Kontrollgeräte zur Überprüfung der Antriebsleistung von Fischereifahrzeugen - Entwicklungen im Institut für Fischereitechnik

Seit der Einführung der Plattfisch-Schutzzonen existiert das Problem der Kontrolle der maximalen Antriebsleistung von Fischkuttern. Nachdem in den letzten Jahren die Motoren der in den Schutzzonen zugelassenen Fahrzeuge zunehmend zu einer höhren Leistungsabgabe umgebaut wurden, entstanden zum Teil erhebliche Wettbewerbsverzerrungen in der EU- Flotte und eine nicht kontrollierte Steigerung des Fischereiaufwandes in den Schutzzonen durch Nichtbeachtung der Vorschriften.

Ultrafast dynamics in ZnO thin films irradiated by femtosecond lasers

The damage morphologies, threshold fluences in ZnO films were studied with femtosecond laser pulses. Time-resolved reflectivity and transmissivity have been measured by the pump-probe technique at different pump fluences and wavelengths. The results indicate that two-phase transition is the dominant damage mechanism, which is similar to that in narrow band gap semiconductors. The estimated energy loss rate of conduction electrons is 1.5 eV/ps. (c) 2005 Elsevier Ltd. All rights reserved.

Sozioökonomischer Vergleich der niedersächsischen und schleswig-holsteinischen Fischereiwirtschaft

In der "Ökosystemforschung niedersächsisches Wattenmeer" wird in einem Teilprojekt seit Januar 1993 "Die sozioökonomische Entwicklung der Fischerei im niedersächsischen Wattenmeer und ihr Bezug zu Naturschutzforderungen" untersucht. Im Rahmen dieses Projektes wurde am 19.05.1994 auf dem 4. Wissenschaftlichen Symposium der Ökosystemforschung Wattenmeer in Husum ein Vortrag gehalten, dessen Kurzfassung im folgenden wiedergegeben wird.

Elektronische Registrierung von Untersuchungsdaten auf See

Die elektronische Erfassung von auf See gewonnenen Daten direkt bei der Entstehung ist eine wesentliche Voraussetzung zur rationellen Nutzung elektronischer Datenverarbeitungssysteme. Die Online-Erfassung erspart nicht nur den späteren zeitaufwand bei der Übertragung der Daten von handschriftlichen Strichlisten in den Rechner, sondern schließt gleichzeitig dabei u.U. entstehende Fehler aus. Darüberhinaus ermöglicht die direkte Eingabe von gewonnenen Daten eine schnelle vorläufige Sichtung von Ergebnissen und erlaubt dadurch die Anpassung von Untersuchungsprogrammen an die an Ort und Stelle erzielten Resultate.

Determination of optimum stocking density of Macrobrachium rosenbergii larvae using multiple feed in a commercial hatchery at Cox’s Bazar, Bangladesh

Experimental stocking density of Macrobrachium rosenbergii in larval rearing was conducted in A.G. Aqua Hatchery, Chakaria, Bangladesh to study the effect of different stocking densities on growth, survival rate and diseases stress under hatchery condition. The research work was conducted using six cemented rectangular tanks having 3m3 capacity (1.5mX2mX1m) each. Stocking density were maintained in three experimental setup as 200, 150 and 100ind/L of the T1, T2 and T3 respectively with one replicate each. The larvae were fed with Artemia nauplii, Custard, Maxima and brine shrimp flakes. Water quality was maintained by exchanging 20-30% (12ppt saline water) daily. During the study period, temperature, pH, DO, salinity, nitrite-nitrogen, ammonia and alkalinity were maintained from 28.5-31.5ºC, 7.5-7.8, 5.8-5.9mg/L, 12-13ppt, 0.14-0.2 mg/L, 0.22-0.3mg/L, and 140-160mg/L respectively. The growth rates of larvae at 11th stage were recorded in terms of body length 0.115, 0.136, and 0.169 mm/day whereas body weight were observed 0.000115, 0.000180, and 0.000240g/day. The survival rate of larvae were found 21.8%, 30.4% and 51.3% in treatments T1, T2 and T3 respectively. PL was obtained as 43, 45, and 51PL/L and days required of 41, 38 and 34 days in stocking density of 200, 150, and 100ind/L respectively. It was found that the minimum of 34 days was required to attain the PL (12th stage) using the stocking density of 100 individuals/L. Cannibalism, Zoothamnium, Exuvia Entrapment Disease (EED), and Bacterial Necrosis (BN) were found to be the threat to the commercial hatchery operation that might responsible for potential larval damages which can be reduced by lowering the stocking densities in larval rearing tank that also increased the survival and growth rate.

