scholarly journals Different Performance of Factors Affecting the Estimation of the Corrosion Rate in Magnesium Alloys by Implementation of the Common Methods for Electrochemical Measurements

10.5772/58370 ◽  
2014 ◽  
Author(s):  
Alejandro Samaniego ◽  
Sebastián Feliu
Keyword(s):  
Corrosion Rate ◽  
Magnesium Alloys ◽  
Electrochemical Measurements ◽  
Factors Affecting ◽  
The Common

scholarly journals Understanding Urban Commercial Vehicle Driver Behaviors and Decision Making

2021 ◽  
pp. 036119812110035
Author(s):  
Giacomo Dalla Chiara ◽  
Klaas Fiete Krutein ◽  
Andisheh Ranjbari ◽  
Anne Goodchild
Keyword(s):  
Commercial Vehicle ◽  
Operating Time ◽  
Common Belief ◽  
Policy Makers ◽  
Factors Affecting ◽  
Urban Freight ◽  
The Road ◽  
Commercial Drivers ◽  
The Common ◽  
Printed Materials

As e-commerce and urban deliveries spike, cities grapple with managing urban freight more actively. To manage urban deliveries effectively, city planners and policy makers need to better understand driver behaviors and the challenges they experience in making deliveries. In this study, we collected data on commercial vehicle (CV) driver behaviors by performing ridealongs with various logistics carriers. Ridealongs were performed in Seattle, Washington, covering a range of vehicles (cars, vans, and trucks), goods (parcels, mail, beverages, and printed materials), and customer types (residential, office, large and small retail). Observers collected qualitative observations and quantitative data on trip and dwell times, while also tracking vehicles with global positioning system devices. The results showed that, on average, urban CVs spent 80% of their daily operating time parked. The study also found that, unlike the common belief, drivers (especially those operating heavier vehicles) parked in authorized parking locations, with only less than 5% of stops occurring in the travel lane. Dwell times associated with authorized parking locations were significantly longer than those of other parking locations, and mail and heavy goods deliveries generally had longer dwell times. We also identified three main criteria CV drivers used for choosing a parking location: avoiding unsafe maneuvers, minimizing conflicts with other users of the road, and competition with other commercial drivers. The results provide estimates for trip times, dwell times, and parking choice types, as well as insights into why those decisions are made and the factors affecting driver choices.

Effect of Sn, Zn and Bi Addition on Corrosion Characteristics of Magnesium Alloys Sintered by Spark Plasma Sintering

2018 ◽  
Vol 941 ◽  
pp. 1760-1765
Author(s):  
Satoshi Sunada ◽  
Yoshitaka Matsui ◽  
Syogo Takeuchi ◽  
Taku Iwaoka ◽  
Koichi Sato ◽  
...  
Keyword(s):  
Melting Point ◽  
Corrosion Rate ◽  
Spark Plasma Sintering ◽  
Magnesium Alloys ◽  
Electrochemical Method ◽  
Corrosion Potential ◽  
Elemental Mapping ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Metallic Compounds

Sintered magnesium alloys, which were fabricated by Spark Plasma Sintering (SPS) method, were examined to study corrosion characteristics by electrochemical method, XRD and EPMA. The binary mixtures alloys of a low-melting-point metal powder (Sn, Bi, Sb) of1.0 vol.% and the pure magnesium powder were prepared. In the Mg-1.0vol.%Bi and Mg-1.0vol.%Sn, Mg3Bi2 and Mg2Sn precipitates was recognized by XRD, respectively. In addition, formation of oxide along powder particle boundaries was observed by EPMA elemental mapping in all specimens. In the case of Mg-1.0vol.%Zn, precipitation of metallic compounds was not recognized by these experiments. According to the results of polarization curve measurements, the Mg-1.0vol.%Bi shows highest corrosion potential. However, corrosion rate which was estimated by Tafel method is relatively larger than other alloys due to Mg3Bi2 precipitation. This result suggests that Mg3Bi2 acts as cathode site. The Mg-1.0vol.%Sn shows superior corrosion rale in these alloys.

scholarly journals Factors affecting the motivation of Chemistry university students

