Numerical Calculation of Temperature and Microstructure for Induction Surface Hardening

2014 ◽  
Vol 698 ◽  
pp. 251-257
Author(s):  
Dirk Schlesselmann ◽  
Aleksandr Nikanorov ◽  
Bernard Nacke
Keyword(s):  
Surface Hardening ◽  
Hardened Layer ◽  
Temperature History ◽  
Heating Process ◽  
Work Piece ◽  
Quenching Process ◽  
History Of ◽  
To Receive ◽  
Induction Surface Hardening ◽  
Martensite Microstructure

In the present paper, a new numerical model for calculating martensite microstructure in induction surface hardening processes is introduced. It takes into account the heating as well as the quenching process and uses the temperature history of a work piece to calculate martensite formation. The calculation is based on an empirical equation found by Koistinen and Marburger [1].A comparison between the heat distribution within a work piece at the end of the heating process and the distribution of martensite after quenching is performed for different process parameters. Thus, it is determined, in which case the temperature distribution is sufficient to predict the hardened layer and in which case the microstructure has to be calculated to receive accurate results. The model is verified by comparing simulation results with different experiments.

scholarly journals The Microstructure and Mechanical Properties of Cylindrical Elements from Steel 38Mn6 after Continuous Induction Heating

2016 ◽  
Vol 61 (4) ◽  
pp. 1969-1974 ◽  
Author(s):  
A. Smalcerz ◽  
J. Barglik ◽  
D. Kuc ◽  
K. Ducki ◽  
S. Wasiński
Keyword(s):  
Mechanical Properties ◽  
Surface Hardening ◽  
Induction Hardening ◽  
Hardened Layer ◽  
Second Stage ◽  
Hardening Process ◽  
Microstructure And Mechanical Properties ◽  
University Of Technology ◽  
Induction Surface Hardening ◽  
Continuous Induction

Abstract The paper deals with the influence of induction surface hardening on the microstructure and mechanical properties of cylindrical elements made of steel 38Mn6. The first stage was based on computer simulation of the induction hardening process. The second stage - experiments were provided on laboratory stand for induction surface hardening located at the Silesian University of Technology. Microstructure tests were conducted on light and scanning microscopes. The hardness penetration pattern and thickness of hardened layer were marked. It was found that due to properly chosen parameters of the process, the appropriate properties and thickness of hardened layer were achieved.

Pseudo-Parkinson Disease Secondary to Ritonavir–Buspirone Interaction

2003 ◽  
Vol 37 (2) ◽  
pp. 202-205 ◽  
Author(s):  
Patrick G Clay ◽  
Molly M Adams
Keyword(s):  
Drug Interaction ◽  
Inhibitory Effect ◽  
Hiv Positive ◽  
High Dose ◽  
Resting Tremor ◽  
Case Summary ◽  
History Of ◽  
Drug Drug Interaction ◽  
To Receive

OBJECTIVE: To report a case of Parkinson-like symptoms appearing in a patient after introduction of ritonavir to buspirone therapy. CASE SUMMARY: A 54-year-old HIV-positive white man presented to the clinic with a 2-week history of ataxia, shuffling gait, cogwheel rigidity, resting tremor, and sad affect with masked features. This patient had been receiving high-dose buspirone (40 mg every morning and 30 mg every evening) for 2 years prior to the introduction of ritonavir/indinavir combination therapy (400 mg/400 mg twice daily) 6 weeks prior to initiation of the above symptoms. Buspirone was decreased to 15 mg 3 times daily, ritonavir/indinavir was discontinued, and amprenavir 1200 mg twice daily was added. The patient's symptoms began to subside after 1 week, with complete resolution after about 2 weeks. The patient continued to receive buspirone for an additional 12 months without recurrence of symptoms. DISCUSSION: This is the first reported interaction of buspirone and antiretrovirals. Buspirone, extensively metabolized by CYP3A4, was likely at supratherapeutic levels due to the inhibitory effect of ritonavir and, secondarily, indinavir. The Parkinson-like symptoms developed rapidly and severely, impacted this patient's quality of life, and necessitated significant clinic expenditures to identify this drug–drug interaction. CONCLUSIONS: This case demonstrates a severe drug–drug interaction between buspirone and ritonavir and further demonstrates the need for awareness of the metabolic profile for all agents an HIV-infected patient is receiving.

