Characterization of thin films based on reflectance and transmittance measurements at oblique angles of incidence

The optical parameters of a SiO2 thin-film coating determined from the spectral reflectance and transmittance measurements at various incidence angles, including the normal incidence and the Brewster's angle, are compared in this paper. The high-accuracy measurements were carried out through visible-near-infrared spectral regions by using our purpose-built instruments. The optical parameters obtained from the reflectance and the transmittance data are consistent over the angles of incidence and agree within 0.2%. The effect of important systematic factors in the oblique-incidence spectrophotometric measurements is also discussed.     

The aroma of the fruit of sea Buckthorn,Hippophae rhamnoides, L.

Summary Volatile components of Sea Buckthorn fruit were studied by combined gas chromatography-mass spectrometry. A total of 60 components were identified, corresponding to about 36 mg/kg of the total volatile oil. The aroma of Sea Buckthorn fruit was characterized by the presence of several aliphatic esters such as ethyl, 3-methylbutyl andcis-3-hexen-1-y1 esters. The most important compounds were ethyl hexanoate, 3-methylbutyl 3-methylbutanoate, 3-methylbutanoic acid, 3-methylbutyl hexanoate, 3-methylbutyl benzoate and 3-methylbutyl octanoate. The concentrations of terpenes and aromatic compounds were surprising low.

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Das Aroma von Sanddornfrüchten,Hippophae rhamnoides, L.

Zusammenfassung Die flüchtigen Aromastoffe von Sanddornfrüchten wurden gaschromatographisch-massenspektrometrisch bestimmt. Bei einem Gehalt von etwa 36 mg/kg wurden insgesamt 60 flüchtige Verbindungen identifiziert. Für das Aroma ist die Anwesenheit von zahlreichen aliphatischen Estern wie Ethyl-, 3-Methylbutyl- und cis-3-Hexen-1-y1-Estern charakteristisch. Die Hauptkomponenten sind Ethyl-hexanoat, 3-Methylbutyl-3-methylbutanoat, 3-Methylbutansäure, 3-Methylbutylhexanoat, 3-Methylbutylbenzoat und 3-Methylbutyloctanoat. Dagegen sind die Konzentrationen an Terpenen und aromatischen Verbindungen überraschend niedrig.

     

Overcoming the Cut‐Off Charge Transfer Bandgaps at the PbS Quantum Dot Interface

Light harvesting from large size of semiconductor PbS quantum dots (QDs) with a bandgap of less than 1 eV is one of the greatest challenges precluding the development of PbS QD‐based solar cells because the interfacial charge transfer (CT) from such QDs to the most commonly used electron acceptor materials is very inefficient, if it occurs at all. Thus, an alternative electron‐accepting unit with a new driving force for CT is urgently needed to harvest the light from large‐sized PbS QDs. Here, a cationic porphyrin is utilized as a new electron acceptor unit with unique features that bring the donor–acceptor components into close molecular proximity, allowing ultrafast and efficient electron transfer for QDs of all sizes, as inferred from the drastic photoluminescence quenching and the ultrafast formation of the porphyrin anionic species. The time‐resolved results clearly demonstrate the possibility of modulating the electron transfer process between PbS QDs and porphyrin moieties not only by the size quantization effect but also by the interfacial electrostatic interaction between the positively charged porphyrin and the negatively charged QDs. This approach provides a new pathway for engineering QD‐based solar cells that make the best use of the diverse photons making up the Sun's broad irradiance spectrum.     

