A Highly Active and Selective Manganese Oxide Promoted Cobalt-on-Silica Fischer�CTropsch Catalyst

A highly active and selective manganese oxide-promoted silica-supported cobalt catalyst for the Fischer?CTropsch reaction is reported. Co/MnO/SiO₂ catalysts were prepared via impregnation of a cobalt nitrate and manganese nitrate precursor, followed by drying and calcination in an NO/He flow. The catalysts were studied with STEM?CEELS, infrared spectroscopy measurements of adsorbed CO and Steady-State Isotopic Transient Kinetic Analysis experiments. Based on those experiments, a relation between C₅₊-selectivity and surface-coverages of CH _x -intermediates on cobalt was found.     

Growth of single-walled carbon nanotubes with controlled diameters and lengths by an aerosol method

On the basis of combined study of the transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and ultraviolet–visible–near infrared absorption spectroscopy, the properties of the single-walled carbon nanotubes (SWCNTs), synthesized by aerosol (floating catalyst) chemical vapor deposition method by ferrocene vapor decomposition in the presence of carbon monoxide, are studied in details. The results show that increasing the temperature gives rise to the formation of high quality and large diameter SWCNTs. By monitoring the water-cooled probe position, both the bundle length and the diameter of the SWCNTs are effectively tuned due to the variation of the residence time and temperature profile in the reactor. An introduction of a small amount of CO₂ suppresses the growth of small diameter nanotubes and enlarges the mean diameter of SWCNT samples. The mean diameter of SWCNTs could be easily altered in a broad range from 1.1 to 1.9 nm during growth, which is essential for the SWCNT applications in optical and electronic devices.     

Dietary Fat in Relation to Erythrocyte Fatty Acid Composition in Men

Erythrocyte membrane fatty acid (EMFA) composition is used in the validation of food frequency questionnaires (FFQ) and the evaluation of dietary fat quality. In this cross-sectional study we aimed to investigate associations of diet with EMFA. Altogether, 1,033 randomly selected Finnish men, aged from 47 to 75 years filled in a FFQ and their EMFA composition was analyzed. Marine polyunsaturated fatty acid (PUFA) intake correlated positively with erythrocyte eicosapentaenoic and docosahexaenoic acids (r _s = 0.415 and r _s = 0.340, respectively, P < 0.001) and inversely with all n-6 PUFA analyzed (P < 0.001). PUFA intake from spreads and cooking fats correlated positively with alpha-linolenic (ALA), linoleic (LNA) and nervonic acids (r _s = 0.229, r _s = 0.160 and r _s = 0.143, respectively, P < 0.001). Milk fat intake was associated with myristic and behenic acids (r _s = 0.186 and r _s = 0.132, respectively P < 0.001). Butter users had lower ALA and LNA proportions (mol%) than non-users (0.16 ± 0.04 vs. 0.19 ± 0.05, P < 0.001 and 7.77 ± 1.02 vs. 8.12 ± 1.11, P = 0.001). Higher PUFA intake from meat was related to decreased long-chain n-3 (P < 0.001) and increased n-6 PUFA (P < 0.001) proportions. In conclusion, EMFA composition reflects particularly well the intakes of n-3 PUFA, whereas other associations remained lower. Yet, all main sources of dietary fat were related with EMFA. The dietary effect on the nervonic acid proportion was confirmed.     

Characterization of Process Conditions in Industrial Stainless Steelmaking Electric Arc Furnace Using Optical Emission Spectrum Measurements

Emission spectroscopy is a potential method for gaining information on electric arc furnace (EAF) process conditions. Previous studies published in literature on industrial EAF emission spectra have focused on a smaller scales and DC arc furnaces. In this study emission spectrum measurements were conducted for 140t AC stainless steelmaking EAF at Outokumpu Stainless Oy, Tornio Works, Finland. Four basic types of emission spectra were obtained during the EAF process cycle. The first one is obscured by scrap steel, the second is dominated by thermal radiation of the slag, the third is dominated by alkali peaks and sodium D-lines and the fourth is characterized by multiple atomic emission peaks. The atomic emission peaks were identified by comparing them to the NIST database for atomic emission lines and previous laboratory measurements on EAF slag emission spectra. The comparison shows that the optic emission of an arc is dominated by slag components. Plasma conditions were analyzed by deriving plasma temperature from optical emissions of Ca I lines. The analysis suggests that accurate information on plasma conditions can be gained from outer plasma having a plasma temperature below 7000 K (6727 °C).     

