scholarly journals Cost-Effective Alternatives to Conventional Charpy Tests for Measuring the Impact Toughness of Very-High-Toughness Steels

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Enrico Lucon
Keyword(s):  
Electrical Discharge Machining ◽  
Test Procedure ◽  
Cost Effective ◽  
Moderate Increase ◽  
Type Specimens ◽  
Charpy Test ◽  
Line Pipe ◽  
High Toughness ◽  
The Impact ◽  
Very High

For modern plate steels exhibiting high toughness and ductility, the conventional Charpy test is ostensibly stretched beyond its limits of applicability. Impact tests yield absorbed energy values in excess of 300–400 J, which are associated with limited material fracture and mostly derive from plastic deformation of the specimen (bending), friction, and vibrations of the swinging hammer. It would be therefore very desirable to measure the actual fracture toughness of very-high-toughness steels by means of an alternative specimen and/or methodology, entailing just a moderate increase of cost and test complexity with respect to Charpy testing. The investigation presented here was aimed at establishing a reasonable, yet cost-effective test procedure utilizing Charpy-type specimens for measuring the dynamic toughness of high-toughness steels, such as line pipe steels. Promising results have been obtained from notches cut by electrical-discharge machining (EDM) using a thin wire of 0.1 mm diameter, as compared to specimens where an actual crack was generated and propagated by fatigue at the root of the machined notch.

scholarly journals Cost-Effective Alternatives to Conventional Charpy Tests for Measuring the Impact Toughness of Very-High-Toughness Steels

2017 ◽  
Author(s):  
Enrico Lucon
Keyword(s):  
Electrical Discharge Machining ◽  
Test Procedure ◽  
Cost Effective ◽  
Moderate Increase ◽  
Type Specimens ◽  
Charpy Test ◽  
Line Pipe ◽  
High Toughness ◽  
The Impact ◽  
Very High

For modern plate steels exhibiting high toughness and ductility, the conventional Charpy test is ostensibly stretched beyond its limits of applicability. Impact tests yield absorbed energy values in excess of 300 J – 400 J, which are associated with limited material fracture and mostly derive from plastic deformation of the specimen (bending), friction and vibrations of the swinging hammer. It would be therefore very desirable to measure the actual fracture toughness of very-high-toughness steels by means of an alternative specimen and/or methodology, entailing just a moderate increase of cost and test complexity with respect to Charpy testing. The investigation presented here was aimed at establishing a reasonable, yet cost-effective test procedure utilizing Charpy-type specimens for measuring the dynamic toughness of high-toughness steels, such as line pipe steels. Promising results have been obtained from notches cut by Electrical-Discharge Machining (EDM) using a thin wire of 0.1 mm diameter, as compared to specimens where an actual crack was generated and propagated by fatigue at the root of the machined notch.

scholarly journals Addition of Flucytosine to Fluconazole for the Treatment of Cryptococcal Meningitis in Africa: A Multicountry Cost-effectiveness Analysis

2019 ◽  
Vol 70 (1) ◽  
pp. 26-29 ◽  
Author(s):  
Tinevimbo Shiri ◽  
Angela Loyse ◽  
Lawrence Mwenge ◽  
Tao Chen ◽  
Shabir Lakhi ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Cost Effectiveness ◽  
Cryptococcal Meningitis ◽  
Cost Effective ◽  
Immunodeficiency Virus ◽  
The Mean ◽  
The Cost ◽  
The Impact ◽  
Costing Analysis ◽  
Very High

Abstract Background Mortality from cryptococcal meningitis remains very high in Africa. In the Advancing Cryptococcal Meningitis Treatment for Africa (ACTA) trial, 2 weeks of fluconazole (FLU) plus flucytosine (5FC) was as effective and less costly than 2 weeks of amphotericin-based regimens. However, many African settings treat with FLU monotherapy, and the cost-effectiveness of adding 5FC to FLU is uncertain. Methods The effectiveness and costs of FLU+5FC were taken from ACTA, which included a costing analysis at the Zambian site. The effectiveness of FLU was derived from cohorts of consecutively enrolled patients, managed in respects other than drug therapy, as were participants in ACTA. FLU costs were derived from costs of FLU+5FC in ACTA, by subtracting 5FC drug and monitoring costs. The cost-effectiveness of FLU+5FC vs FLU alone was measured as the incremental cost-effectiveness ratio (ICER). A probabilistic sensitivity analysis assessed uncertainties and a bivariate deterministic sensitivity analysis examined the impact of varying mortality and 5FC drug costs on the ICER. Results The mean costs per patient were US $847 (95% confidence interval [CI] $776–927) for FLU+5FC, and US $628 (95% CI $557–709) for FLU. The 10-week mortality rate was 35.1% (95% CI 28.9–41.7%) with FLU+5FC and 53.8% (95% CI 43.1–64.1%) with FLU. At the current 5FC price of US $1.30 per 500 mg tablet, the ICER of 5FC+FLU versus FLU alone was US $65 (95% CI $28–208) per life-year saved. Reducing the 5FC cost to between US $0.80 and US $0.40 per 500 mg resulted in an ICER between US $44 and US $28 per life-year saved. Conclusions The addition of 5FC to FLU is cost-effective for cryptococcal meningitis treatment in Africa and, if made available widely, could substantially reduce mortality rates among human immunodeficiency virus–infected persons in Africa.

