An alternative approach to evaluate the average Nusselt number for mixed boundary layer conditions in parallel flow over an isothermal flat plate

In this paper, we present an alternative approach to evaluate the average Nusselt number for mixed boundary layer conditions in parallel flow over an isothermal flat plate. This approach can be used regardless of the critical Reynolds number where the flow transitions from laminar flow to turbulent flow. This approach is simple and uses graphical visualisation of the physical situation. This should assist comprehension and retention. It utilises the average quantity for the laminar boundary layer and the average value for turbulent boundary layer to obtain the average quantities for mixed boundary layers without the need to perform the usual integration. It can easily be incorporated into part of undergraduate chemical, mechanical and petroleum engineering curricula. A worked example is included to show the utility of the approach

Assessment of DNA separation and recovery using DNA profiles from a temperature controlled differential extraction

In 2010, Bright et al. created two person mixtures to determine how effective traditional differential extraction was in determining mixtures by examining mixture proportion variation by using the peak heights from each sample. This project aims to follow that method, however, in this case using a Temperature Controlled Differential Extraction (TCDE) to analyze post coital swabs in place of a traditional differential extraction. The project also aims to determine how efficient the separation of sperm cells from epithelial cells was by comparing the mixture proportion mean of male deoxyribonucleic acid (DNA) from an Acrosolv digest that did not undergo the TCDE to the proportion of male DNA from the TCDE. The amount of DNA remaining on a swab after undergoing the TCDE was also assessed as a material fraction. Many of the material fractions generated a mixture in their profiles and thus enough DNA to generate a male profile was remaining on the swab after the TCDE in almost all cases. The sperm fractions were mostly single source male profiles or profiles with the male DNA as a major contributor and the female DNA as a minor contributor

‘The only learning I’m going to get’: Students with intellectual disabilities learning a second language through performative pedagogy

Traditionally, adults with intellectual disabilities have not been given the option of participating in and thus benefiting from higher and post-secondary education. However, over the last number of years, an increasing number of inclusive tertiary educational programmes have come into existence. This article focuses on one such programme entitled Arts, Science and Inclusive Applied Practice delivered in the Trinity Centre for People with Intellectual Disabilities, School of Education, Trinity College Dublin, Ireland. The aim of this study was to consider the role of embodiment in supporting the Second Language Acquisition (SLA) process of a group of students with intellectual disabilities. The paper describes a project which integrated two of the programme modules – Italian for Beginners and Exploring Art: Renaissance to Modern. Findings presented support the use of a performative approach to second language learning for students with intellectual disabilities and sheds light on the connection between embodiment, language and learning in a performative key

Silicon Micromachined Microlens Array for THz Antennas

5 5 silicon microlens array was developed using a silicon micromachining technique for a silicon-based THz antenna array. The feature of the silicon micromachining technique enables one to microfabricate an unlimited number of microlens arrays at one time with good uniformity on a silicon wafer. This technique will resolve one of the key issues in building a THz camera, which is to integrate antennas in a detector array. The conventional approach of building single-pixel receivers and stacking them to form a multi-pixel receiver is not suited at THz because a single-pixel receiver already has difficulty fitting into mass, volume, and power budgets, especially in space applications. In this proposed technique, one has controllability on both diameter and curvature of a silicon microlens. First of all, the diameter of microlens depends on how thick photoresist one could coat and pattern. So far, the diameter of a 6- mm photoresist microlens with 400 m in height has been successfully microfabricated. Based on current researchers experiences, a diameter larger than 1-cm photoresist microlens array would be feasible. In order to control the curvature of the microlens, the following process variables could be used: 1. Amount of photoresist: It determines the curvature of the photoresist microlens. Since the photoresist lens is transferred onto the silicon substrate, it will directly control the curvature of the silicon microlens. 2. Etching selectivity between photoresist and silicon: The photoresist microlens is formed by thermal reflow. In order to transfer the exact photoresist curvature onto silicon, there needs to be etching selectivity of 1:1 between silicon and photoresist. However, by varying the etching selectivity, one could control the curvature of the silicon microlens. The figure shows the microfabricated silicon microlens 5 x5 array. The diameter of the microlens located in the center is about 2.5 mm. The measured 3-D profile of the microlens surface has a smooth curvature. The measured height of the silicon microlens is about 280 microns. In this case, the original height of the photoresist was 210 microns. The change was due to the etching selectivity of 1.33 between photoresist and silicon. The measured surface roughness of the silicon microlens shows the peak-to-peak surface roughness of less than 0.5 microns, which is adequate in THz frequency. For example, the surface roughness should be less than 7 microns at 600 GHz range. The SEM (scanning electron microscope) image of the microlens confirms the smooth surface. The beam pattern at 550 GHz shows good directivity

