Heats of Immersion of Uranium Oxides in n-Nitropropane III.

Heats of wetting· of uranium oxides with different O / U ratios were measured in n-nitropropane and these heats were found to decrease with increasing oxygen content of the oxide\u27s. This behaviour was compared with the opposite t endency in water. It was concluded that a definite amount of U03 is relatively easily formed on the surface of U02 at lower temperatures

On the Synthesis of and Magnetic Measurements on Xenon Tetrafluoride

Recently the synthesis of XeF4 was reported from the Argonne Nationlll Laborato·ry, and some of its physical properties were given1• In order to obtalin further information on this extraordinarily interesting compound XeF4 was prepared in our laboratory. Siince the details of the synthesis were not available the direct fluorination was performed under pressure at 400°C. The basic .idea was to obtain the maximum possible amount of the product in a small v.ol\u27l.lllle. The p.roduct was identified by mass spectroscopic analysis2 • The X-ray pattern was taken and the magnetic susceptibility was also measured. At present the NMR spectra are al!so under investigatioiil

Die Synthese von Calciummetatitanat bei niedriger Temperatur. I.

Die Reaktionsfanigkeit des Gemenges Ca(OH)2 und Ca(N03h mit Ti02 wurde eingehend studiert. Fiir ein standardes Ti02 wurde die Abhangigkeit der Ausbeute von der Reaktionsdauer, Temperatur, Dispersitat der Agglomerate, Zusammensetzung und Uberschuss des Ca(OH)2 und Ca(N03)2 Gemenges untersucht. Verglichen wurde die Ausbeute wenn Ca(OH)2 im Gemenge mit Cao ersetzt wird, sowie die Ausbeute bei Reaktionen mit anderen Calciumverbindungen. Auf Grund dieser Untersuchungen kann auf den Einfluss der Schmelze, Atmosphare und Cao in statu nascendi auf den Verlauf dieser Synthese geschlossen werden. Mit geeignetem Ti02 Gel kann man bei 575oc mit einem Gemenge von 1,0 Ti02 + 0,7 Ca(OH)2 + 0,3 Ca(N03)2 bei 1-2 stiindiger Reaktionsdauer praktisch eine 100°/e Ausbeute von Cao . Ti02 erzielen

Die Synthese von Calciummetatitanat bei niedriger Temperatur. II Zur Kenntnis der Reaktion zwischen CaC03 und Ti02 in der C02-Atmosphare oder an der Luft

Die Re aktion wurde zwis che n 800 und 1000°C unter sucht. Im Gegen satz zu d en in de r Lite r atur gefund e n e n A n gab en ist es nicht gelunge n die q u a n titative Synthese zu erzielen . F estges t ellt wurde d e r positive Ein fl u s s d er Ca CO a-Dberschusses. Di e C02- -Atmospha re begi.in s tigt b ei a lle n Be ding u ngen e ine besser e Umsetzung des Ti02

Die Synthese von Calciummetatitanat bei niedriger Temperatur. II Zur Kenntnis der Reaktion zwischen CaC03 und Ti02 in der C02-Atmosphare oder an der Luft

Die Re aktion wurde zwis che n 800 und 1000°C unter sucht. Im Gegen satz zu d en in de r Lite r atur gefund e n e n A n gab en ist es nicht gelunge n die q u a n titative Synthese zu erzielen . F estges t ellt wurde d e r positive Ein fl u s s d er Ca CO a-Dberschusses. Di e C02- -Atmospha re begi.in s tigt b ei a lle n Be ding u ngen e ine besser e Umsetzung des Ti02

Use of biodegradable materials to reduce marine plastic pollution in small scale coastal longline fisheries

