Netherlands Planning: The Higher Truth

Progressive planners—those who are involved in radical reform—confront dilemmas in their work that do not apply to traditional social reformers. Because they seek to transform society into something other than what it is, progressive planners must evolve new responses to everyday problems. At the same time, they must change commonly held perceptions of how society defines those problems. Finally, they cannot avoid working with traditional political and economic organizations. The ability of progressive planners to perceive and confront those dilemmas can affect the success of their initiatives.     

A Bold Vision and a Brand Identity for the Planning Profession

R. W. Firestone's Cityscape Pink is a bold image capturing the essence of a city. In this Longer View essay, Bruce McClendon argues that the profession of planning needs a similarly bold vision and compelling brand identity in order to claim its proper place among many competitors offering similar services. He aims to distinguish the planning profession in the eyes of the public and the minds of planners themselves. Three commenters respond with different perspectives on the status of the profession and how best to improve it.

Firestone is a psychotherapist with a PhD in clinical psychology from the University of Denver and the author of nine books. He grew up in the New York City area and opened his private practice in Los Angeles, treating patients suffering from schizophrenia. With a group of friends he has sailed to many parts of the world, and both his practice and his travels figure into the subjects of his artwork.

Planning has become a generic product in a confusing, overcrowded, and highly competitive marketplace. The public does not know what planning is or how to differentiate among planning specialists. Relying on a bold back-to-the-future approach, I argue that it is the production, administration, and implementation of comprehensive plans that once was and still is the profession's unique and distinctive technical competency and core mission. By using branding techniques to define, link, and reconnect planners with comprehensive planning, it will be possible to tell the planning story in a way that communicates the emotional benefits and value of the profession and strengthens the public's respect and appreciation for planners.     

The commercial currency of construction framework agreements

A critique is presented of construction client–main contractor framework agreements. In the midst of an unpredictable and volatile construction environment, the commercial currency of collaborative working practice, and by extension framework agreements, is being put under increasing management scrutiny. Drawing on a literature review, the guiding principles of framework agreements are examined. A dramatic downturn in construction demand has created considerable surplus in supply. Under such conditions the buyer–supplier interdependencies become imbalanced and commercial relationships fraught. Reports by construction industry analysts demonstrate a number of private sector clients rejecting framework agreements in favour of traditional competitive procurement practices. Drawing upon a neoclassical lens, three guiding principles embedded within economic orthodoxy are employed to examine business-to-business tensions within construction framework agreements, namely, individualism, instrumentalism and equilibrium. This neoclassical interpretation of construction framework agreements reveals a potential relational management bias within mainstream rhetoric. Notably, providing a complementary account of framework agreements practice should not be construed as a rejection of collaborative working practices. An alternative account of framework agreements is presented that does not rely upon the mainstream behavioural model of contemporary contracting.     

Interface

The activity of planning is inextricably concerned with the conceptualization of future possibilities. In many respects to plan is to conceive of the future; a future, hopefully, rather better than the present but at least no worse. Such an observation is easy to make but the enormity of the challenge even simply to envisage a collective aspiration of alternative spatial possibilities should not be underestimated, whether as planner, politician or citizen. The process of conceiving the future does not of course take place in a vacuum. We are all part of an intricate web of histories and of memories which inevitably influence the way we see the future. Much has been written in the recent past about the nature of identity, particularly on the importance of developing greater understanding and sensitivity towards the variety of individual lived experiences with respect to city. However, alongside this impressive body of work there has been relatively little comment about how our individual and collective notions of time, history and permanence impact on our assumptions about what makes for good places and good planning. In this issue of Interface therefore we seek to explore to what extent cultural attitudes to time impact on the way we plan. What is taken for granted must necessarily influence what is regarded as possible or desirable. Consequently, our planning solutions would vary markedly if we see our lives as transitory and impermanent rather than as part of an on-going dialogue between centuries of past and future generations. From a British perspective the burden of history, including both ideas and physical forms, often seem to weigh so heavily that there is a tendency to back-off from engaging with the future (and some might argue the present). The elaborate structure of building conservation regulations bears witness to such attitudes. However, while this is perhaps the most obvious manifestation of British ‘conservatism’ it can also be seen in a general assumption as to the longevity of the built environment; permanence is taken for granted and it is presumed that what is built this week will not be knocked down next. It is possible that I am offering up an unfair stereotype of my compatriots but that does not deny the validity of the observation that notions of permanence are likely to influence the nature of the planning activity and in turn the places created. Moreover, this is not just about cultural attitudes that fit neatly within national boundaries for the priorities of individuals and communities confronted by circumstances of impermanence and vulnerability are likely to be very different from those who perceive themselves to be comfortably embedded within the long traditions of their context.     

