Numerical study of a M-cycle cross-flow heat exchanger for indirect evaporative cooling

In this paper, numerical analyses of the thermal performance of an indirect evaporative air cooler incorporating a M-cycle cross-flow heat exchanger has been carried out. The numerical model was established from solving the coupled governing equations for heat and mass transfer between the product and working air, using the finite-element method. The model was developed using the EES (Engineering Equation Solver) environment and validated by published experimental data. Correlation between the cooling (wet-bulb) effectiveness, system COP and a number of air flow/exchanger parameters was developed. It is found that lower channel air velocity, lower inlet air relative humidity, and higher working-to-product air ratio yielded higher cooling effectiveness. The recommended average air velocities in dry and wet channels should not be greater than 1.77 m/s and 0.7 m/s, respectively. The optimum flow ratio of working-to-product air for this cooler is 50%. The channel geometric sizes, i.e. channel length and height, also impose significant impact to system performance. Longer channel length and smaller channel height contribute to increase of the system cooling effectiveness but lead to reduced system COP. The recommend channel height is 4 mm and the dimensionless channel length, i.e., ratio of the channel length to height, should be in the range 100 to 300. Numerical study results indicated that this new type of M-cycle heat and mass exchanger can achieve 16.7% higher cooling effectiveness compared with the conventional cross-flow heat and mass exchanger for the indirect evaporative cooler. The model of this kind is new and not yet reported in literatures. The results of the study help with design and performance analyses of such a new type of indirect evaporative air cooler, and in further, help increasing market rating of the technology within building air conditioning sector, which is currently dominated by the conventional compression refrigeration technology.

Is intrinsic energy efficiency reflected in the pricing of office leases?

This paper investigates whether the intrinsic energy efficiency rating of an office building has a significant impact on its rental value. A sample of 817 transactions for offices with Energy Performance Certificates (EPCs) in the UK is used to assess whether a pricing differential can be identified, depending on the energy rating. While previous analyses of this topic have typically relied on appraisal-based and/or asking rent data, the dataset used in this research contains actual contract rents as well as information on lease terms. The results indicate a significant rental premium for energy-efficient buildings. However, it is found that this premium appears to be mainly driven by the youngest cohort of state-of-the-art energy-efficient buildings. The results also show that tenants of more energy-efficient buildings tend to pay a lower service charge, but this link appears to be rather weak and limited to newer buildings. Hence, it is argued that the information contained in the EPC is still not fully taken into account in the UK commercial property market with the possible exception of both the highest and the lowest EPC ratings.

Post-occupancy studies of an office environment: Energy performance and occupants’ satisfaction

It is generally accepted that the physical workplace environment affects employees’ satisfaction and, consequently, their perceived productivity and well-being. This study investigated whether employee “satisfaction” variables can predict perceived productivity, well-being and enjoyment at work, and if so, to what extent. The study also explored whether limiting employees’ control over their environment could save energy without compromising employees’ satisfaction and perceived productivity. Preoccupancy and post-occupancy evaluation studies were conducted, in terms of both energy consumption and employee perceptions, to make comparisons between a company’s old and current headquarters buildings, both located in the same area of London. The results showed that employees were more satisfied with their work environment at their new HQ, in general, than with that of their previous office. Also, employees’ self-reported productivity, well-being and enjoyment at work improved after the move. It was revealed that the combination of employees’ level of satisfaction with “interior use of space” and “physical conditions” was the best predictor of their perceived productivity, while satisfaction with “indoor facilities” was not a good predictor. In terms of energy performance, although the new HQ’s energy consumption per m2 was significantly less than that of the previous building, there was still a gap between the refurbishment design target and the actual performance of the building. The findings suggest that this gap could be due to a number of factors, including an ineffective use of interior space, and occupants’ behaviour.

Does energy efficiency matter to home-buyers? An investigation of EPC ratings and transaction prices in England

This paper investigates whether energy performance ratings, as measured by mandatory Energy Performance Certificates (EPCs), are reflected in the sale prices of residential properties. This is the first large-scale empirical study of this topic in England involving 333,095 dwellings sold at least twice in the period from 1995 to 2012. Applying hedonic regression and an augmented repeat sales regression, we find a positive relationship between the energy efficiency rating of a dwelling and the transaction price per square metre. The price effects of superior energy performance tend to be higher for terraced dwellings and flats compared to detached and semi-detached dwellings. The evidence is less clear-cut for rates of house price growth but remains supportive of a positive association. Overall, the results of this study suggest that energy efficiency labels have a measurable and significant impact on house prices in England

