Signatures of the slow solar wind streams from active regions in the inner corona

Some of local sources of the slow solar wind can be associated with spectroscopically detected plasma outflows at edges of active regions accompanied with specific signatures in the inner corona. The EUV telescopes (e.g. SPIRIT/CORONAS-F, TESIS/CORONAS-Photon and SWAP/PROBA2) sometimes observed extended ray-like structures seen at the limb above active regions in 1MK iron emission lines and described as "coronal rays". To verify the relationship between coronal rays and plasma outflows, we analyze an isolated active region (AR) adjacent to small coronal hole (CH) observed by different EUV instruments in the end of July - beginning of August 2009. On August 1 EIS revealed in the AR two compact outflows with the Doppler velocities V =10-30 km/s accompanied with fan loops diverging from their regions. At the limb the ARCH interface region produced coronal rays observed by EUVI/STEREO-A on July 31 as well as by TESIS on August 7. The rays were co-aligned with open magnetic field lines expanded to the streamer stalks. Using the DEM analysis, it was found that the fan loops diverged from the outflow regions had the dominant temperature of ~1 MK, which is similar to that of the outgoing plasma streams. Parameters of the solar wind measured by STEREO-B, ACE, WIND, STEREO-A were conformed with identification of the ARCH as a source region at the Wang-Sheeley-Arge map of derived coronal holes for CR 2086. The results of the study support the suggestion that coronal rays can represent signatures of outflows from ARs propagating in the inner corona along open field lines into the heliosphere.Comment: Accepted for publication in Solar Physics; 31 Pages; 13 Figure

Norms, Networks, Power, and Control: Understanding Informal Payments and Brokerage in Cross-Border Trade in Sierra Leone

Recent research has cast light on the variety of informal payments and practices that govern the day-to-day interactions between traders and customs agents at border posts in low-income countries. Building on this literature, this paper draws on survey and qualitative evidence in an effort to explore which groups are most advantaged and disadvantaged by the largely informal processes and norms governing cross-border trade. We find that understanding variation in strategies and outcomes across traders can only be effectively understood with reference to the importance of norms, networks, power, and the logic of control.Department for International DevelopmentBill and Melinda Gates Foundatio

PROFIL WISATAWAN MUSEUM RADYA PUSTAKA SURAKARTA

Anggit Margaret, C9407031 2011. Profil Wisatawan Museum Radya Pustaka Surakarta. Program Studi Diploma III Usaha Perjalanan Wisata Fakultas Sastra Dan Seni Rupa Universitas Sebelas Maret Surakarta. Penelitian tugas akhir ini mengkaji tentang Profil Wisatawan di Museum Radya Pustaka Surakarta. Tujuan dari penelitian ini adalah untuk mengetahui dari daerah mana saja wisatawan yang berkunjung ke Museum Radya Pustaka, bagaimana ciri-ciri wisatawan yang berkunjung ke Museum Radya Pustaka serta harapan-harapan yang diinginkan wisatawan terhadap Museum Radya Pustaka. Penelitian dilakukan dengan metode kualitatif. Pengumpulan data dilakukan melalui wawancara dengan narasumber wisatawan yang berkujung di Museum Radya Pustaka Surakarta tempat penulis melakukan penelitian, serta studi pustaka dan studi dokumen guna menambah sumber data. Hasil penelitian menunjukkan bahwa (1) Sebagian besar wisatawan yang datang berasal dari Semarang sebesar 32%. (2) Mayoritas wisatawan yang berkunjung ke Museum Radya Pustaka berusia antara 17-25 tahun dan kebanyakan dari mereka adalah pelajar atau mahasiswa dengan prosentase 52%. (3) Sebagian besar wisatawan yang datang ke Museum Radya Pustaka adalah bertujuan untuk melakukan penelitian yaitu sebesar 34%. (4) Harapan wisatawan yang berkunjung terhadap kelangsungan Museum Radya Pustaka sebagian besar adalah agar ditingkatkan lagi pengelolaan dan keamanan museum, agar kejadian hilangnya benda-benda koleksi museum tidak terulang lagi dikemudian hari. Kesimpulan dari hasil penelitian ini bahwa wisatawan yang berkujung ke Museum Radya Pustaka Surakarta mayoritas berasal dari Semarang, mayoritas berusia 17-25 tahun dan kebanyakan dari mereka adalah berprofesi sebagai pelajar dan mahasiswa. Kebanyakan wisatawan yang datang bertujuan untuk melakukan penelitian, serta harapan wisatawan terhadap Museum Radya Pustaka adalah supaya lebih ditingkatkan lagi pengelolaan dan keamanan museum