Flow Visualization in a Pocketed Thrust Washer

The objectives of this study were to experimentally and numerically investigate oil flow in surface-pocketed thrust washers. In order to achieve the experimental aspects of this investigation, a thrust washer test rig was designed and developed to visualize the lubricant flow at the contact interface. A novel approach for creating the pockets was developed to allow optical inspection of the lubricant during thrust washer operation. The thrust washers were fabricated using a glass disk with a thin layer of steel shim stock adhered to the surface. The micrometer-thick shim stock was machined using an Nd:YAG laser to create the circular pocket geometries and then glued to the glass disk. A mirror and camera were placed below the semitransparent washer to observe the lubricant flow in the pocket. The results obtained from this configuration illustrate a cavitation bubble forming on the leading edge of the pocket followed by a sharp transition back to liquid. The size of the cavitation area was found to be a function of rotational speed, nominal bearing pressure (NBP), viscosity, and pocket geometry. The cavitation area ratio (gaseous region divided by the pocket area) increased for greater speeds and higher viscosities and decreased for larger pocket diameters, deeper pockets, and higher NBPs. The friction force for various thrust washer designs was also measured as a function of load, speed, and lubricant. The results showed that shallower, wider pockets provided the lowest friction. It was found that, generally, the conditions that minimize friction also result in a stable cavitation region. ANSYS Fluent computational fluid dynamics software was used to develop a three-dimensional model of the pocketed thrust washer utilizing the full Navier-Stokes equations to investigate the cavitation and pressure distribution occurring at the contact and corroborate the experimental results.     

Time-Correlated Single Photon Counting With Microchannel Plate Detectors

ABSTRACT

We describe the experimental techniques and methods of analysis used in our laboratory in the study of a wide range of chemical and biological systems. In addition to standard single exponential decay time measurements we discuss the resolution of multiexponential decays and the analysis of fluorescence anisotropy experiments.     

Friction and Wear at High Sliding Speeds

Sliding tests have been carried out using a variety of soft metal and nonmetal pins on a rotating steel disk at speeds up to 150 m/s. A new high-speed friction apparatus in which the normal force, the friction force and the friction coefficient are recorded, was used. In general, the wear rate increased drastically, and the friction coefficient decreased moderately as the sliding speed was raised, these changes being especially pronounced when pin materials of low melting temperature were used. The friction data are in good agreement with those obtained by others using the pin-on-disk geometry. However, although in many cases the interface reached the melting temperature of the lower melting sliding material, the very low friction coefficient values of under 0.05 reported by some investigators were not reached.     

Moisture Removal Substantially Improves the Efficiency of in Situ Biodiesel Production from Soybeans

In an effort to reduce the production cost of biodiesel, we previously described an approach termed “in situ transesterification” wherein the transesterification of a vegetable oil occurred directly in its raw agricultural material. In that method, substantial quantities of reagents were required to achieve high-efficiency transesterification. Here we report that by drying the substrate a marked reduction in the reagent requirements was achieved. Reaction conditions for maximum fatty acid methyl ester (FAME) production were identified using statistical experimental design methods. In 16-h reactions with 5 g of flakes (2.6% moisture) and 18 mL of 0.10 N NaOH in methanol, 97% theoretical maximum transesterification was achieved. For dry flakes, optimal transesterification was achieved in 10 h in reactions containing 5 g of flakes and 12 mL of 0.10 N NaOH in methanol. This represented a 60% reduction in methanol and a 56% reduction in NaOH use compared with the transesterification of full-moisture flakes. Under these conditions the degree of transesterification was 100% of the theoretical maximum. The transesterification of 20 kg of flakes with a moisture content of 0.8% was conducted under optimal reaction conditions. Both triacylglycerols (TAG) and phosphoacylglycerols (PL) were transesterified to high degrees, with an overall efficiency of 97.3% of the maximum theoretical efficiency. PL were not detected in the flakes following transesterification, and the amount of remaining unreacted TAG was only 1.0% of that input. Following washes with water, 0.5 M NaCl, and dilute NaOH, the recovered FAME met the ASTM specifications for biodiesel. The tocopherol levels of the FAME exceeded by 76% those of a representative commercial biodiesel. Soy flakes retained 97% of their protein following in situ transesterification. Mention of brand or firm names does not constitute an endorsement by the US Department of Agriculture over others of a similar nature not mentioned.     