Solid-State Reactions between Cu(Ni) Alloys and Sn

Solid-state interfacial reactions between Sn and Cu(Ni) alloys have been investigated at the temperature of 125°C. The following results were obtained. Firstly, the addition of 0.1 at.% Ni to Cu decreased the total thickness of the intermetallic compound (IMC) layer to about half of that observed in the␣binary Cu/Sn diffusion couple; the Ni addition decreased especially the thickness of Cu₃Sn. Secondly, the addition of 1 to 2.5 at.% Ni to Cu further decreased the thickness of Cu₃Sn, increased that of Cu₆Sn₅ (compared to that in the binary Cu/Sn couple) and produced significant amount of voids at the Cu/Cu₃Sn interface. Thirdly, the addition of 5 at.% Ni to Cu increased the total thickness of the IMC layer to about two times that observed in the binary Cu/Sn diffusion couple and made the Cu₃Sn disappear. Fourthly, in contrast to the previous case, the addition of 10 at.% Ni to Cu decreased the total IMC (Cu₆Sn₅) thickness again close to that of the Cu/Sn couple. With this Ni content no voids were detected. The results are rationalized with the help of␣the thermodynamics of the Sn-Cu-Ni system as well as with kinetic considerations.     

GTPP: General Truncated Pyramid Peer-to-Peer Architecture over Structured DHT Networks

Hierarchical Distributed Hash Table (DHT) architectures have been among the most interesting research topics since the birth of flat DHT architecture. However, most of the previous work has merely focused on the two-tier hierarchy. In this paper, we study and analyze General Truncated Pyramid Peer-to-Peer (GTPP) architecture, the generalized version of Partially Vertical Hierarchical Architecture (PV-HA). The idea is to study whether added tiers of hierarchy can provide added value in performance and functionality. Through mathematical analysis, we demonstrate performance results in comparison to flat architecture, which helps understanding the typical characteristics of hierarchical architectures. Firstly, GTPP has slightly higher expected lookup hop count, although it can be decreased with optimizing the sub-overlay setup. However, GTPP significantly decreases the expected lookup routing latency. Secondly, GTPP has clearer and more reasonable traffic distribution among all the peers from different tiers of sub-overlays, and can work with slightly lower maintenance traffic. Thirdly, our studies indicate that two to three tiers are most suitable in most cases for GTPP, considering all the parameters.     

黑液加热处理—改善非木材纤维黑液的蒸发和燃烧性能

讨论了黑液加热处理对芦苇硫酸盐浆和麦草碱法浆黑液的影响。试验采用工厂的黑液，黑液热处理有效地降低了这两种黑液的粘度，在相同２００ｍＰａｓ的粘度值，处理后的芦苇硫酸盐浆黑液固形物含量增加了约１０％，而麦草碱黑液增加了近１５％。增加黑液固形物含量可明显提高碱回收锅炉的生产效率，根据计算的结果，锅炉生产能力可增加１３％。     

The aroma of blueberries

The volatile components of bilberry, bog blueberry and cultivated high-bush blueberry (cv. Rancocas) were analysed by gas chromatography and mass spectrometry. Several new compounds not reported previously as blueberry volatiles were detected. These included methyl and ethyl 2-hydroxy-3-methylbutanoate, methyl and ethyl 3-hydroxy-3-methylbutanoate, 2-phenylethyl formate, methyl salicylate, farnesol, farnesyl acetate, vanillin, myristicine, 4-vinylphenol, 2-methoxy-5-vinylphenol, citronellol, hydroxycitronellol and some γ- and δ-lactones. The character impact compounds of bilberry were found to be the above-mentioned hydroxy esters together with 2-phenylethanol and its esters and the γ- and δ-lactones, whereas myristicine, citronellol, hydroxycitronellol, farnesol and farnesyl acetate were typical of the aroma of high-bush blueberry.     

Spectral and chemical analyses of mould development on Scots pine heartwood

Scots pine heartwood specimens were exposed to mould in controlled humid atmosphere (RH 95%, T?=20 °C) and the responses of electrical impedance and Fourier transform infrared spectroscopy (EIS and FTIR) methods were studied. The concentration of methanol soluble heartwood extractives and the emission of volatile organic compounds (VOC) were determined from the parallel samples. Results show that the spectral responses and VOC emissions were related to the mould development. According to this study, VOC emissions might be used for discriminating mould susceptible and resistant samples. FTIR spectra showed that the relation of amide (1655 cm^-1) and carbonyl peaks (1736 cm^-1) was significantly affected by mould. In the EIS analyses, there also were electrical parameters, which were significantly affected by mould. In conclusion, both spectral methods hold potential for non-destructive mould detection and monitoring of mould development.     