Modulation of the effectiveness of 17-alpha-hydroxy-20-beta-dihydroprogesterone or of a gonadotrophic extract on the in vitro intrafollicular maturation of oocytes of the rainbow trout Salmo gairdnerii by various non-maturing steroids [Translation from: Compte Rendu Hebdomadaire des Seances de l'Academie des Sciences, Paris, Series D 281, 811-814, 1975]

The effectiveness of 17 α-hydroxy-20 β-dihydroprogesterone (17 α-20 β Pg) or of a trout hypophyseal gonadotrophic extract on the in vitro intrafollicular maturation of trout oocytes can be modulated by steroids which do not have a direct maturing effect; the effectiveness of the gonadotrophic extract is lowered by oestradiol and oestrone and increased by testosterone. As these steroids have no significant effect on maturation induced by 17 α-20 β Pg, the site of their activity is probably in the follicular envelopes. Corticosteroids, and Cortisol and cortisone in particular increase the effectiveness of the gonadotrophic extract, but increase the effectiveness of 17 α-20 β Pg even more strongly, suggesting that this 'progestagen' has a direct effect on oocyte sensitivity.

Vivienda energeticamente sostenible ubicada en Xàtiva.

[ES]Se van a diseñar las instalaciones necesarias para que una vivienda unifamiliar sea energeticamente sostenible. La unica fuente disponible es la solar y los paneles se van a encargar de convertir la energia disponible para los usuarios.La documentación del presente Proyecto de Ejecución de la instalación fotovoltaica en vivienda aislada, tanto gráfica como escrita, se redacta para establecer todos los datos descriptivos, urbanísticos y técnicos, para conseguir llevar a buen término, la instalación fotovoltaica de una vivienda unifamiliar aislada, según el reglamento eléctrico de baja tensión.

Comparação in vitro do desgaste dental em função da dureza de três diferentes tipos de materiais antagonistas

O objetivo deste estudo foi comparar in vitro o desgaste dental de pré-molares (PM) e molares (M) e sua relação com o valor de dureza Vickers dos materiais utilizados como antagonistas em uma máquina de abrasão simulada para provocar o desgaste nos dentes testados. Os materiais antagonistas utilizados foram VeraBond II (liga de Ni-Cr), Solidex (resina composta) e IPS Empress 2 (cerâmica). Para cada ensaio de dureza, foram preparados seis corpos-de-prova de cada material, os quais foram polidos sob refrigeração, com ciclo de 20 min para cada granulação. Num microdurômetro (HMV-2), foram realizadas três mossas por quadrante, cada uma sob carga de 19,614 N por 30 s, totalizando 12 mossas de base quadrada com ângulo de 136 entre os planos. O teste de abrasão foi realizado numa máquina simuladora de abrasão, freqüência de 265 ciclos/min e 4,4 Hz, com um percurso do antagonista de 10 mm à velocidade de 88 mm/s. Cada dente foi testado em oposição a um antagonista (foram 6 pares dente/material para cada grupo), em água deionizada, sob carga de 5 N, por 150 min, num total de 39.750 ciclos. Foram utilizados dezenove dentes 1 pré-molares, dezenove 3 molares e confeccionados doze antagonistas em cada material em forma de pastilha. Cada grupo de seis dentes foi testado em oposição a seis antagonistas do mesmo material. Ademais, um dente 1 pré-molar (PM) e um dente 3 molar (M) foram testados em oposição ao Plexiglass. Com relação ao desgaste do esmalte dentário (PM+M) segundo o material antagonista, o teste de Kruskal-Wallis evidenciou diferença significativa com p-valor < 0,001 e o teste de Mann-Whitney evidenciou diferença significativa nas comparações PM+M/resina X PM+M/metal (p-valor < 0,001), PM+M/resina X PM+M/cerâmica (p-valor < 0,001) e PM+M/metal X PM+M/cerâmica (p-valor = 0,002). A análise isolada, considerando pré-molares e molares separadamente, encontrou diferença significativa em relação ao desgaste do esmalte dentário no teste de Kruskall-Wallis, porém não detectou diferença significativa no teste de comparação múltipla Mann-Whitney quando comparou o desgaste sofrido pelo PM/metal em relação ao PM/cerâmica. Em relação à dureza Vickers detectou-se diferença significativa da dureza dos materiais no teste de Kruskall-Wallis (p-valor < 0,001) e também no teste de Mann-Whitney nas comparações múltiplas com p-valor = 0,002. Comparando-se a dureza com a perfilometria, observou-se uma correlação estatisticamente significativa (p ≤ 0,05) na correlação negativa (ρ= -0,829) entre a dureza do metal como material antagonista e o desgaste do esmalte dentário do dente molar. Os resultados sugeriram que todo material restaurador indireto estudado causou desgaste ao esmalte dentário quando submetido a forças de simulação de abrasão com carga. Embora tenha sido observada correlação entre dureza e resistência à abrasão, essa correlação foi pouco significativa.

Laser beam shaping system with a radial birefringent filter

Reshaping of a Gaussian laser beam into a uniform or other intensity distribution is required for various applications. The laser beam shaping system with a radial birefringent filter is presented in this paper. With such a system the Gaussian beams can be transformed into uniform or annular beams. The theory and simulation of the proposed systems are described in detail. The primary advantage of such a system is that the out beam pro. le can be tunable with the rotation of the radial birefringent element.