Ausdünnung von Äpfeln durch Beschattung

Shading with nets of 2 m and 3 m width respectively, which reduce the photosynthetic active radiation by 74%, lead to successful fruit thinning of apple trees. In field trials, three days of shading reduced fruits per 100 flower clusters to a satisfactory extent for Golden Delicious (if shading occurred after 19, 26 and 33 days after full bloom (DAFB)) and Topaz (if shading occurred after 19 and 26 DAFB). For Elstar, seven days shading at 25 DAFB resulted in a good thinning effect. However, practicability of the method in commercial orchards has to be improved

Den Diskurs anders denken

Wir legen Texte über diese Welt, um sie uns verfügbar zu machen. Verfügbarkeiten folgen Strategien, die sich wiederum aus dem Stimmengewirr von selbst ergeben, so scheinbar universeller, vormals göttlicher Logik entstammen, in weiterer Folge nicht mehr verhandelbar scheinen. Gerade weil sie sich der Autorenschaft entziehen, die Strategie nicht im Subjekt verortbar ist, wird ihnen Objektivität angedichtet. Es genügt das wiederholende Sprechen der immer selben Worte von institutionell legitimierten Menschen, um Gedachtes zu manifestieren. Es ist dies ein Wahr-Sprechen von Mythen, die einer Auslese unterzogen werden, wobei sich Letztere der Strategie zu fügen hat, schließlich muss Sinn geschaffen werden, der wiederum erst im Einklang von Strategie entstehen kann. So gehen Strategie, Mythos und Sinn einen Pakt ein, der von einer Welt erzählt, die immer schon so war, also selbst Mythos ist. Ein vierblättriges Kleeblatt etwa, hat da wie dort vier Blätter, die Bedeutung des Glücks allerdings, ist Zuschreibung, ist auf einer Metaebene verhandelt worden, liegt nicht im Objekt begraben, ist einer speziellen Art von Logik entsprungen, der wiederum selbst eine Geschichte zu eigen ist, nicht Zeuge eines So-Seins von Welt war. Das wissenschaftlich geschulte Auge meint zu erkennen, dass Erkenntnis vormals Logos und Mythos benötigte, um die Welt zu ordnen, uns allerdings mit der Aufklärung - quasi der Logos-stasierung von Welt - Letzterer abhanden gekommen ist. Diese Sicht der Dinge verkennt, dass der Mythos in den Logos integriert wurde, immer schon war, der Logos selbst Mythos ist. Da nun allerdings der Mythos als besiegt geglaubt wird, wird der Logos selbst zur Wahrheit erhoben. Nunmehr ist es das Wort selbst, das Wahrheit spricht, Kampfplatz ist, Kampfplatz um Wahrheit. Eben diesen Kampfplatz zu untersuchen, das Entstehen, das Produzieren von Wahrheiten, die nicht absolut zu denken sind, war Foucaults Anliegen. Das marxistisch gedachte Außen, das für eine Revolution nötig ist, wurde überwunden. Damit Einiges mehr. Sprache ist nicht länger Vehikel, mit dem eine Ideologie transportiert wird, vielmehr liegt in ihr selbst die Entstehung von Welt. Das Wort wird zum produktiven Ereignis, durch welches ebenso erst das Subjekt im Werden begriffen ist. Dadurch erkennt man den Machtcharakter des Wortes, erkennt man, dass Macht nur durch das Wort verteilt werden kann. Diese normschaffende Instanz ist nicht länger repressiv zu denken, sie lässt vielmehr Wissen durch das Wort entstehen. Sprache, Macht und das Selbst, drei Dinge, denen Ereignischarakter zukommen, welche die Welt als solche erst gebären, drei Dinge, die im Mittelpunkt foucault´scher Denkweise stehen. Da ist die geordnete, produzierende Rede, der Diskurs, sowie Strategien, welche nach „sinnhaften“ Machtspielen zu Dispositiven gerinnen und das endliche Selbst, welches durch Hervorbringen all dessen sich selbst zugleich permanent verändert. Diese Arbeit vergleicht insbesondere zwei Denkgebäude, um dadurch herauszufinden, welche Effekte die neu gedachten Elemente auf den Diskurs, mithin die Diskursanalyse selbst haben

Control-oriented modeling of a LiBr/H2O absorption heat pumping device and experimental validation

