Interrogating liquid surfaces via reactive atom scattering

An investigation of the structure of various liquid surfaces has been conducted using Reactive Atom Scattering coupled to laser-induced fluorescence spectroscopy (RAS-LIF). In this technique, reactive collisions of gas-phase O(3P) atoms with hydrocarbon-based liquid surfaces produce OH radicals which are probed by laserinduced fluorescence in the gas phase. The relative fraction of the surface occupied by groups containing abstractable hydrogen atoms is quantified by the yield of OH. Therefore, RAS-LIF can be used to study the surface composition of liquids and mixtures containing alkyl groups. In addition, the technique yields information on the fundamental dynamics of gas-liquid interactions. The dynamics of the interfacial H-abstraction reaction between O(3P) and the partially unsaturated hydrocarbon squalene (C30H50) has been studied for the first time. The yield and internal-state distribution of OH produced by this reaction have been characterised by RAS-LIF. In comparison with the fully saturated analogue, squalane (C30H62), the results show that the O(3P) atoms are extremely sensitive to the type of C– H bond where reaction takes place, and the products partially accommodate their energy at the liquid surface. There is an additional channel for O(3P) loss on squalene, inferred to be addition to exposed unsaturated sites at the liquid surface. RAS-LIF has been employed to characterise the surfaces of ionic liquids containing alkyl chains. The O(3P) atoms react selectively with CH2 groups, acting as a quantitative surface-specific probe of the alkyl chains at the surface. The results show that the interfacial composition is different from that of the bulk, with alkyl chains being preferentially exposed at the surface. A series of ionic liquids and mixtures containing 1-alkyl-3-methylimidazolium and 1-alkyl-1-methylpyrrolidinium cations has been investigated. It has been found that alkyl surface coverage depends strongly on the length of the alkyl chain and the chemical identity of the anion, but not on the cation headgroup (imidazolium or pyrrolidinium). Measurements on ionic liquid mixtures show that their surfaces are enriched in cations and anions that are relatively nonpolar, and depleted in polar ions

PENGARUH KEPRIBADIAN (EKSTROVERT vs INTROVERT) TERHADAP WATER FOOTPRINT SISWA SEKOLAH MENENGAH ATAS DI JAKARTA

Pertumbuhan ekonomi yang terus meningkat mempengaruhi kualitas kehidupan masyarakat yang berdampak kepada meningkatnya perilaku mengkonsumsi berbagai jenis kebutuhan. Ecological Footprint sebagai salah satu alat yang dapat digunakan untuk mengestimasi konsumsi dan perilaku individu terhadap dampaknya bagi alam. Perilaku individu dalam mengkonsumsi kebutuhan dapat dipengaruhi oleh kepribadian. Penelitian ini bertujuan untuk mengetahui pengaruh kepribadian terhadap Ecological Footprint siswa Sekolah Menengah Atas di Jakarta. Pengukuran Ecological Footprint difokuskan pada komponen penggunaan air di rumah dan di sekolah. Kegiatan penggunaan air difokuskan pada aktivitas buang air kecil, buang air besar, minum, mencuci wajah, mandi, mencuci tangan, dan wudhu. Pengukuran Water Footprint dilakukan terhadap 54 siswa SMA Negeri 107 yang dipilih secara simple random sampling, Cakung- Jakarta Timur selama Januari-Februari 2016. Hasil uji t yakni thitung < ttabel, yaitu 1,37 < 2,00. Hal ini menunjukkan tidak terdapat perbedaan Water Footprint siswa berkepribadian ekstrovert maupun introvert. The increasing of economic growth evoked the prosperity of its citizen which subsequently would lead to the consumption behaviors of such population for goods andservices. Ecological Footprint is a individual or population as well as the services needed to assimilate west in term of land. Social factors, such as personality, is known as a crucial factor that cause the consumption pattern of individuals is vary considerably. This research was aimed to determine the effect of personality on Ecological Footprint of students at senior high school in Jakarta. Measuring of Ecological Footprint is concentrated on water using at home and school. The activities of water using focused on urinating, defecating, face washing, taking a bath, hand washing, and ritual ablution before Moslem prayers. Water Footprint was calculated from 54 students enrolled in SMAN 107 which are selected acording to simple random sampling, Cakung Jakarta Timur This study was conducted from January to February 2016.The result of t score is tcounted< ttable,1,37 < 2,00. The finding indicated that there was no significantly difference between extraversion and intraversion based on their total Water Footprint value

