Calculating the Solar Heat Gain of Window Frames

© 1999 ASHRAE (www.ashrae.org). Published in ASHRAE Transactions, Volume 105, Part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permissioIt is not practical to measure the solar heat gain of a window frame. It is more practical to do so by calculation. Typically, the frame solar heat gain is a small component of the total or is small in absolute terms so an approximate method is satisfactory. A simple approach for calculating the solar heat gain coefficient of any opaque window component is developed. The parameters appearing in the expression clearly identify the mechanisms of frame solar gain and indicate the ways in which it can be controlled. A particularly simple expression can be applied to any frame geometry for cases in which the solar radiation is incident normal to the window. This is especially useful because this condition is frequently used for energy rating purposes, code compliance, and design. It is shown that this expression is also valid for off-normal incidence as long as no part of the frame is shaded. An adjustment, based only on frame surface geometry, can be applied if the frame is partially shaded. Sample calculations closely reproduce the results of detailed two-dimensional numerical simulation.Natural Sciences and Engineering Research Council of Canada || Natural Resources Canad

A Comparison of Calculated and Measured Indoor-Side Window Temperature Profiles

© 2003. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions, Vol. 109, Part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission.Computer-generated surface temperature profiles are presented for the indoor side, vertical centerline of two windows and a calibration transfer standard (CTS). These specific configurations were chosen because they match test specimens used in a previous test program, and the resulting temperature profiles, measured using a thermographic camera, are available in the literature. Calculations were completed using the VISION4 program for one-dimensional center-glass analysis and the FRAME 4.0 program for two-dimensional analysis of the edge-glass and frame. Three different computational models were used: (1) the conventional procedure used widely to generate total-window solar gain and heat loss coefficients, (2) a procedure to account for fill-gas motion was added, and (3) the convective heat transfer coefficients were reduced near the recessed corners of the indoor surface. Profiles were scrutinized most closely at the bottom edge-glass section-where condensation most readily occurs. Simulation provides useful qualitative information, and each of the two features added to the model provides better agreement with measurement. It is concluded that simple, inexpensive, and easy-to-use computer software can offer reliable design guidance and performance verification regarding condensation resistance.Natural Sciences and Engineering Research Council of Canad

Computer Simulation of Window Condensation Potential

© 1998 ASHRAE (www.ashrae.org). Published in Thermal Performance of the Exterior Envelopes of Buildings VII . For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.Condensation on windows creates obscured view, can cause building damage, and may lead to mold growth and poor indoor air quality. The Canadian Standards Association (CSA) has developed new procedures to evaluate window condensation potential, using a combination of computer simulation and testing. This paper summarizes results of a study into various aspects of computer simulation related to the evaluation of condensation potential. These findings were used to assist in the development of the CSA procedures

Mouse nuclear myosin I knock-out shows interchangeability and redundancy of myosin isoforms in the cell nucleus.

Nuclear myosin I (NM1) is a nuclear isoform of the well-known "cytoplasmic" Myosin 1c protein (Myo1c). Located on the 11(th) chromosome in mice, NM1 results from an alternative start of transcription of the Myo1c gene adding an extra 16 amino acids at the N-terminus. Previous studies revealed its roles in RNA Polymerase I and RNA Polymerase II transcription, chromatin remodeling, and chromosomal movements. Its nuclear localization signal is localized in the middle of the molecule and therefore directs both Myosin 1c isoforms to the nucleus. In order to trace specific functions of the NM1 isoform, we generated mice lacking the NM1 start codon without affecting the cytoplasmic Myo1c protein. Mutant mice were analyzed in a comprehensive phenotypic screen in cooperation with the German Mouse Clinic. Strikingly, no obvious phenotype related to previously described functions has been observed. However, we found minor changes in bone mineral density and the number and size of red blood cells in knock-out mice, which are most probably not related to previously described functions of NM1 in the nucleus. In Myo1c/NM1 depleted U2OS cells, the level of Pol I transcription was restored by overexpression of shRNA-resistant mouse Myo1c. Moreover, we found Myo1c interacting with Pol II. The ratio between Myo1c and NM1 proteins were similar in the nucleus and deletion of NM1 did not cause any compensatory overexpression of Myo1c protein. We observed that Myo1c can replace NM1 in its nuclear functions. Amount of both proteins is nearly equal and NM1 knock-out does not cause any compensatory overexpression of Myo1c. We therefore suggest that both isoforms can substitute each other in nuclear processes

HIV Infection and Gut Mucosal Immune Function: Updates on Pathogenesis with Implications for Management and Intervention

HIV is primarily a sexually transmitted infection. However, given that the gastrointestinal tract (GIT) houses most of the body’s lymphocytes, including activated memory CD4+ T cells that are preferential targets for HIV, recent research has focused on the role of the GIT in transmission and pathogenesis. In health, the GIT maintains a balance between immune tolerance and rapid responsiveness. A complex network of innate and adaptive responses maintains this balance, which is severely perturbed in HIV infection. Recent studies have focused on mechanisms of GIT CD4+ T-cell depletion and epithelial disruption in HIV infection, the role of inflammation in accelerating viral dissemination, the kinetics of the adaptive response following transmission, and the extent of T-cell reconstitution following antiretroviral therapy. This review summarizes the results of recent investigations that may have important implications for the development of vaccines, microbicides, and therapeutic interventions for HIV and other mucosal pathogens

A novel emergency department based prevention intervention program for people living with HIV: evaluation of early experiences

<p>Abstract</p> <p>Background</p> <p>HIV prevention is increasingly focused on people living with HIV (PLWH) and the role of healthcare settings in prevention. Emergency Departments (EDs) frequently care for PLWH, but do not typically endorse a prevention mission. We conducted a pilot exploratory evaluation of the first reported ED program to address the prevention needs of PLWH.</p> <p>Methods</p> <p>This retrospective observational cohort evaluation reviewed program records to describe the first six months of participants and programmatic operation. Trained counselors provided a risk assessment and counseling intervention combined with three linkage interventions: i) linkage to health care, ii) linkage to case management, and iii) linkage to partner counseling and referral.</p> <p>Results</p> <p>Of 81 self-identified PLWH who were approached, 55 initially agreed to participate. Of those completing risk assessment, 17/53 (32%, 95 CI 20% to 46%) reported unprotected anal/vaginal intercourse or needle sharing in the past six months with a partner presumed to be HIV negative. Counseling was provided to 52/53 (98%). For those requesting services, 11/15 (73%) were linked to healthcare, 4/23 (17%) were coordinated with case management, and 1/4 (25%) completed partner counseling and referral.</p> <p>Conclusion</p> <p>Given base resources of trained counselors, it was feasible to implement a program to address the prevention needs for persons living with HIV in an urban ED. ED patients with HIV often have unmet needs which might be addressed by improved linkage with existing community resources. Healthcare and prevention barriers for PLWH may be attenuated if EDs were to incorporate CDC recommended prevention measures for healthcare providers.</p

Studying neuroanatomy using MRI

The study of neuroanatomy using imaging enables key insights into how our brains function, are shaped by genes and environment, and change with development, aging, and disease. Developments in MRI acquisition, image processing, and data modelling have been key to these advances. However, MRI provides an indirect measurement of the biological signals we aim to investigate. Thus, artifacts and key questions of correct interpretation can confound the readouts provided by anatomical MRI. In this review we provide an overview of the methods for measuring macro- and mesoscopic structure and inferring microstructural properties; we also describe key artefacts and confounds that can lead to incorrect conclusions. Ultimately, we believe that, though methods need to improve and caution is required in its interpretation, structural MRI continues to have great promise in furthering our understanding of how the brain works