Architecture of the city reinterpreted: a critical review

When Aldo Rossi first published his monograph L'architettura della città in 1966, he probably did not imagine that in 1982 it would not only have been republished three times in Italian, but also translated and published in Spanish (in 1971, with four subsequent republications), German (in 1973), Portugese (in 1977), French (in 1981) and in English.The Graham Foundation for Advanced Studies in the Fine Arts (Chicago) and the Institute for Architecture and Urban Studies (New York) were jointly responsible for the English edition of Rossi's monograph, published by Massachusetts Institute of Technology Press in 1982¹. While the prolific translation and publication of any book is no guarantee of its academic worth, nor its internal coherence, it is rare for a contemporary architectural monograph to generate such wide appeal. Therefore it is interesting and perhaps instructive to analyse Rossi's contribution to current architectural theory, to highlight the merits and shortcomings of his monograph, and to relate his approach to other contemporary contributions, particularly those which explore the mediations between the spatial and the behavioural features of the built environment. This is the purpose of this review paper.     

On the detection and selective separation of inclusions in liquid metal cleanliness analyzer (LiMCA) systems

A new design of electric sensing zone (ESZ) probe for the liquid metal cleanliness analyzer (LiMCA) system is proposed, which comprises a contoured orifice and a co-axially built cylindrical extension. This extension is used to collect larger particles whose sizes are larger than the diameter of sensing zone orifice, resolving the orifice blocking problem. A generalized mathematical model was developed for the motion of particles entrained in liquid metals flowing into this newly designed probe. The results showed that the separation of larger from smaller particles is affected by the applied electric current, orifice size, orifice length, orifice shape, extension length, and radius, as well as mean fluid velocity through the orifice. Increasing the electric current, or decreasing the orifice size, is predicted to lower the pass-through fraction of particles of all sizes, but the effects are much greater for larger particles. A longer orifice length gives rise to a lower pass-through fraction, the effect diminishing as the ESZ length increases up to 0.5 mm. The shape of the orifice has little effect on the pass-through fraction of the particles, but it is critical that the entrance to the orifice be smooth in order to prevent the generation of recirculation zone inside the orifice. Increasing the radius of the extension piece increases pass-through fraction of small particles, but decreases that of larger ones. Moreover, the fractional pass-through of inclusions also increases with the decrease of extension length and increase in mean fluid velocity through the orifice. The separation of particles of different density with this newly designed probe can only be achieved when the difference in density is dramatic. Design of probes for magnesium and steel LiMCA is proposed for detecting particles below the detection limit of conventional probes.     

Choosing a multivariate model: Noncentrality and goodness of fit.

Anumber of goodness-of-fit indices for the evaluation of multivariate structural models are expressed as functions of the noncentrality parameter in order to elucidate their mathematical properties and, in particular, to explain previous numerical findings. Most of the indices considered are shown to vary systematically with sample size. It is suggested that H. Akaike's (1974; see record 1989-17660-001) information criterion cannot be used for model selection in real applications and that there are problems attending the definition of parsimonious fit indices. A normed function of the noncentrality parameter is recommended as an unbiased absolute goodness-of-fit index, and the Tucker–Lewis (see record 1973-30255-001) index and a new unbiased counterpart of the Bentler–Bonett (see record 1981-06898-001) index are recommended for those investigators who might wish to evaluate fit relative to a null model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spirometry as a motivational tool to improve smoking cessation rates: a systematic review of the literature.

Obtaining spirometric testing and providing those results to individuals who smoke has been advocated as a motivational tool to improve smoking cessation. However, its effectiveness is not known. We conducted a systematic review to determine if this approach improves rates of smoking cessation. Data sources included MEDLINE (1966 to October 2005), the Cochrane Library, and experts in the field. Eligible randomized controlled trials (RCTs) enrolled at least 25 smokers per arm, evaluated spirometry with associated counseling or in combination with other treatments, followed subjects at least 6 months, and provided smoking abstinence rates. Results from nonrandomized studies also were summarized. The primary outcome was patient-reported long-term (at least 6 months) sustained abstinence with biological validation. Additional outcomes included self-reported abstinence and point-prevalence abstinence. Seven RCTs (N = 6,052 subjects) met eligibility criteria. Follow-up duration ranged from 9 to 36 months. In six trials, the intervention group received concomitant treatments previously demonstrated to increase cessation independently. The range of abstinence was 3%-14% for control subjects and 7%-39% among intervention groups, statistically significantly in favor of intervention in four studies. The only RCT that assessed the independent contribution of spirometry in combination with counseling demonstrated a nonsignificant 1% improvement in patient-reported point-prevalence abstinence at 12 months in the group that received spirometry plus counseling versus counseling alone (6.5% versus 5.5%). Findings from observational studies were mixed, and the lack of controls makes interpretation problematic. Available evidence is insufficient to determine whether obtaining spirometric values and providing that information to patients improves smoking cessation compared with other smoking cessation methods. Spirometric values are of limited benefit as a predictor of smoking cessation or as a tool to "customize" smoking cessation strategies.     