A comparative review of skill assessment: performance, prediction and profiling

The assessment of chess players is an increasingly attractive opportunity and an unfortunate necessity. The chess community needs to limit potential reputational damage by inhibiting cheating and unjustified accusations of cheating: there has been a recent rise in both. A number of counter-intuitive discoveries have been made by benchmarking the intrinsic merit of players’ moves: these call for further investigation. Is Capablanca actually, objectively the most accurate World Champion? Has ELO rating inflation not taken place? Stimulated by FIDE/ACP, we revisit the fundamentals of the subject to advance a framework suitable for improved standards of computational experiment and more precise results. Other domains look to chess as the demonstrator of good practice, including the rating of professionals making high-value decisions under pressure, personnel evaluation by Multichoice Assessment and the organization of crowd-sourcing in citizen science projects. The ‘3P’ themes of performance, prediction and profiling pervade all these domains.

A web-based system for visualizing upper limb motor performance of Parkinson’s disease patients

Objective To design, develop and set up a web-based system for enabling graphical visualization of upper limb motor performance (ULMP) of Parkinson’s disease (PD) patients to clinicians. Background Sixty-five patients diagnosed with advanced PD have used a test battery, implemented in a touch-screen handheld computer, in their home environment settings over the course of a 3-year clinical study. The test items consisted of objective measures of ULMP through a set of upper limb motor tests (finger to tapping and spiral drawings). For the tapping tests, patients were asked to perform alternate tapping of two buttons as fast and accurate as possible, first using the right hand and then the left hand. The test duration was 20 seconds. For the spiral drawing test, patients traced a pre-drawn Archimedes spiral using the dominant hand, and the test was repeated 3 times per test occasion. In total, the study database consisted of symptom assessments during 10079 test occasions. Methods Visualization of ULMP The web-based system is used by two neurologists for assessing the performance of PD patients during motor tests collected over the course of the said study. The system employs animations, scatter plots and time series graphs to visualize the ULMP of patients to the neurologists. The performance during spiral tests is depicted by animating the three spiral drawings, allowing the neurologists to observe real-time accelerations or hesitations and sharp changes during the actual drawing process. The tapping performance is visualized by displaying different types of graphs. Information presented included distribution of taps over the two buttons, horizontal tap distance vs. time, vertical tap distance vs. time, and tapping reaction time over the test length. Assessments Different scales are utilized by the neurologists to assess the observed impairments. For the spiral drawing performance, the neurologists rated firstly the ‘impairment’ using a 0 (no impairment) – 10 (extremely severe) scale, secondly three kinematic properties: ‘drawing speed’, ‘irregularity’ and ‘hesitation’ using a 0 (normal) – 4 (extremely severe) scale, and thirdly the probable ‘cause’ for the said impairment using 3 choices including Tremor, Bradykinesia/Rigidity and Dyskinesia. For the tapping performance, a 0 (normal) – 4 (extremely severe) scale is used for first rating four tapping properties: ‘tapping speed’, ‘accuracy’, ‘fatigue’, ‘arrhythmia’, and then the ‘global tapping severity’ (GTS). To achieve a common basis for assessment, initially one neurologist (DN) performed preliminary ratings by browsing through the database to collect and rate at least 20 samples of each GTS level and at least 33 samples of each ‘cause’ category. These preliminary ratings were then observed by the two neurologists (DN and PG) to be used as templates for rating of tests afterwards. In another track, the system randomly selected one test occasion per patient and visualized its items, that is tapping and spiral drawings, to the two neurologists. Statistical methods Inter-rater agreements were assessed using weighted Kappa coefficient. The internal consistency of properties of tapping and spiral drawing tests were assessed using Cronbach’s α test. One-way ANOVA test followed by Tukey multiple comparisons test was used to test if mean scores of properties of tapping and spiral drawing tests were different among GTS and ‘cause’ categories, respectively. Results When rating tapping graphs, inter-rater agreements (Kappa) were as follows: GTS (0.61), ‘tapping speed’ (0.89), ‘accuracy’ (0.66), ‘fatigue’ (0.57) and ‘arrhythmia’ (0.33). The poor inter-rater agreement when assessing “arrhythmia” may be as a result of observation of different things in the graphs, among the two raters. When rating animated spirals, both raters had very good agreement when assessing severity of spiral drawings, that is, ‘impairment’ (0.85) and irregularity (0.72). However, there were poor agreements between the two raters when assessing ‘cause’ (0.38) and time-information properties like ‘drawing speed’ (0.25) and ‘hesitation’ (0.21). Tapping properties, that is ‘tapping speed’, ‘accuracy’, ‘fatigue’ and ‘arrhythmia’ had satisfactory internal consistency with a Cronbach’s α coefficient of 0.77. In general, the trends of mean scores of tapping properties worsened with increasing levels of GTS. The mean scores of the four properties were significantly different to each other, only at different levels. In contrast from tapping properties, kinematic properties of spirals, that is ‘drawing speed’, ‘irregularity’ and ‘hesitation’ had a questionable consistency among them with a coefficient of 0.66. Bradykinetic spirals were associated with more impaired speed (mean = 83.7 % worse, P < 0.001) and hesitation (mean = 77.8% worse, P < 0.001), compared to dyskinetic spirals. Both these ‘cause’ categories had similar mean scores of ‘impairment’ and ‘irregularity’. Conclusions In contrast from current approaches used in clinical setting for the assessment of PD symptoms, this system enables clinicians to animate easily and realistically the ULMP of patients who at the same time are at their homes. Dynamic access of visualized motor tests may also be useful when observing and evaluating therapy-related complications such as under- and over-medications. In future, we foresee to utilize these manual ratings for developing and validating computer methods for automating the process of assessing ULMP of PD patients.