Pollution from lost, abandoned, or discarded fishing gear is recognized as a global nature conservation concern. Longlining with hooks is a commonly applied fishing method in fisheries around the world. The longline gear consists of a mainline with a number of baited hooks that are attached to it by thinner twine (snoods) which are often made of plastic material such as polyamide (nylon) or polyester that degrades very slowly in the marine environment. During longline fishing, some of the snoods are lost at sea contributing to marine macro- and micro-plastic pollution. The extent of the snood loss is often unknown and can vary between different longline fisheries and fishing grounds. In this study, we estimated and compared the risk for the biodegradable and nylon snood loss in an Adriatic small scale longline fishery. Further, we compared the catch composition and estimated catch efficiency between biodegradable and nylon snoods for capture of common pandora (Pagellus erythrinus), two-banded seabream (Diplodus vulgaris) and axillary seabream (Pagellus acarne). The risk for nylon snood loss in this longline fishery (3 % for each snood for each deployment), demonstrate that the use of more environmentally friendly materials is necessary for nature conservation. No significant differences between the performance of the two materials regarding snood loss rate, hook loss rate, catch efficiency and catch composition were found during short-term usage in the fishery. Based on these results, future long-term testing is encouraged to investigate whether this promising performance of the biodegradable snood material is persistent over longer fishing periods

Uber die Synthese von XeF6

Claassen und Mitarb.1 berlichten iiber die Syinthese von XeF4 , R. Hoppe und Mifarb.2 iiber die Synthese von XeF2 • Wir haiben die Synthese VO!!l XeF43 reproduzii.ert und koomten bei der massenspektrometrischen Analyse des Produktes schwache Andeutungen fiir die .Ainwesenheit hoherer Fluoride feststellen

On the Synthesis of and Magnetic Measurements on Xenon Tetrafluoride

Recently the synthesis of XeF4 was reported from the Argonne Nationlll Laborato·ry, and some of its physical properties were given1• In order to obtalin further information on this extraordinarily interesting compound XeF4 was prepared in our laboratory. Siince the details of the synthesis were not available the direct fluorination was performed under pressure at 400°C. The basic .idea was to obtain the maximum possible amount of the product in a small v.ol\u27l.lllle. The p.roduct was identified by mass spectroscopic analysis2 • The X-ray pattern was taken and the magnetic susceptibility was also measured. At present the NMR spectra are al!so under investigatioiil

Bycatch reduction in the deep-water shrimp (Pandalus borealis) trawl fishery by increasing codend mesh openness

In most trawl fisheries, drag forces tend to close the meshes in large areas of diamond mesh codends, negatively affecting their selective potential. In the Barents Sea deep-water shrimp (Pandalus borealis) trawl fishery, selectivity is based on a sorting grid followed by a diamond mesh codend. However, the retention of juvenile fish as well as undersized shrimp is still a problem. In this study, we estimated the effect of applying different codend modifications, each aimed at affecting codend mesh openness and thereby selectivity. Changing from a 4-panel to a 2-panel construction of the codend did not affect size selectivity. Shortening the lastridge ropes of a 4-panel codend by 20% resulted in minor reductions for juvenile fish bycatch, but a 45% reduction of undersized shrimp was observed. Target-size catches of shrimp were nearly unaffected. When the codend mesh circumference was reduced while simultaneously shortening the lastridge ropes, the effect on catch efficiency for shrimp or juvenile fish bycatch was marginal compared to a 4-panel codend design with shortened lastridge ropes.acceptedVersio

Quantitative analysis of arbutin and hydroquinone in strawberry tree (Arbutus unedo L., Ericaceae) leaves by gas chromatography-mass spectrometry

The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R-2 gt 0.9987) in the tested concentration range (0.5-200 mu g mL(-1)), as well as good precision (RSD lt 5 %), analytical recovery (96.2-98.0 %), and sensitivity (limit of detection=0.009 and 0.004 mu g mL(-1) for arbutin and hydroquinone, respectively). The results obtained by the validated GC-MS method corresponded well to those obtained by high performance liquid chromatography (HPLC) method. The proposed method was then applied for determining arbutin and hydroquinone content in methanolic leaf extracts. The amount of arbutin in the leaves collected on the island of Kolocep (6.82 mg g(-1) dry weight) was found to be higher (t(paired)=43.57, t(c)=2.92) in comparison to the amount of arbutin in the leaves collected on the island of Mali Losinj (2.75 mg g(-1) dry weight). Hydroquinone was not detected in any of the samples. The analytical features of the proposed GC-MS method demonstrated that arbutin and hydroquinone could be determined alternatively by gas chromatography. Due to its wide concentration range, the method could also be suitable for arbutin and hydroquinone analysis in leaves of other plant families (Rosaceae, Lamiaceae, etc.)