Absorption heat pumping devices (AHPDs, comprising absorption heat pumps and chillers) are devices that use thermal energy instead of electricity to generate heating and cooling, thereby facilitating the use of waste heat and renewable energy sources such as solar or geothermal energy. Despite this benefit, widespread use of AHPDs is still limited. One reason for this is partly unsatisfactory control performance under varying operating conditions, which can result in poor modulation and part load capability. A promising approach to tackle this issue is using dynamic, model-based control strategies, whose effectiveness, however, strongly depend on the model being used. This paper therefore focuses on the derivation of a viable dynamic model to be used for such model-based control strategies for AHPDs such as state feedback or model-predictive control. The derived model is experimentally validated, showing good modeling accuracy. Its modeling accuracy is also compared to alternative model versions, that contain other heat transfer correlations, as a benchmark. Although the derived model is mathematically simple, it does have the structure of a nonlinear differential-algebraic system of equations. To obtain an even simpler model structure, linearization at an operating point is discussed to derive a model in linear state space representation. The experimental validation shows that the linear model does have slightly worse steady-state accuracy, but that the dynamic accuracy seems to be almost unaffected by the linearization. The presented new modeling approach is considered suitable to be used as a basis for the design of advanced, model-based control strategies, ultimately aiming to improve the modulation and part load capability of AHPDs