Testing of combined heating systems for small houses: Improved procedures for whole system test methods : Deliverable 2.3

Dynamic system test methods for heating systems were developed and applied by the institutes SERC and SP from Sweden, INES from France and SPF from Switzerland already before the MacSheep project started. These test methods followed the same principle: a complete heating system – including heat generators, storage, control etc., is installed on the test rig; the test rig software and hardware simulates and emulates the heat load for space heating and domestic hot water of a single family house, while the unit under test has to act autonomously to cover the heat demand during a representative test cycle. Within the work package 2 of the MacSheep project these similar – but different – test methods were harmonized and improved. The work undertaken includes:  • Harmonization of the physical boundaries of the unit under test. • Harmonization of the boundary conditions of climate and load. • Definition of an approach to reach identical space heat load in combination with an autonomous control of the space heat distribution by the unit under test. • Derivation and validation of new six day and a twelve day test profiles for direct extrapolation of test results.   The new harmonized test method combines the advantages of the different methods that existed before the MacSheep project. The new method is a benchmark test, which means that the load for space heating and domestic hot water preparation will be identical for all tested systems, and that the result is representative for the performance of the system over a whole year. Thus, no modelling and simulation of the tested system is needed in order to obtain the benchmark results for a yearly cycle. The method is thus also applicable to products for which simulation models are not available yet. Some of the advantages of the new whole system test method and performance rating compared to the testing and energy rating of single components are:  • Interaction between the different components of a heating system, e.g. storage, solar collector circuit, heat pump, control, etc. are included and evaluated in this test. • Dynamic effects are included and influence the result just as they influence the annual performance in the field. • Heat losses are influencing the results in a more realistic way, since they are evaluated under "real installed" and representative part-load conditions rather than under single component steady state conditions.   The described method is also suited for the development process of new systems, where it replaces time-consuming and costly field testing with the advantage of a higher accuracy of the measured data (compared to the typically used measurement equipment in field tests) and identical, thus comparable boundary conditions. Thus, the method can be used for system optimization in the test bench under realistic operative conditions, i.e. under relevant operating environment in the lab.   This report describes the physical boundaries of the tested systems, as well as the test procedures and the requirements for both the unit under test and the test facility. The new six day and twelve day test profiles are also described as are the validation results.

The value of work in younger and older adults' lives: an Australian perspective

In the present study we examined the perceived role of work in the lives of younger and older adults in three different occupations: teaching, nursing, and small business. On the basis of lifespan developmental theory of changes in work-related values across the lifespan we expected that (1) older adults would rate their job satisfaction and organisational commitment more highly than younger adults, and (2) younger adults would rate the importance of work more highly than older workers. Based on utility theory we expected that nurses and teachers would view early retirement more positively than small business employees because of early retirement incentives in these two careers. One-hundred-sixty-two participants completed a 118-item survey. Overall few age differences were found between older and younger workers. On average, all participants rated work as moderately important and their job satisfaction as moderately high. Nonetheless, older participants rated their job satisfaction higher than younger participants. On average, all groups believed they would retire before 65 years of age. The latter finding is important for workability theory and raises issues about how to change attitudes, perceptions and values about working past traditional retirement ages.

