12,850 research outputs found
Longmen Da Fengxian si de qiyuan ji diwei” ???????????? (“On the Beginning and Status of Big Fengxian Temple at the Longmen Grotto”)
No full textThe article is a Chinese translation (unchecked by the author) of a preliminary version of Forte, “The Origins and Role of the Great Fengxian Monastery ???? at Longmen,” 1996. Published under the author’s Chinese name of Fu Andun ???
Skilled people or specialists? Knowledge and expertise in copper age vessels from central Italy
No full textStudying craft specialisation in archaeology involves investigating and reconstructing how production was organised. This article focuses on prehistoric communities and asks who performed specific tasks. Ceramic specialisation is traditionally approached through models of production organisation that are largely based on ethnoarchaeological case studies and are usually difficult to link with the archaeological evidence. Based on these models, the economic framework plays a key role in associating the emergence of specialisation with the intensification of the demand for goods and identifying specialists by the amount of time required for production. This approach neglects the social value of products and the social context sustaining skills development. This article discusses surface treatments as a means to understand the skills of potters and the social values of specific ceramic products in Copper Age communities from central Italy. The methodology combines the analysis of technological traces and experimental archaeology used to infer craftspeople's expertise and reveals differences in the chaîne opératoire and skills involved in the production of domestic and funerary vessels. The results support a hypothesis of household specialisation that developed in these communities based upon differences in skills, knowledge and dedication among potters and the recurrent association of skilled productions with ritual contexts
Intorno ai mss. danteschi Strozzi 152 e Additional 19587: una prima collazione iconografica
No full textSi propone la collazione iconografica integrale di due manoscritti danteschi riccamente miniati (ms. Strozzi 152 della Laurenziana di Firenze e ms. Additional 19587, conservato presso la British Library di Londra), in evidenti - e riconosciuti - rapporti di parentela
Traceological analyses applied to textile implements. An assessment of the method through the case study of the 1st millennium BCE ceramic tools in Central Italy
No full textLo studio delle attività di tessitura in archeologia si basa sull’analisi di resti di tessuti, fonti iconografiche e manufatti utilizzati durante i processi di trasformazione delle materie prime in prodotti finiti. Il rinvenimento di oggetti come fuseruole e rocchetti in un contesto archeologico rappresenta una prova indiretta della pratica di attività di filatura e tessitura. Il sempre maggiore utilizzo di questi oggetti nei contesti funerari del I millennio a.C. fa sorgere una serie di interrogativi sul loro significato nella quotidianità; diversi studi a riguardo hanno cercato di chiarire se fossero stati realmente utilizzati dal defunto, dalla sua famiglia o da altri individui che erano in contatto con il defunto stesso quando era ancora in vita, o ancora, in che modo siano stati utilizzati oppure se, al contrario, venivano introdotti nel corredo funerario senza essere mai stati impiegati nelle attività di tessitura (BARTOLONI 1989; 2000; 2002; TOMS 1998, GLEBA 2008).
Fuseruole e rocchetti sono oggetti apparentemente semplici che, tuttavia, sono relazionati a gesti molto specifici e altamente vincolati al background culturale di chi li utilizzava. Inoltre, l’esistenza di un’ampia variabilità di tecniche di filatura e tessitura, ben documentate ad oggi in contesti tradizionali, suggerisce come strumenti simili possono essere stati utilizzati in svariati modi (vedi HUDSON 2014).
Questo contributo è un primo tentativo di investigare l’uso di strumenti archeologici da un punto di vista sperimentale e traceologico che può aiutare a definire con maggiore precisione le caratteristiche tecnologiche di fuseruole e rocchetti ed identificare le principali modificazioni che le attività di filature e tessitura possono provocare sulle superfici degli strumenti
A preliminary study of ceramic pastes in the copper age pottery production of the Rome area
No full textThis paper presents the preliminary results of an analytical study on domestic pottery samples originating from the Copper Age sites of Casetta Mistici, Tor Pagnotta, Osteria del Curato-Via Cinquefrondi, Torre della Chiesaccia and Valle dei Morti, all of which are located in the Rome area (Latium, Italy). The aim of this research is to define the compositional features of the ceramic pastes and to reconstruct the main technological choices characterising pottery production in these contexts. The importance of these archaeological sites lies in their geographic position, being located in an area bounded by the Tiber and Aniene rivers and the Colli Albani volcano, and in their stratigraphic sequence, spanning from the mid-fourth to the end of the third millennium bc. This research, based on a petrographic and chemical investigation of pottery samples, led to the distinction of eight petrographic groups that reflect specific choices in pottery production. Moreover, the analytical results provide indications about the prehistoric pottery production of the Rome area in relation to the ceramic recipes used, the pastes that were obtained and their sourcing areas
Traceological analysis applied to textile implements: An assessment of the method through the case study of the 1st millennium BCE ceramic tools in central Italy
No full textThis contribution focuses on the application of traceological analysis to ceramic textile tools. Traceological analysis has been rarely applied to the study of this specific category of artefacts. A dedicated reference collection needed to be created for a proper understanding of the development of both technological and use traces, on apparently simple artefacts that, nevertheless, are connected with very specific gestures highly constrained by cultural background of their users. Our experimental framework was based on the ceramic textile tools from the cemeteries of Cerveteri, Vulci, Narce and Falerii in Central Italy, dated to the 1st millennium BCE. The macroscopic analyses of archaeological and experimental ceramic textile tools allowed to define the technological features of production, such as the exploited ceramic pastes and the traces related to the various steps of tool production including modelling, surface treatment, decoration and firing techniques. Moreover, this investigation allowed to define the technological traces and to distinguish them from use wear traces and post-depositional alterations
Profiling the people behind clay figurines. Technological trace and fingerprint analysis applied to ancient Egypt (Lahun village, MBA II, c. 1800–1700 BC)
No full textClay figurines represent one of the ideal object categories for tracing the profile of their makers since they preserve traces of the maker’s gestures. The scope of the article is to reconstruct the different manufacturing steps of clay figurines, assess the complexity of the shaping sequences and study fingerprints to trace the profile of people who produced such artefacts in the ancient village of Lahun (Egypt, MBA II, c. 1800–1700 BC). The high number of production chains revealed that, despite an apparent roughness, clay figurine production was characterised by high stylistic and technological variability, indicating several levels of skill possessed by their producers. On this basis, Lahun clay figurines were not an extemporary or standardised product. A neat division can be established between anthropomorphic figurines and those representing animals, which show a lower degree of complexity and an attempt not to define clear shapes. Most of the figurines were revealed to be mainly shaped by adults, while children contributed in a marginal way to their production. However, the presence of sub-adult fingerprints on some of the clay figurines indicates that children were active agents producing material culture and integrating part of the adult production process through cooperation and/or playing
Prediction models for the dynamical behaviour of multi-phase annular seals
No full textSempre maggior interesse è stato dedicato nelle ultime due decadi nello studio e sviluppo di pompe multifase. Le pompe multifase elaborano miscele di fluidi immiscibili (compressibili e non) ad alte velocità e potenze specifiche per stadio in modo da ridurre dimensioni e costi. Tali peculiarità rendono questo tipo di turbomacchine molto attraenti in settori industriali come l’Oil&Gas, sia per applicazioni sottomarine che in superficie, industria chimica e farmaceutica. Di primaria importanza, in fase di progettazione della macchina, è la valutazione della stabilità rotordinamica della turbomacchina, in modo da assicurare alta affidabilità e continuità di servizio specialmente quando i lavori di manutenzione sono difficili e costosi. A tal riguardo, la valutazione dei coefficienti rotordinamici della tenuta è di solito realizzata attraverso l’uso di modelli semplificati di flusso medio, basate sulle equazioni di Navier-Stokes mediate sul meato fluido (i.e. la distanza rotore-statore); la chiusura del problema si ottiene attraverso l’utilizzo di correlazioni sia numeriche che sperimentali. I modelli di flusso medio sono caratterizzati da alcune importanti peculiarità come facilità di utilizzo e velocità. Mostrano tuttavia qualche punto debole. Nel caso specifico delle pompe multifase, ad esempio, l’applicazione delle correlazioni monofase al campo multifase, può portare a inaccuratezza e risultati fuorvianti. A tal riguardo, lo scopo di questa ricerca di dottorato è quello di proporre un nuovo modello di flusso medio per la caratterizzazione della risposta strutturale di una tenuta anulare in pressione operante in regime di flusso multifase. Il modello proposto è basato sull’ipotesi principale di una stratificazione regolare dei due fluidi. È stato ipotizzato che il liquido venga centrifugato verso lo statore, lasciando il rotore in contatto con il solo gas. Tale premessa rende possibile derivare un modello di flusso medio a due strati per ognuna delle due fasi.