BIOTIN-ACTIVE COMPOUNDS,THEIR EXISTENCE IN NATURE AND THE BIOTIN REQUIREMENTS OF YEASTS

After a short account of the discovery of biotin and the progress of early biotin research, the natural occurrence of biotin with particular consideration to the raw materials used in the fermentation industry and its products is described. Of the many known biotin derivatives, those appearing in nature and those which can be converted to biotin-active (or inactive) compounds by simple procedures are reported. Ways to by-pass the need for biotin in microbes is discussed. The importance of biotin in yeast production, the biotin requirements of yeast, and the effect of culture conditions on these requirements are reported. The close relationship between the participation of biotinylenzymes and the biotin requirements is noted.     

The aroma of cranberries

Summary Volatile components of European and American cranberries were studied by combined gas chromatography-mass spectrometry. A total of 70 components were identified, corresponding to about 16.1 ppm and 3.7 ppm of the total volatile oil, in European and American cranberries, respectively. The aroma of cranberries is characterised by the presence of several aromatic compounds together with-terpineol. More than 35 compounds not reported previously as cranberry volatiles were identified. These included terpinolene, p-mentha-1,8-diene, thujene, p-mentha-1,8-diol, carvenone, 1-phenylethanol, 3-phenylpropan-1-ol,trans-cinnamyl alcohol, 2-(4-hydroxyphenyl)-ethanol, 2-(4-methoxyphenyl) ethanol, salicylaldehyde, 4-methoxybenzaldehyde, 3-phenylpropanal,trans-cinnamaldehyde, vanillin, 4-hydroxyacetophenone, 4-methoxyacetophenone, 4-(4-hydroxphenyl)butan-2-one, 4-(4-hydroxy-3-methoxyphenyl)butan-2-one, methyl cinnamate, 2-phenylethyl formate, and some-and-lactones. p-Methan-1,8-diol (terpin hydrate) has not been identified in any berries or fruits. In general, the concentrations of the individual components in European cranberries were 4–5 times higher than in American berries.

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Das Aroma von Moosbeeren

Zusammenfassung Die flüchtigen Aromastoffe der europäischen und amerikanischen Moosbeeren wurden gaschromatographisch-massenspektrometrisch bestimmt. Insgesamt 70 Bestandteile wurden identifiziert, entsprechend einem Gehalt an ätherischem Öl von etwa 16,1 ppm in europäischen und 3,7 ppm in amerikanischen Moosbeeren. Charakteristisch für das Aroma von Moosbeeren ist die Anwesenheit von zahlreichen aromatischen Komponenten und-Terpineol. Mehr als 35 Komponenten wurden festgestellt, die bisher nicht in Moosbeeren identifiziert worden sind. Zu diesen gehören: Terpinolen, p-Menthadien, Thujen, p-Menthan-1,8-diol, Carvenon, 1-Phenylaethanol, 3-Phenylpropan-1-ol,trans-Zimtalkohol, 2-(4-Hydroxyphenyl)-aethanol, 2-(4-Methoxyphenyl)aethanol, Salicylaldehyd, 4-Methoxybenzaldehyd, 3-Phenylpropanal,trans Zimtaldehyd, Vanillin, 4-Hydroxyacetophenon, 4-Methoxyacetophenon, 4-(4-Hydroxphenyl)butan-2-on, 4-(4-Hydroxy-3-methoxyphenyl)butan-2-on, Zimtsäuremethylester, Ameisensäure-2-phenylethylester sowie einige- und-Lactone. p-Menthan-1.8-diol (Terpinhydrat) ist bisher in keinen Beeren und Früchten gefunden worden. Im allgemeinen sind die Konzentrationen der einzelnen Komponenten in der Europäischen Moosbeere 4 bis 5mal so hoch wie in amerikanischen Moosbeeren.