Методи визначення оптимальних виробничих програм за фінансовими критеріями розвитку підприємства

Запропоновано методи визначення оптимальних обсягів виробництва за критеріями максимізації чистого прибутку і рентабельності продукції підприємства. За результатами розрахунків, проведених за допомогою розроблених моделей для промислових підприємств Львівської області, доведена методологічна різниця між абсолютним і відносним критеріями ефективності

Национальная академическая библиография военного времени

В статье прослеживается подвижническая работа в годы Великой Отечественной войны коллектива БАН СССР, стремящегося в тяжелейших условиях блокады обеспечить ученых страны научными изданиями, обслужить передвижными библиотечками воинские части, госпитали, производственные предприятия; проводившего выставочную работу, библиографическую деятельность. В частности, воссоздается история подготовки в военные годы библиографического справочника, охватывающего всю издательскую деятельность Академии наук СССР за 1941-1943 гг

Doorlatendheidsmetingen: absolute noodzaak of luxe uit het verleden?

De bepaling van de doorlatendheid van zandpakketten houdt de gemoederen van hydrologen al meer dan een eeuw bezig. Vele bepalingsmethoden zijn in die tijd ontwikkeld. Sommige geven een globale waarde, toepasbaar in grootschalige modellen; andere gevenwaarden die meer voor lokale problemen geschikt zijn. Dit artikel geeft een overzicht van de bestaande methoden. De vraag wordt gesteld of in een tijd van krappe financiële mogelijkheden het verantwoord is dergelijk kostbaar onderzoek uit te voeren. Het artikel richt zich op een discussie tussen de instanties die zich met dergelijk onderzoek bezighouden, met als doel een betere afstemming van het onderzoek en de uitwisselbaarheid van de resultaten

Muddy lateral accretion and low stream power in a sub-recent confined channel belt, Rhine-Meuse delta, central Netherlands

The Hennisdijk fluvial system in the central Rhine-Meuse delta is an abandoned Rhine distributary that was active on a wide floodplain from 3800 to 3000 years BP. Cross-sectional geometry, lithological characteristics and planform patterns of the channel-belt deposits indicate lateral migration of the Hennisdijk palaeochannel. Channel-belt deposits are around 10 m thick and 200¿400 m wide. A gravelly facies near the base of the channel-belt deposits represents channel-lag and lower point-bar deposits. The axis of the channel belt is dominated by a sandy facies (medium and coarse sand), showing an overall fining upward trend with multiple cycles. This facies is interpreted as lower and middle point-bar deposits. The sandy facies is capped by a muddy facies, which is 1¿2 m thick near the axis of the channel belt and thickens to 5¿6 m along the margins. It laterally interfingers with the sandy facies that occurs near the channel-belt axis, but it has sharp, erosive outer contacts marking the edges of the channel belt. The muddy facies comprises inclined heterolithic stratification (IHS) (fine/medium sand¿mud couplets) in its upper part. The relatively thin muddy facies with IHS that occurs near the channel-belt axis is interpreted as upper point-bar deposits with lateral accretion surfaces, formed under marine influence. Along the margins of the channel belt the muddy facies consists of thick, fairly homogeneous, successions of mud with variable sand content, and fine sand. Based on facies geometry and position, this part of the muddy facies is interpreted as counterpoint deposits, formed along the upstream limb of the concave bank of a channel bend. Counterpoint accretion seems to have been associated with the confined nature of the channel belt, which was the result of low stream power (4·5¿7·8 W m2, based on reconstructions of palaeodischarge and channel slope) and cohesive bank material, i.e. clayey floodbasin deposits with intercalated peat beds occurring next to the channel belt. In the literature, counterpoint accretion is mostly reported from alluvial valleys, where meandering is confined by limited floodplain width, whereas muddy lateral accretion surfaces are commonly reported from much wider marine-influenced floodplains. The present study shows juxtaposition of both forms of muddy channel deposits in a low-energy, wide coastal plain setting, where preservation potential is considerable

Burgemeester Jaslaan/terrein De Vlaming : gemeente Dordrecht : geo-archeologisch vooronderzoek: een bureau- en inventariserend veldonderzoek

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Plangebied Loudonstraat, kadastrale sectie M, nrs. 1716 en 2406, gemeente Dordrecht : een inventariserend archeologisch onderzoek

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Dordrecht-Dubbelmondepark

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Avulsion in action: reconstruction and modeling sedimentation pace and upstream flood water levels following a Medieval tidal-river diversion catastrophe (Biesbosch, The Netherlands, 1421–1750 AD)

Deltaic land inundated by storm surges may reform by sedimentation from natural or human-induced river diversions. This is a well-known trigger mechanism for creation of new channels in coastal plains and deltas, which may develop into main channels and lead to abandonment of older (avulsion), particularly in the downstream parts of deltas that host tidal rivers. These new channels develop as part of deltaic splay complexes that heal initial diversion scars and fill up flooded basins at a certain pace. We study a case with excellent historical and geological data of a diversion of the river Rhine following catastrophic inundations (1421–1424 AD) into medieval reclaimed land. Numerical modelling of deltaic splay and channel development is combined with reconstructions from historical maps and geological data. This yields detailed insight in pacing of splay sedimentation and changing hydrodynamics in the channel upstream of the diversion in the two centuries following the inundation. The equivalent of the full sand budget of the river Rhine was effectively trapped in the developing splay. The tidal-avulsion splay evolution on aspects is similar to that of fluvial crevassing into flood basins documented for settings lacking ‘downstream’ tidal control. The typical small-scale delta-lobe avulsion cycles: mouth bar formation, backward sedimentation, upstream avulsion, channel progradation and mouth bar formation are reproduced in the splay-modelling. The pacing of splay development, however, is relatively fast due to the presence of tides and the water depth in the receiving basin. The diversion had a strong upstream impact, in particular on water levels in the feeding river channel at stages of peak flow. For two centuries levels were significantly raised, because bifurcation-imposed reduced transport capacity and associated sedimentation at the diversion site increased hydraulic roughness and hampered flow. These findings have implications regarding flood mitigation for presently-planned lower-delta engineered diversions. Furthermore, they elucidate the differences between upstream fluvial avulsion and downstream tidal-river avulsion that are important to recognise if we want to understand how deltaic distributarynetworks are maintained