally and geographically, resulting in distinct disease spectra. In this study, we analyzed antibiotic resistance and resistance gene expression patterns among S. pyogenes isolates from pediatric patients in China and investigated the relationship between virulence gene expression, emm type, and disease categories. Forty-two representative emm1.0 and emm12.0 strains (n = 20 and n = 22, respectively) isolated from patients with scarlet fever or obstructive sleep apnea-hypopnea syndrome were subjected to whole-genome sequencing and phylogenetic analysis. These strains were further analyzed for susceptibility to vancomycin. We found a high rate and degree of resistance to macrolides and tetracycline in these strains, which mainly expressed ermB and tetM. The disease category correlated with emm type but not superantigens. The distribution of vanuG and virulence genes were associated with emm type. Previously reported important prophages, such as φHKU16.vir, φHKU488.vir, Φ5005.1, Φ5005.2, and Φ5005.3 encoding streptococcal toxin, and integrative conjugative elements (ICEs) such as ICE-emm12 and ICE-HKU397 encoding macrolide and tetracycline resistance were found present amongst emm1 or emm12 clones from Shenzhen, China.

scholarly journals The main natural lows of high-rate coal pyrolysis

2003 ◽  
Vol 7 (2) ◽  
pp. 77-87 ◽  
Author(s):  
Nikola Chemyavsky
Keyword(s):  
Fluidized Bed ◽  
Total Yield ◽  
Pilot Scale ◽  
Thermal Conversion ◽  
High Rate ◽  
Coal Pyrolysis ◽  
Heating Rates ◽  
Method Of Calculation ◽  
Entrained Flow ◽  
Energy Technologies

The importance of coal pyrolysis studies for the development of energy technologies is evident, since pvrolysis is the first stage of any process of coal thermal conversion. In combustion, pyrolysis determines conditions of coal ignition and the rate of char after-burning, in gasification, pyrolysis determines total yield of gasification products. It must be noted that in modern energy technologies pyrolysis occurs at high late of coal particle heating (=10 K/s for different fluidized bed, or FB-technologies) or super-high-rate (>10**5 K/s for entrained-flow gasification), and in some of them at high pressure. In CETI during last 12 years the detailed study of pyrolysis in FB laboratory-scale PYROLYSIS-D plant and entramed-flow pilot-scale GSP-01 plant, was carried out. In this paper main results of mentioned investigations are given. Kinetic constants for bituminous coals and anthracite high heating rates in entrained flow for high temperatures (>1500 ?C and >1900 ?C), and in fluidized bed conditions in temperature range 972-1273 K. In order to describe data obtained in fluidized bed conditions, G--model based method of calculation of devolatization dynamics was suited to FB heating conditions. Calculated and experimental kinetic data are in good agreement. The result proves that at FB-pvrolysis conditions intrinsic mass-transfer limitations are negligible and devolatilization is really kinetic-controlled.

scholarly journals Flow and heat transfer performance of plate phase change energy storage heat exchanger

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1989-2000
Author(s):  
Ji-Min Zhang ◽  
Shi-Ting Ruan ◽  
Jian-Guang Cao ◽  
Tao Xu
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Heat Exchanger ◽  
Phase Change ◽  
Thermal Control ◽  
Heat Transfer Characteristics ◽  
Liquid Distribution ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Short Time

In the present work, the phase change energy storage heat exchanger in thermal control system of short-time and periodic working satellite payloads is taken as the research object. Under the condition of constant heated power of the satellite payload, the heat transfer characteristics of phase change energy storage heat exchanger are analyzed by numerical simulation and experimental method. The heat exchanger with fin arrays to enhance heat transfer is filled with tetradecane, whose density varies with temperature. The flow field distribution, the solid-liquid distribution, the temperature distribution, and the phase change process in the plate phase change energy storage heat exchanger unit are analyzed. The flow and heat transfer characteristics of heat exchangers under different fluid-flow rates and temperature were investigated.

Health Problems Encountered by Short-Term European Volunteers in a Nongovernmental Organization in Cambodia

2022 ◽  
Author(s):  
Jaime Barrio Cortes ◽  
Claudia Rojas Muñoz ◽  
Miguel Ángel Acosta Benito ◽  
Ángela Hidalgo Baz ◽  
Ángel Vicario Merino ◽  
...  
Keyword(s):  
Respiratory Infections ◽  
Wide Spectrum ◽  
Health Problems ◽  
Nongovernmental Organization ◽  
High Rate ◽  
Short Term ◽  
Regular Treatment ◽  
Preventative Health ◽  
Health Course ◽  
Health Related

Short-term volunteers are susceptible to a wide spectrum of morbidities, mostly infectious diseases preventable with general hygiene and preventive measures. This study aimed to identify the health problems encountered by European short-term volunteers collaborating for 1 month with a nongovernmental organization (NGO) in Cambodia and to describe their characteristics. A prospective, descriptive observational study was conducted on short-term volunteers who collaborated with an NGO in Cambodia during August 2018. Informed consent and sociodemographic, clinical, and preventative health-related questionnaire data were provided by 198 volunteers. The health problems encountered were confirmed in a primary care consultation with healthcare professionals. Univariate and bivariate analyses were performed. The median age of the volunteers was 22 years (interquartile range = 21–24), and 64% were women. Some (18.2%) had allergies, 8.6% had preexisting health conditions, and 10.6% were under regular treatment. A total of 77.3% visited a pretravel consultation clinic, 39.9% completed a specific pretravel health course, 21.7% took malaria prophylaxis, 92.4% received hepatitis A vaccination, and 82.3% received typhoid fever vaccination. Medical assistance was sought by 112 (57.3%) of the volunteers. The average number of health problems was 2.5 (standard deviation = 1.5), and the total number of health problems attended by the medical team was 279. The most common health problems were upper respiratory infections (12.2 per 1,000 person-days), wounds (10.8 per 1,000 person-days), and diarrhea (6.3 per 1,000 person-days). Short-term volunteers experienced a high rate of health problems during their stay in Cambodia, but most of the problems were mild and preventable and resolved quickly. Pretravel consultation and specific pretravel health training seemed to increase disease awareness.