2013 ◽  
Vol 1 (1) ◽  
pp. 3-16
Author(s):  
Johanna Havia
Keyword(s):  
University Students ◽  
Group Formation ◽  
Self Determination Theory ◽  
Self Determination ◽  
Motivation To Learn ◽  
Laboratory Practice ◽  
Factors Affecting ◽  
Research Results ◽  
Chemistry Students ◽  
The Common

As a part of this research, a survey and four student interviews were done on the motivation of chemistry students of University of Oulu. The aim was to find out the formation of motivation, and seek factors that affect the students’ motivation to study chemistry. The survey measured the inner motivation, outer motivation and lack of motivation based on self-determination theory. The most common aspect of motivation among the students was the inner motivation to learn more about chemistry. Among the common aspects were also the aspects of outer motivation: outside regulation and benefit. By interviewing four of the students, a deeper understanding of the factors behind motivation was sought. Among the positive factors were the parallel lectures and laboratory practices, and including recent research results into teaching. The significance of laboratory practice was the most evident factor. Among the factors reducing motivation were problems with group formation, unclear issues and lectures where everything was readily given. By paying attention to group formation, motivation to study could be increased relatively easily.

scholarly journals Exploration of Factors Affecting Learners' Motivation in E-learning

2019 ◽  
pp. 1269-1275
Author(s):  
Shubham Dubey ◽  
Biro Piroska ◽  
Manjulata Gautam
Keyword(s):  
Dropping Out ◽  
Individual Factor ◽  
Factors Affecting ◽  
E Learning ◽  
Learning Platforms ◽  
The Common ◽  
Khan Academy ◽  
Future Work ◽  
The Impact

The world is changing rapidly, so is academics. E-learning has altered the area of academics and education. ICT enabled learning has given ideal services to students by providing any type of content on demand which is proportional to the performance of students. The concentration of learner has been found instinctive; thus there is a need of engaging mind towards course progress with its entirety till the objectives of the course will be achieved. There are several e-learning platforms available as EdX, Udacity, Khan Academy, Alison those have a number of learners registered for various courses. Studies suggest that these platforms suffer from the common problem of learners’ dropping out. Investigations also claim early leaving rate is increasing due to lack of quality of content, distraction factors, learners’ mind change, outdated and succinct information, and some more detraction factors. These issues have been observed on the basis of early leaving rates in various MOOCs. Thus there is a mammoth scope for minimizing the impact of these reasons on the learners’ mind. It can be achieved by identifying these factors affecting learners’ motivation during the course. This study is aiming on identifying these factors. The approach is to explore some certain keywords on previous literature (total 41) and then calculating their frequencies and co-factors associated with them. Both grouped factors contribution and individual factor contribution have been taken care. The study gives a direction for future work towards overcoming these actor and engaging learners in ICT enabled learning.

scholarly journals The inhibition performance of mono-ethylene glycol on corrosion rate of x-80 grade carbon steel in saturated brine environment.

2020 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Acetic Acid ◽  
Charge Transfer ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Ethylene Glycol ◽  
Oil And Gas ◽  
Gas Production ◽  
Electrochemical Measurements ◽  
Co2 Corrosion ◽  
Formation Water

