Dolmabahtsche Palast

Taha Toros Arşivi, Dosya No: 120-Saraylarİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Controlling the size and shape of Mg-MOF-74 crystals to optimise film synthesis on alumina substrates

Mg-MOF-74 is a metal organic framework with the highest CO2 adsorption capacity of any porous material. Therefore, it has been suggested for CO2 separations as both an adsorbent and incorporated into membranes. Design of the Mg-MOF-74 crystal morphology is important to expand the applicability of the material. In this paper one step synthesis of Mg-MOF-74 films has been achieved by controlling the Mg-MOF-74 crystal morphology. Results show that increasing the fraction of ethanol and water in the reaction solution relative to dimethyl formamide (DMF) increases the size of the crystals produced, while resulting in a subsequent drop in yield. By using solvent composition to control the Mg-MOF-74 crystal size and shape the synthesis of Mg-MOF-74 thin films was achieved in one step, without the need for seeding. Films could be produced as thin as 1 μm, ten times thinner than any other previous membranes in the M-MOF-74 series, in a fraction of the time (only 2.5 h). Thicker films (up to 14 μm) could also be produced by increasing the fraction of ethanol and water in reaction solution, offering a methodology by which the thickness of Mg-MOF-74 membranes can be controlled. Films were produced on porous tubular alumina supports, and single gas measurements were conducted resulting in a CO2 permeance of 7.4 × 10−7 mol m−2 s−1 Pa−1 and an ideal CO2/CH4 selectivity of 0.5

Vakıf Eseri İstanbul Çeşmelerinin Koruma Sorunları ve Öneriler

[No Abstract Available

Synthesis of hydrophobic MIL-53(Al) nanoparticles in low molecular weight alcohols: systematic investigation of solvent effects

The effects of using low-weight alcohols, methanol and ethanol, for the synthesis of MIL-53(Al) are investigated and the results directly compared with analogous synthesis in water and N,N-dimethylformamide (DMF). When methanol is employed in the synthesis of MIL-53(Al), termed MIL 53(MeOH), several unique properties are observed. The breathing phenomenon which is known for MIL-53(Al) derivatives, prepared using water or DMF as reaction solvent, is not observed for samples prepared from methanol and the framework adopts, and remains in, the large-pore form. Thus, measurement of N2-isotherms and calculation of internal surface areas have verified that the synthesis of MIL-53(MeOH) leads to a product which is highly porous without the requirement for an energy-consuming activation process. Furthermore, X-ray diffraction measurements and scanning electron microscopy at different humidity levels reveal a reversible loss of crystallinity at high humidity levels for MIL-53(MeOH) which was not observed previously for any other known MIL-53 derivative. In contrast the synthesis of MIL-53(Al) in ethanol leads of a product with low crystallinity

Evolution of drop size distribution in natural rain

Both numerical modeling and laboratory experiments document the possibility of a raindrop size distribution (DSD) to evolve to an equilibrium stage (EDSD), where all the principal processes occur at steady rates. The aim of this work is to observe the temporal behavior of the DSD and to directly investigate the conditions favorable to the onset of the EDSD in natural rain. We exploited a large disdrometer dataset collected in the framework of the Ground Validation activities related to the NASA Global Precipitation Measurement mission. More than 200,000 one-minute data of two-dimensional video disdrometer (2DVD) are collected over USA to represent a wide range of precipitation types. The original data are averaged over 2 min and an automatic algorithm is used on a selected subset to identify samples with EDSD. Results show that the EDSD occurs mainly in convective events and lasts for very short time intervals (2 to 4 min). It is more frequent for rain rate between 20 and 40 mm h−1 and it mostly occurs during sharp increase of precipitation rates

Observations and analysis of uncorrelated rain

Most microphysical models in precipitation physics and radar meteorology assume (at least implicitly) that raindrops are completely uncorrelated in space and time. Yet, several recent studies have indicated that raindrop arrivals are often temporally and spatially correlated. Resolution of this conflict must begin with observations of perfectly uncorrelated rainfall, should such “perfectly steady rain” exist at all. Indeed, it does. Using data with high temporal precision from a two-dimensional video disdrometer and the pair-correlation function, a scale-localized statistical tool, several ∼10–20-min rain episodes have been uncovered where no clustering among droplet arrival times is found. This implies that (i) rain events exist where current microphysical models can be tested in an optimal manner and (ii) not all rain can be properly described using fractals