scholarly journals Ketogenic diet reduces alcohol withdrawal symptoms in humans and alcohol intake in rodents

2021 ◽  
Vol 7 (15) ◽  
pp. eabf6780
Author(s):  
Corinde E. Wiers ◽  
Leandro F. Vendruscolo ◽  
Jan-Willem van der Veen ◽  
Peter Manza ◽  
Ehsan Shokri-Kojori ◽  
...  
Keyword(s):  
Ketogenic Diet ◽  
Alcohol Withdrawal ◽  
Alcohol Use Disorder ◽  
Alcohol Intake ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Beneficial Effects ◽  
Alcohol Cues ◽  
History Of ◽  
To Receive

Individuals with alcohol use disorder (AUD) show elevated brain metabolism of acetate at the expense of glucose. We hypothesized that a shift in energy substrates during withdrawal may contribute to withdrawal severity and neurotoxicity in AUD and that a ketogenic diet (KD) may mitigate these effects. We found that inpatients with AUD randomized to receive KD (n = 19) required fewer benzodiazepines during the first week of detoxification, in comparison to those receiving a standard American (SA) diet (n = 14). Over a 3-week treatment, KD compared to SA showed lower “wanting” and increased dorsal anterior cingulate cortex (dACC) reactivity to alcohol cues and altered dACC bioenergetics (i.e., elevated ketones and glutamate and lower neuroinflammatory markers). In a rat model of alcohol dependence, a history of KD reduced alcohol consumption. We provide clinical and preclinical evidence for beneficial effects of KD on managing alcohol withdrawal and on reducing alcohol drinking.

scholarly journals Effect of frailty on treatment, hospitalisation and death in patients with chronic heart failure

2021 ◽  
Author(s):  
S. Sze ◽  
P. Pellicori ◽  
J. Zhang ◽  
J. Weston ◽  
I. B. Squire ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Clinical Frailty Scale ◽  
Mineralocorticoid Receptor Antagonist ◽  
Reduced Ejection Fraction ◽  
Frail Patients ◽  
History Of ◽  
Poor Outcomes ◽  
To Receive

Abstract Background Frailty is common in patients with chronic heart failure (CHF) and is associated with poor outcomes. The natural history of frail patients with CHF is unknown. Methods Frailty was assessed using the clinical frailty scale (CFS) in 467 consecutive patients with CHF (67% male, median age 76 years, median NT-proBNP 1156 ng/L) attending a routine follow-up visit. Those with CFS > 4 were classified as frail. We investigated the relation between frailty and treatments, hospitalisation and death in patients with CHF. Results 206 patients (44%) were frail. Of 291 patients with HF with reduced ejection fraction (HeFREF), those who were frail (N = 117; 40%) were less likely to receive optimal treatment, with many not receiving a renin–angiotensin–aldosterone system inhibitor (frail: 25% vs. non-frail: 4%), a beta-blocker (16% vs. 8%) or a mineralocorticoid receptor antagonist (50% vs 41%). By 1 year, there were 56 deaths and 322 hospitalisations, of which 25 (45%) and 198 (61%), respectively, were due to non-cardiovascular (non-CV) causes. Most deaths (N = 46, 82%) and hospitalisations (N = 215, 67%) occurred in frail patients. Amongst frail patients, 43% of deaths and 64% of hospitalisations were for non-CV causes; 58% of cardiovascular (CV) deaths were due to advancing HF. Among non-frail patients, 50% of deaths and 57% of hospitalisations were for non-CV causes; all CV deaths were due to advancing HF. Conclusion Frailty in patients with HeFREF is associated with sub-optimal medical treatment. Frail patients are more likely to die or be admitted to hospital, but whether frail or not, many events are non-CV. Graphical abstract

scholarly journals 1339. Antibiotic Prescribing Varies among Patients with a Documented Penicillin or Cephalosporin Adverse Drug Reaction

