bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Pulse-photoconductivity of Poly(N-vinylbenzocarbazole)s
Authors: Itaya Akira , Okamoto Ken-ichi , Kusabayashi Shigekazu 
Published: July 2006

Abstract
The hole-drift mobility and the carrier-photogeneration efficiency of holes in poly(5-vinylbenzo[b]carbazole)(P5VBCz) and poly(7-vinylbenzo[c]carbazole)(P7VBCz) films were investigated by means of the time-offlight method and compared with those in poly (N-vinylcarbazole)(PVCz) films. The mobilities of these polymers were nearly equal to each other and smaller than that of PVCz by a factor of ca. 1/3. The electric field and temperature dependence of the mobilities fit Gill’s empirical equation. The small mobilities of both P5VBCz and P7VBCz were apparently attributable to the small values of the pre-exponential factor, μ0. The carrier-photogeneration efficiencies, φ, of these polymers were larger than that of PVCz by a factor of ca. 10. The field dependence of φ of these polymers for the excitation of the 1Ba absorption band was in good agreement with the Onsager theory of geminate recombination. These results indicate that the introduction of bulky and unsymmetric benzocarbazolyl chromophores instead of carbazolyl ones as a pendant group of vinyl polymers is a good modification from the point of view of the carrier-photogeneration, but not from the viewpoint of the carrier transport.
Rearrangement Approaches to Cyclic Skeletons. I. Photochemical Rearrangement Approaches to (±)-Sesquicarene and (±)-Sirenin, [3–6] Fused-Ring Sesquiterpenes
Authors: Uyehara Tadao , Yamada Jun-ichi , Ogata Koichi , Kato Tadahiro 
Published: July 2006

Abstract
The 4-alkyl, 4-alkenyl, and 4-aryl derivatives of bicyclo[3.2.2]nona-3,6-dien-2-one (9) were prepared from 9 itself by ultrasound-promoted Barbier reaction followed by PCC oxidation. Photochemical transformation of the 4-(4-methyl-3-pentenyl) derivative of 9, namely 13, in THF–water gave endo-7-[exo-7-(4-methyl-3-pentenyl)bicyclo[4.1.0]hept-2-ene]acetic acid (14). Acid 14 was converted into endo-7-methyl-exo-7-(4-methyl-3-pentenyl)bicylo[4.1.0]heptan-2-one (4), a key intermediate of (±)-sesquicarene and (±)sirenin total syntheses. Furthermore, a highly stereospecific total synthesis of (±)-sesquicarene was acomplished by the photochemical transformation of the 1-methyl derivative of 13 prepared from 2-methyltropone (21).
Dopant Structure in FeCl3-doped Polyacetylene Studied by X-Ray Absorption Spectroscopy and X-Ray Photoelectron Spectroscopy
Authors: Asakura Kiyotaka , Ikemoto Isao , Kuroda Haruo , Kobayashi Takaaki , Shirakawa Hideki 
Published: July 2006

Abstract
The dopant structure in FeCl3-doped polyacetylene was studied from the analysis of Fe K-edge EXAFS and XANES, measured by use of synchroton radiation. It is concluded that Fe atom is surrounded by four Cl atoms with Fe–Cl distance of 2.19–2.20 Å, and the dopant exists in the state of [FeCl4]−. The following mechanism is proposed for the doping process:
(CH)x+2yxFeCl3→[CH(Fe(Cl4−)y]x+yxFeCl2
It is also shown that the chlorination of polyacetylene occurs significantly on performing a “heavy doping.”
Regioselectivity of the Coupling of Phenoxyallyllithium with Allylic Electrophiles
Authors: Butsugan Yasuo , Goto Tomokazu , Araki Shuki 
Published: July 2006

Abstract
The regioselectivity of the coupling of phenoxyallyllithium with allylic electrophiles was investigated. The allylation pattern corresponded with the hardness of the leaving group and the highest α-selectivity was observed in the reaction with allylic phosphate.
N-Nitroso Compounds. IV. Reaction of N-Nitrosourea with Thiol. A New Synthesis of Thiocarbamic S-Esters
Authors: Yoshida Kitaro , Isobe Masayoshi , Yano Kazuyuki , Nagamatsu Kazuo 
Published: July 2006