Urenheter i breis : akkumulasjon, transport og albedo

The Greenland ice sheet is the largest ice mass in the Northern Hemisphere and has experienced accelerating mass loss in recent decades. An increase in surface melt is the major cause for the loss of mass. Albedo is a major control of surface melt and has decreased over the entire Greenland ice sheet, especially at lower elevations near the margin where glacier ice is exposed for part of each year. The albedos of ice and snow are lowered by dark impurities such as mineral dust and black carbon, a by-product of combustion. These impurities are a heterogeneous group of highly absorbent particles which reach the ice sheet via atmospheric transport from distant and local sources. Parts of these impurities are buried in the accumulation zone and become part of the moving ice. After a significant transport time, up to tens of thousands of years, these englacial impurities re-emerge in the ablation zone near the margin. These re-emerging impurities, together with those directly deposited, accumulate on the ice surface. Once located on the ice surface, these impurities darken the ice surface for several years and lower the albedo, causing more melt. Current sea-level projections rarely include albedo as a dynamic model component. In models which consider albedo, snow albedo is often treated with sophisticated methods, while ice albedo is still treated as a constant. Albedo lowering is a major cause of the current mass loss of the Greenland ice sheet, and the role of ice albedo will increase under a warmer climate. Therefore, this study presents a model with a dynamic component of ice albedo. The model framework includes the effect of impurities on the mass balance and ice sheet geometry. The framework consists of an ice dynamics component which is linked to a module of englacial impurity transport. This component feeds into the impurity accumulation module, which deals with both snow and ice. An albedo module which accounts for mineral dust and black carbon accumulation uses this output to derive daily albedo values. A simplified surface energy balance model is used to derive the surface melt rate and surface mass balance, which is then fed back into the ice dynamics component. This model framework is used to investigate the role of melt-out and impurity accumulation on the melt of the Greenland ice sheet. For that purpose, simplified geometry and different temperature pathways are used to simulate the evolution of the ice sheet over 1000 years. Due to the feedback between melt-out, ice albedo and impurity accumulation, the role of impurities is disproportionally larger in warmer scenarios. In the warmest scenario (RCP8.5), a conservative estimate for the additional mass loss due to impurity accumulation in the year 3000 was 7%. Melt-out of dust is the largest source of impurities on the ice surface. Darkening is not always dominated by dust, however, due to the high absorption of black carbon. The amount of impurities from melt-out depends on the englacial impurity concentration and surface melt. The englacial impurity concentration, in turn, relies on the computed age of the ice and a time series of impurity concentration. Therefore, the accuracy of the transport scheme, which provides the age of the ice, is crucial for overall accuracy. A semi-Lagrangian transport scheme of second-order accuracy was implemented in the 3D ice sheet model SICOPOLIS (SImulation COde for POLythermal Ice Sheets). The model was applied to the ice sheets of Greenland and Antarctica. Artificial ice cores of 18O, a proxy for surface temperature, were compared to ice core data. The results of the second-order scheme were identical to the results of the first-order scheme in the ice sheet interior. The results deviated substantially, however, in the outer regions near the margin. The results emphasise that the role of ice albedo and impurities for the surface mass balance will be even greater under warmer conditions. Furthermore, the presented model framework is not limited to Greenland but can also be adapted for valley glaciers and paleo-ice sheets.Iskappen på Grønland er den største ismassen på den nordlige halvkule og massetapet her har vært akselererende de siste tiårene. En økning i overflatesmeltingen er den viktigste årsaken til tap av masse. Albedoen, som er hovedfaktoren for overflatesmeltingen, har avtatt over hele iskappen på Grønland, og særlig i lavere høyde nær iskanten hvor breisen er eksponert for et visst tidsrom årlig. Albedoen for is og snø er redusert pga mørkere partikler og urenheter, som mineralstøv og black carbon (sot), et bi-produkt av forbrenning. Disse urenhetene er en heterogen gruppe av svært absorberende partikler som transporteres til iskappen via atmosfæren fra lokale og fjerntliggende kilder. Deler av disse urenhetene opptas i akkumulasjonssonen og blir del av den bevegelige isen. Etter lang tids transport, opptil titusener av år, vil disse englasiale urenhetene komme frem i ablasjonssonen nær brekanten. Både englasialt transporterte urenhetene og dirkete avsatte urenheter akkumuleres på isoverflaten. Når urenhetene først er avsatt på isoverflaten vil de bidra til en mørkere isoverflate med redusert albedo, og derved bidra til økt smelting. Nåværende havnivå prognoser inkluderer sjelden albedo som en dynamisk modellkomponent. I modeller som inkluderer albedo blir snøalbedoen ofte justert med sofistikerte metoder, mens isalbedoen blir holdt konstant. Albedo er hoveddriveren av det pågående massetapet for Grønlandsisen, og isalbedoens rolle vil forsterkes under et varmere klima. Av denne grunn presenteres det i dette studie en modell med en dynamisk komponent for isalbedo. Dette modellrammeverket blir brukt til å undersøke hvilken rolle utsmelting og akkumulasjon av urenheter spiller på avsmeltingen av iskappen på Grønland. En forenklet geometri og forskjellige temperaturtraseer blir brukt til å simulere utviklingen av iskappen over 1000 år. På grunn av tilbakekoblingsmekanismene mellom utsmelting, isalbedo, og akkumulasjon av urenheter er rollen av urenheter uproporsjonalt større i varmere scenarier. I det varmeste scenariet (RCP8.5) er et konservativt estimat for massetap på grunn av akkumulasjon av urenheter i året 3000 på 7 %. Utsmelting av støv er den største kilden til urenheter på isoverflaten. Sverting av overflaten er allikevel ikke alltid dominert av støv, pga. den høye absorbsjonen av black carbon. Mengden av urenheter pga. utsmelting avhenger av den englasiale urenhetskonsentrasjonen og overflatesmelting. Den englasiale konsentrasjonen avhenger igjen av den beregnede alderen av isen og av en tidsserie av urenhetskonsentrasjoner. Derfor er nøyaktigheten av transportskjema, som gir alderen på isen, essensiell for den generelle nøyaktigheten. Et semi-Lagrangian transport skjema av annen ordens nøyaktighet ble implementert i den tre dimensjaonale iskappemodellen SICOPOLIS (SImulation COde for POLythermal Ice Sheets). Modellen ble anvendt for iskappene på Grønland og Antarktis. Genererte iskjerne data av 18O, en proxy for overflate temperatur, ble sammenlignet med iskjerne data. Resultatet av annen ordens skjemaet var identisk til resultatet til første ordens skjemaet i det indre av iskappen, men resultatene avvek vesentlig i de ytre regionene nær iskanten. Resultatene understreker rollen isalbedo og urenheter har for overfalte massebalansen, en rolle som også vil bli enda større ved varmere forhold. Videre er det presenterte modellrammeverket ikke begrenset til Grønland men det kan også tilpasses dalbreer og paleo-iskapper.NCoE SVALI ; ResCli

Albedo reduction of ice caused by dust and black carbon accumulation: A model applied to the K-Transect, West Greenland

publishedVersio

Studien zur kallimacheischen Lexis

von Franz GöllesGraz, Univ., Diss., 191

Talangfull? : En studie om hur medarbetare i en stor organisation upplever att deras kompetens och talang tillvaratas

