ALBANIAN LAW ON CITY PLANNING: CRITICAL SUMMARY OF ITS MAJOR PROVISIONS

This paper includes, as an annex, Law No. 7693, "On Urban Planning," from the People's Assembly of the Republic of Albania. Conceptually, this law has five major parts: (1) planning generally, (2) getting construction permission, (3) special provisions for tourist zones, (4) special provisions for military zones and zones with singular (that is, archaeological, historical, or cultural) value, and (5) penalties for violations. These parts are described and discussed.Cities and towns--Planning--Law and legislation--Albania, City planning and redevelopment law--Albania, Land use, Urban--Government policy--Albania, Land administration--Albania, Community/Rural/Urban Development,

Assessment of clear and cloudy sky parameterizations for daily downwelling longwave radiation over different land surfaces in Florida, USA

Clear sky downwelling longwave radiation (Rldc) and cloudy sky downwelling longwave radiation (Rld) formulas were tested across eleven sites in Florida. The Brunt equation, using air vapor pressure and temperature measurements, provides the best Rldc estimates with a root mean square error of less than around 12 Wm−2 across all sites. The Crawford and Duchon\u27s cloudiness factor with Brunt equation is recommended for Rld calculations. This combined approach requires no local calibration and estimates Rld with a root mean square error of less than around 13 Wm−2 and squared correlation coefficients that typically exceed 0.9

Self-Assembly of Structures with Addressable Complexity.

The self-assembly of structures with "addressable complexity", where every component is distinct and is programmed to occupy a specific location within a target structure, is a promising route to engineering materials with precisely defined morphologies. Because systems with many components are inherently complicated, one might assume that the chances of successful self-assembly are extraordinarily small. Yet recent advances suggest otherwise: addressable structures with hundreds of distinct building blocks have been designed and assembled with nanometer precision. Despite this remarkable success, it is often challenging to optimize a self-assembly reaction to ensure that the intended structure is kinetically accessible. In this Perspective, we focus on the prediction of kinetic pathways for self-assembly and implications for the design of robust experimental protocols. The development of general principles to predict these pathways will enable the engineering of complex materials using a much wider range of building blocks than is currently possible.This work was carried out with support from the Engineering and Physical Sciences Research Council Programme Grant EP/I001352/1. We would like to acknowledge discussions with Aleks Reinhardt, Rebecca Schulman, Thomas Ouldridge, Oleg Gang and Alexei Tkachenko. DF acknowledges the hospitality of the NYU Center for Soft Matter Research.This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/jacs.5b1191

Nonequilibrium interfacial properties of chemically driven fluids

Chemically driven fluids can demix to form condensed droplets that exhibit phase behaviors not observed at equilibrium. In particular, nonequilibrium interfacial properties can emerge when the chemical reactions are driven differentially between the interior and exterior of the phase-separated droplets. Here, we use a minimal model to study changes in the interfacial tension between coexisting phases away from equilibrium. Simulations of both droplet nucleation and interface roughness indicate that the nonequilibrium interfacial tension can either be increased or decreased relative to its equilibrium value, depending on whether the driven chemical reactions are accelerated or decelerated within the droplets. Finally, we show that these observations can be understood using a predictive theory based on an effective thermodynamic equilibrium

Programmable phase behavior in fluids with designable interactions

We introduce a method for solving the "inverse" phase equilibria problem: How should the interactions among a collection of molecular species be designed in order to achieve a target phase diagram? Using techniques from convex optimization theory, we show how to solve this problem for phase diagrams containing a large number of components and many coexisting phases with prescribed compositions. We apply our approach to commonly used mean-field models of multicomponent fluids and then use molecular simulations to verify that the designed interactions result in the target phase diagrams. Our approach enables the rational design of "programmable" fluids, such as biopolymer and colloidal mixtures, with complex phase behavior

The biogeochemical influence of nitrate, dissolved oxygen, and dissolved organic carbon on stream nitrate uptake

Streams are potential hotspots for retention and removal of NO3−, and understanding the mechanisms that enhance NO3− reactivity in stream systems is critical for predicting and preventing eutrophication. Both dissolved organic C (DOC) and dissolved O2 (DO) influence NO3− removal processes. Assessing the individual impacts of NO3−, DO, and DOC concentrations on stream NO3− removal is difficult because these factors covary and are coupled through the C and N cycles. We used an experimental approach to quantify the influences of NO3−, DOC, and DO on NO3− transport in headwater streams of the Ipswich and Parker River watersheds (Massachusetts, USA) with contrasting levels of DOC and DO. In a 1st set of experiments, we added NO3− to address how uptake kinetics differed between a low-DO/high-DOC stream (Cedar Swamp Creek) and a high-DO/low-DOC stream (Cart Creek). In a 2nd set of experiments, we manipulated, for the first time at the reach scale, both DO and DOC in a factorial experiment. DO was added to the low-DO stream by injecting O2 and was removed from the high-DO stream by adding sodium sulfite. DOC was added both alone and in combination with the DO manipulations. NO3− concentration was an important control of NO3− uptake velocity in our study streams, consistent with previous findings. The results of the DOC and DO manipulations suggested that DO determines whether a stream has net NO3− uptake or production and that the presence of DOC magnifies the DO response processes. Addition of DOC by itself did not lead to increased NO3− uptake. In addition, we observed organic matter priming effects, wherein the addition of labile organic matter resulted in accelerated metabolism of naturally occurring DOC in the water column. Priming effects have not been reported previously in stream systems. Results from our experiments suggest that NO3− uptake in streams might arise from complex interactions among DOC, DO, and NO3−, and ultimately, from the influence of DO on dominant stream processes

Rational design of self-assembly pathways for complex multicomponent structures.