Abstract
Thirteen thiocarbamic S-esters have been synthesized in good yield by the reaction of thiol with substituted N-methyl-N-nitrosourea in anhydrous acetonitrile.
Synthesis of Macrocarbocycles Utilizing Intramolecular 1,3-Dipolar Cycloaddition of Nitrile Oxides. Synthesis of (±)-Muscone
Authors: Asaoka Morio , Abe Masayoshi , Takei Hisashi 
Published: July 2006

Abstract
Intramolecular 1,3-dipolar cycloaddition of nitrile oxides generated from ω-nitro-1-alkenes gave isoxazoline-fused macrocarbocycles (ring size 12, 14, 15, and 16) in fair to good yields. The 15-membered derivative was converted into (±)-muscone.
The Reactions of Silicon Phosphate with Alkaline Earth Metal Oxides at High Temperatures
Authors: Narita Eiichi , Sango Kazuhiro , Naito Hiroyuki 
Published: July 2006

Abstract
The reactions of Si3(PO4)4 with CaO and MgO at high temperatures up to 1150 °C yielded silicon phosphate glass, Me3(PO4)2, Me2P2O7, and α-cristobalite, depending on the temperature, the heating time, and the MeO/Si3(PO4)4 molar ratio (Me: Ca and Mg). These reactions were found to proceed by means of the one-way diffusion of alkaline earth metal oxides into the Si3(PO4)4 phase.
Reaction of Olefins with Malonamide in the Presence of Manganese(III) Acetate. Formation of α,β-Unsaturated γ-Lactones and γ-Lactams
Authors: Nishino Hiroshi 
Published: July 2006

Abstract
The reaction of olefins with malonamide in the presence of manganese(III) acetate gave 2-buten-4-olides and/or 1H-pyrrol-2(5H)-ones in one-step, short reaction time, and moderate yields. The product distribution can be accounted for in terms of the stabilization of the intermediate carbocation in the oxidation process. The synthetic application and limitation, and the oxidation mechanism for the formations of α,β-unsaturated γ-lactones and γ-lactams are discussed.
Synthesis and Molecular Structure of the 2:1-Cycloadduct of 1-Methoxy-2-benzopyrylium-4-olate with Acenaphthylene
Authors: Toyoda Jiro , Ibata Toshikazu , Tamura Hatsue , Ogawa Kazuhide , Nishino Tsuyoshi , Takebayashi Matsuji 
Published: July 2006

Abstract
The Cu(acac)2-catalyzed decomposition of o-methoxycarbonyl-α-diazoacetophenone in the presence of acenaphthylene gave a 2:1-cycloadduct of the corresponding carbonyl ylide, 1-methoxy-2-benzopyrylium-4-olate, with acenaphthylene along with exo- and endo-1:1-adducts. The molecular structure of the 2:1-adduct was determined by means of X-ray analysis. The colorless crystals of the adduct are triclinic with the space group P\bar1,and with the unit-cell dimensions of a=12.104(2), b=12.477(3), c=9.112(2)Å, α=102.98(3), β=110.16(2), γ=70.65(1)°, and Z=2. The structure was determined by direct methods and refined by block-diagonal least-squares methods. All hydrogen atoms were revealed by a difference-Fourier synthesis, and further least-squares refinement gave the final R value of 0.057 for 3681 observed reflections. The configurations of methine protons obtained by X-ray methods are compatible with the NMR coupling pattern of the adduct.
Studies of the Formation of Complexes of Np(V) with Inorganic Ligands by Means of Solvent Extraction with 2-Thenoyltrifluoroacetone and 1,10-Phenanthroline. II. Fluoro, Sulfato, and Phosphato Complexes
Authors: Inoue Yasushi , Tochiyama Osamu 
Published: July 2006

Abstract
The formation constants of the complexes of Np(V) with fluoride, sulfate, and phosphate have been determined in 1 mol dm−3 NaClO4 at 25 °C by means of the solvent-extraction method using 2-thenoyltrifluoroacetone and 1,10-phenanthroline. Extractions at various pH values revealed that H2PO4− and HPO42− participate in the complex formation of Np(V).
The Bound Ligand Effect in the Complexation Kinetics of Some Anionogallium(III) Complexes
Authors: Yamada Shinkichi , Tanaka Motoharu 
Published: July 2006

