The influence of low-temperature surface induction on evacuation, pump-out hole sealing and thermal performance of composite edge-sealed vacuum insulated glazing

Hermeticity of vacuum edge-sealing materials are one of the paramount requirements, specifically, to the evolution of energy-efficient smart windows and solar thermal evacuated flat plate collectors. This study reports the design, construction and performance of high-vacuum glazing fabrication system and vacuum insulated glazing (VIG). Experimental and theoretical investigations for the development of vacuum edgeseal made of Sn-Pb-Zn-Sb-AlTiSiCu composite in the proportion ratio of 56:39:3:1:1 by % (CS-186) are presented. Experimental investigations of the seven constructed VIG samples, each of size 300mm·300mm·4 mm, showed that increasing the hot-plate surface temperatures improved the cavity vacuum pressure whilst expediting the pump-out hole sealing process but also increases temperature induced stresses. Successful pump-out hole sealing process of VIG attained at the hot-plate set point temperature of 50˚C and the approximate cavity pressure of 0.042 Pa was achieved. An experimentally and theoretically validated finite volume model (FVM) was utilised. The centre-of-pane and total thermal transmittance values are calculated to be 0.91 Wm-2K-1 and 1.05 Wm-2K-1, respectively for the VIG. FVM results predicted that by reducing the width of vacuum edge seal and emissivity of coatings the thermal performance of the VIG is improved

Quantitative LEED I-V and ab initio study of the Si(111)-3x2-Sm surface structure and the missing half order spots in the 3x1 diffraction pattern

We have used Low Energy Electron Diffraction (LEED) I-V analysis and ab initio calculations to quantitatively determine the honeycomb chain model structure for the Si(111)-3x2-Sm surface. This structure and a similar 3x1 recontruction have been observed for many Alkali-Earth and Rare-Earth metals on the Si(111) surface. Our ab initio calculations show that there are two almost degenerate sites for the Sm atom in the unit cell and the LEED I-V analysis reveals that an admixture of the two in a ratio that slightly favours the site with the lower energy is the best match to experiment. We show that the I-V curves are insensitive to the presence of the Sm atom and that this results in a very low intensity for the half order spots which might explain the appearance of a 3x1 LEED pattern produced by all of the structures with a 3x2 unit cell.Comment: 10 pages, 13 figures. Preliminary work presented at the the APS March meeting, Baltimore MD, 2006. To be published in Phys. Rev. B. April/May 200

Record and analysis with conclusions upon the examination of 1,041 school children attending the Bradford Eye and Ear Hospital, from April 1902 to November 1905