Hydride donating abilities of the tetracoordinated boron hydrides

The hydride donating ability (HDA), determined as Gibbs free energy (ΔG°H −) for the reaction of H− dissociation, was assessed via the DFT/M06/6-311++G (d,p) calculations for 90 tetracoordinated borohydrides Li [L3B-H] taking into account the solvent effects via the optimization in MeCN and CH2Cl2 under SMD model. Obtained this way, the HDAMeCN values vary from 118.2 to 13.4 kcal/mol and correlate well with the Lewis acidity parameters (AN, HA and FA) of parent trigonal boranes (L3B). These data show numerically how the variation of the substituents at the boron atom allows the fine-tuning the B–H bond reactivity (reduction power) in the reactions involving hydride transfer as well as the selectivity of the reduction processes. The analysis of the data obtained shows that by varying the number of substituents and their nature, it is possible not only to change the properties of neutral trisubstituted boranes from highly electrophilic (represented by halogenide- and pseudohalogenide-boranes) to highly nucleophilic (exemplified by alkoxy-an amidoboranes), but also to repolarize the boron-bound hydrogen and make the proton transfer process more favourable than the hydride transfer. © 2018 Elsevier B.V

Hydride donating abilities of the tetracoordinated boron hydrides

The hydride donating ability (HDA), determined as Gibbs free energy (ΔG°H −) for the reaction of H− dissociation, was assessed via the DFT/M06/6-311++G (d,p) calculations for 90 tetracoordinated borohydrides Li [L3B-H] taking into account the solvent effects via the optimization in MeCN and CH2Cl2 under SMD model. Obtained this way, the HDAMeCN values vary from 118.2 to 13.4 kcal/mol and correlate well with the Lewis acidity parameters (AN, HA and FA) of parent trigonal boranes (L3B). These data show numerically how the variation of the substituents at the boron atom allows the fine-tuning the B–H bond reactivity (reduction power) in the reactions involving hydride transfer as well as the selectivity of the reduction processes. The analysis of the data obtained shows that by varying the number of substituents and their nature, it is possible not only to change the properties of neutral trisubstituted boranes from highly electrophilic (represented by halogenide- and pseudohalogenide-boranes) to highly nucleophilic (exemplified by alkoxy-an amidoboranes), but also to repolarize the boron-bound hydrogen and make the proton transfer process more favourable than the hydride transfer. © 2018 Elsevier B.V

Comprehensive Insight into the Hydrogen Bonding of Silanes

The interaction of a set of mono-, di- and trisubstituted silanes with OH proton donors of different strength was studied by variable temperature (VT) FTIR and NMR spectroscopies at 190–298 K. Two competing sites of proton donors coordination: SiH and π-density of phenyl rings—are revealed for phenyl-containing silanes. The hydrogen bonds SiH⋅⋅⋅HO and OH⋅⋅⋅π(Ph) are of similar strength, but can be distinguished in the νSiH range: the νSiH⋅⋅⋅HO vibrations appear at lower frequencies while OH⋅⋅⋅π(Ph) complexes give Si–H vibrations shifted to higher frequency. The calculations showed the manifold picture of the noncovalent interactions in hydrogen-bonded complexes of phenylsilanes. As OH⋅⋅⋅HSi bonds are weak, the other noncovalent interactions compete in the stabilization of the intermolecular complexes. Still, the structural and electronic parameters of “pure” DHB complexes of phenylsilanes are similar to those of Et3SiH. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Comprehensive Insight into the Hydrogen Bonding of Silanes

The interaction of a set of mono-, di- and trisubstituted silanes with OH proton donors of different strength was studied by variable temperature (VT) FTIR and NMR spectroscopies at 190–298 K. Two competing sites of proton donors coordination: SiH and π-density of phenyl rings—are revealed for phenyl-containing silanes. The hydrogen bonds SiH⋅⋅⋅HO and OH⋅⋅⋅π(Ph) are of similar strength, but can be distinguished in the νSiH range: the νSiH⋅⋅⋅HO vibrations appear at lower frequencies while OH⋅⋅⋅π(Ph) complexes give Si–H vibrations shifted to higher frequency. The calculations showed the manifold picture of the noncovalent interactions in hydrogen-bonded complexes of phenylsilanes. As OH⋅⋅⋅HSi bonds are weak, the other noncovalent interactions compete in the stabilization of the intermolecular complexes. Still, the structural and electronic parameters of “pure” DHB complexes of phenylsilanes are similar to those of Et3SiH. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Competition between the Hydride Ligands of Two Types in Proton Transfer to [{κ3-P-CH3C(CH2CH2PPh2)3}RuH(η2-BH4)]

The interaction of the mixed hydrido–tetrahydridoborate ruthenium(II) complex [(Triphos)RuH(η2-BH4)] [1; Triphos = κ3-P-CH3C(CH2CH2PPh2)3] with alcohols of variable acidic strength [MeOH, FCH2CH2OH (MFE), CF3CH2OH (TFE), (CF3)2CHOH (HFIP), and (CF3)3COH (PFTB)] was the subject of a combined computational (DFT) and spectroscopic (VT FTIR, NMR) study. The experimental spectra suggests that RuH···HO bond formation precedes the protonation of 1, and H2 evolution leads to the loss of boron and the formation of the dimetallic [{(Triphos)RuH}2(µ,η2:η2-BH4)]+ cation. The experimentally determined basicity factor [Ej(RuH)] of the Ru-bound hydrido ligand of 1.43 is among the highest determined for ruthenium hydrides. Such high basicity leads to very easy proton transfer to the RuH ligand for strong alcohols (HFIP and PFTB). An alternative reaction pathway involving the migration of the bridging hydride (BHbr) to the ruthenium center is suggested for weaker proton donors (MeOH and TFE). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei