115 research outputs found
Firestones in the near Eastern Neolithic
Les pierres à feu en silex montrent une usure caractéristique : une série de coups aiguisés, irréguliers et des marques sur des surfaces restreintes de la tranche. On les connaît bien depuis l’âge de la Pierre et l’âge du Bronze en Europe du Nord. Au Proche-Orient, des pierres à feu ont été identifiées sur plusieurs sites néolithiques (Çatal Höyük, Aşıklı Höyük, Labweh et Beidha). On suggère que, au Néolithique, la méthode qui consiste à frapper un morceau de silex ou de soufre contre un autre morceau de silex pour obtenir du feu était généralement utilisée en Anatolie et au Levant. Mais l’absence apparente de pierres à feu – et de pointes de flèche à pédoncule également – dans les assemblages de pierres taillées du Zagros et de Hassuna/Samarra pourrait suggérer qu’au Néolithique nous avons affaire à deux traditions lithiques différentes, régionalement déterminées : une tradition occidentale, prévalant en Anatolie et en Méditerranée orientale, et une tradition orientale couvrant la Mésopotamie du Nord et le Zagros.Firestones or strike-a-lights made of flint exhibit a characteristic kind of wear, seen as a series of sharp, irregular blow-offs and scars within restricted areas of the edge. They are well known from the Stone and Bronze Ages of Northern Europe. In the Near East firestones have been identified at several Neolithic sites (Çatal Höyük, Aşıklı Höyük, Labweh and Beidha). It is suggested that the method of making fire by striking a piece of flint or sulphur against another piece of flint was generally used in Anatolia and in the Levantine Neolithic, whereas the apparent lack of firestones – and of tanged arrowheads as well – in the Zagros and in the Hassuna/Samarra chipped stone assemblages might suggest that in the Neolithic we are dealing with two different, regionally determined lithic traditions: a western tradition, prevailing in Anatolia and the Eastern Mediterranean, and an eastern tradition covering Northern Mesopotamia and the Zagros.خلاصة – تظهر لنا الأحجار الصوانية المستخدمة في إشعال النار تلفاً ملحوظاً: سلسلة من الضربات المشحوذة غير المنتظمة مع وجود علامات على أسطح محددة من الشريحة. عرفت هذه الحجارة بشكل جيد منذ العصر الحجري والعصر البرونزي في أوروبا الشمالية. وجدت حجارة النار في الشرق الأدنى، في عدة مواقع نيوليتية (شاتال هيوك، أسيكلي هيوك، اللبوة، بيضا). نعتقد أن استخدام هذه التقنية للحصول على النار من ضرب حجر صوان أو كبريتي على حجر آخر كانت تقنية مستخدمة بشكل عام في الأناضول والمشرق. لكن النقصان الظاهر في حجارة النار ـ وأيضاً في رؤوس السهام ذات الفرضات ـ في مجاميع الحجارة المطروقة في زاغروس، وحسونة/سامراء يستطيع أن يثبت أنه في الفترة النيوليتية يوجد تقليدين مختلفين للطرق، مميزين محلياً: تقليد غربي وهو الغالب في الأناضول والمتوسط المشرقي، وتقليد مشرقي يغطي منطقة بلاد مابين النهرين الشمالية وزاغروس
Proces neolitizacije v osrednjem delu Zagrosa:: ponovni pregled najdišč Asiab in Ganj Dareh
In the 1960–70s, fieldwork in the central Zagros Mountains produced evidence of early Holocene Neolithic settlements in this mountainous zone along the ‘Eastern wing’ of the Fertile Cre-scent. Following a long hiatus in fieldwork, new investigations have highlighted once more the po-tential of the transitional Neolithic (c. 9600–8000 BC) and early Neolithic (c. 8000–7000 BC) se-quence in this region. However, some of the pivotal sites that had originally been excavated in the 1960–70s were not published in adequate detail, leaving many questions unanswered. Recent field-work at Asiab and Ganj Dareh directed by the authors has sought to address the issues raised by these previously unpublished excavations. Here we summarise the results of our recent work at these two sites and discuss their implications for our understanding of neolithisation in the central Zagros.Izkopavanja v 60. in 70. letih 20. stoletja v osrednjem delu gorovja Zagros, tj. v goratem predelu na vzhodnem kraku rodovitnega polmeseca, so odkrila zgodnje holocenske neolitske naselbine. Po daljši prekinitvi so nove raziskave ponovno izpostavile potenciale za preučevanje obdobja prehodnega neolitika (ok. 9600–8000 pr. n. št.) in zgodnjega neolitika (ok. 8000–7000 pr. n. št.) v tej regiji. Nekatera ključna najdišča, ki so bila prvotno izkopana v 60. in 70. letih 20. stoletja, do danes še niso bila natančno objavljena, zato ostajajo številna vprašanja povezana s temi najdišči še odprta. Avtorji prispevka so želeli z novimi izkopavanji na najdiščih Asiab in Ganj Dareh pridobiti nove podatke in odgovore na nerešena vprašanja iz starejših neobjavljenih raziskav. V prispevku predstavljamo rezultate izkopavanj na obeh najdiščih in razpravljamo o njuni vlogi pri razumevanju procesa neolitizacije v osrednjem Zagrosu
Addressing the Climate Problem:Choice between Allowances, Feed-in Tariffs and Taxes
Instruments chosen to pursue climate related targets are not always efficient. In this paper we consider an economy with three climate related targets for its electricity generation: a given share of “green” electricity, a given expansion of “green” electricity, and a given reduction of “black” (fossil based) electricity. At its disposal the country has three instruments: an allowance system (tradable green certificates), a subsidy system (feed-in tariffs) and a Pigouvian fossil tax. Each of these instruments may be used to attain any of the given targets. Within the setting of the model it is verified that each kind of the target has only a single efficient instrument under certainty, and that there is a deadweight loss of using other instruments to achieve the target. Similarly, there is also an analysis of instrument choice when several targets are to be attained at the same time. The paper also discusses the case of simultaneous targets as well as the relevance of the various targets