Chapter 1 introduce la notazione abituale per l’analisi di stabilità strutturale. Viene delineato il modello di risposta strutturale della tenuta.
Chapter 2 riesamina la letteratura nel campo della caratterizzazione e modellazione delle tenute anulari in pressione in regime monofase. Vengono scrutinati sia i metodi CFD che i modelli a flusso medio. Infine, entrambi i metodi vengono comparati con i risultati sperimentali.
Chapter 3 tratta della modellazione delle tenute anulari multifase. Il capitolo in particolare analizza il modello bifase più adottato in letteratura: il modello bifase omogeneo. Viene introdotto una revisione globale della letteratura. Una nuova formulazione generale delle condizioni al contorno è proposta. La valutazione del modello è fatta attraverso il confronto con i risultati sperimentali.
Chapter 4 presenta il nuovo modello stratificato. Vengono introdotte le equazioni di flusso medio. Le correlazioni sia degli integrali del flusso di quantità di moto che dei fattori di attrito sono modellate per ognuna delle due fasi in funzione dello specifico regime di flusso (turbolento piuttosto che laminare). Le portate predette mostrano buon accordo con i risultati sperimentali.An increasing interest has been devoted in the last two decades in the study and development
of multiphase pumps. Multiphase pumps elaborate mixtures of immiscible fluids (both
compressible and not) at high speed and power density per stage in order to reduce size and cost.
These peculiarities make this kind of turbomachinery very attractive in different industrial sectors
such as Oil&Gas, both for sub-sea and topside applications, chemical and pharmaceutical
industry. Of primary importance, in the machine design phase, is the evaluation of the turbomachinery
rotordynamic stability, to ensure high reliability and service continuity specially
when maintenance works are difficult and expensive. In this respect, the evaluation of the seal
rotordynamic coefficients is usually achieved through simplified bulk flow models, based on the
Navier-Stokes equations averaged over the fluid meatus (i.e. the rotor-stator clearance); the
problem closure is achieved with the aid of both numerical and experimental correlations. Bulk
flow models are characterized by some important peculiarities such as ease of use and fastness.
They show however some weakness. In the specific case of multiphase pumps, for example,
the application of the single phase correlations to the multiphase field can lead to inaccuracy
and misleading results. In this regard, the aim of this doctoral research is to propose a new
bulk flow model for the characterization of the structural response of an annular pressure seal
operating in the multiphase flow regime. The proposed model is based on the major hypothesis
of a smooth stratification of the two fluids. It is hypothesized that the liquid is centrifuged
toward the stator, leaving the rotor in contact only with the gas. This assumption allows to
derive a two-layer bulk model for each of the two phases.
Chapter 1 introduces the usual notation of the structural stability analysis. The model of
the seal structural response is outlined.
Chapter 2 reviews the literature in the field of the single phase annular pressure seal
modeling and characterization. Both CFD and bulk flow models are scrutinized. Finally, both
the methods are compared with experimental measurements.
Chapter 3 deals about the multi-phase annular seal modeling. The chapter especially
analyzes the widest adopted two-phase bulk model in literature: the homogeneous two-phase
model. A global review about the specific literature is introduced. A new general formulation
of the boundary conditions is proposed. Model assessment in done through the comparison
with experimental results.
Chapter 4 presents the new stratified bulk flow model. Bulk flow equations are introduced.
