scholarly journals Accuracy of the typological classifications of the Late Glacial and Early Holocene osseous projectile points according to the new AMS dates of selected artifacts from Poland

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Justyna Orłowska ◽  
Grzegorz Osipowicz
Keyword(s):  
Current Knowledge ◽  
Raw Materials ◽  
Late Glacial ◽  
Early Holocene ◽  
Projectile Points ◽  
Relative Dating ◽  
Ams Dating ◽  
Processing Techniques ◽  
The Given ◽  
Made In

AbstractLate Glacial and Early Holocene bone and antler artifacts are recovered from all over the Polish Lowland. Elements of projectile weaponry, in the form of various points made of osseous raw materials, were an important part of hunter-gatherer equipment of that time. We present the results of AMS dating of a unique collection of thirteen artifacts that had previously been chrono-culturally attributed by means of relative dating using typological approaches only. The results obtained are considered alongside current knowledge and typological arrangements for these types of tools in Europe. We also attempt to determine the interpretative potential of the technological studies to which the discussed osseous points were subjected in terms of possibly identifying processing techniques that can be specific to the given periods of the Stone Age. Suggestions made in this respect are verified through the radiocarbon dating results.

scholarly journals Detecting Lithium (Li) Mineralizations from Space: Current Research and Future Perspectives

2020 ◽  
Vol 10 (5) ◽  
pp. 1785 ◽  
Author(s):  
Joana Cardoso-Fernandes ◽  
Ana C. Teodoro ◽  
Alexandre Lima ◽  
Mônica Perrotta ◽  
Encarnación Roda-Robles
Keyword(s):  
Remote Sensing ◽  
Raw Materials ◽  
Remote Sensing Data ◽  
Sensing Data ◽  
Research Perspectives ◽  
Technological Advances ◽  
Processing Techniques ◽  
Remote Sensing Methods ◽  
Near Future ◽  
Made In

Optical and thermal remote sensing data have been an important tool in geological exploration for certain deposit types. However, the present economic and technological advances demand the adaptation of the remote sensing data and image processing techniques to the exploration of other raw materials like lithium (Li). A bibliometric analysis, using a systematic review approach, was made to understand the recent interest in the application of remote sensing methods in Li exploration. A review of the application studies and developments in this field was also made. Throughout the paper, the addressed topics include: (i) achievements made in Li exploration using remote sensing methods; (ii) the main weaknesses of the approaches; (iii) how to overcome these difficulties; and (iv) the expected research perspectives. We expect that the number of studies concerning this topic will increase in the near future and that remote sensing will become an integrated and fundamental tool in Li exploration.

Impact of Raw Materials and Processing Techniques on The Microbiological Quality of Egyptian Domiati Cheese

2020 ◽  
Keyword(s):  
Raw Materials ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Plate Count ◽  
E Coli ◽  
Fresh Cheese ◽  
Processing Techniques ◽  
The Impact ◽  
Total Yeast

Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.

scholarly journals Synthesis of Metal Organic Frameworks by Ball-Milling

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Cheng-An Tao ◽  
Jian-Fang Wang
Keyword(s):  
Ball Milling ◽  
Large Scale ◽  
Raw Materials ◽  
Metal Organic Frameworks ◽  
Research Topic ◽  
Mass Ratio ◽  
Time Consumption ◽  
Metal Organic ◽  
Short Time ◽  
Made In

Metal-organic frameworks (MOFs) have been used in adsorption, separation, catalysis, sensing, photo/electro/magnetics, and biomedical fields because of their unique periodic pore structure and excellent properties and have become a hot research topic in recent years. Ball milling is a method of small pollution, short time-consumption, and large-scale synthesis of MOFs. In recent years, many important advances have been made. In this paper, the influencing factors of MOFs synthesized by grinding were reviewed systematically from four aspects: auxiliary additives, metal sources, organic linkers, and reaction specific conditions (such as frequency, reaction time, and mass ratio of ball and raw materials). The prospect for the future development of the synthesis of MOFs by grinding was proposed.

scholarly journals Colors and dyes of archaeological textiles from Tarapacá in the Atacama Desert (South Central Andes)

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Marcela Sepúlveda ◽  
Cecilia Lemp Urzúa ◽  
José Cárcamo-Vega ◽  
Edgar Casanova-Gónzalez ◽  
Sebastián Gutiérrez ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Raw Materials ◽  
Physicochemical Characterization ◽  
Atacama Desert ◽  
Central Andes ◽  
Formative Period ◽  
Animal Origin ◽  
Carminic Acid ◽  
Cultural Traditions ◽  
South Central