Similarity considerations in the physical modelling of steel making tundish systems

To assess and quantify the relative importance of Reynolds and Froude numbers in reduced scale model studies (these cannot be simultaneously respected when the scale factor is less than unity), aqueous model investigations were carried out on three different laboratory scale tundish models. The experimental tundish systems included two strand, five strand skewed delta shaped and six strand rectangular shaped vessels. Experimental observations show that the depth of liquid in the model would only correspond to that in the full scale system, provided the model flow rate is scaled in accordance with the relationship: Q_m = λ^5/2 Q_f.S, in which, A is the geometrical scaling factor. Furthermore, on the basis of residence time distribution measurements in two different configurations of the five strand tundish, it was demonstrated explicitly that flow phenomena in tundish systems are largely dominated by inertial forces and are therefore, essentially Froude dominated.     

Wind energy for the 1990s and beyond

Electrical power must be available to the consumer in any amount upon demand. Conventional methods of power generation, such as the burning of fossil fuels, hydroelectric plants, and nuclear power plants, have considerable shortcomings. Governmental regulations have increased in quantity and have raised the already rigid standards of producing electric power without further damage to the environment. Electrical power produced by wind energy conversion systems are undergoing extensive research and revitalization as a viable solution to clean air power generation. The basic challenge to scientists and engineers is to develop wind energy conversion systems that produce adequate amounts of power, but at a cost comparable to present conventional methods. This article discusses the background and impact of the modern wind energy conversion system on future power generation.     

An epidemiological needs assessment of carotid endarterectomy in an English health region. Is the need being met?

OBJECTIVE: To compare the level of provision of carotid endarterectomy (an intervention of proved efficacy for prevention of stroke in patients with symptomatic high grade carotid artery stenosis) with estimates of need. DESIGN: Comparison of regional, district, and age-sex specific operation rates derived from hospital episode statistics with estimates of need based on demographic and epidemiological data; interviews with regional vascular surgeons and a joint provider-purchaser workshop to discuss implications. SETTING: Former Wessex Regional Health Authority, 1991-2 to 1995-6. SUBJECTS: All residents covered by Wessex region treated for carotid artery reconstruction. MAIN OUTCOME MEASURES: Regional, district, and age-sex operation rates as three year average 1993-6 (use) compared with respective estimates of need for carotid endarterectomy among those who presented with symptomatic carotid disease-transient ischaemic attack or minor stroke. RESULTS: The operation rate more than doubled between 1991-2 and 1995-6, from 35 to 89 per million population, compared with an estimated level of need in the region's general population of 153 per million population (transient ischaemic attack 77, minor stroke 76). The ratio of use to need was 0.47 (95% confidence interval 0.4 to 0.54); district ratios were 0.28 (0.19-0.38) to 0.81 (0.62 to 1.06). The annual use:need ratio rose over the three years 1993-6 from 0.38 to 0.59. Use:need ratios were lower in elderly and female patients. Providers were keen to develop guidelines for referral and to increase access to diagnostic facilities; purchasers were more reluctant, given the limited impact of this intervention on the incidence of stroke and the relatively high cost of the operation. CONCLUSION: Although treatment rates increased in Wessex there is still unmet need. Further research is needed to determine the referral pathways of patients with symptomatic carotid disease for diagnosis and operation and to evaluate strategies to improve access to diagnostic facilities.     

Invasion genetics of the Mediterranean fruit fly: variation in multiple nuclear introns

Biological invasions generally start from low initial population sizes, leading to reduced genetic variation in nuclear and especially mitochondrial DNA. Consequently, genetic approaches for the study of invasion history and population structure are difficult. An extreme example is the Mediterranean fruit fly, Ceratitis capitata (Medfly), for which successive invasions during this century have resulted in a loss of 60% of ancestral genetic variation in isozymes and 75% of variation in mitochondrial DNA. Using Medflies as an example, we present a new approach to invasion genetics that measures DNA sequence variation within introns from multiple nuclear loci. These loci are so variable that even relatively recently founded Medfly populations within California and Hawaii retain ample genetic diversity. Invading populations have only lost 35% of the ancestral genetic variation. Intron variation will allow high-resolution genetic characterization of invading populations in both natural and managed systems, although non-equilibrium methods of analysis may be necessary if the genetic diversity represents sorting ancestral polymorphism.     

The effect of thermal mismatch on Z-pinned laminated composite structures

Z-pinning is a method of improving the through-thickness properties of composite laminates by inserting a solid pin through the laminate prior to curing. The thermal expansion mismatch between the Z-pin and base laminate produces large residual stresses during the cure cycle. Finite element modelling has shown that these stresses are greater than the failure stress of standard resin systems indicating the resin around the Z-pin should fail. This was confirmed through microscopy, which showed cracking around the perimeter of the Z-pin. Changing the material properties and dimension of the model to represent different Z-pinning situations could not significantly reduce the residual stresses, indicating cracking should occur in all Z-pinned laminates. These results show that probably all published Z-pinning properties have been obtained from laminates that would have exhibited cracking, indicating that the improved through-thickness properties are due more to mechanical interlocking than bonding. Questions are raised about the suitability of using Z-pinned laminates in specific applications, and the effects of increased moisture ingress and long term durability.