N-(Pyridin-2-ylmeth­yl)pyridin-2-amine

The title compound, C11H11N3, crystallizes with two mol­ecules (A and B) in the asymmetric unit. The geometries of both mol­ecules are very similar, with the exception of the torsion angles of the inter-ring chains; the values for C—N—C—C are 67.4 (5) and −69.3 (5)° for mol­ecules A and B, respectively. The dihedral angles between the pyridyl ring planes are 84.0 (2) and 83.2 (2)° for mol­ecules A and B, respectively. In the crystal, weak inter­molecular N—H⋯N hydrogen bonds and C—H⋯π inter­actions contribute to the stabilization of the packing

Novel water filtration of saline water in the outermost layer of mangrove roots

The scarcity of fresh water is a global challenge faced at present. Several desalination methods have been suggested to secure fresh water from sea water. However, conventional methods suffer from technical limitations, such as high power consumption, expensive operating costs, and limited system durability. In this study, we examined the feasibility of using halophytes as a novel technology of desalinating high-concentration saline water for long periods. This study investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water, and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses a hierarchical, triple layered pore structure in the epidermis, and most Na+ ions are filtered at the first sublayer of the outermost layer. The high blockage of Na+ ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures, also facilitates Na+ ion filtration. This study provides insights into the mechanism underlying water filtration through halophyte roots and serves as a basis for the development of a novel bio-inspired desalination method.Creative Research Initiative (Diagnosis of Biofluid Flow Phenomena and Biomimic Research) of the Ministry of Science, ICT and Future Planning (MSIP) , National Research Foundation (NRF) of Korea , ICT R&D program of MSIP/IITP (Korea

3,3′-Dimethyl-1,1′-[2,2′-bipyridine-5,5′-diylbis(methyl­ene)]diimidazol-3-ium bis­(hexa­fluoro­phosphate)

The title compound, C20H22N6 2+·2PF6 −, was prepared by the reaction of 5,5′-bis­(bromo­meth­yl)-2,2′-bipyridine with 1-methyl­imidazole. The main mol­ecule lies on an inversion center located at the mid-point of the C—C bond joining the two pyridine rings. The asymmetric unit therefore contains one half-mol­ecule and one hexa­fluoro­phosphate anion. The dihedral angle between the pyridine and imidazole rings is 76.93 (7)°. In the crystal, weak inter­molecular C—H⋯F hydrogen bonds contribute to the stabilization of the packing

2011 International Design Exchange Project, Hidden Space Project. Volume 2, Urban rooftops

Urban Rooftops: Our cities are now having to rethink and redevelop the use of space more creatively and ingeniously than ever before. Space is precious in any context but the extra pressure cities’ face with the ever growing need to accommodate increasing populations mean that every open area is now a new possibility for spatial development. One of the most recent and fascinating trends is the use of rooftops. Their appeal lies in their surprise and undiscovered disposition. Their purpose might involve a large community or an individual but because of its elevated position, each journey to that roof space provides a chance for adventure. They are an addition to older established buildings but come with a new brief and therefore a new spirit, encouraging creativity and positive thinking, using a different energy. The master planners and the local communities need to consider a more responsible composition of ideas to our urban and earthly needs. Sustainable energy use and material choice are to be rewarded but what of the function? Is just viewing the simple horizon above the rooftops function enough? relieving us of our daily stresses and seeing the city as sleeping giant or should we be industrious, striking balances of nature, pulling it back from disaster, giving space to synergistic projects. The students were asked to design a Rooftop structure in a densely inhabited urban neighbourhood, namely Burbage House, Curtain Road, Shoreditch London E2. Aim: The aim of this lofty structure or series of structures sets out to encourage, inspire a community or an individual to cultivate positive practices. The rooftop should connect and bond visually or through metaphor within its surrounding neighbourhood. The space should take account of the social and cultural diversity that resides close by. Context: Shoreditch is weave of close knit streets with its former industrial context provide an area for those that want to step out of the norm and the corporate, it’s place to imagine new business. Innovative creative houses have set up home using space imaginatively, sharing with like minded disciplines. The narrowness of the streets encourages networking and enhances collective working practices. Warehouse constructions reveal their previous activity and function, reminding us of the busy people, the noise and the industry. The buildings allow a maximum of light though to the interior, the detail in the window frames and brickwork show a sense of pride. The Interiors are simple and true the outer structure, revealing angles and curves. The space is unattractive to the Multi-national corporations, and as there is little capacity for charging large rents makes this area economically suitable for young and emerging practices to set up. The rawness of the interior spaces, unadulterated by recent 20th century trends provide the perfect utilitarian and vacant habitat for the fresh ideas where pioneering and ground breaking professions materialize. View: In some respects the rawness of such a landscape, its lack of conformity compares well with an open landscape. When standing on the roof looking across London, its openness and horizontal neutrality engenders a sense of calm and invigoration. Suddenly there are possibilities and scope for living positively. Hurried life slows down and London becomes picturesque. Novalis wrote ‘Everything seen from a distance becomes poetry :distant mountains, distant people, distant events. Everything become romantic’