First-Timer Learning Experiences in Global Game Jam

2019 ◽  
Vol 9 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Mikko Meriläinen
Keyword(s):  
Wide Spectrum ◽  
Learning Experiences ◽  
Self Determination Theory ◽  
Psychological Needs ◽  
Basic Psychological Needs ◽  
Self Determination ◽  
Global Game ◽  
Psychological Mechanisms ◽  
Time Period ◽  
Short Time

Game jams are accelerated game creation events usually taking place over the course of a short time period. A variety of learning outcomes from game jamming has been discussed in previous research, with learning being a common motivation for attending game jams. Despite this, there has been little research into the psychological mechanisms driving learning and participation. In this article, the learning experiences of four first-time participants in the Global Game Jam are examined through self-determination theory. Results suggest that a wide spectrum of learning is experienced during a game jam, and game jams offer at least a temporary heightened sense of creativity and competence. Assessment remains an issue, however, and learning benefits may be contingent on the jam setting. All three basic psychological needs listed in self-determination theory are potentially fulfilled by game jam attendance, suggesting the relevance of self-determination theory in further jam research.

The Magnificent VWF SNPs and Where to Find Them: A Journey in Exon 28 of the Hispanic Population

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S16-S17
Author(s):  
Mohammad Barouqa ◽  
Jui Choudhuri ◽  
Roger Fecher ◽  
Jack Jacob ◽  
Saed Sadeghi ◽  
...  
Keyword(s):  
African American ◽  
African Americans ◽  
Wide Spectrum ◽  
Von Willebrand Disease ◽  
High Rate ◽  
Coagulation Disorder ◽  
Hispanic Population ◽  
Protein Ratio ◽  
A1 Domain

Abstract von Willebrand disease (VWD) is a common coagulation disorder with a prevalence of 0.1% to 1.0% manifesting as a wide spectrum of bleeding symptoms. Type 1 is diagnosed by confirming a quantitative decrease in VWF level, while type 3 has undetectable levels of VWF. Type 2 VWD variants are characterized by functional and binding defects. Initial diagnosis and follow-up depend mainly on measuring VWF protein and VWF activity and calculating the activity to protein ratio. Ristocetin cofactor activity (VWF:RCo) is the most widely used and gold standard activity assay. In our institute, we use a cutoff of VWF:RCo/VWF:Ag <0.7 to screen for possible type 2 VWD. However, the use of this ratio is flawed by the presence of specific SNPs (I1380V, N1435S, and D1472H) in the A1 domain, especially in African Americans. These SNPs lead to a decrease in ristocetin binding to VWF and hence decreased VWF:RCo/VWF:Ag ratio. In this retrospective study, we analyzed the levels of VWF:AG and VWF:RCo based on patients’ ethnicity using an in-house data mining software from 2011 to 2016. Then, we validated several exon 28 primers, kindly provided by Dr. Montgomery (Blood Center of Wisconsin), used to detect type 2 mutations and SNPs in African Americans. We excluded cases diagnosed as positive for VWD and included only cases rendered nondiagnostic of VWD following a comprehensive panel including multimers, collagen binding, and molecular studies when indicated. In our Hispanic population (n = 936), VWF:Ag was 138.9% and 117% (average and median) and VWF:RCo was 110.5% and 93.0% (average and median); 43.2% of Hispanics had VWF:RCo/VWF:Ag <0.7. In our African American population (n = 664), VWF:Ag was 163.0% and 138.5% (average and median) and VWF:RCo was 108.5% and 92.0% (average and median); 50.6% of the African American patients had VWF:RCo/VWF:Ag <0.7. Patients from Caucasian origins (n = 242) had VWF:Ag of 149.6% and 113.0% (average and median) and VWF:RCo of 137.6% and 116.0% (average and median), respectively; 30.9% of Caucasian patients had VWF:RCo/VWF:Ag of less than 0.7. We then selected four random Hispanic cases with VWF:RCo/VWF:Ag <0.5 as part of the validation study of exon 28 sequencing. Using a Sanger sequence assay, we found multiple benign/likely benign single-nucleotide polymorphisms (SNPs) at exon 28 that code for VWF antigen A1 domain. All four cases showed P.Thr1381Ala and P.Thr1547 = [OC1] polymorphism, three showed p.Val1565Leu polymorphism, and two showed p.Ala1555 = polymorphism. The statistical analysis of VWF:Ag/VWF:RCo levels from Hispanics shows a similar trend to African Americans with a high rate of cases with VWF:RCo/VWF:Ag <0.7 in comparison to Caucasians. However, the finding of SNPs and absence of known African American polymorphisms suggest that these SNPs may be the cause of decreased ristocetin binding in Hispanics. This study calls for ethnic-based considerations in VWD workflows.

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