Denna studie har som syfte att se hur medarbetare på ”golvet” i en stor organisation upplever att deras kompetens och talang tas tillvara på. Avsikten är dessutom att jämföra hur denna hantering av kompetens och talang skiljer sig i två likadana verksamheter på olika platser i Sverige. För att undersöka detta har enkäter delats ut, där medarbetare ombads skatta hur de anser att organisationen tar tillvara på deras kompetens och talang. De ombads även skatta den egna kompetensen och talangen samt besvara en rad bakgrundsfrågor som senare låg till grund för analysen. Enkätens innehåll bygger på en teoretisk referensram där en samlad bild av kompetens och Talent management ligger till grund för utformandet. Teorin om Talent management menar att det finns två sätt att arbeta, att se varje medarbetare som en talang, eller endast ett fåtal. I denna undersökning menar den undersökta organisationen att varje medarbetare ses som en talang. Resultatet visar att det finns ett fåtal faktorer som har inverkan på hur kompetens och talang tas tillvara i det undersökta företaget. Ju mer kompetens de svarande anser att de besitter, samt hur god kännedom organisationen har om kompetensen och talangen hos medarbetarna, desto bättre är organisationen på att tillvarata denna. Dessutom visar resultatet att om medarbetarna har för avsikt att utvecklas inom organisationen, upplever de att organisationen är bättre på att tillvarata kompetens och talang. The purpose of this study is to examine how co-workers on the “ground-level” of a big organization experience that their competence and talent is used. The purpose is also to compare how the use of competence and talent differs in two similar units within the same organization in two different parts of Sweden. To examine this, surveys was handed out to the co-workers, and they were asked to estimate how they think that the organization make use of their competence and talent. They were also asked to estimate their own competence and talent, along with answering some background questions which later on was used as foundation for the analysis. The survey was conducted from a theoretical viewpoint, where theory on competence and Talent management were the base for the survey. The theory of Talent management suggests that there are two ways of using the term; either every co-worker is seen as a talent, or only a few. The organization in this study sees every employee as a talent. The results show that there are some factors that effects who is seen as a talent. The more competence the answerer has, and how good knowledge the organization has of the competence and talent, the better they make use of it. The results also show that if the co-workers want to develop within the organization, the better their competence and talent is used

Talangfull? : En studie om hur medarbetare i en stor organisation upplever att deras kompetens och talang tillvaratas

Denna studie har som syfte att se hur medarbetare på ”golvet” i en stor organisation upplever att deras kompetens och talang tas tillvara på. Avsikten är dessutom att jämföra hur denna hantering av kompetens och talang skiljer sig i två likadana verksamheter på olika platser i Sverige. För att undersöka detta har enkäter delats ut, där medarbetare ombads skatta hur de anser att organisationen tar tillvara på deras kompetens och talang. De ombads även skatta den egna kompetensen och talangen samt besvara en rad bakgrundsfrågor som senare låg till grund för analysen. Enkätens innehåll bygger på en teoretisk referensram där en samlad bild av kompetens och Talent management ligger till grund för utformandet. Teorin om Talent management menar att det finns två sätt att arbeta, att se varje medarbetare som en talang, eller endast ett fåtal. I denna undersökning menar den undersökta organisationen att varje medarbetare ses som en talang. Resultatet visar att det finns ett fåtal faktorer som har inverkan på hur kompetens och talang tas tillvara i det undersökta företaget. Ju mer kompetens de svarande anser att de besitter, samt hur god kännedom organisationen har om kompetensen och talangen hos medarbetarna, desto bättre är organisationen på att tillvarata denna. Dessutom visar resultatet att om medarbetarna har för avsikt att utvecklas inom organisationen, upplever de att organisationen är bättre på att tillvarata kompetens och talang. The purpose of this study is to examine how co-workers on the “ground-level” of a big organization experience that their competence and talent is used. The purpose is also to compare how the use of competence and talent differs in two similar units within the same organization in two different parts of Sweden. To examine this, surveys was handed out to the co-workers, and they were asked to estimate how they think that the organization make use of their competence and talent. They were also asked to estimate their own competence and talent, along with answering some background questions which later on was used as foundation for the analysis. The survey was conducted from a theoretical viewpoint, where theory on competence and Talent management were the base for the survey. The theory of Talent management suggests that there are two ways of using the term; either every co-worker is seen as a talent, or only a few. The organization in this study sees every employee as a talent. The results show that there are some factors that effects who is seen as a talent. The more competence the answerer has, and how good knowledge the organization has of the competence and talent, the better they make use of it. The results also show that if the co-workers want to develop within the organization, the better their competence and talent is used