Design In / Designing the First-Year Studio: An Experimental Study

This article focuses on first-year design studios, which include of “firsts” and difficulties at the same time for both instructors and students in architectural education. The study questions knowledge that students would encounter tools that they would use and experiences that they would practice and a course was developed accordingly. The course was planned in two phases and lasted 14 (8+6) weeks. The first phase included consecutive practices that were supported by theoretical knowledge, the second one focused on a single complex problem (3D-Portfolio design/tower) which consists of basic knowledge and skills. This problem was designed in a way that it contained the following components: (1) ensuring that pluralistic environment in studio becomes a part of the process (2) in this environment, students learn by experience through back-and-forth steps (3) making the model as an active component of design process and (4) ability to handle 1-1 scale. In this article, definition/process of this problem, which can be defined as experimental, is demonstrated in detail. Finally design question is evaluated by course executors through components of this design problem and it is revealed that how and to what extend design components determinant/directive in this process.. Keywords: first year design studio, design education

Üniversite Özerkliği ve Akademik Özgürlük

Üniversite özerkliği ve akademik özgürlük konuları güncelliğini sürdürmekte ve en gelişmiş yükseköğretim sistemlerinde bile bu iki konu özellikle akademik çevrelerde tartışılmaktadır. Bunun nedeni üniversite özerkliği ve akademik özgürlüğün yükseköğretim kurumları ve öğretim elemanlarınca akademik yaşamın ve yönetimin temel unsurları olarak görülmeleridir. Esasen bu iki kavram arasında çok yakın bir ilişki vardır ve birbirlerinden ayrı düşünülemezler. Şöyle ki, özerk yükseköğretim kurumları aynı zamanda akademik özgürlüğün gelişmesi ve kullanılması için gerekli olan ortamlardır

Status epilepticus enhances depotentiation after fully established LTP in an NMDAR-Dependent but GluN2B-independent manner

N-Methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) can be reversed by low-frequency stimulation (LFS) referred to as depotentiation (DP). We previously found GluN2B upregulated in CA1 neurons from post-status epilepticus (post-SE) tissue associated with an enhanced LTP. Here,we testedwhether LFS-inducedDP is also altered in pathologicalGluN2B upregulation. Although LTP was enhanced in post-SE tissue, LTP was significantly reversed in this tissue, but not in controls. We next tested the effect of the GluN2B subunit-specific blocker Ro 25-6981 (1 M) on LFS-DP. As expected, LFS had no effect on synaptic strength in the presence of the GluN2B blocker in control tissue. In marked contrast, LFS-DP was also attained in post-SE tissue indicating that GluN2B was obviously not involved in depotentiation. To test for NMDA receptor-dependence, we applied the NMDA receptor antagonist D-AP5 (50 M) prior to LFS and observed that DPwas abolished in both control and post- SE tissue confirming NMDA receptor involvement. These results indicate that control Schaffer collateral-CA1 synapses cannot be depotentiated after fully established LTP, but LFS was able to reverse LTP significantly in post-SE tissue. However, while LFS-DP clearly requiredNMDA receptor activation, GluN2B-containingNMDA receptors were not involved in this formof depotentiatio

Observations and analysis of uncorrelated rain

Most microphysical models in precipitation physics and radar meteorology assume (at least implicitly) that raindrops are completely uncorrelated in space and time. Yet, several recent studies have indicated that raindrop arrivals are often temporally and spatially correlated. Resolution of this conflict must begin with observations of perfectly uncorrelated rainfall, should such “perfectly steady rain” exist at all. Indeed, it does. Using data with high temporal precision from a two-dimensional video disdrometer and the pair-correlation function, a scale-localized statistical tool, several ∼10–20-min rain episodes have been uncovered where no clustering among droplet arrival times is found. This implies that (i) rain events exist where current microphysical models can be tested in an optimal manner and (ii) not all rain can be properly described using fractals