Monitoring physical and chemical parameters of Delaware Bay waters with an ERTS-1 data collection platform

The author has identified the following significant results. Evaluation of the probe performances during the initial phase indicates that the dissolved oxygen sensor available as part of the package is not sufficiently reliable for long term operation. The turbidity probe requires frequent visits to the site to maintain it in proper operating condition. The cost of these visits would have to be weighed against the information obtained. The conductivity/salinity, temperature, pH, and depth indicators have worked extremely well over the course of the study. Monthly cleanings would maintain all these probes in top operating condition. Currently the accuracy of each measurement returned via satellite is being compared to the accuracy of the probe reading and water samples analyzed in the laboratory

CFD modelling of double-skin facades with venetian blinds

This paper describes CFD modelling of Double Skin Façades (DSF) with venetian blinds inside the façade cavity. The 2-D modelling work investigates the coupled convective, conductive and radiative heat transfer through the DSF system. The angles of the venetian blind can be adjusted and a series of angles (0, 30, 45, 60 and 80 degrees) has been modelled. The modelling results are compared with the measurements from a section of façade tested within a solar simulator and with predictions from a component based nodal model. Agreement between the three methods is generally good. Discrepancies in the results are generally caused by the simplification of the CFD model resulting less turbulence mixing within the façade cavity. The CFD simulation output suggests that the presence of the venetian blinds has led up to 35 percent enhancement in natural ventilation flow for the façade cavity and 75 percent reduction in heat loads for the internal environment. It was also found that little changes of the convective heat transfer coefficients on the glazing surfaces have been caused by the venetian blinds with different angles

Heating Ventilating and Air-Conditioning (HVAC) equipment taxonomy

Past efforts to reduce carbon emissions from the non-domestic building sector have had limited success in the UK. One of the reasons for this is a general absence of data addressing the non-domestic building sector, leading further to a lack of transparent and validated methods for energy use benchmarks and both statistical and predictive energy use modelling. This paper addresses this issue by proposing a heating ventilating and air-conditioning (HVAC) equipment taxonomy that will allow compatibility across building sector energy modelling, benchmarking and surveying. The paper presents a comprehensive, yet easily expandable, friendly to use HVAC equipment taxonomy. The main aim of the HVAC equipment taxonomy is to assist both predictive and statistical building energy end use modelling, surveying fieldwork and analysis of all building types and the allocation of energy to end uses. The HVAC equipment taxonomy developed also includes information about equipment energy efficiency in terms of efficiency coefficients or auxiliary energy consumption for both design and part load. This is supported by a review of what are sometimes contradicting and ill-defined energy efficiency indices, especially with regard to part-load operation

Magnetron sputtered thin films and composites for automotive and aerospace electrical insulation