Determining the Composition of the Vacuum-Liquid Interface in Ionic-Liquid Mixtures

The vacuum-liquid interfaces of a number of ionic-liquid mixtures have been investigated using a combination of reactive-atom scattering with laser-induced fluorescence detection (RAS-LIF), selected surface tension measurements, and molecular dynamics (MD) simulations. The mixtures are based on the widespread 1-alkyl-3-methylimidazolium ([Cnmim]+) cation, including mixed cations which differ in chain length or chemical functionality with a common anion; and different anions for a common cation. RAS-LIF results imply that the surface compositions exhibit a general form of non-stoichiometric behaviour that mimics the well-known Henry’s and Raoult’s laws at low and high mole fraction, respectively. The Extended Langmuir model provides a moderately good single-parameter fit, but higher-order terms are required for an accurate description. The quantitative relationship between RAS-LIF and surface tension, which probes the surface composition only indirectly, is explored for mixtures of [C2mim]+ and [C12mim]+ with a common bis(trifluoromethylsulfonyl)imide ([NTf2]-) anion. Extended Langmuir model fits to surface tension data are broadly consistent with those to RAS-LIF; however, several other common approaches to extracting surface compositions from measured surface tensions result in much larger discrepancies. MD simulations suggest that RAS-LIF faithfully reports on the alkyl-chain exposure at the surface, which is only subtly modified by composition-dependent structural reorganisation

Reactive-Atom Scattering from Liquid Crystals at the Liquid-Vacuum Interface : [C12mim][BF4] and 4-Cyano-4′-Octylbiphenyl (8CB)

Two complementary approaches were used to study the liquid-vacuum interface of the liquid-crystalline ionic liquid 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C12mim][BF4]) in the smectic A (SmA) and isotropic phases. O atoms with two distinct incident translational energies were scattered from the surface of [C12mim][BF4]. Angle-dependent time-of-flight distributions and OH yields, respectively, were recorded from high- and low-energy O atoms. There were no significant changes in the measurements using either approach, nor the properties derived from them, accompanying the transition from the SmA to the isotropic phase. This indicates that the surface structure of [C12mim][BF4] remains essentially unchanged across the phase boundary, implying that the bulk order and surface structure are not strongly correlated for this material. This effect is ascribed to the strong propensity for the outer surfaces of ionic liquids to be dominated by alkyl chains, over an underlying layer rich in anions and cation head groups, whether or not the bulk material is a liquid crystal. In a comparative study, the OH yield from the surface of the liquid crystal, 8CB, was found to be affected by the bulk order, showing a surprising step increase at the SmA-nematic transition temperature, whose origin is the subject of speculation

Determining the Composition of the Vacuum-Liquid Interface in Ionic-Liquid Mixtures

The vacuum-liquid interfaces of a number of ionic-liquid mixtures have been investigated using a combination of reactive-atom scattering with laser-induced fluorescence detection (RAS-LIF), selected surface tension measurements, and molecular dynamics (MD) simulations. The mixtures are based on the widespread 1-alkyl-3-methylimidazolium ([Cnmim]+) cation, including mixed cations which differ in chain length or chemical functionality with a common anion; and different anions for a common cation. RAS-LIF results imply that the surface compositions exhibit a general form of non-stoichiometric behaviour that mimics the well-known Henry’s and Raoult’s laws at low and high mole fraction, respectively. The Extended Langmuir model provides a moderately good single-parameter fit, but higher-order terms are required for an accurate description. The quantitative relationship between RAS-LIF and surface tension, which probes the surface composition only indirectly, is explored for mixtures of [C2mim]+ and [C12mim]+ with a common bis(trifluoromethylsulfonyl)imide ([NTf2]-) anion. Extended Langmuir model fits to surface tension data are broadly consistent with those to RAS-LIF; however, several other common approaches to extracting surface compositions from measured surface tensions result in much larger discrepancies. MD simulations suggest that RAS-LIF faithfully reports on the alkyl-chain exposure at the surface, which is only subtly modified by composition-dependent structural reorganisation