The formation/deposition of hydrate and scale in gas production and transportation pipeline has continue to be a major challenge in the oil and gas industry. Pipeline transport is one of the most efficient, reliable and safer means of transporting petroleum products from the well sites to either the refineries or to the final destinations. Acetic acid (HAc), is formed in the formation water which also present in oil and gas production and transportation processes. Acetic acid aids corrosion in pipelines and in turn aids the formation and deposition of scales which may eventually choke off flow. Most times, Monethylene Glycol (MEG) is added into the pipeline as an antifreeze and anticorrosion agent. Some laboratory experiments have shown that the MEG needs to be separated from unwanted substance such as HAc that are present in the formation water to avoid critical conditions in the pipeline. Internal pipeline corrosion slows and decreases the production of oil and gas when associated with free water and reacts with CO2 and organic acid by lowering the integrity of the pipe. In this study, the effect of Mono-Ethylene Glycol (MEG) and Acetic acid (HAc) on the corrosion rate of X-80 grade carbon steel in CO2 saturated brine were evaluated at 25oC and 80oC using 3.5% NaCl solution in a semi-circulation flow loop set up. Weight loss and electrochemical measurements using the linear polarization resistance (LPR) and electrochemical impedance spectroscope (EIS) were used in measuring the corrosion rate as a function of HAc and MEG concentrations. The results obtained so far shows an average corrosion rate increases from 0.5 to 1.8 mm/yr at 25oC, and from 1.2 to 3.5 mm/yr at 80oC in the presence of HAc. However, there are decrease in corrosion rate from 1.8 to 0.95 mm/yr and from 3.5 to 1.6mm/yr respectively at 25oC and 80oC on addition of 20% and 80% MEG concentrations to the solution. It is also noted that the charge transfer with the electrochemical measurements (EIS) results is the main corrosion controlling mechanism under the test conditions. The higher temperature led to faster film dissolution and higher corrosion rate in the presence of HAc. The EIS results also indicate that the charge transfer controlled behaviour was as a result of iron carbonate layer accelerated by the addition of different concentrations of MEG to the system. Key words: CO2 corrosion, Carbon steel, MEG, HAc, Inhibition, Environment.

Catheters at home: managing urinary catheters in the home environment

2021 ◽  
Vol 26 (8) ◽  
pp. 370-376
Author(s):  
Drew Payne
Keyword(s):  
Emergency Department ◽  
Health Service ◽  
Literature Review ◽  
Home Environment ◽  
Negative Impact ◽  
Community Settings ◽  
Urinary Catheters ◽  
Factors Affecting ◽  
The Common ◽  
At Home

In England, there are some 90000 people with catheters in the community, and community nurses often have to manage catheter-related problems. This article looks at these common catheter problems found in the community, for example, blockage, infections and positioning problems. These problems were identified by a literature review and from the author's experience, from many years working in the community. It has been found that education, knowledge, empowerment and communication are vital factors affecting patients' ability to manager their catheters themselves. The article begins with a discussion about how patients can be involved in and manage many aspects of care for their own catheters. It goes on to talk about the common catheter-associated problems and how these can be avoided or addressed. It is hoped that better management of catheter-associated complications in the community settings can prevent unnecessary visits to the emergency department, which will save time and costs for the health service, as well as avoid the negative impact of these on patient lives.

Gut microbiota in a host–brood parasite system: insights from common cuckoos raised by two warbler species

2020 ◽  
Vol 96 (9) ◽  
Author(s):  
Lucie Schmiedová ◽  
Jakub Kreisinger ◽  
Milica Požgayová ◽  
Marcel Honza ◽  
Jean-François Martin ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Gut Microbiota ◽  
Acrocephalus Arundinaceus ◽  
Brood Parasite ◽  
Bacterial Strains ◽  
Factors Affecting ◽  
The Common ◽  
Animal Hosts ◽  
Bacterial Sources ◽  
Selection Of

ABSTRACT An animal's gut microbiota (GM) is shaped by a range of environmental factors affecting the bacterial sources invading the host. At the same time, animal hosts are equipped with intrinsic mechanisms enabling regulation of GM. However, there is limited knowledge on the relative importance of these forces. To assess the significance of host-intrinsic vs environmental factors, we studied GM in nestlings of an obligate brood parasite, the common cuckoo (Cuculus canorus), raised by two foster species, great reed warblers (Acrocephalus arundinaceus) and Eurasian reed warblers (A. scirpaceus), and compared these with GM of the fosterers’ own nestlings. We show that fecal GM varied between cuckoo and warbler nestlings when accounting for the effect of foster/parent species, highlighting the importance of host-intrinsic regulatory mechanisms. In addition to feces, cuckoos also expel a deterrent secretion, which provides protection against olfactory predators. We observed an increased abundance of bacterial genera capable of producing repulsive volatile molecules in the deterrent secretion. Consequently, our results support the hypothesis that microbiota play a role in this antipredator mechanism. Interestingly, fosterer/parent identity affected only cuckoo deterrent secretion and warbler feces microbiota, but not that of cuckoo feces, suggesting a strong selection of bacterial strains in the GM by cuckoo nestlings.

Sign in / Sign up

Export Citation Format

Share Document