Ceramics are highly prised as insulating materials because of their high stability under demanding conditions (thermal, chemical and radiological). However, the use of ceramics as wire insulation is currently limited to powder packed and relatively thick low voltage coatings. This work follows the development of sputtered Al2O3 and Al2O3, SiO2 and Ta2O5 composite films as deposited onto copper. Copper disk studies will ultimately be translated onto Cu wire for a proof of concept study. Initial Al2O3 deposition utilised RF or DC sputtering but this found to have low deposition rate (up to 16 nmh 1) and to contain crystallite and metallic defects (up to 19.6 at. % Al0) respectively. These issues were addressed by introducing pulsed DC (PDC) deposition conditions, producing films with no crystalline or metallic defects (up to 146 nmh 1). The dielectric strength of PDC films measured by AFM time dependant dielectric breakdown was 310 ± 21 Vμm 1, higher than that of the DC deposited films which had a dielectric strength of between 165 ± 19 and 221 ± 20 Vμm 1. A dielectric strength of 310 Vμm 1 is suitable for applications with a voltage rating below 150 V and is also a good platform for the production of higher quality coatings. The mechanical properties of the films did suffer from a lower amount of blending at the interface, DC pull off strength was 25.8 ± 9.8 - 72.3 ± 5.6 MPa with the PDC pull off strength being 55.7 ± 2.9 MPa). Wires coated with such PDC Al2O3 showed promise with full circumference coating, however, short circuiting was apparent in the wires potentially caused by micro cracking induced either during or post deposition. The use of multilayer composites consisting of the aforementioned PDC Al2O3 and RF SiO2 or RF Ta2O5 resulted in significant gains with respect to the material’s electrical properties. The films deposited with 2 layers of each PDC Al2O3 and the RF addition performed best in terms of dielectric strengths of 513 ± 18 and 466 ± 86 Vμm 1 for Ta2O5 and SiO2 composites respectively. The success of the 2x2 layer configuration resulted from a compromise between the number of RF layers and their thickness. The mechanical properties did, however, suffer as a result of increased intrinsic stress caused by the use of multilayers of materials with varying expansion coefficients, reducing pull off adhesion strength to a maximum of 34.4 ± 4.4 MPa, where ideally the pull off adhesion would be above 80 MPa. Heat treatment of these coatings resulted in decreased adhesive properties, with a maximum pull off adhesion strength of 20.1 ± 0.9 MPa being apparent. Most of the electrical properties remained the same or were decreased by heat treatment, however the dielectric strength of the SiO2 composites improved by an average of 12 % resulting in a maximum dielectric strength of 517 ± 24 Vμm 1 due to a reduction in the defect density in the films. Conversely the electrical properties of Ta2O5 composites suffered greatly following heat treatment with a maximum dielectric strength of 358 ± 31 Vμm 1. This was theorised to result from Cu migration from the substrate and the potential for Ta2O5 to crystallise at temperatures close to 500 °C. Coating of Cu wires with PDC alumina was shown to be possible, with coatings of various interlayer and coating thickness. Characterisation showed that the wire coating rig enabled the whole circumference of the wire to be coated with alumina. Tensile testing resulted in transvers cracking followed by longitudinal cracking above an applied strain of 1.5 and 4.0 % respectively. Following heat treatment the copper substrate softened and resulted in delamination failures in the coatings during tensile testing. Electrical testing of the wires was inconsistent due micro cracking in the wire coatings. It has been shown that the use of mixed material composites sputtered by PDC and RF sputtering have potential as high dielectric strength insulating materials, improving upon the base Al2O3 believed to be a result of passivation of structural and compositional defects. Additionally, it has been shown that physical vapour deposition in conjunction with a modified sample holder can be utilised for coating of bare copper wire with the potential to act as isolative coatings

Magnetron sputtered thin films and composites for automotive and aerospace electrical insulation

