Water cooled anode increases life of high temperature arc lamp

Water cooling system increases the life of the anode of a high temperature compact arc lamp. A shaped water passage is provided through the tip or hottest point of the anode so that water will flow through it at a relatively high velocity

How does additional education affect willingness to work in rural remote areas?

The main objective of this paper is to evaluate the effect of offering educational opportunities as a strategy to recruit health workers to rural areas. Tanzania, like the rest of sub-Saharan Africa, has a very small and unequally distributed health workforce. It has been suggested that rural remote jobs can be made more attractive to health workers with basic clinical skills by offering them the opportunity to upgrade their skills after a certain period of service. A data set capturing stated job preferences among freshly educated Tanzanian health workers with basic and more advanced clinical education is applied in order to investigate how additional education as an incentive mechanism affects willingness to work in rural areas. In order to control for selection effects into the additional education scheme, the two cadres are matched on propensity scores. It turns out that those health workers with advanced clinical education would have been more likely to prefer a job in a rural remote area had they not received the advanced clinical education. This effect (the ATT) is significant and substantial with several different specifications. The result is robust with regards to omitted variables and goes a long way in suggesting that a policy aimed at recruiting health personnel with basic clinical education to rural remote areas by offering jobs that include possibilities of upgrading after a certain period of service may be a temporary measure only.Education; Propensity Score Matching; Human Resources for Health; Mobility

How to make rural jobs more attractive to health workers. Findings from a discrete choice experiment in Tanzania

The geographical imbalance of the health workforce in Tanzania represents a serious problem when it comes to delivering crucial health services to a large share of the population. This study provides new quantitative information about how to make jobs in rural areas more attractive to newly educated clinical officers. A unique data set stemming from a discrete choice experiment with clinical officer finalists in Tanzania is applied. The results show that offering continuing education after a certain period of service is one of the most powerful recruitment instruments the authorities have available. Increased salaries and hardship allowances will also substantially increase recruitment in rural areas. Offers of decent housing and good infrastructure, including the provision of equipment, will increase recruitment to rural remote areas but not as much as higher wages and offers of education. Women are less responsive to pecuniary incentives and are more concerned with factors that directly allow them to do a good job, while those with parents living in a remote rural area are generally less responsive to the proposed policies. When the willingness to help other people is a strong motivating force, policies that improve the conditions for helping people appear particularly effective.Human resources for health; Discrete choice experiments; Tanzania

Pro-social preferences and self-selection into the public health sector: evidence from economic experiments

There is growing interest in the role of pro-social motivation in public service delivery. In general, economists no longer question whether people have social preferences, but ask how and when such preferences will influence their economic and social decisions. Apart from revealing that individuals on average share and cooperate even when such actions lower their own material pay-off, economic experiments have documented substantial individual heterogeneity in the strength and structure of social preferences. In this paper we study the extent to which these differences are related to career choices, by testing whether preferences vary systematically between Tanzanian health worker students who prefer to work in the private health sector and those who prefer to work in the public health sector. Despite its important policy implications, this issue has received hardly any attention to date. By combining data from a questionnaire and two economic experiments, we find that students who prefer to work in the public health sector have stronger pro-social preferences than those who prefer to work in the private sector. We also show that the extent to which these students care about others can be conditional and linked to inequality aversion. A systematic selfselection of pro-socially motivated health workers into the public sector suggests that it is a good idea to have two sectors providing health services: this can ensure efficient matching of individuals and sectors by allowing employers in the two sectors to use different payment mechanisms tailored to attract and promote good performance from different types of health workers.pro-social preferences; career choice; economic experiments; health workers

Mixed logit estimation of willingness to pay distributions: a comparison of models in preference and WTP space using data from a health-related choice experiment.