scholarly journals Fast Falling Weight Deflectometer Method for Condition Assessment of RC Bridges

2021 ◽  
Vol 11 (4) ◽  
pp. 1743
Author(s):  
Mauro Coni ◽  
Fausto Mistretta ◽  
Flavio Stochino ◽  
James Rombi ◽  
Mauro Sassu ◽  
...  
Keyword(s):  
Test Procedure ◽  
Cost Effective ◽  
Dynamic Force ◽  
Falling Weight Deflectometer ◽  
Annual Average Daily Traffic ◽  
Short Period ◽  
Cost Efficient ◽  
Action Measures ◽  
Falling Weight ◽  
The Impact

In this paper, the use of Fast Falling Weight Deflectometer (Fast-FWD) is analyzed as a non-destructive and quick test procedure to evaluate the efficiency of short-span bridges. The Fast-FWD is an instrument that can produce a broadband dynamic force up to an impact value of 120 KN: The impact is constant and replicable, providing accurate action measures of bridge stiffness in a truly short period (30 ms). In this paper, a single-span reinforced concrete bridge is investigated, using the Fast-FWD. The considered bridge, approximately 12.0 m long and 15.5 m wide, was in critical condition. The bridge is in a suburban principal road near to the City of Cagliari in Sardinia (Italy), with an Annual Average Daily Traffic of 13,500 vehicles/day, and was suddenly closed, creating serious problems for urban mobility. In these conditions, the investigation through other standard techniques is time-consuming and labor intensive. For this reason, it is important to introduce methods that can be rapid, accurate and cost-efficient. In this paper, bridge stiffness values obtained during the in situ experimental campaign were compared with finite element models values. The Fast-FWD has the potential to provide engineering information that can help us to better understand bridge condition, in a rapid and cost-effective procedure.

A rubber-modified epoxy composite with very high toughness and heat resistance

2019 ◽  
Vol 27 (9) ◽  
pp. 582-586 ◽  
Author(s):  
Binghai Li ◽  
Xiaohong Zhang ◽  
Guicun Qi ◽  
Xiang Wang ◽  
Jiangru Zhang ◽  
...  
Keyword(s):  
Impact Strength ◽  
Heat Resistance ◽  
Epoxy Resin ◽  
High Performance ◽  
Epoxy Composite ◽  
High Heat ◽  
High Toughness ◽  
The Impact ◽  
Modified Epoxy ◽  
Very High

A high performance epoxy composite with very high toughness and heat resistance had been designed and prepared. Epoxy resin TDE-85 with an impact strength of 10.2 kJ m−2, a heat distortion temperature (HDT) of 121°C, and a glass transition temperature of 127°C was chosen as the matrix of the composite, while carboxylic nitrile-butadiene elastomeric nanoparticles (CNB-ENPs) coated with triethanolamine on the surface with a diameter of about 100 nm was selected as the modifier. Surprisingly, the rubber-modified epoxy resin exhibited not only very high toughness but also very high heat resistance. The HDT of epoxy resin TDE-85 after modification increased 57°C, reaching 178°C, while the impact strength increased by 107%, increasing to 21.1 kJ m−2. The relationship between the microstructure and performance had been evaluated by transmission electron microscopy, mechanical testing, and dynamic mechanical analysis. The results showed that the CNB-ENP/TDE-85 composite resulted in large interface and a special morphology after modification.

Finite element simulation of dynamic brittle fracture in pipeline steel: A XFEM-based cohesive zone approach

2016 ◽  
Vol 232 (5) ◽  
pp. 357-370
Author(s):  
Reza Hojjati-Talemi ◽  
Steven Cooreman ◽  
Dennis Van Hoecke
Keyword(s):  
Finite Element ◽  
Brittle Fracture ◽  
Cohesive Zone ◽  
Pipeline Steel ◽  
Temperature Drop ◽  
Charpy Impact ◽  
Large Temperature ◽  
Charpy Test ◽  
Line Pipe ◽  
The Impact

Leaking in a CO2 pipeline could escalate to sudden crack propagation, due to a large temperature drop. The resulting drop in fracture toughness together with the pressure stresses at the defect plane leads to pipeline brittle fracture. The main objective of this study is to monitor and predict brittle fracture behaviour of API X70 pipeline steel by means of experimental and numerical approaches, respectively. Dynamic fracture properties of CO2 line pipe steels are generally assessed using the Charpy impact test. To this end, Charpy V-notch tests are performed at different temperatures in order to study the resistance of materials subjected to impact loading conditions. The Charpy test provides valuable indications on the impact properties of materials. Using the experimental results the ductile to brittle transition temperature curve is presented. The extended finite element method based cohesive zone approach is introduced to model the brittle fracture at low temperature. After validation of the developed model against experimental observation significant results from the simulation are graphically presented and discussed.