Abstract
The formation rate of some anionogallium(III) complexes (GaA) with 4,5-dihydroxy-1,3-benzenedisulfonate (H2L2−) in the presence of thiocyanate ion has been studied spectrophotometrically by a stopped-flow technique. The rate law is expressed as d[GaL−]/dt=kGa[Ga3+[H2L2−]+kGaOH[GaOH2+][H2L2−]+kGa(OH)2[Ga(OH)2+][H2L2−]+kGaNCS[GaNCS2+][H2L2−], with kGa=101.23 M−1 s−1 (M=mol dm−3), kGaOH=103.36 M−1 s−1, kGa(OH)2=104.37 M−1 s−1, and kGaNCS=103.90 M−1 s−1 at 25 °C and I=0.50M. The enhanced reactivity of GaA as compared to that of Ga3+ is attributable to the labilizing effect of the bound ligand A on the rate of loss of coordinated water molecules at GaA. Together with the additional formation rate constants of monoisothiocyanato- and monooxalatogallium(III) with 2-hydroxy-2,4,6-cycloheptatrien-1-one, this labilizing effect is quantitatively discussed in terms of the electron-donating ability of the ligand.
Preparation and Characterization of [Co(acetylacetonato)(diamine or 2,2′-bipyridyl)(aminoalkylphosphine)]2+. Crystal Structure of (+)531CD-Λ-fac(N)-(Acetylacetonato){(1R,2R)-1,2-cyclohexanediamine}{(2-aminoethyl)diphenylphosphine}cobalt(III) Perchlorate, [Co(C5H7O2)(C6H14N2)(C14H16NP)](ClO4)2
Authors: Takata Masakazu , Kashiwabara Kazuo , Ito Haruko , Ito Tasuku , Fujita Junnosuke 
Published: July 2006

Abstract
Nine new cobalt(III) complexes of the types, [Co(acac)(L)(edpp)]2+ (L=ethylenediamine(en), (1R,2R)-1,2-cyclohexanediamine(RR-chxn), 2,2′-bipyridyl(bpy)), [Co(acac)(L′)(empp)]2+ (L′=en, bpy), and structurally related [Co(acac)(bpy)(en)]2+ were prepared and resolved into optical isomers, where acac, edpp, and empp denote an acetylacetonate ion, (2-aminoethyl)diphenylphosphine, and (2-aminoethyl)methylphenylphosphine, respectively. The molecular structure of (+)531CD-[Co(acac)(RR-chxn)(edpp)](ClO4)2 was determined by single-crystal X-ray analysis. Crystal data; monoclinic, P21, a=19.562(3)Å, b=16.882(1)Å, c=9.696(1)Å, β=91.22(1)°, V=3201.3(6)Å3, Z=4. Three nitrogen donor atoms in the complex ion are arranged in the facial mannar (fac(N)) and the absolute configuration of the complex ion is Λ. The structures of other complexes were assigned by comparing the 1H NMR and circular dichroism spectra with those of the fac(N)-Λ-[Co(acac)(RR-chxn)(edpp)]2+ complex. The complexes containing a 1,2-diamine yielded selectively the fac(N) isomer, whereas those containing bpy the mer(N) isomer.
Mössbauer, Raman, and DTA Studies on the Structure of BaF2–ZrF4–FeF2 Glasses
Authors: Nishida Tetsuaki , Nonaka Toshiaki , Takashima Yoshimasa 
Published: July 2006

Abstract
Structural studies on the ternary BaF2–ZrF4–FeF2 glasses have been performed to elucidate the local structure of the ZrF4-based glasses which are known to be excellent in the optical transparency and the electric conductivity due to F− ion. Mössbauer and Raman measurements reveal that iron (Fe2+ and Fe3+) plays a structural role similar to that of Ba2+ ion surrounded by eight fluorine atoms at the interstitial site of one- or two-dimensional zigzag chains composed of ZrF6 octahedra. Raman and DTA measurements reveal that the increase in the fraction of BaF2 causes an increase in the coordination number of Zr from 6 to 7. Mössbauer measurements of 25BaF2·65ZrF4·10FeF2 glass at lower temperatures lead to a conclusion that the glass undergoes a phase transition at 225±5K, of which structural change is easily reflected in the isomer shift, quadrupole splitting, and the absorption area. This is supported by the DTA measurement of the same sample at lower temperatures, i.e., the DTA curve consists of two exothermic peaks and a wide endothermic peak observed at about 220–230 K and 180–210 K, respectively.
Determination of Rate Constants for Reactions of Bichloride Anion Radical with Some Dipeptides in Aqueous Solution of KCl and K2S2O8 by Flash Photolysis
Authors: Neda Osamu , Yamauchi Kotaro , Masuda Takahiro 
Published: July 2006

