4′-Formyl­benzo-15-crown-5

In the title compound (systematic name: 17-formyl-2,5,8,11,14-penta­oxabicyclo­[13.4.0]nona­deca-15,17,19-triene), C15H20O6, the 15-crown-5 ring adopts a twisted conformation. The formyl group is coplanar with the benzene ring. The crystal packing is stabilized by C—H⋯O inter­actions involving the C=O group and ether O atoms as acceptors and methyl­ene CH groups as donors

Water uptake by biomass burning aerosol at sub- and supersaturated conditions: closure studies and implications for the role of organics

We investigate the CCN activity of freshly emitted biomass burning particles and their hygroscopic growth at a relative humidity (RH) of 85%. The particles were produced in the Mainz combustion laboratory by controlled burning of various wood types. The water uptake at sub- and supersaturations is parameterized by the hygroscopicity parameter, κ (c.f. Petters and Kreidenweis, 2007). For the wood burns, κ is low, generally around 0.06. The main emphasis of this study is a comparison of κ derived from measurements at sub- and supersaturated conditions (κG and κCCN), in order to see whether the water uptake at 85% RH can predict the CCN properties of the biomass burning particles. Differences in κGand κCCN can arise through solution non-idealities, the presence of slightly soluble or surface active compounds, or non-spherical particle shape. We find that κG and κCCN agree within experimental uncertainties (of around 30%) for particle sizes of 100 and 150 nm; only for 50 nm particles is κCCN larger than κG by a factor of 2. The magnitude of this difference and its dependence on particle size is consistent with the presence of surface active organic compounds. These compounds mainly facilitate the CCN activation of small particles, which form the most concentrated solution droplets at the point of activation. The 50 nm particles, however, are only activated at supersaturations higher than 1% and are therefore of minor importance as CCN in ambient clouds. By comparison with the actual chemical composition of the biomass burning particles, we estimate that the hygroscopicity of the water-soluble organic carbon (WSOC) fraction can be represented by a κWSOC value of approximately 0.2. The effective hygroscopicity of a typical wood burning particle can therefore be represented by a linear mixture of an inorganic component with κ ≅ 0.6, a WSOC component with κ ≅ 0.2, and an insoluble component with κ = 0

Analisis yuridis terhadap kedudukan dan bagian ahli waris pengganti menurut hukum kewarisan islam di indonesia (Studi kasus penetapan pengadilan agama kediri nomor : 0044/Pdt.P/2013/PA.Kdr)

xi, 89 hlm . : ilus. ; 27 c

Emissions of organic trace gases from savanna fires in Southern Africa during SAFARI 92 and their impact on the formation of tropospheric ozone

CO, CH4, and organic trace gases were measured in air samples collected during several flights with a DC‐3 aircraft through the plumes from savanna fires and agricultural fires during the SAFARI 92 campaign in southern Africa in September and October 1992. In all samples a variety of higher molecular weight organic compounds was found, most of which are very reactive. More than 70 of the roughly 140 major components present could be identified. Typically, mixing ratios of several hundred parts per billion carbon of organic compounds were measured inside the plumes, corresponding to an emission ratio of total organic carbon relative to CO2 of up to 1%. About 50% of these emissions were in the form of oxygenated and unsaturated compounds. The contributions of still unknown compounds to the total emission of organic compounds add up to another 20–30%. The observed emission ratios relative to CO2 show a considerable variation depending on the fuel type and the burning stages of the fire. The lowest value of the emission ratio of the sum of all identified organic compounds relative to CO2 was found for a sugar cane fire with (1.7 ± 0.7) × 10−3 (ppb C/ppb CO2). For a large savanna fire in Kruger National Park the ratio was (7.4 ± 1.6) × 10−3 (ppb C/ppb CO2). The highest value was (13.7 ± 0.9) × 10−3 (ppb C/ppb CO2) for an uncontrolled fire of mainly wood and shrub in the Drakensberg region. Results of model calculations show that in biomass‐burning plumes, reactive organic compounds contribute significantly to the formation of ozone, especially during the initial phase of photochemical processing