Bis[μ-N-(pyridin-2-ylmeth­yl)pyridin-2-amine-κ2 N:N′]disilver(I) bis(trifluoro­methane­sulfonate)

In the binuclear title compound, [Ag2(C11H11N3)2](CF3O3S)2, the complex cation is centrosymmetric, with the unique Ag+ cation coordinated by two pyridine N atoms from two symmetry-related N-(pyridin-2-ylmeth­yl)pyridin-2-amine ligands in a geometry slightly distorted from linear [N—Ag—N 161.02 (7)°]. This set-up leads to the formation of a 14-membered cyclic dimer. The two pyridine rings coordinated to the Ag+ cation are tilted by 80.19 (7)° with respect to each other. Inter­molecular N—H⋯O hydrogen-bonding inter­actions between the cyclic dimer and the anion exist. A two-dimensional network parallel to the ac plane is constructed by three weak Ag⋯(O,N) inter­actions as well as an F⋯F contact of 2.890 (4) Å

Optimal set of grid size and angular increment for practical dose calculation using the dynamic conformal arc technique: a systematic evaluation of the dosimetric effects in lung stereotactic body radiation therapy

Purpose To recommend the optimal plan parameter set of grid size and angular increment for dose calculations in treatment planning for lung stereotactic body radiation therapy (SBRT) using dynamic conformal arc therapy (DCAT) considering both accuracy and computational efficiency. Materials and methods Dose variations with varying grid sizes (2, 3, and 4 mm) and angular increments (2°, 4°, 6°, and 10°) were analyzed in a thorax phantom for 3 spherical target volumes and in 9 patient cases. A 2-mm grid size and 2° angular increment are assumed sufficient to serve as reference values. The dosimetric effect was evaluated using dose–volume histograms, monitor units (MUs), and dose to organs at risk (OARs) for a definite volume corresponding to the dose–volume constraint in lung SBRT. The times required for dose calculations using each parameter set were compared for clinical practicality. Results Larger grid sizes caused a dose increase to the structures and required higher MUs to achieve the target coverage. The discrete beam arrangements at each angular increment led to over- and under-estimated OARs doses due to the undulating dose distribution. When a 2° angular increment was used in both studies, a 4-mm grid size changed the dose variation by up to 3–4% (50 cGy) for the heart and the spinal cord, while a 3-mm grid size produced a dose difference of \u3c1% (12 cGy) in all tested OARs. When a 3-mm grid size was employed, angular increments of 6° and 10° caused maximum dose variations of 3% (23 cGy) and 10% (61 cGy) in the spinal cord, respectively, while a 4° increment resulted in a dose difference of \u3c1% (8 cGy) in all cases except for that of one patient. The 3-mm grid size and 4° angular increment enabled a 78% savings in computation time without making any critical sacrifices to dose accuracy. Conclusions A parameter set with a 3-mm grid size and a 4° angular increment is found to be appropriate for predicting patient dose distributions with a dose difference below 1% while reducing the computation time by more than half for lung SBRT using DCAT

5,5′-Bis[(1H-imidazol-1-yl)meth­yl]-2,2′-bipyridine methanol disolvate

The title compound, C18H16N6·2CH3OH, was prepared by the reaction of 5,5′-bis­(bromo­meth­yl)-2,2′-bipyridine with imidazole. The main mol­ecule lies on an inversion center located at the mid-point of the C—C bond joining the two pyridine rings. The asymmetric unit therefore contains one half-mol­ecule and one methanol solvent mol­ecule. The dihedral angle between the pyridine and imidazole rings is 72.32 (5)°. In the crystal, weak inter­molecular O—H⋯N, C—H⋯N and C—H⋯O hydrogen bonds contribute to the stabilization of the packing