Exempt treatment of financial intermediation services under a value-added tax: an assessment of alternatives

Most countries with a value-added tax (VAT) exempt financial intermediation services from the tax. While exemption is generally perceived to be undesirable, it is also widely regarded as unavoidable because of technical difficulties in applying VAT to these services. This article reviews the standard rationale for exempt treatment and then considers the relative merits of two recent challenges raised in the tax literature. The first challenge involves the application of cash flow taxation to financial intermediation services in a manner that is consistent with an invoice/credit VAT (which is the dominant form). The second challenge proposes a comprehensive system of zero-rating of financial intermediation services, which is supported by a characterization of the household consumption of such services as non-taxable. The author argues that each of these alternatives to an exemption system suffers from both theoretical and practical implementation difficulties that make maintenance of exempt treatment the preferred approach, at least in the short term. There is, however, a simpler alternative to these fundamental reform options, involving modification of just one aspect of an exemption system to relieve some of its more problematic aspects. Many of the interpretative problems and associated inefficiencies that plague an exemption system arise from the need to distinguish between taxable and exempt financial services. The author argues that these difficulties can be eliminated, to a large extent, by basing the distinction on the form of prices. In support of this approach, he points out that it is consistent with the underlying reasons for the application of exempt treatment. The author considers a number of other possible modifications, but these are either rejected outright or viewed with a healthy skepticism. For example, the author is critical of the apparent rationale for the application of cash flow taxation to property and casualty insurers. He also rejects proposals that accept some looseness in the formulaic allocation by financial intermediaries of the costs of business inputs between exempt and taxable services for input credit purposes. In his view, an explicit reliance on pricing structures to draw the boundary between exempt and taxable services is preferable to the provision of relief for blocked input tax credits of financial intermediaries. Finally, the author is skeptical of the case for a policy response intended to address the tax bias under an exemption system for financial intermediaries to insource supplies.

Employer satisfaction with employees with a disability: comparisons with other employees

This paper is based on survey responses from 656 employers who had employed someone with a disability using support from disability employment agencies. Differences in employers' ratings of employees with and without a disability in relation to employer satisfaction and work performance are outlined. Employers were found to be less satisfied with their employee with a disability than with other employees; determinants of employer satisfaction differed between the two employee groups; and employers were predisposed to be more satisfied with employees with a disability than with other employees in relation to the work performance variables tested. Identifying areas directly related to employer satisfaction, and highlighting important differences in factors that determine employer satisfaction between these two employee groups, provides valuable direction for effective strategic planning of service interventions

How well do ecosystem-based planning units represent different componenets of biodiversity?

There are many proposals for managing biodiversity by using surrogates, such as umbrella, indicator, focal, and flagship species. We use the term biodiversity management unit for any ecosystem-based classificatory scheme for managing biodiversity. The sufficiency of biodiversity management unit classification schemes depends upon (1) whether different biotic elements (e.g., trees, birds, reptiles) distinguish between biodiversity management units within a classification (i.e., coherence within classes}; and (2) whether different biotic elements agree upon similarities and dissimilarities among biodiversity management unit classes (i.e., conformance among classes). Recent evaluations suggest that biodiversity surrogates based on few or single taxa are not useful. Ecological vegetation classes are an ecosystem-based classification scheme used as one component for biodiversity management in Victoria, Australia. Here we evaluated the potential for ecological vegetation classes to be used as biodiversity management units in the box-ironbark ecosystem of central Victoria, Australia. Eighty sites distributed among 14 ecological vegetation classes were surveyed in the same ways for tree species, birds, mammals, reptiles, terrestrial invertebrates, and nocturnal flying insects. Habitat structure and geographic separations also were measured, which, with the biotic elements, are collectively referred to as variables. Less than half of the biotic element-ecological vegetation class pairings were coherent. Generalized Mantel tests were used to examine conformance among variables with respect to ecological vegetation classes. While most tests were not significant, birds, mammals, tree species, and habitat structure together showed significant agreement on the rating of similarities among ecological vegetation classes. In this system, use of ecological vegetation classes as biodiversity management units may account reasonably well for birds, mammals, and trees; but reptiles and invertebrates would not be accommodated. We conclude that surrogates will usually have to be augmented or developed as hierarchies to provide general representativeness.