With -- regard to the Hypermetropíc eye becoming Myopic, I fail to find sufficient evidence as to whether the cause is due to the strain pure and simple, or to a diseased condition of the Choroid etc: Personally I think it is due to a combination of both of these conditions, although the: strain certainly plays a very important part.In comparing the different groups it is a noticeable fact that girls are greater sufferers than boys, and I would emphasize the fact that it is in children between the ages of 7 and 11 years that the strain upon the eyesight appears to be the greatest.The absolute necessity for school children having both eyes examined separately for visual acuity upon admission to the school.I have tabulated a series of cases (see appendix) showing that undoubtedly children may have fairly good, or very good vision in one eye, whilst the vision of the other eye is moderate, or even bad.Several of these cases which have been tabulated were not-sent-by the school authorities but, brought by the parent, these children having passed the tests employed.It certainly appears to me to be a distinct advantage for children to have the combined use of.both eyes. If they are allowed to go on using one eye only, the other eye eventually becomes Amblyopic, thus they are handicapped during their school life, and also in after ' life.Spasm of Accommodation is a condition which is frequently met with in our children, and it is on this account that I strongly condemn the practice which is very much in . vogue, of parents, and even school authorities sending children to so -.called "Opticians "; for it is impossible for anyone to fully estimate the degree of error of refraction in any child unless its "accommodation" is properly paralysed; a fact which has been well illustrated in numerous instances in my paper.In many of the children who had Homatropine dropped into their eyes, their retinoscopy taken, yet obtained no improvement with glasses, I find that when Atropine was given for a week, and retinoscopy again taken, there was found to be a great difference'between the first and second examination, showing the fact that "Spasm of " Accommodation" may lead one into error.Although the visual acuity may be bad in some cases, upon examination by retinoscopy the eye is proved to be Emmetropic. Of the 110 cases of Spasm of Accommodation: 91 were Hypermetropes, 12 were Myopes, 3 were Mixed Astig: 1 was Hyper: c Myopia, 4 were Normal. This shows, that the condition occurs most frequently in Hypermetropes.From the complications which occurred in the various groups I think we can safely deduct that it is absolutely necessary to have the eyes of every child examined as soon as there is any inflammatory condition of the mechanism of the eye; for although the defect in refraction may not be the actual cause, yet, it does aggravate the trouble, and if the proper correcting glasses are given, this prevents a recurrence.It is suggested that very many of these complications are produced and aggravated by the child rubbing its tired eye.Here again I consider we have a very strong argument against unqualified men being, partially trained as so- called "Opticians" when they would be quite unable to diagnose any of these diseased conditions.Children should not be admitted to any school before the age of six, and even at that age the work should be light.It. should be forcibly impressed upon parents that schools are not nurseriesè The early training of all children should be in the hands of the mothers, and they alone are responsible for the care and training of their children.It would certainly be interesting to compare the eyesight of children who have attended school from the age-of three and upwards with those who have not been sent to school before the age of five or six years.I consider that a wise course has been adopted by the authorities during the past. twelve months in stopping the grant for children under five years. of age.I am convinced that the authorities are taking precautions in all directions save that of compelling-parents to have the eyes of their children properly examined by an Ophthalmologist.What might be done with advantage would be to point out to'the parents by a "printed letter" the absolute necessity of their children having the full and combined use of both eyes, and the folly of not allowing them to wear glasses simply for the sake of appearance; and also to point out that from the disuse of one eye, the child may eventually lose the sight of this eye, and thus be considerably handicapped in his after life.I am fully aware of the fact that no action could be taken if the parent refused to have his child attended to, yet I feel certain that if compulsory education is enforced, then it is not sufficient for the authorities to simply give one, two, or three notices, and then take no further action, but they must,in the interest of the child, and thus, of the community, refuse to allow children t take advantage of free education; for undoubtedly drastic measures are necessary, otherwise, through lack of thoughts or through ignorance, our children may become useless citizens.Another alternative is to provide a properly trained Ophthalmologist and have children attending all schools thoroughly examined, ignoring- the'parent. Upon this point I will make same observations later.Home lessons for children. under nine or ten years old, should be strongly discouraged, and even at this age it should depend upon the child's capabilities as to the amount given.It should be impressed upon the parent the importance of seeing that the child when doing home lessons, should be in a properly lighted room, and that the desk, form or chair, and paper, be in proper relationship.Children who have defective eyesight or are otherwise weakly, should have a modified curriculum.There should be a period of rest between all lessons, also constant change from reading or writing to black board, or object lessons etc.Teachers should be instructed as to the elementary facts of the relationship of school work and strain to the eyesight. I find that upon this point very many teachers are extremely ignorant, and I would enforce a special class of instruction upon this subject.That there is an advantage of having the eyesight of school children properly examined and their error of refraction corrected, I think no one will doubt, but I think the following-tables. which give the visual acuity of the right and left eye of 683 cases upon their first "visit, and the visual acuity of 407 of these cases upon their last visit to the Hospital, will give an indication of the advantages which are obtained by treatment

STM and ab initio study of holmium nanowires on a Ge(111) Surface

A nanorod structure has been observed on the Ho/Ge(111) surface using scanning tunneling microscopy (STM). The rods do not require patterning of the surface or defects such as step edges in order to grow as is the case for nanorods on Si(111). At low holmium coverage the nanorods exist as isolated nanostructures while at high coverage they form a periodic 5x1 structure. We propose a structural model for the 5x1 unit cell and show using an ab initio calculation that the STM profile of our model structure compares favorably to that obtained experimentally for both filled and empty states sampling. The calculated local density of states shows that the nanorod is metallic in character.Comment: 4 pages, 12 figures (inc. subfigures). Presented at the the APS March meeting, Baltimore MD, 200

The Team of Life: A narrative approach to building resilience in UK school children

Concern about children and young people's mental health is high on the UK national agenda. Access to specialist Child and Adolescent Mental Health Services (CAMHS) is perceived as problematic due to high thresholds, clinic-based service delivery and associated stigma. Schools and youth work contexts present alternative and more accessible settings for early intervention and preventative work aimed at promoting positive mental health. The Team of Life is a narrative group methodology with sporting metaphors, which encourages young people to recognise the strength and resilience in their life teams. The approach has been used within diverse contexts internationally, for example with former child soldiers in Uganda, young men from refugee backgrounds and young people in Australian schools. Innovative partnership work between health and education has led to the implementation of the Team of Life in a UK school and the development of a manualised Team of Life Programme. We now report findings from pilot work evaluating feasibility and outcomes for the programme within a UK secondary school setting. Quantitative findings include significant positive change in Goal Based Outcomes as well as significant reductions in emotional and behaviour difficulties measured by the Child Behaviour Checklist. Qualitative thematic analysis of participant feedback indicates benefits relating to the experience of 'shared understanding', 'confidence', 'peer support' and the 'positive impact of sport'. Further research is planned to evaluate the effectiveness on a larger scale. This pilot study was undertaken as part of CAMHS Extended Schools work. Potential for collaboration between clinical and education psychology colleagues in relation to the promotion of positive mental health in schools is discussed