Displacement control of a mobile crane using a digital hydraulic power management system

The Digital Hydraulic Power Management System (DHPMS) is an innovation that is claimed to significantly improve the energy efficiency of hydraulic systems. It is based on digital pump-motor technology but has multiple independent outlets; hence, the transformer function can be realized as well. A new idea is to connect the outlets of the DHPMS directly into the cylinder chambers without any throttling valves in order to minimize hydraulic losses and to enable energy recovery. This article introduces the first experimental results of using this direct connection approach. Firstly, the system under study is presented and then a method for the displacement control is proposed. Open-loop position tracking responses with different loadings are presented, as is an analysis of the accuracy of steady-state velocity tracking. In addition, energy losses in the system are studied. The results show that the technique is valid. Moreover, the open-loop positioning error is under one percent in the measured trajectories, even though the DHPMS used has only six pistons. However, more pistons will be needed to improve the control of low velocities and to reduce the pressure ripple. On/off valve technology is a challenge, and compact, fast and leak-free valves with high flow capacity are required.     

Single‐Pot Ethane Carboxylation Catalyzed by New Oxorhenium(V) Complexes with N,O Ligands

The oxorhenium(V) chelates [ReOCl(N,O‐L)(PPh₃)] [N,O‐L=(OCH₂CH₂)N(CH₂CH₂OH)(CH₂COO) ( 2 ), (OCH₂CH₂)N(CH₂COO)(CH₂COOCH₃) ( 3 )] and [ReOCl₂(N,O‐L)(PPh₃)] [N,O‐L=C₅H₄N(COO‐2) ( 4 ) C₅H₃N(COOCH₃‐2)(COO‐6) ( 5 )] have been prepared by reaction of [ReOCl₃(PPh₃)₂] ( 1 ), in refluxing methanol, with N,N‐bis(2‐hydroxyethyl)glycine [bicine; N(CH₂CH₂OH)₂(CH₂COOH)], N‐(2‐hydroxyethyl)iminodiacetic acid [N(CH₂CH₂OH)(CH₂COOH)₂], picolinic acid [NC₅H₄(COOH‐2)] or 2,6‐pyridinedicarboxylic acid [NC₅H₃(COOH‐2,6)₂], respectively, with ligand esterification in the cases of 3 and 5 . All these complexes have been characterized by IR and multinuclear NMR spectroscopy, FAB⁺‐MS, elemental and X‐ray diffraction structural analyses. They act as catalysts, in a single‐pot process, for the carboxylation of ethane by CO, in the presence of potassium peroxodisulfate K₂S₂O₈, in trifluoroacetic acid (TFA), to give propionic and acetic acids, in a remarkable yield (up to ca. 30%) and under relatively mild conditions, with some advantages over the industrial processes. The picolinate complex 4 provides the most active catalyst and the carboxylation also occurs, although much less efficiently, by the TFA solvent in the absence of CO. The selectivity can be controlled by the ethane and CO pressures, propionic acid being the dominant product for pressures about ca. 7 and 4 atm, respectively (catalyst 4 ), whereas lower pressures lead mainly to acetic acid in lower yields. These reactions constitute an unprecedented use of Re complexes as catalysts in alkane functionalization.     

Evaluation of the Acute Toxicity and Genotoxicity of Orange,Red, Violet and Yellow Pyrotechnic Smokes In Vitro

The acute toxicity and the genotoxicity of four colored smokes were studied by an in vitro method based on the exposure of human bronchial epithelial cell cultures to the smokes. All smoke formulations consisted of the oxidizer fuel mixture (potassium chlorate/lactose), talcum and the following dyes: 1,4‐dihydroxy anthraquinone (orange), 1‐(p‐tolylamino)‐4‐hydroxy anthraquinone (violet), 1‐methylamino anthraquinone (red) and 4,4′‐methylidyne‐bis‐3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one (yellow). The experiments were carried out in a laboratory scale chamber and in a large container. The toxicity was compared to that of hexachloroethane (HC)‐based reference smoke with known toxicity. All the colored smokes displayed acute toxicity. The order of toxicity in the laboratory scale tests was orange>violet≈red>HC>yellow and in the container tests orange>violet≈yellow>red. The orange smoke appeared genotoxic in all the tests. With the yellow and the violet smokes, the genotoxicity could not be totally excluded. The red smoke showed evidence of weak genotoxicity only in one test series at the highest concentration level.     

Cell phone usage and broad feature preferences: A study among Finnish undergraduate students

The purpose of this study is to investigate the cell phone use and broad cell phone feature preferences among high school and undergraduate in Finland. Of particular interest is the issue of gender differences regarding the use of the cell phones and the broad phone feature preferences, and their conceptualization. In this research the female respondents seem to use the calendar, Internet, music, and E-mail significantly more than the male respondents. As far as the feature preferences are concerned the female respondents seem to appreciate more price, aesthetics, design, standard processes and parts used, local language capability, safety in terms of radiation, and ringing tones. Male respondents on the other hand appreciate significantly more the use of business services. Also the broad feature preferences were compared to the actual usage areas of the cell phone. With many of these (parts, process, water, solidity, safety, ease of use, and ringing tones) there were no significant relationship with the actual usage. Interestingly the game feature had a significant correlation with the usage of the games, but the correlation was quite low. Finally the conceptualization of the cell phone by different genders was analyzed, and differences in the conceptualization were discovered.