The field of complex self-assembly is moving toward the design of multiparticle structures consisting of thousands of distinct building blocks. To exploit the potential benefits of structures with such "addressable complexity," we need to understand the factors that optimize the yield and the kinetics of self-assembly. Here we use a simple theoretical method to explain the key features responsible for the unexpected success of DNA-brick experiments, which are currently the only demonstration of reliable self-assembly with such a large number of components. Simulations confirm that our theory accurately predicts the narrow temperature window in which error-free assembly can occur. Even more strikingly, our theory predicts that correct assembly of the complete structure may require a time-dependent experimental protocol. Furthermore, we predict that low coordination numbers result in nonclassical nucleation behavior, which we find to be essential for achieving optimal nucleation kinetics under mild growth conditions. We also show that, rather surprisingly, the use of heterogeneous bond energies improves the nucleation kinetics and in fact appears to be necessary for assembling certain intricate 3D structures. This observation makes it possible to sculpt nucleation pathways by tuning the distribution of interaction strengths. These insights not only suggest how to improve the design of structures based on DNA bricks, but also point the way toward the creation of a much wider class of chemical or colloidal structures with addressable complexity.This work was carried out with support from the Eu- ropean Research Council (Advanced Grant 227758) and the Engineering and Physical Sciences Research Council Programme Grant EP/I001352/1. W.M.J. acknowledges support from the Gates Cambridge Trust and the Na- tional Science Foundation Graduate Research Fellowship under Grant No. DGE-1143678.This is the author accepted manuscript. The final version is available from PNAS at http://www.pnas.org/content/112/20/6313.abstract

Phase separation in solutions with specific and nonspecific interactions.

Protein solutions, which tend to be thermodynamically stable under physiological conditions, can demix into protein-enriched and protein-depleted phases when stressed. Using a lattice-gas model of proteins with both isotropic and specific, directional interactions, we calculate the critical conditions for phase separation for model proteins with up to four patches via Monte Carlo simulations and statistical associating fluid theory. Given a fixed specific interaction strength, the critical value of the isotropic energy, which accounts for dispersion forces and nonspecific interactions, measures the stability of the solution with respect to nonspecific interactions. Phase separation is suppressed by the formation of protein complexes, which effectively passivate the strongly associating sites on the monomers. Nevertheless, we find that protein models with three or more patches can form extended aggregates that phase separate despite the assembly of passivated complexes, even in the absence of nonspecific interactions. We present a unified view of the critical behavior of model fluids with anisotropic interactions, and we discuss the implications of these results for the thermodynamic stability of protein solutions.Protein solutions, which tend to be thermodynamically stable under physiological conditions, can demix into protein-enriched and protein-depleted phases when stressed. Using a lattice-gas model of proteins with both isotropic and specific, directional interactions, we calculate the critical conditions for phase separation for model proteins with up to four patches via Monte Carlo simulations and statistical associating fluid theory. Given a fixed specific interaction strength, the critical value of the isotropic energy, which accounts for dispersion forces and nonspecific interactions, measures the stability of the solution with respect to nonspecific interactions. Phase separation is suppressed by the formation of protein complexes, which effectively passivate the strongly associating sites on the monomers. Nevertheless, we find that protein models with three or more patches can form extended aggregates that phase separate despite the assembly of passivated complexes, even in the absence of nonspecific interactions. We present a unified view of the critical behavior of model fluids with anisotropic interactions, and we discuss the implications of these results for the thermodynamic stability of protein solutions.This is the final published version, which can also be found on the publisher's website at: http://scitation.aip.org/content/aip/journal/jcp/140/20/10.1063/1.4878836 © 2014 AIP Publishing LL

Interplay between self-assembly and phase separation in a polymer-complex model

We present a theoretical model for predicting the phase behavior of polymer solutions in which phase separation competes with oligomerization. Specifically, we consider scenarios in which the assembly of polymer chains into stoichiometric complexes prevents the chains from phase-separating via attractive polymer-polymer interactions. Combining statistical associating fluid theory with a two-state description of self-assembly, we find that this model exhibits rich phase behavior, including re-entrance, and we show how system-specific phase diagrams can be derived graphically. Importantly, we discuss why these phase diagrams can resemble -- and yet are qualitatively distinct from -- phase diagrams of polymer solutions with lower critical solution temperatures