An experimental investigation of the heat transfer and energy storage characteristics of a latent heat thermal energy storage system with a vertically-oriented multi-pass tube heat exchanger for domestic hot water applications

This paper presents the experimental performance analysis of a latent heat energy storage system (LHESS) designed for domestic hot water (DHW) applications. The designed, fabricated and characterised thermal store comprised of a vertically-oriented multi-pass tube heat exchanger in a rectangular cross-section container filled with PCM paraffin RT44HC. The experimental investigation evaluated the heat transfer within the system, measured the transient temperature distribution, determined the cumulative thermal energy stored, charging time and the instantaneous charging power. The experimental work was conducted under controlled experimental conditions using different heat transfer fluid (HTF) inlet temperatures and different volume flow rates for store charging. It was found that during charging process natural convection in the melt played a significant role. Higher HTF inlet temperature during charging significantly decreased store charging time. Increasing HTF inlet temperature from 60 to 70 oC shortened the charging time by 3.5 hours, a further increase to 80 oC decreased melting time by a further 2 hours

An experimental investigations of the melting of RT44HC inside a horizontal rectangular test cell subject to uniform wall heat flux

This study experimentally investigates the effect of different values of wall heat flux intensity on the melting of RT44HC Phase Change Material (PCM) in a rectangular test cell. A new novel experimental test rig to provide accurate data for the validation of numerical models of phase change was developed. The designed and constructed test rig consists of a horizontal rectangular cross-section test cell formed from polycarbonate sheet with copper plates and mica heaters to provide controlled uniform wall heat flux. Experiments were performed for three constant uniform wall heat flux values (q00 wall = 675, 960 and 1295 W/m2 ) applied to both left and right sides of the test cell. An imaging technique was used to visualize and record the movement of the solid-liquid interface using a Canon EOS DSLR Camera. The results obtained show a strong correlation between the magnitude of wall heat flux which drives the convective heat transfer and melt fraction development in the PCM. The results also show that increasing the input power from 675 W/m2 to 960 W/m2 to 1295 W/m2 reduces the total time for the melting process by 26.3% and 42.10% respectively. The raw data set comprised of measured temperatures and observation of melt fraction development provide a useful data set for validation of numerical models aiming to simulate the melting process in a rectangular cross-section test cell

Numerical investigation of the influence of mushy zone parameter Amush on heat transfer characteristics in vertically and horizontally oriented thermal energy storage systems

The effect of the value used for the mushy zone parameter (Amush) on predicted heat transfer and melting characteristics of a phase change material (PCM) Lauric acid, in both vertical and horizontal enclosures was studied. There is a lack of clarity regarding which value of this parameter should be used for accurate simulations of phase change heat transfer, addressing this will aid in accurate simulation and design of systems for LHTES (Latent heat thermal energy storage). The numerical analysis undertaken used a commercial CFD code ANSYS FLUENT 18.2 and the enthalpy-porosity formulation. The range of mushy zone parameter used was from 105 to 107. The predicted locations of the melt front were compared to published experimental data available in the literature. The simulations provided quantitative information about the amount of energy stored and the melt fraction and providing improved understanding of the heat transfer process. Comparison between predictions using different values of Amush, and experimental data showed that correct selection of the value of Amush to be used in the momentum equations is an important parameter for accurate modelling of LHTES and has a significant influence on the solid-liquid interface shape and progression. The study reveals that increasing the value of Amush leads to a decrease in fluid velocity, decreasing convection and the rate of heat transfer, therefore, proper selection of the mushy zone parameter is necessary to accurately simulate LHTES systems and provide a better understanding of the phase change behaviour and heat transfer characteristics

Arrival direction distribution of cosmic rays of energy 10 (18) eV

The Haverah Park air-shower experiment recorded over 8500 events with primary energy 10 to the 18th power eV between 1963 and 1983. An analysis of these events for anisotropies in celestial and galactic coordinates is reported. No very striking anisotropies are observed