An Investigation Into Thermal Comfort In Residential Buildings In The Hot Humid Climate Of Sub-Saharan Africa: A Field Study In Abuja-Nigeria

A field study was conducted to understand the real and preferred conditions of thermal comfort in low-income residential buildings in Abuja, Nigeria. Knowing the temperatures people are experiencing in their houses and the limits which residents can tolerate is a first step to proffer passive solutions to reduce discomfort. During the study, 40 people responded to a post occupancy questionnaire and two households were issued a comfort survey questionnaire. Physical measurements were taken simultaneously during the comfort survey in both an air-conditioned and naturally ventilated residential building. The ASHRAE and air flow sensation scale were chosen as voting scales. The results from this study show that during the monitoring period the average and maximum temperatures in an air conditioned residential building were 31°C and 34°C; and 33°C and 36°C for natural ventilated buildings in Abuja. This compares with the external average and maximum air temperatures of 31°C and 39°C

Thermal comfort of occupants during the dry and rainy seasons in Abuja, Nigeria

The paper presents the results of a recent study on the thermal comfort of occupants in four low-income residential buildings, at two different locations, within the hot-humid climate of Abuja. A comfort survey questionnaire was administered to occupants of four casestudies to assess their perception of their thermal environment. Simultaneously, the indoor temperatures and relative humidity of the living room and bedroom spaces were monitored as well as outdoor parameters to evaluate the actual building performance. To support the comfort survey, a post-occupancy survey was carried out to evaluate an additional 86 buildings nearby in the case studies areas. The paper focuses on analysing the thermal conditions of respondents of the post-occupancy survey, the comfort survey and indoor monitoring findings from the case studies. The maximum daytime average temperature of the naturally ventilated buildings was only 2.0°C more than in the air-conditioned buildings. The maximum indoor air temperature in the living spaces during the dry season was 36.8°C(and 26.4% RH) and the minimum 28.4°C (and 66.6% RH),while during the rainy season these were respectively 35.9°C(and 43.7% RH) and the minimum 24.3°C (and 75.5% RH). The results suggest that there was significant thermal discomfort in the low income residential buildings

Factors influencing transfusion-associated HLA sensitization in patients bridged to heart transplantation using ventricular assist device.

BackgroundBridging heart failure patients with mechanical ventricular assist devices (VAD) enables access to transplantation. However, VAD is associated with increased risk for anti-HLA antibodies associated with rejection of subsequent allografts. Factors determining alloantibody formation in these patients remain undefined.MethodsWe performed a single-center retrospective cohort study of 164 patients undergoing heart transplantation from 2014 to 2017. Medical records including use of VAD, transfused blood products, anti-HLA antibody testing, crossmatch, and time to transplant were evaluated.ResultsPatients received an average of 13.8 red blood cell and 1.9 single-donor platelet units associated with VAD. There was a 28.7% increase in the incidence of anti-HLA antibodies after VAD. Development of anti-HLA antibodies did not correlate with volume or type of blood products, but with pre-VAD HLA sensitization status; relative risk of new alloantibodies in patients with pre-VAD antibodies was 3.5-fold higher than those without prior antibodies (P = .008). Development of new anti-HLA antibodies was associated with an increased time to transplant (169 vs 330 days, P = .013).ConclusionsOur findings indicate that the presence of anti-HLA antibodies pre-VAD was the most significant risk factor for developing additional antibodies post-VAD, suggesting that a subset of patients may be predisposed to alloantibody formation

Architecture Is Concealed unto Itself: Helmuth Plessner and his Influence on Twentieth-Century Architecture

The Human in Architecture and Philosophy: Towards an Architectural Anthropology ‘Architecture is concealed to itself: Helmuth Plessner and his influence on twentieth-century architects’ ‘[…] man never returns. We have to renounce the romanticism of alienation and homecoming inherent in Marxism and admit to ourselves its illusionary character.’ Helmuth Plessner, 1969 Architectural anthropology is currently experiencing great traction, as a reaction to the perceived aridity and exclusivity of much contemporary philosophy and evincing a renewed interest in empirical methods of seeing the world and enacting changes in it. This is hardly surprising: most architects will act pragmatically, adjusting existing models of buildings and terrains in their attempt at balancing competing demands of site, client needs and organisational logistics. In recent years many have been under the impression that this was insufficient and intellectually weak: many architects sought solace in philosophy, and the thinking of choice was the Continental variety, especially that brand that was highly suggestive of architectural form-making. The fact that deconstruction held sway for so long, or that Gilles Deleuze’s rhizomes reminiscent of networks of circulation, structure and other architectural connective tissue should have largely replaced it as lodestar for the avant-garde, is testimony to this. More recently, and productively, architects have found increased confidence in their innate nous, and have felt greater affinity with the quantifiable premises of the social sciences than with the airier descendants of Idealist philosophy. This paper examines the work of the German philosopher-anthropologist Hermann Plessner (1892-1985), one of the earliest modern thinkers in this tradition, beginning with his notion of ‘positionality’. His long career enables us to view his enduring relationship to a variety of architects. His view of humans as life-forms has obvious connections to today’s environmentalism, and is one that transcends any crude ideological, alienated reading of man. Plessner’s work has serious implications for an anthropological locus of architectural practice (one thinks of the work of Bruno Latour and Albena Yaneva); the political implications of his notion of humans as ‘ex-centric’ beings capable of self-reflection extend far beyond the world of building design. Finally the self-concealed nature of architecture, a play on the title of one of Plessner’s late texts, leads to a consideration of the enigmatic qualities of great buildings, to the ‘black box’ of both Reyner Banham and Latourian social scientists today

Two-Loop Euler-Heisenberg QED Pair-Production Rate

We study the divergence of large-order perturbation theory in the worldline expression for the two-loop Euler-Heisenberg QED effective Lagrangian in a constant magnetic field. The leading rate of divergence is identical, up to an overall factor, to that of the one-loop case. From this we deduce, using Borel summation techniques, that the leading behaviour of the imaginary part of the two-loop effective Lagrangian for a constant E field, giving the pair-production rate, is proportional to the one-loop result. This also serves as a test of the mass renormalization, and confirms the earlier analysis by Ritus.Comment: 12 pages, 5 figure