Urban Form, Density and Solar Potential

Rapid urbanization in recent years has exerted tremendous pressure on urban development. In the face of the largely unexamined fashion for densification, it is vital that the environmental impact of compaction be researched. This study comprises solar simulation of eighteen generic models; each represents a particular combination of built form and density. This paper examines the relationships between built forms, density and solar potential, with reference to three design criteria i.e. openness at ground level, daylight factor on building façade and PV potential on building envelope. The result shows the different effects of horizontal and vertical randomness on urban solar potential and it also reveals the interrelation between randomness, plot ratio and site coverage, which can provide helpful insights for planning solar cities

La Ville Radieuse by Le Corbusier, once again a case study

ABSTRACT: La Ville Radieuse, ‘The Contemporary City for Three Million Inhabitants’ proposed by Le Corbusier for central Paris is a myth in the history of contemporary town planning. The proposal, according to Le Corbusier, could increase the urban capacity and at the same time improve the urban environment and the efficiency of the city. The thoughts and design principles embedded in the proposal of La Ville Radieuse quickly became models for architects of the post-war period. Le Corbusier was ambitious for the proposal and he even suggested demolishing the whole part of central Paris in order to adopt it; this of course raised strong objections. Though the proposal has never been realized, it has attracted a lot of discussion. This study employs computer simulation to evaluate the daylight and solar performance of La Ville Radieuse; it attempts to test the propositions of Le Corbusier, with reference to daylight design and to draw conclusions about the design of high density solar cities

Compact cities in a sustainable manner

Densification is generally assumed to exert negative impacts on urban daylight and solar potential, however, this paper demonstrates the possibilities to increase usable floor area and plot ratio without undermining the opportunities of daylight and solar applications. The paper investigates the diverse influences of built density on daylight access and the potential of two solar systems. The findings suggest that plot ratio is influential to quantities such as daylight factor, sky view factor and the potential of solar thermal and photovoltaic applications on roof, whilst the potential of solar thermal and photovoltaic applications on building facades are more dependent on site coverage and the extent of horizontal obstruction

IRMPD spectroscopy sheds new (InfraRed) light on the sulfate pattern of carbohydrates

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A method of strategic evaluation of energy performance of Building Integrated Photovoltaic in the urban context

This paper presents an integrated bottom-up approach aimed at helping those dealing with strategical analysis of installation of Building Integrated Photo Voltaic (BIPV) to estimate the electricity production potential along with the energy needs of urban buildings at the district scale. On the demand side, hourly energy profiles are generated using dynamic building simulation taking into account actual urban morphologies. On the supply side, electricity generated from the system is predicted considering both the direct and indirect components of solar radiation as well as local climate variables. Python-based Algorithm editor Grasshopper is used to interlink four types of modelling and simulation tools as 1) generation of 3-D model, 2) solar radiation analysis, 3) formatting weather files (TMY data set) and 4) dynamic energy demand. The method has been demonstrated for a cluster of 20 buildings located in the Yasar University in Izmir (Turkey), for which it is found the BIPV system could achieve an annual renewable share of 23%, in line with the Renewable Energy Directive target of 20%. Quantitatively-compared demand and supply information at hourly time step shows that only some energy needs can be met by BIPV, so there is a need for an appropriate matching strategy to better exploit the renewable energy potential

Utilization of mechanical power and associations with clinical outcomes in brain injured patients. a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

BackgroundThere is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes.MethodsIn this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale <= 12 before intubation) who required mechanical ventilation (MV) >= 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS).ResultsWe included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22).ConclusionsExposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation

Vascular clamping in liver surgery: physiology, indications and techniques

This article reviews the historical evolution of hepatic vascular clamping and their indications. The anatomic basis for partial and complete vascular clamping will be discussed, as will the rationales of continuous and intermittent vascular clamping