Abstract
Determination of rate constants for reactions of dichloride anion radical was conducted by conventional flash photolysis of aqueous solutions of KCl and K2S2O8, where no participation of HOCL−· is expected in decay kinetics of dichloride anion radical. The optimum conditions found for the determination are 0.1 mol dm−3 KCl and 10−4 mol dm−3 K2S2O8. Under the present experimental conditions, S2O82− serves to convert chloride ion to dichloride anion radical through reaction with hydrated electron produced by photolysis of chloride ion. For glycyltryptophan, the competition method was employed, because its transient absorption overlaps the absorption due to dichloride anion radical. The rate constants determined are almost the same as those obtained in N2O-saturated aqueous solution of KCl (1 mol dm−3). The reactivity of dipeptides toward dichloride anion radical is discussed.
Polarization in Light-scattering by Aerosol
Authors: Matsuzaki Akiyoshi 
Published: July 2006

Abstract
The polarization of the light scattered by aerosol has been studied by the theoretical calculation based on the Mie scattering theory. The present calculation obtains the polarization of the light scattered by aerosol as a function of size parameter, i.e. x=2πr⁄λ, where r and λ are the radius of aerosol and the wavelength of the scattered light, respectively, for various refractive indexes. These results give the useful informations for the experimental study on the size-growth in aerosol formation by the measurement of the scattered light polarization. The characteristic of the scattered light intensity, which is usually used as a kind of concentration parameter in the study on aerosol formation, is also discussed.
The Iodine-127 Nuclear Quadrupole Resonance of Several Iodine Complexes with Sulfur-containing Organic Molecules
Authors: Terao Hiromitsu , Sakai Hiroshi , Negita Hisao 
Published: July 2006

Abstract
The 127I NQR spectra of 1,4-dithiane–2I2, thiane–I2, 1,4-thioxane–I2, and 1,3,5-trithiane–I2 are reported. Two distinct iodine atoms are observed in the former three complexes, whereas only one iodine atom is present in the last-named complex. The charge densities on the donors and the iodine atoms are obtained according to the Townes-Dailey approximation. The order of donor strength toward the iodine molecule is: thiane&gt;1,4-thioxane&gt;1,4-dithiane&gt;&gt;1,3,5-trithiane. The thioethers can compete with amines in terms of the donor strength to iodine molecules. The no-bond ionic structure of the ground state is less important in the thioether–iodine complexes than in amine–iodine complexes. The positive temperature coefficients found previously in a few similar complexes of amines are observed for the terminal iodine atoms of 1,4-dithiane–2I2, thiane–I2, and 1,4-thioxane–I2. This phenomenon is ascribed to the increasing shift of the dative structure to the no-bond covalent structure with the rise in the temperature.
Voltammetric Studies of the Metal–Ligand Interaction in Low-valent Metal–Olefin π-Complexes. II. Palladium(0) and Platinum(0) Complexes with Olefin–Diimine Mixed Ligands
Authors: Ito Naoyuki , Saji Tetsuo , Aoyagui Shigeru 
Published: July 2006

Abstract
Cyclic voltammograms for the reduction of Pd0 and Pt0 complexes with mixed ligands of diimine and olefin exhibit, respectively, two or four reversible one-electron steps. The half-wave potentials of each step give a straight line with a slope of 1.0, when plotted against the half-wave potentials of diimine ligands, and a slope smaller than 0.2, when plotted aganist the half-wave potentials of olefinic ligands. The half-wave potentials of the complexes are affected only a little by the difference in the central metal. These findings lead to the conclusion that each LUMO of these complexes is dominated by the diimine π*-orbital, though it is higherlying than the olefinic π*-orbital in free ligands.
Bitter Principles of Ailanthus altissima Swingle. Conversion of Ailanthone into Shinjulactone C
Authors: Ishibashi Masami , Tsuyuki Takahiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
Ailanthone was converted into shinjulactone C with a hexacyclic 1α,12α:5α,13α-dicyclo-9βH-picrasane skeleton. The key reaction consists of an intramolecular ionic [4+2] cycloaddition between a pentadienyl cation and an olefin.
Studies with Inorganic Ion-exchange Membranes. I. Effect of Binding Material on the Permeation of Electrolyte Solutions across Titanium Tungstoarsenate Membranes
Authors: Srivastava S K , Kumar Satish , Kumar Surendra 
Published: July 2006