Ceramics are highly prised as insulating materials because of their high stability under demanding conditions (thermal, chemical and radiological). However, the use of ceramics as wire insulation is currently limited to powder packed and relatively thick low voltage coatings. This work follows the development of sputtered Al2O3 and Al2O3, SiO2 and Ta2O5 composite films as deposited onto copper. Copper disk studies will ultimately be translated onto Cu wire for a proof of concept study. Initial Al2O3 deposition utilised RF or DC sputtering but this found to have low deposition rate (up to 16 nmh 1) and to contain crystallite and metallic defects (up to 19.6 at. % Al0) respectively. These issues were addressed by introducing pulsed DC (PDC) deposition conditions, producing films with no crystalline or metallic defects (up to 146 nmh 1). The dielectric strength of PDC films measured by AFM time dependant dielectric breakdown was 310 ± 21 Vμm 1, higher than that of the DC deposited films which had a dielectric strength of between 165 ± 19 and 221 ± 20 Vμm 1. A dielectric strength of 310 Vμm 1 is suitable for applications with a voltage rating below 150 V and is also a good platform for the production of higher quality coatings. The mechanical properties of the films did suffer from a lower amount of blending at the interface, DC pull off strength was 25.8 ± 9.8 - 72.3 ± 5.6 MPa with the PDC pull off strength being 55.7 ± 2.9 MPa). Wires coated with such PDC Al2O3 showed promise with full circumference coating, however, short circuiting was apparent in the wires potentially caused by micro cracking induced either during or post deposition. The use of multilayer composites consisting of the aforementioned PDC Al2O3 and RF SiO2 or RF Ta2O5 resulted in significant gains with respect to the material’s electrical properties. The films deposited with 2 layers of each PDC Al2O3 and the RF addition performed best in terms of dielectric strengths of 513 ± 18 and 466 ± 86 Vμm 1 for Ta2O5 and SiO2 composites respectively. The success of the 2x2 layer configuration resulted from a compromise between the number of RF layers and their thickness. The mechanical properties did, however, suffer as a result of increased intrinsic stress caused by the use of multilayers of materials with varying expansion coefficients, reducing pull off adhesion strength to a maximum of 34.4 ± 4.4 MPa, where ideally the pull off adhesion would be above 80 MPa. Heat treatment of these coatings resulted in decreased adhesive properties, with a maximum pull off adhesion strength of 20.1 ± 0.9 MPa being apparent. Most of the electrical properties remained the same or were decreased by heat treatment, however the dielectric strength of the SiO2 composites improved by an average of 12 % resulting in a maximum dielectric strength of 517 ± 24 Vμm 1 due to a reduction in the defect density in the films. Conversely the electrical properties of Ta2O5 composites suffered greatly following heat treatment with a maximum dielectric strength of 358 ± 31 Vμm 1. This was theorised to result from Cu migration from the substrate and the potential for Ta2O5 to crystallise at temperatures close to 500 °C. Coating of Cu wires with PDC alumina was shown to be possible, with coatings of various interlayer and coating thickness. Characterisation showed that the wire coating rig enabled the whole circumference of the wire to be coated with alumina. Tensile testing resulted in transvers cracking followed by longitudinal cracking above an applied strain of 1.5 and 4.0 % respectively. Following heat treatment the copper substrate softened and resulted in delamination failures in the coatings during tensile testing. Electrical testing of the wires was inconsistent due micro cracking in the wire coatings. It has been shown that the use of mixed material composites sputtered by PDC and RF sputtering have potential as high dielectric strength insulating materials, improving upon the base Al2O3 believed to be a result of passivation of structural and compositional defects. Additionally, it has been shown that physical vapour deposition in conjunction with a modified sample holder can be utilised for coating of bare copper wire with the potential to act as isolative coatings

Optimization of MVAC systems for energy management by evolutionary algorithm

Energy management in existing building services installations is an essential focus of contemporary facilities management. The subway company that is one of the major utilities services in Hong Kong Special Administrative Region (HKSAR) has considered better energy management schemes in its subway stations to reduce the running cost. In the past few years, in order to achieve energy saving in the stations, some feasible measures in the Mechanical Ventilation and Air Conditioning (MVAC) systems were implemented, however the engineering decisions were supported by the trial-and-error or imprecise estimation. Improvement to this process would be possible if numerical optimization methods were to be used. Evolutionary algorithm coupled with external plant simulation programme was applied to determine the optimum conditions of the essential parameters of the MVAC systems, in order to provide a holistic energy management approach. For the centralized MVAC systems of the 5 subway stations under studies, the developed optimization and simulation model was found useful to appraise the energy management opportunities for effective design and facilities management

Development and characterisation of a 3D multi-cellular in vitro model of normal human breast: a tool for cancer initiation studies.

Multicellular 3-dimensional (3D) in vitro models of normal human breast tissue to study cancer initiation are required. We present a model incorporating three of the major functional cell types of breast, detail the phenotype and document our breast cancer initiation studies. Myoepithelial cells and fibroblasts were isolated and immortalised from breast reduction mammoplasty samples. Tri-cultures containing non-tumorigenic luminal epithelial cells HB2, or HB2 overexpressing different HER proteins, together with myoepithelial cells and fibroblasts were established in collagen I. Phenotype was assessed morphologically and immunohistochemically and compared to normal breast tissue. When all three cell types were present, polarised epithelial structures with lumens and basement membrane production were observed, akin to normal human breast tissue. Overexpression of HER2 or HER2/3 caused a significant increase in size, while HER2 overexpression resulted in development of a DCIS-like phenotype. In summary, we have developed a 3D tri-cellular model of normal human breast, amenable to comparative analysis after genetic manipulation and with potential to dissect the mechanisms behind the early stages of breast cancer initiation