Regulatory and sustainability initiatives lead to improved polyaminopolyamide epichlorohydrin (PAE) wet-strength resins and paper products

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle
Keyword(s):  
Health And Safety ◽  
Cost Effective ◽  
Worker Safety ◽  
Regulatory Requirements ◽  
Wet Strength ◽  
The Past ◽  
Consumer Safety ◽  
Federal Institute ◽  
Sustainability Initiatives ◽  
The Impact

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).

Exploring the Benefits of Early Contractor Involvement (ECI) and the Mechanism for Automated 5D BIM Quantification Process in Offsite Modular Construction

2016 ◽  
Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Modular Construction ◽  
Automated Quantification ◽  
Building Information ◽  
Project Risks ◽  
Value Add ◽  
The Uk ◽  
The Impact ◽  
Level 2

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.

Pound Wise and Penny Foolish? Weight Loss and The Dynamics of Health Care Spending

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch
Keyword(s):  
Weight Loss ◽  
Cost Savings ◽  
Cost Effective ◽  
Economic Consequences ◽  
Health Care Spending ◽  
Order Of Magnitude ◽  
Dynamic Measures ◽  
The Cost ◽  
The Impact ◽  
The Relationship

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.

Motivating Compliance: Firm Response to Mandatory Disclosure Policies

2018 ◽  
Vol 32 (2) ◽  
pp. 103-119
Author(s):  
Colleen M. Boland ◽  
Chris E. Hogan ◽  
Marilyn F. Johnson
Keyword(s):  
Conflict Of Interest ◽  
Low Cost ◽  
Cost Effective ◽  
Data Availability ◽  
Policy Adoption ◽  
Future Research ◽  
Regulated Firms ◽  
Firm Response ◽  
Disclosure Rules ◽  
The Impact

SYNOPSIS Mandatory existence disclosure rules require an organization to disclose a policy's existence, but not its content. We examine policy adoption frequencies in the year immediately after the IRS required mandatory existence disclosure by nonprofits of various governance policies. We also examine adoption frequencies in the year of the subsequent change from mandatory existence disclosure to a disclose-and-explain regime that required supplemental disclosures about the content and implementation of conflict of interest policies. Our results suggest that in areas where there is unclear regulatory authority, mandatory existence disclosure is an effective and low cost regulatory device for encouraging the adoption of policies desired by regulators, provided those policies are cost-effective for regulated firms to implement. In addition, we find that disclose-and-explain regulatory regimes provide stronger incentives for policy adoption than do mandatory existence disclosure regimes and also discourage “check the box” behavior. Future research should examine the impact of mandatory existence disclosure rules in the year that the regulation is implemented. Data Availability: Data are available from sources cited in the text.

scholarly journals Do Prospective Teachers Care About PISA Studies? A Pilot Study among University Students in Germany

2017 ◽  
Vol 10 (5) ◽  
pp. 26 ◽  
Author(s):  
Olga Ioannidou ◽  
Despoina Georgiou ◽  
Andreas Obersteiner ◽  
Nilufer Deniz Bas ◽  
Christine Mieslinger
Keyword(s):  
Teacher Education ◽  
University Students ◽  
Prospective Teachers ◽  
International Student ◽  
Teacher Education Program ◽  
Student Assessment ◽  
International Student Assessment ◽  
The Impact ◽  
Very High ◽  
Expected Outcomes

The results of international comparison studies such as the Program for International Student Assessment (PISA) have initiated intense discussions about educational reforms in Germany. Although in-service and pre-service teachers are an essential part of such reforms, little is known about their attitudes towards PISA studies. The present study aims to fill this gap through the investigation of pre-service teachers’ awareness, interest, perception, and attitudes towards PISA. A questionnaire was used to survey a sample of 107 university students who were participating in a teacher education program. The results reveal that 100% of the participants are aware of PISA. Nearly 69% of the participants think that the impact of PISA is rather high or very high, while 41% of them believe that PISA results are reliable. Accordingly, half of the participants seem to be interested in PISA results for their country. The present study discusses these findings in the light of the expected outcomes as proposed in standards for teacher education.

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