Different approaches to modelling the distribution of WTP are compared using stated preference data on Tanzanian Clinical Officers’ job choices and mixed logit models. The standard approach of specifying the distributions of the coefficients and deriving WTP as the ratio of two coefficients estimation in preference space) is compared to specifying the distributions for WTP directly at the estimation stage (estimation in WTP space). The models in preference space fit the data better than the corresponding models in WTP space although the difference between the best fitting models in the two estimation regimes is minimal. Moreover, the willingness to pay estimates derived from the preference space models turn out to be unrealistically high for many of the job attributes. The results suggest that sensitivity testing using a variety of model specifications, including estimation in WTP space, is recommended when using mixed logit models to estimate willingness to pay distributions.WTP space; Stated preference methods; Discrete choice; Mixed logit; Willingness to pay*

Experimental evaluation of the axial capacity of cracked tubular member

This thesis experimentally investigated the compressive axial capacity of cracked tubular members. Then compared it to NORSOK N-004 (Standard Norge 2004) formulae. Further, the test results were compared with other analytical models, such as non-linear finite element analysis from a separate thesis (Vågen 2021) and basic column formulae e.g. Perry Robertson and the Secant method. In this study, 11 tubular columns were tested with a diameter of 70 mm, 2.9 mm thickness, and 1.5 m height, due to the testing facilities limitation. Different crack sizes were placed perpendicular to the loading direction with sizes corresponding to NORSOK N-004 reduced capacity of 25, 50 and 75%. The material properties were obtained by stub column tests. To further study the effect of cracks on tubular members, angled cracks with respect to the loading direction were introduced to the stub column. For the specimens with cracks perpendicular to the loading direction, The test results were somewhat unexpected and showed an inconsiderable reduction in the axial capacity, as the crack surfaces bear on each other. However, the angled cracks introduced to the stub columns showed a considerable capacity reduction. The reduction is assumed to result from the crack surface slipping, discontinuity in the material, and torsion due to the angled crack in the stub column. The conclusion was that angled cracks have the most significant impact on the compressive axial capacity. On the other hand, cracks placed perpendicular to the loading direction had an insignificant effect on the capacity. Hence, the NORSOK N-004 formulae provide inaccurate formulas for capacity determination for such cases. Among the analytical methods presented in this thesis, Perry Robertson gave the most accurate capacity. This result was somewhat expected as the method was best adapted to the actual column behavior in the tests.This thesis experimentally investigated the compressive axial capacity of cracked tubular members. Then compared it to NORSOK N-004 (Standard Norge 2004) formulae. Further, the test results were compared with other analytical models, such as non-linear finite element analysis from a separate thesis (Vågen 2021) and basic column formulae e.g. Perry Robertson and the Secant method. In this study, 11 tubular columns were tested with a diameter of 70 mm, 2.9 mm thickness, and 1.5 m height, due to the testing facilities limitation. Different crack sizes were placed perpendicular to the loading direction with sizes corresponding to NORSOK N-004 reduced capacity of 25, 50 and 75%. The material properties were obtained by stub column tests. To further study the effect of cracks on tubular members, angled cracks with respect to the loading direction were introduced to the stub column. For the specimens with cracks perpendicular to the loading direction, The test results were somewhat unexpected and showed an inconsiderable reduction in the axial capacity, as the crack surfaces bear on each other. However, the angled cracks introduced to the stub columns showed a considerable capacity reduction. The reduction is assumed to result from the crack surface slipping, discontinuity in the material, and torsion due to the angled crack in the stub column. The conclusion was that angled cracks have the most significant impact on the compressive axial capacity. On the other hand, cracks placed perpendicular to the loading direction had an insignificant effect on the capacity. Hence, the NORSOK N-004 formulae provide inaccurate formulas for capacity determination for such cases. Among the analytical methods presented in this thesis, Perry Robertson gave the most accurate capacity. This result was somewhat expected as the method was best adapted to the actual column behavior in the tests