Abstract
A comparative study of permeability for various electrolytes is made on parchment-, polystyrene-, and Araldite based membranes of titanium tungstoarsenate at 20, 25, 30, and 35 °C. At any given temperature the order of permeability increase is K+&gt;Na+&gt;Li+ for 1:1 electrolytes and Ba2+&gt;Ca2+&gt;Mg2+ for 2:1 electrolytes. Permeability values are higher for parchment-based than polystyrene-based membranes. The diffusion of these electrolyte solutions across Araldite based membrane is almost negligible. Thermodynamic parameters of diffusion process, viz., ΔH≠, ΔS≠, ΔF≠ have been evaluated at 25 °C by applying the theory of absolute reaction rates. ΔS≠ values are negative for all the cations for both the membranes except that of Li+ which is positive for parchment-based membranes. ΔF≠ values are higher for the polystyrene-based than parchment-based membranes.
The Fluorescence Lifetimes of Jet-cooled Alkylnaphthalenes
Authors: Ichimura Teijiro , Auty Andrew R , Jones Anita C , Phillips David 
Published: July 2006

Abstract
The measured fluorescence lifetime of the origin of jet-cooled 1-methylnaphthalene is close to that of naphthalene, whereas the corresponding lifetimes of the 2-substituted are longer. The fluorescence lifetime decreased with increasing excitation energy; this can be attributed to an increase in the rate of intersystem crossing with vibrational excitation.
Reaction of Trimethylsilyl Azide with C=N–O Bond
Authors: Nishiyama Kozaburo , Miyata Izumi 
Published: July 2006

Abstract
Trimethylsilyl azide (TMSA) was reacted with an oxime ester or a Reissert salt in the presence of trimethylsilyl trifluoromethanesulfonate to give tetrazole derivative. The details of these reactions are examined.
Desulfurization of Thioketones and Thioamides with Diphosphorus Tetraiodide
Authors: Suzuki Hitomi , Tani Hiroyuki , Takeuchi Setsuko 
Published: July 2006

Abstract
On heating with diphosphorus tetraiodide in benzene, thioketones undergo reductive desulfurization to afford parent hydrocarbons, while thioamides are slowly converted into nitriles.
Absolute Configuration of Platyphylloside and (−)-Centrolobol
Authors: Ohta Shinji , Koyama Mika , Aoki Tadashi , Suga Takayuki 
Published: July 2006

Abstract
The absolute configuration of platyphylloside was established to be S by 13C NMR spectroscopy. On the basis of this establishment, the S-configuration previously assigned to the chirality at C-3 of (−)-centrolobol was revised to the R-configuration.
Studies of Collectors. VI. Application of β-Diketone-type Surfactants to Ion Flotation
Authors: Koide Yoshifumi , Kitaoka Shuichi , Yamada Kimiho 
Published: July 2006

Abstract
β-Diketone-type surfactants(2,4-alkanedione, RnA) were applied as ion-flotation collectors and as extraction reagents. Fe3+, Ga3+, and Cu2+ were floated effectively with RnA as a 1:1 complex from an acidic solution. From a mixture of metal ions(Fe3+, Ga3+, Cu2+, Zn2+, Pb2+, Cd2+, and Ca2+), the Cu2+ was floated selectively at pH 6 by R8A or R12A. Then, the metal ions were extracted with RnA into a benzene layer as coordination-saturated species at regions of a neutral pH. The order of selectivity at pH 6.0 was Fe3+&gt;Cu2+&gt;···. The difference between the properties of RnA as an ion-flotation collector and as an extraction reagent was explained using the HLB value and the surface activity based on the composition of RnA–metal complexes. The metal ions and RnA could be recovered from the scum.
Molecular Deformation Caused by Hydrogen Bonding and Resonance. 1,3-Dimethyl-2-imidazolidinone
Authors: Fukushima Kunio , Haraoka Takashi 
Published: July 2006