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S681-S681
Author(s):  
Brian R Lee ◽  
Jason Newland ◽  
Jennifer Goldman
Keyword(s):  
Pediatric Patients ◽  
Antibiotic Prescribing ◽  
Hospitalized Children ◽  
Beta Lactam ◽  
Research Support ◽  
Point Prevalence Study ◽  
History Of ◽  
Gi Infections ◽  
To Receive ◽  
Indication For Treatment

Abstract Background Studies have shown that over half of hospitalized children receive an antibiotic during their encounter, of which between 30-50% is considered inappropriate. Antibiotic prescribing is further complicated as approximately 10% of children are labeled beta-lactam allergic, resulting in the use of either broad-spectrum or suboptimal therapy. The purpose of this study was to compare antibiotic prescribing between patients with a documented ADR vs. those without using a nationwide sample of hospitalized children. Methods We performed a point prevalence study among 32 hospitals between July 2016-December 2017 where data were collected via chart review on pediatric patient and antimicrobial characteristics, including the indication for all antimicrobials. In additional, ADR history data were collected on which antimicrobial(s) were documented (e.g., penicillin, cephalosporins). Patients were mutually assigned into either: 1) no documented ADR; 2) penicillin ADR-only; 3) cephalosporin ADR-only; and 4) ADR for both penicillin and cephalosporin. The distribution of antibiotics were compared between the ADR groups, stratified by the indication for treatment. Results A total of 12,250 pediatric patients (17,929 antibiotic orders) who were actively receiving antibiotics were identified. A history of penicillin and cephalosporin ADR was documented in 5.5% and 2.8% of these patients, respectively. When compared to patients with no documented ADR, penicillin ADR patients were more likely to receive a fluoroquinolone for a SSTI infection (odds ratio [OR]: 5.6), surgical prophylaxis (OR: 18.8) or for surgical treatment (OR: 5.2) (see Figure). Conversely, penicillin ADR patients were less likely to receive first-line agents, such as narrow-spectrum penicillin for bacterial LRTI (OR: 0.08) and piperacillin/tazobactam for GI infections (OR: 0.22). Cephalosporin ADR patients exhibited similar patterns with increased use of carbapenems and fluoroquinolones when compared to patients with no ADR. Figure 1: Odds of Receiving Select Antimicrobials Among PCN ADR Patients When Compared to Non-ADR patients, by Indication Conclusion A large, nationwide sample of pediatric patients who were actively prescribed antibiotics helped identify several diagnoses where comprehensive guidelines for appropriate ADR prescribing and increased ADR de-labeling initiatives are needed to ensure optimal treatment. Disclosures Brian R. Lee, MPH, PhD, Merck (Grant/Research Support) Jason Newland, MD, MEd, FPIDS, Merck (Grant/Research Support)Pfizer (Other Financial or Material Support, Industry funded clinical trial)

The Mechanical Behavior of Aluminium Alloy Quenching Process

2011 ◽  
Vol 228-229 ◽  
pp. 822-827
Author(s):  
Jia Yuan Luo ◽  
Rong Fan ◽  
Cheng Xiang Shi
Keyword(s):  
Surface Layer ◽  
Aluminum Alloy ◽  
Dynamic Simulation ◽  
Strain Field ◽  
Method Development ◽  
Experimental Tests ◽  
Analysis Method ◽  
Process Dynamic ◽  
Quenching Process ◽  
History Of

Since the aluminum alloy quenching is a complicated and a prompt heat-pressure coupling processing, traditional experimental tests and empirical judgments cannot explain and predict the physical and the force behavior completely during the quenching process. Dynamic simulation of the quenching process is conducted using the finite analysis method. Development laws of the stress and the strain field of the surface layer and core of the alloy during the quenching process are described based on the verification of the simulation. States and process history of the stress and the strain in each phase during the quench are obtained, which provides ponderable data and theoretical value for a fully understanding of the aluminum alloy quenching.

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