Nano-Segregation and Structuring in the Bulk and at the Surface of Ionic-Liquid Mixtures

Ionic-liquid (IL) mixtures hold great promise, as they allow liquids with a wide range of properties to be formed by mixing two common components, rather than by synthesizing a large array of pure ILs with different chemical structures. In addition, these mixtures can exhibit a range of properties and structural organization that depend on their composition, which opens up new possibilities for the composition-dependent control of IL properties for particular applications. However, the fundamental properties, structure and dynamics of IL mixtures are currently poorly understood, which limits their more widespread application. This paper presents the first comprehensive investigation into the bulk and surface properties of IL mixtures formed from two commonly encountered ILs: 1-ethyl-3-methylimidazolium and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][Tf2N] and [C12mim][Tf2N]). Physical property measurements (viscosity, conductivity and density) find that these IL mixtures are not well described by simple mixing laws, suggesting that their structure and dynamics are strongly composition-dependent. Small-angle X-ray and neutron scattering (SAXS and SANS) measurements, alongside molecular dynamics (MD) simulations, show that at low mole fractions of [C12mim][Tf2N], the bulk of the IL is composed of small aggregates of [C12mim]+ ions in a [C2mim][Tf2N] matrix, which is driven by nano-segregation of the long alkyl chains and the polar parts of the IL. As the proportion of [C12mim][Tf2N] in the mixtures increases, the size and number of aggregates increases until the C12 alkyl chains percolate through the system and a bicontinuous network of polar and non-polar domains is formed. Reactive atom scattering-laser-induced fluorescence (RAS-LIF) experiments, also supported by MD simulations, have been used to probe the surface structure of these mixtures. It is found that the vacuum-IL interface is enriched significantly in C12 alkyl chains, even in mixtures low in the long-chain component. These data show, contrary to previous suggestions, that the [C12mim]+ ion is surface active in this binary IL mixture. However, the surface does not become saturated in C12 chains as its proportion in the mixtures increases and remains unsaturated in pure [C12mim][Tf2N]

Nanosegregation and Structuring in the Bulk and at the Surface of Ionic-Liquid Mixtures

Ionic-liquid (IL) mixtures hold great promise, as they allow liquids with a wide range of properties to be formed by mixing two common components, rather than by synthesizing a large array of pure ILs with different chemical structures. In addition, these mixtures can exhibit a range of properties and structural organization that depend on their composition, which opens up new possibilities for the composition-dependent control of IL properties for particular applications. However, the fundamental properties, structure and dynamics of IL mixtures are currently poorly understood, which limits their more widespread application. This paper presents the first comprehensive investigation into the bulk and surface properties of IL mixtures formed from two commonly encountered ILs: 1-ethyl-3-methylimidazolium and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][Tf2N] and [C12mim][Tf2N]). Physical property measurements (viscosity, conductivity and density) find that these IL mixtures are not well described by simple mixing laws, suggesting that their structure and dynamics are strongly composition-dependent. Small-angle X-ray and neutron scattering (SAXS and SANS) measurements, alongside molecular dynamics (MD) simulations, show that at low mole fractions of [C12mim][Tf2N], the bulk of the IL is composed of small aggregates of [C12mim]+ ions in a [C2mim][Tf2N] matrix, which is driven by nano-segregation of the long alkyl chains and the polar parts of the IL. As the proportion of [C12mim][Tf2N] in the mixtures increases, the size and number of aggregates increases until the C12 alkyl chains percolate through the system and a bicontinuous network of polar and non-polar domains is formed. Reactive atom scattering-laser-induced fluorescence (RAS-LIF) experiments, also supported by MD simulations, have been used to probe the surface structure of these mixtures. It is found that the vacuum-IL interface is enriched significantly in C12 alkyl chains, even in mixtures low in the long-chain component. These data show, contrary to previous suggestions, that the [C12mim]+ ion is surface active in this binary IL mixture. However, the surface does not become saturated in C12 chains as its proportion in the mixtures increases and remains unsaturated in pure [C12mim][Tf2N]