Abstract
The Raman spectra of 1,3-dimethyl-2-imidazolidinone were found to change due to a hydrogen bonding to its nitrogen atoms, especially at low temperatures. The change in the spectra included the unusual change for CH2 bending vibrations, suggesting that the deformation of the ring of the molecule takes place by hydrogen bonding.
A Thermodynamic Study on Micellization of Nonionic Surfactant in Water and in Water–Ethanol Mixture by Gel Filtration
Authors: Goto Ayako , Takemoto Masumi , Endo Fumio 
Published: July 2006

Abstract
Micellization of hexa(oxyethylene) dodecyl ether (C12E6) was studied in water and in ethanol–water mixtures at different temperatures by gel filtration on Sphacryl S-200. Standard enthalpies and entropies of micellization were determined from variation of critical micelle concentration(cmc) with temperature. Compensation plots were obtained, slopes for alcohol–water mixtures being indentical with that for pure water. Therefore, the micelle formation in water and ethanol–water mixtures has been explained in terms of its bulk structure. Gel fitration of C12E6 micelle with addition of a large amount of ethanol has led to a finding that the micelle size gradually becomes small with increasing ethanol content until micelles disappear above 35%v/v.
Glass Formation Study of Aqueous HX Solutions (X=F, Cl, and Br)
Authors: Kanno Hitoshi , Satoh Kenji 
Published: July 2006

Abstract
Glass-forming composition regions of aqueous HX solutions (X=F, Cl, and Br) were determined. It was found that oxonium ions play an important role in glass-forming behavior of these solutions. Including the results for HI solution previously reported, the general trends of glass-formation behavior of aqueous HX solutions are summarized.
Kinetic Analysis of the High-pressure Diels-Alder Reactions of Tropone with Maleic Anhydride and Norbornene
Authors: Takeshita Hitoshi , Sugiyama Shigeru , Hatsui Toshihide 
Published: July 2006

Abstract
The kinetics of Diels-Alder reactions of tropone with maleic anhydride and norbornene were studied at pressures up to 2000 bar. The activation volumes, obtained from the former at 378.2 K in isopropylbenzene (IPB) and N,N-dimethylformamide (DMF), were ΔV≠(IPB)=−21.4 cm3/mol and ΔV≠(DMP)=−16.8 cm3/mol. Those from the latter (at 408.2 K) were ΔV≠(IPB)=−30.0 cm3/mol and ΔV≠(DMF)=−27.8 cm3/mol. These ΔV≠ and ΔV showed a large deviation from those of the (6+4)π process of tropone with cyclopentadiene (by le Noble) and a small deviation from those of other typical Diels-Alder reactions to support the concerted cycloaddition mechanism which has been established by the kinetic analysis at atmospheric pressure.
Critical Peptide Size for Insolubility Caused by a β-Sheet Aggregation and Solubility Improvement in Hydrophobic Peptides by Replacement of Alanine Residues with α-Aminoisobutyric Acid Residues
Authors: Narita Mitsuaki , Chen Junn-Yann , Sato Hiroyuki , Kim Yukio 
Published: July 2006

Abstract
In order to demonstrate an important role of a β-sheet aggregation on insolubility of peptides, hydrophobic peptides having partial amino acid sequences found in natural proteins have been prepared by the step-wise elongation and fragment condensation methods. In conformity with the solubility prediction for protected peptides in our previous paper, solubility data indicate that insolubility of peptides appears to begin at octa- or nonapeptide levels. In hydrophobic sequences found in proteins, the structure of peptide backbones, namely, the β-structure clearly plays an important role on insolubility of peptides, but the composition of peptides does not. Solubility improvement in hydrophobic peptides included in α-helical regions of proteins is easily achieved by replacement of Ala residues with Aib residues. High solubility of the peptides containing Aib residues is clearly explained by the observation that replacement of Cα hydrogen atoms with methyl groups greatly disturbs β-sheet structures, promoting helical folding in peptides. The great ability of an Aib residue to promote helical folding is distinctly revealed in the peptide fragments included in α-helical regions of proteins as demonstrated before in model oligo(Leu)s.