340 Ghz Multipixel Transceiver

A multi-pixel terahertz transceiver is constructed using a stack of semiconductor layers that communicate using vias defined within the semiconductor layers. By using a stack of semiconductor layers, the various electrical functions of each layer can be tested easily without having to assemble the entire transceiver. In addition, the design allows the production of a transceiver having pixels set 10 mm apart

Wafer-To-Wafer Alignment Method

A silicon alignment pin is used to align successive layer of component made in semiconductor chips and/or metallic components to make easier the assembly of devices having a layered structure. The pin is made as a compressible structure which can be squeezed to reduce its outer diameter, have one end fit into a corresponding alignment pocket or cavity defined in a layer of material to be assembled into a layered structure, and then allowed to expand to produce an interference fit with the cavity. The other end can then be inserted into a corresponding cavity defined in a surface of a second layer of material that mates with the first layer. The two layers are in registry when the pin is mated to both. Multiple layers can be assembled to create a multilayer structure. Examples of such devices are presented

The Very Short Period M Dwarf Binary SDSS J001641-000925

We present follow-up observations and analysis of the recently discovered short period low-mass eclipsing binary, SDSS J001641-000925. With an orbital period of 0.19856 days, this system has one of the shortest known periods for an M dwarf binary system. Medium-resolution spectroscopy and multi-band photometry for the system are presented. Markov chain Monte Carlo modeling of the light curves and radial velocities yields estimated masses for the stars of M1 = 0.54 +/- 0.07 Msun and M2 = 0.34 +/- 0.04 Msun, and radii of R1 = 0.68 +/- 0.03 Rsun and R2 = 0.58 +/- 0.03 Rsun respectively. This solution places both components above the critical Roche overfill limit, providing strong evidence that SDSS J001641-000925 is the first verified M-dwarf contact binary system. Within the follow-up spectroscopy we find signatures of non-solid body rotation velocities, which we interpret as evidence for mass transfer or loss within the system. In addition, our photometry samples the system over 9 years, and we find strong evidence for period decay at the rate of dP/dt ~8 s/yr. Both of these signatures raise the intriguing possibility that the system is in over-contact, and actively losing angular momentum, likely through mass loss. This places SDSS J001641-000925 as not just the first M-dwarf over-contact binary, but one of the few systems of any spectral type known to be actively undergoing coalescence. Further study SDSS J001641-000925 is on-going to verify the nature of the system, which may prove to be a unique astrophysical laboratory.Comment: 11 figures, ApJ Accepte

The uses of peer learning with older adults in formal, non-formal and informal learning activities

The uses of peer learning with older adults in formal, non-formal and informal learning activities. PROSPERO 2022 CRD42022307145 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD4202230714

Three Strategies for Changing Attributions about Severe Mental Illness

The effects of three strategies for changing stigmatizing attitudes—education (which replaces myths about mental illness with accurate conceptions), contact (which challenges public attitudes about mental illness through direct interactions with persons who have these disorders), and protest (which seeks to suppress stigmatizing attitudes about mental illness)—were examined on attributions about schizophrenia and other severe mental illnesses. One hundred and fifty-two students at a community college were randomly assigned to one of the three strategies or a control condition. They completed a questionnaire about attributions toward six groups—depression, psychosis, cocaine addiction, mental retardation, cancer, and AIDS—prior to and after completing the assigned condition. As expected, results showed that education had no effect on attributions about physical disabilities but led to improved attributions in all four psychiatric groups. Contact produced positive changes that exceeded education effects in attributions about targeted psychiatric disabilities: depression and psychosis. Protest yielded no significant changes in attributions about any group. This study also examined the effects of these strategies on processing information about mental illness