Frequent mutation of histone-modifying genes in non-Hodgkin lymphoma

Follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) are the two most common non-Hodgkin lymphomas (NHLs). Here we sequenced tumour and matched normal DNA from 13 DLBCL cases and one FL case to identify genes with mutations in B-cell NHL. We analysed RNA-seq data from these and another 113 NHLs to identify genes with candidate mutations, and then re-sequenced tumour and matched normal DNA from these cases to confirm 109 genes with multiple somatic mutations. Genes with roles in histone modification were frequent targets of somatic mutation. For example, 32% of DLBCL and 89% of FL cases had somatic mutations in MLL2, which encodes a histone methyltransferase, and 11.4% and 13.4% of DLBCL and FL cases, respectively, had mutations in MEF2B, a calcium-regulated gene that cooperates with CREBBP and EP300 in acetylating histones. Our analysis suggests a previously unappreciated disruption of chromatin biology in lymphomagenesis

Pengaruh variasi konsentrasi blackstrap molasses terhadap produksi minyak dan komposisi pufa (Polyunsaturated fatty acid) oleh Rhizomucor miehei FNCC 6102

Beberapa jenis mikroorganisme seperti bakteri, kapang, dan khamir dapat menghasilkan minyak dalam jumlah tinggi sehingga digolongkan dalam jenis oleaginous. Rhizomucor miehei FNCC 6102 merupakan salah satu jenis kapang oleaginous dengan sistem fermentasi terendam dapat menghasilkan minyak yang mengandung PUFA (polyunsaturated fatty acid) di dalam selnya terutama asam linoleat, asam linolenat, EPA dan DHA. Ketersediaan nutrisi pada media yang digunakan merupakan faktor penting yang harus dipenuhi dalam produksi minyak dan komposisi PUFA oleh kapang. Blackstrap molasses merupakan hasil samping dari industri gula tebu dengan kandungan nutrisi seperti karbohidrat, protein, vitamin dan mineral dengan jumlah cukup tinggi sehingga dapat digunakan sebagai alternatif media fermentasi. Perbedaan jumlah nutrisi dalam media fermentasi akan mempengaruhi aktivitas Rhizomucor miehei FNCC 6102 terutama untuk pertumbuhan dan sintesa minyak intraseluler, oleh karena itu untuk memenuhi kebutuhan kapang akan nutrisi yang terkandung dalam blackstrap molasses maka perlu dilakukan pengaturan konsentrasi blackstrap molasses sebagai media fermentasi. Penelitian ini bertujuan untuk mengetahui pengaruh variasi konsentrasi blackstrap molasses terhadap produksi minyak dan komposisi PUFA terutama EPA dan DHA oleh Rhizomucor miehei FNCC 6102. Pengamatan yang dilakukan adalah analisa media fermentasi yaitu kadar gula reduksi sebelum fermentasi dan analisa produk yaitu kadar gula reduksi sesudah fermentasi, biomassa, kadar minyak, serta konsentrasi EPA dan DHA. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) dengan satu faktor yaitu konsentrasi blackstrap molasses yang terdiri dari 5 perlakuan yaitu blackstrap molasses dengan konsentrasi 5% v/v (K1), 10% v/v (K2), 15% v/v (K3), 20% v/v (K4) 25%v/v (K5) dan dilakukan pengulangan sebanyak 5 kali. Data yang diperoleh dianalisa dengan uji Anava pada α = 5%, dan apabila terdapat perbedaan nyata maka analisa dilanjutkan dengan uji Beda Jarak Nyata Duncan (BJND). Berdasarkan penelitian yang telah dilakukan menunjukkan bahwa perlakuan variasi konsentrasi blackstrap molasses tidak berpengaruh nyata terhadap penurunan kadar gula reduksi dan biomassa, namun berpengaruh nyata terhadap kadar minyak intraseluler yang diproduksi oleh Rhizomucor miehei FNCC 6102. Produksi minyak tertinggi diperoleh dari Rhizomucor miehei FNCC 6102 yang ditumbuhkan pada konsentrasi media blackstrap molasses 20% (v/v) dengan perolehan kadar minyak sebesar 21,09% (b/b). Semua perlakuan menghasilkan minyak yang mengandung EPA dan DHA dimana konsentrasi EPA dan DHA tertinggi diperoleh dari Rhizomucor miehei FNCC 6102 yang ditumbuhkan pada konsentrasi media blackstrap molasses 15% (v/v) yaitu sebesar 0,47% dan 0,33%