Silver–polyimide nanocomposite membranes: Macromolecular‐matrix‐mediated metallization of an aromatic,fluorinated polyimide yielding highly reflective films at low metal concentrations

Highly reflective, surface‐metalized, flexible polyimide films were prepared by the incorporation of a soluble silver‐ion complex, (hexafluoroacetylacetonato)silver(I) (AgHFA), into dimethylacetamide solutions of poly(amic acid) prepared from 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride and 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane. The thermal curing of solution‐cast silver(I)–poly(amic acid) films to 300°C led to cycloimidization of the amic acid with concomitant silver(I) reduction and the formation of a reflective, air‐side‐silvered surface at very low (2 wt % and 0.3 vol %) silver concentrations. The reflective surface evolved only when the cure temperature reached about 275°C, although X‐ray diffraction showed metallic silver in the hybrid film by 200°C. After a maximum specular reflectivity greater than 80% was achieved for the 2 wt % silver film, the specular reflectivity diminished sharply with further heating at a constant temperature of 300°C. Incorporating the AgHFA complex into the soluble, fully imidized form of poly{(1,3‐dihydro‐1,3‐dioxo‐2H‐isoindole‐2,5‐diyl)[2,2,2‐trifluoro‐1‐(trifluoromethyl)ethylidene](1,3‐dihydro‐1,3‐dioxo‐2H‐isoindole‐5,2‐diyl)‐1,4‐phenyleneoxy‐1,4‐phenylene[2,2,2‐trifluoro‐1‐(trifluoromethyl)ethylidene]‐1,4‐phenyleneoxy‐1,4‐phenylene} gave films that were 25% less reflective than those beginning with poly(amic acid). Though highly reflective, the films were not electrically conductive. The metalized membranes were thermally stable and maintained mechanical properties similar to those of the parent polyimide. Transmission electron microscopy revealed an air‐side, near‐surface layer of silver that was about 40 nm thick; the interior of the film had well‐dispersed metal particles with diameters mostly less than 2 nm. The near‐surface silver layer maintained its integrity because of physical entrapment of the metal nanoparticles beneath a thin layer of polyimide; that is, the practical adhesion of the metal layer was good. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2409–2418, 2007     

Effect of backwashing on activated carbon adsorption using plug flow pore surface diffusion model

A fixed bed is gradually exhausted from top to bottom without backwashing; however, backwashing can rearrange the concentration gradient in the bed. After backwashing, saturated particles which are located at the top of the bed are homogeneously distributed in the bed. The used model to predict adsorption and backwashing effect of organic component is the plug flow pore surface diffusion model (PFPSDM). A sensitivity analysis was performed to determine which parameters have the greatest impact on the model results for components which can represent various organics. In addition, the effects of backwashing were examined by rearranging concentration gradient. For single component sensitivity analysis, the molecular weight was an important parameter. The breakthrough of the smaller molecular weight component was impacted more by backwashing. The SPDFR showed a significant impact on the breakthrough pattern. When surface diffusion was the dominant mechanism, high SPDFR, the breakthrough profile was sharper than when pore diffusion was dominant, low SPDFR. The adsorbability was an important parameter in determining the breakthrough pattern. As expected, the strongly adsorbable component showed the later breakthrough. Backwashing yielded earlier breakthrough for all single components and multi-components examined.