Clinical measurement of muscle tone using a velocity-corrected modified ashworth scale

Objective: To develop a new form of the modified Ashworth scale (MAS) for muscle-tone assessment that combines the MAS score with the passive muscle-stretching velocity during the assessment of muscle tone, resulting in a measure that has higher intertester reliability than the MAS.

Design: Twanty-two volunteer subjects with spinal cord injuries at a tertiary care outpatient and inpatient spinal cord injury rehabilitation center affiliated with a university were recruited for this study.

Results: A decision tree in which V-MAS scores were obtained was developed. The data obtained from three independent raters, when adjusted by means of the V-MAS, showed an excellent interrater reliability.

Conclusions: Results indicated that the V-MAS is a more reliable measure. In addition, the resulting units of the V-MAS, ranging from 0 to 1, are of the same form as pendulum test data. The V-MAS method is quite simple to use because the rater need only measure the angular range and duration of the passive movement to calculate average velocity during the MAS assessment in addition to the normal MAS rating of muscle tone.

Fire fighters' assessments of fireground risk

Fire fighters are often required to work in dynamic and hazardous environments involving a high level of uncertainty. The present study investigated 110 volunteer fire fighters’ assessments of levels of risk associated with a photographic depiction of a typical grassland fire situation. The fire fighters used a standard fire agency risk-rating matrix procedure requiring them to specify the severity of the hazards depicted and the probability of a mishap in order to rate overall level of risk (1 = Low; 4 = Extreme). The risk ratings made by the fire fighters varied greatly. The overall rate of agreement with the risk level rating of the situation made by a panel of expert fire officers (=1, Low) was only 27%. It seems that use of a standard risk-rating matrix procedure by fire fighters at incidents, as recommended currently by many fire agencies, is likely to result in unreliable risk assessments, at least in the absence of effective training in the risk assessment procedure. The 110 volunteers were also asked to identify the total number of potential hazards apparent in five photographs depicting different kinds of emergency incidents. Identifying more hazards was found to be associated with (a) previous personal experience of a ‘near-miss’; and (b) higher levels of education. The findings imply that when faced with identical fire ground situations, individual fire fighters are likely to differ in their situational awareness of hazards and consequent risk assessments.

Do organizational service recovery actions impact on hotel guests future intentions and does speed of recovery matter?

This paper investigates hotel guests’ responses to organizational actions dealing with service failure. Eight service failure scenarios were used to identify guests’ intentions towards future visits. Guests’ intentions to switch hotels, revisit the property and remain loyal to the chain were found to vary based on the recovery efforts undertaken. This research found that empowering employees contribute to positive consumer intentions toward the service provider. Compensation was also found effective if offered through empowered employees. Speed of response to service failure was also identified as important action to improve consumer future intentions. Based on these findings, implications for future research are highlighted. Recommendations to the practitioners of hospitality and tourism sector were made for the management of failed service encounter.

Practical application of the Delphi technique in a bicultural mental health nursing study in New Zealand

Background. Numerous studies have employed the Delphi technique to seek expert opinion about aspects of clinical practice. When researching literature on the Delphi technique, however, we discovered discrepancies in its application, and a lack of detail when reporting design, administration, and analysis methods. Such lack of specificity hinders the replicability and assessment of the clinical and cultural validity and reliability of Delphi studies.

Aim. The aim of this paper is to detail the practical application of the Delphi technique as a culturally and clinically valid means of accessing expert opinion on the importance of clinical criteria.

Methods. Reference is made to a bicultural New Zealand mental health nursing clinical indicator study that employed a three-round reactive Delphi survey. Equal proportions of Maori and non-Maori nurses (n = 20) and consumers (n = 10) rated the importance of 91 clinical indicator statements for the achievement of professional practice standards. Additional statements (n = 21) suggested by Delphi participants in round 1 were included in subsequent rounds. In round 2, participants explained the rating they applied to statements that had not reached consensus in round 1, and summarized responses were provided to participants in round 3. Consensus was considered to have been achieved if 85% of round 3 ratings lay within a 2-point bracket on the 5-point Likert-scale overall, or in one of the Maori nurse, non-Maori nurse, or consumer groups. A mean rating of 4·5 after round 3 was set as the importance threshold.

Findings. Consensus occurred overall on 75 statements, and within groups on another 24. Most statements (n = 86) reached the importance benchmark.

Conclusions. When rigorous methods of participant selection, group composition, participant feedback, and determination of consensus and importance are employed, the Delphi technique is a reliable, cost-effective means of obtaining and prioritizing experts judgements.