Multi-scale metrology for automated non-destructive testing systems

This thesis was previously held under moratorium from 5/05/2020 to 5/05/2022The use of lightweight composite structures in the aerospace industry is now commonplace. Unlike conventional materials, these parts can be moulded into complex aerodynamic shapes, which are diffcult to inspect rapidly using conventional Non-Destructive Testing (NDT) techniques. Industrial robots provide a means of automating the inspection process due to their high dexterity and improved path planning methods. This thesis concerns using industrial robots as a method for assessing the quality of components with complex geometries. The focus of the investigations in this thesis is on improving the overall system performance through the use of concepts from the field of metrology, specifically calibration and traceability. The use of computer vision is investigated as a way to increase automation levels by identifying a component's type and approximate position through comparison with CAD models. The challenges identified through this research include developing novel calibration techniques for optimising sensor integration, verifying system performance using laser trackers, and improving automation levels through optical sensing. The developed calibration techniques are evaluated experimentally using standard reference samples. A 70% increase in absolute accuracy was achieved in comparison to manual calibration techniques. Inspections were improved as verified by a 30% improvement in ultrasonic signal response. A new approach to automatically identify and estimate the pose of a component was developed specifically for automated NDT applications. The method uses 2D and 3D camera measurements along with CAD models to extract and match shape information. It was found that optical large volume measurements could provide suffciently high accuracy measurements to allow ultrasonic alignment methods to work, establishing a multi-scale metrology approach to increasing automation levels. A classification framework based on shape outlines extracted from images was shown to provide over 88% accuracy on a limited number of samples.The use of lightweight composite structures in the aerospace industry is now commonplace. Unlike conventional materials, these parts can be moulded into complex aerodynamic shapes, which are diffcult to inspect rapidly using conventional Non-Destructive Testing (NDT) techniques. Industrial robots provide a means of automating the inspection process due to their high dexterity and improved path planning methods. This thesis concerns using industrial robots as a method for assessing the quality of components with complex geometries. The focus of the investigations in this thesis is on improving the overall system performance through the use of concepts from the field of metrology, specifically calibration and traceability. The use of computer vision is investigated as a way to increase automation levels by identifying a component's type and approximate position through comparison with CAD models. The challenges identified through this research include developing novel calibration techniques for optimising sensor integration, verifying system performance using laser trackers, and improving automation levels through optical sensing. The developed calibration techniques are evaluated experimentally using standard reference samples. A 70% increase in absolute accuracy was achieved in comparison to manual calibration techniques. Inspections were improved as verified by a 30% improvement in ultrasonic signal response. A new approach to automatically identify and estimate the pose of a component was developed specifically for automated NDT applications. The method uses 2D and 3D camera measurements along with CAD models to extract and match shape information. It was found that optical large volume measurements could provide suffciently high accuracy measurements to allow ultrasonic alignment methods to work, establishing a multi-scale metrology approach to increasing automation levels. A classification framework based on shape outlines extracted from images was shown to provide over 88% accuracy on a limited number of samples

Assessing the quality of a student-generated question repository

We present results from a study that categorizes and assesses the quality of questions and explanations authored by students, in question repositories produced as part of the summative assessment in introductory physics courses over the past two years. Mapping question quality onto the levels in the cognitive domain of Bloom's taxonomy, we find that students produce questions of high quality. More than three-quarters of questions fall into categories beyond simple recall, in contrast to similar studies of student-authored content in different subject domains. Similarly, the quality of student-authored explanations for questions was also high, with approximately 60% of all explanations classified as being of high or outstanding quality. Overall, 75% of questions met combined quality criteria, which we hypothesize is due in part to the in-class scaffolding activities that we provided for students ahead of requiring them to author questions.Comment: 24 pages, 5 figure

GPs' implicit prioritization through clinical choices – evidence from three national health services

Acknowledgments The authors are grateful for valuable comments and inputs from participants at a series of seminars and conferences as well as to our three anonymous referees.Peer reviewedPostprin

Music therapy as a means for increased bonding and attachment between mother and infant - A qualitative literature review exploring how music therapy, or the use of music could promote bonding and attachment between mothers with postpartum depression and their infants

Masteroppgave i musikkterapiMUTP350MAHF-INMUTMAHF-MUT