Correlations of both momentum flux integrals and friction factors are modeled for each of the
two phases depending on the specific flow regime (turbulent rather than laminar). Predicted
mass flow rates show good agreement with experimental results
Optimization of in vitro cultivation of the blood cells of urodeles
No full textGojenje krvnih celic je pomemben nedestruktiven pristop pridobivanja mitotičnega
materiala (tj. metafaznih kromosomov), ki se ga uporabi za študije citogenetike in
evolucije. Zaradi nezadovoljivega števila metafaznih kromosomov v predhodnih
poskusih in vitro na krvi močerila (Proteus anguinus), smo metodo v tej raziskavi
dodatno optimizirali in vpeljali tudi gojenje krvnih celic modelne repate dvoživke
(Pleurodeles waltl). Primarno celično kulturo smo vzpostavili iz frakcije levkocitov in
polne krvi. S testom proliferacije z BrdU smo ugotovili, da je ustrezna dolžina
inkubacije z mitogenom PHA-M, ki je potreben za proliferacijo limfocitov, 4-5 dni pri
močerilu in manj kot 4 dni pri španskem pupku ter v koncentraciji 6 % (vol/vol).
Ustrezna koncentracija antimitotika kolcemida je bila 3 in 8 μg/ml, dodanega v celično
kulturo za 24 in 48 ur. Kot najbolj obetavni vzorci za gojenje in vitro so se izkazali krvni
vzorci zaporednih odvzemov krvi pri isti živali v kratkem časovnem intervalu (od 7 do
21 dni), saj spodbudimo proliferacijo krvnih celic in vivo. Na ta način smo pri španskem
pupku uspeli pridobiti visoko število setov metafaznih kromosomov (več sto na eno
objektno steklo) in zadovoljivo število setov metafaznih kromosomov pri močerilu (do
10). Vseeno pa je potrebna nadaljnja optimizacija postopkov po zaključku gojitve celic
in vitro, da bo zagotovljena tudi ustrezna razporeditev in morfologija kromosomov za
citogenetske analize.Culturing blood cells is an important non-destructive approach for obtaining mitotic
material (i.e. metaphase chromosomes) that can be used for cytogenetic and
evolutionary studies. As the number of metaphase chromosomes was to low in previous
in vitro experiments with blood of the olm (Proteus anguinus), the method was further
optimized. We also included another urodele, the Iberian ribbed newt (Pleurodeles
waltl), as a model organism in the study. The primary cell culture was established from
the leukocyte fraction and from whole blood. Based on the BrdU proliferation assay, we
found that the incubation time required for lymphocyte proliferation with the mitogen
PHA-M was 4–5 days in the olm and less than 4 days in the Iberian ribbed newt, and at
a concentration of 6% (vol/vol). The appropriate concentration of the antimitotic
colcemid was 3 and 8 µg/ml, which was added to the cell culture for both 24 and 48
hours. The most promising samples for in vitro cultures were blood samples after in vivo
stimulation of cell proliferation with sequential blood sampling in a short time interval
(from 7 to 21 days). With this type of blood samples, we were able to obtain a high
number of metaphase chromosome sets in the Iberian ribbed newt (several hundred per
slide) and a satisfactory number of metaphase chromosome sets in the olm (up to 10).
However, further optimization of the procedures after in vitro culturing is required to
ensure adequate distribution and morphology of chromosomes spread for cytogenetic
analyzes
Six Overtures Composed by C. F. Abel. Adapted for the Harpsichord or Piano Forte : being Opera First / By the Author
No full textSIX OVERTURES COMPOSED BY C. F. ABEL. ADAPTED FOR THE HARPSICHORD OR PIANO FORTE : BEING OPERA FIRST / BY THE AUTHOR
Six Overtures Composed by C. F. Abel. Adapted for the Harpsichord or Piano Forte : being Opera First / By the Author (1)
Cover (1)
Titelseite (2)
Overture I. (3)
Overture II. (8)
Overture III. (12)
Overture IV. (16)
Overture V. (20)
Overture VI. (24
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