Material Limitations on the Detection Limit in Refractometry
We discuss the detection limit for refractometric sensors relying on high-Q
optical cavities and show that the ultimate classical detection limit is given
by min{Dn} > eta with n+i*eta being the complex refractive index of the
material under refractometric investigation. Taking finite Q factors and
filling fractions into account, the detection limit declines. As an example we
discuss the fundamental limits of silicon-based high-Q resonators, such as
photonic crystal resonators, for sensing in a bio-liquid environment, such as a
water buffer. In the transparency window of silicon the detection limit becomes
almost independent on the filling fraction, while in the visible, the detection
limit depends strongly on the filling fraction because silicon absorbs
strongly.Comment: Published in Special Issue "Laser Spectroscopy and Sensing", Edited
by Prof. M.W. Sigris
Udvikling af kundeattraktivitet over for strategisk vigtige leverandører
God leverandørperformance er ikke en selvfølge. Leverandørperformance afhænger imidlertid af andet end leverandørens evne til at styre egne interne processer. Hvordan leverandører performer, afhænger i høj grad også af kundens attraktivitet. Langt de fleste leverandører foretager således en bevidst prioritering af kunders attraktivitet med udgangspunkt i kunders økonomiske, ressourcemæssige og sociale attraktivitet. Artiklen illustrerer med udgangspunkt i et netværksperspektiv, hvordan JAMO via en bevidst håndtering af sine leverandørrelationer kan prioritere og øge sin kundeattraktivitet, og illustrerer samtidig, hvordan JAMO i praksis kan arbejde med attraktivitetsbegrebet over for seks strategisk vigtige kinesiske leverandører. Attraktivitetsbegrebet har tidligere ikke været forsøgt anvendt i praksis og har overvejende været beskrevet teoretisk
Udvikling af kundeattraktivitet over for strategisk vigtige leverandører
God leverandørperformance er ikke en selvfølge. Leverandørperformance afhænger imidlertid af andet end leverandørens evne til at styre egne interne processer. Hvordan leverandører performer, afhænger i høj grad også af kundens attraktivitet. Langt de fleste leverandører foretager således en bevidst prioritering af kunders attraktivitet med udgangspunkt i kunders økonomiske, ressourcemæssige og sociale attraktivitet. Artiklen illustrerer med udgangspunkt i et netværksperspektiv, hvordan JAMO via en bevidst håndtering af sine leverandørrelationer kan prioritere og øge sin kundeattraktivitet, og illustrerer samtidig, hvordan JAMO i praksis kan arbejde med attraktivitetsbegrebet over for seks strategisk vigtige kinesiske leverandører. Attraktivitetsbegrebet har tidligere ikke været forsøgt anvendt i praksis og har overvejende været beskrevet teoretisk
Extravascular lipid deposition and morphology of atherosclerosis in heterozygous WHHL rabbits fed vegetable (n-6) and marine (11-3) oils
The aim of this experiment was to test the cholesterol-fed heterozugous WHHL rabbit as a model for investigation of atherogenicity of different fats. Twentytwo rabbits of both sexes, 8—9.5 months old were randomized in 3 groups, and fed 100 g diet daily: cholesterol enriched standard diet (group I, n=8), cholesterol enriched diet with added vegetable (group II, n=7). or marine (group III, n=7) oils during 14 weeks. The vegetable oil (n-6 = 33 %, n—3 less than 1 %) and a marine oil(n-6 = 18 %, n-3 = 17 %) were adjusted to contain equal amounts of saturated and monounsaturated fatty acids. One percent cholesterol in the diet caused a pronounced hypercholesterolemia which was significantly enhanced by addition of oils.The increase in total cholesterol was especially reflected in the increase in the VLDL concentration. The blood cholesterol and triglyceride levels were comparable between the two of fed groups apart from a transitory lowering in the marine oilfed rabbits. The atherosclerotie lesions caused by 1 % cholesterol in the diet were fibrous plaques and plaques with foam cells. The added oils aggravated the atherosclerosis caused by cholesterol. Based on morphological appearance of the aorticand coronary atherosclerosis the marine oil was more atherogcnic than the vegetable oil. In pulmonary arteries, however, the less severe atherosclerotic changes were found in the marine oil group. In this group no lipid infiltrations were seen in the myocardium but very severe infiltrations were seen in the liver. In the vegetable oil group these infiltrations were severe in the myocardium and less pronounced in the liver. The massive hypereholesterolemia and extravascular lipid deposition in different parenchymatous organs suggest that lower doses of dietary cholesterol should be used when the cholesterol-fed heterozygous WHHL rabbit is chosen to study the ellect ot'van'ous fats on blood lipids and developmentof atherosclerosis
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