Pengaruh variasi konsentrasi blackstrap molasses terhadap produksi minyak dan komposisi pufa (Polyunsaturated fatty acid) oleh Rhizomucor miehei FNCC 6102

Beberapa jenis mikroorganisme seperti bakteri, kapang, dan khamir dapat menghasilkan minyak dalam jumlah tinggi sehingga digolongkan dalam jenis oleaginous. Rhizomucor miehei FNCC 6102 merupakan salah satu jenis kapang oleaginous dengan sistem fermentasi terendam dapat menghasilkan minyak yang mengandung PUFA (polyunsaturated fatty acid) di dalam selnya terutama asam linoleat, asam linolenat, EPA dan DHA. Ketersediaan nutrisi pada media yang digunakan merupakan faktor penting yang harus dipenuhi dalam produksi minyak dan komposisi PUFA oleh kapang. Blackstrap molasses merupakan hasil samping dari industri gula tebu dengan kandungan nutrisi seperti karbohidrat, protein, vitamin dan mineral dengan jumlah cukup tinggi sehingga dapat digunakan sebagai alternatif media fermentasi. Perbedaan jumlah nutrisi dalam media fermentasi akan mempengaruhi aktivitas Rhizomucor miehei FNCC 6102 terutama untuk pertumbuhan dan sintesa minyak intraseluler, oleh karena itu untuk memenuhi kebutuhan kapang akan nutrisi yang terkandung dalam blackstrap molasses maka perlu dilakukan pengaturan konsentrasi blackstrap molasses sebagai media fermentasi. Penelitian ini bertujuan untuk mengetahui pengaruh variasi konsentrasi blackstrap molasses terhadap produksi minyak dan komposisi PUFA terutama EPA dan DHA oleh Rhizomucor miehei FNCC 6102. Pengamatan yang dilakukan adalah analisa media fermentasi yaitu kadar gula reduksi sebelum fermentasi dan analisa produk yaitu kadar gula reduksi sesudah fermentasi, biomassa, kadar minyak, serta konsentrasi EPA dan DHA. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) dengan satu faktor yaitu konsentrasi blackstrap molasses yang terdiri dari 5 perlakuan yaitu blackstrap molasses dengan konsentrasi 5% v/v (K1), 10% v/v (K2), 15% v/v (K3), 20% v/v (K4) 25%v/v (K5) dan dilakukan pengulangan sebanyak 5 kali. Data yang diperoleh dianalisa dengan uji Anava pada α = 5%, dan apabila terdapat perbedaan nyata maka analisa dilanjutkan dengan uji Beda Jarak Nyata Duncan (BJND). Berdasarkan penelitian yang telah dilakukan menunjukkan bahwa perlakuan variasi konsentrasi blackstrap molasses tidak berpengaruh nyata terhadap penurunan kadar gula reduksi dan biomassa, namun berpengaruh nyata terhadap kadar minyak intraseluler yang diproduksi oleh Rhizomucor miehei FNCC 6102. Produksi minyak tertinggi diperoleh dari Rhizomucor miehei FNCC 6102 yang ditumbuhkan pada konsentrasi media blackstrap molasses 20% (v/v) dengan perolehan kadar minyak sebesar 21,09% (b/b). Semua perlakuan menghasilkan minyak yang mengandung EPA dan DHA dimana konsentrasi EPA dan DHA tertinggi diperoleh dari Rhizomucor miehei FNCC 6102 yang ditumbuhkan pada konsentrasi media blackstrap molasses 15% (v/v) yaitu sebesar 0,47% dan 0,33%