AbstractThis work concerns the study of colors and dyes identified on archaeological textiles from the Atacama Desert. The different garments and ornaments come from the excavation of two important pre-Columbian cemeteries of the Tarapacá region: Tarapacá-40 attributed to the Formative period (1100 BC–660 AD) and Pica-8 to the Late Intermediate period (900–1450 AD). For the first time, a multi-analytical approach with non-invasive techniques using FORS and SERS was applied on samples of less than 2 cm of length for physicochemical characterization of the raw materials and the dyes employed in the textile production of northern Chile. The fibers are from animal origin. Blue, green, and yellow are identified as indigo, but we cannot discard a mixture with other dyes to vary hue and shade; while carminic acid and alizarin—to a lesser extent—are found on red, orange, and brown samples. This research provides new elements for the discussion about the textile technology developed in this desertic region, its changes, and continuities along the history. Our results are compared to recent findings on neighboring regions from South-Central Andes, to improve the current knowledge and discuss the existence of dyeing textile cultural traditions.

Formally Normal Operators Having no Normal Extensions

1965 ◽  
Vol 17 ◽  
pp. 1030-1040 ◽  
Author(s):  
Earl A. Coddington
Keyword(s):  
Hilbert Space ◽  
Linear Operator ◽  
Null Space ◽  
Normal Operator ◽  
Closed Linear Operator ◽  
Normal Operators ◽  
The Given ◽  
Densely Defined ◽  
Made In

The domain and null space of an operator A in a Hilbert space will be denoted by and , respectively. A formally normal operatorN in is a densely defined closed (linear) operator such that , and for all A normal operator in is a formally normal operator N satisfying 35 . A study of the possibility of extending a formally normal operator N to a normal operator in the given , or in a larger Hilbert space, was made in (1).

Depressive Illnesses in Children and Adolescents: A Review of Current Concepts

1985 ◽  
Vol 30 (2) ◽  
pp. 119-129 ◽  
Author(s):  
B.J. Mcconville ◽  
R.T. Bruce
Keyword(s):  
Children And Adolescents ◽  
Current Knowledge ◽  
Considerable Progress ◽  
Childhood And Adolescence ◽  
Age Related ◽  
Developmental Age ◽  
The Subject ◽  
Made In

Considerable progress has been made in our understanding of depressive illnesses in childhood and adolescence, especially over the last several years. A number of major books on the subject have now appeared, along with a large number of individual papers. This paper attempts to summarize current knowledge, and indicates developmental, age-related and other issues which still require further study.

The Compounding and Application Mechanism of Polycarboxylate-Based Superplasticizers in the Self-Compacting Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 711-717 ◽  
Author(s):  
Miao Miao Gui ◽  
Yun Hui Fang ◽  
Zi Dong Lan ◽  
Fei Yu Yu ◽  
Tian Xing Lin ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
Graft Copolymerization ◽  
Raw Materials ◽  
The Self ◽  
Main Mechanism ◽  
Self Compacting Concrete ◽  
The Given ◽  
Copolymerization Reaction

Polycarboxylate-based superplasticizers are synthesized by radical graft copolymerization reaction, and the products are divided into ester series (PC-1) and ether series (PC-2) on the basis of different big monomers. This article studies on influence of the different composition and dosages of the synthetic superplasticizers in the self-compacting concrete (SCC). The results show that the requirements of SCC workability can be achieved through simple adjustment kinds and dosages of the synthetic superplasticizers under the given mix proportions and the raw materials. And the main mechanism of the polycarboxylate-based superplasticizers is steric hindrance effect.

Aspects of the geomorphology, genesis and environmental significance of earth hummocks (thúfur, pounus): miniature cryogenic mounds

2005 ◽  
Vol 29 (2) ◽  
pp. 139-155 ◽  
Author(s):  
Stefan Grab
Keyword(s):  
Current Knowledge ◽  
Thermal Characteristics ◽  
Environmental Research ◽  
Environmental Significance ◽  
Research Gaps ◽  
Frozen Ground ◽  
The Past ◽  
Internal Morphology ◽  
Differential Frost Heave ◽  
Made In

Miniature varieties of cryogenic mounds that are capable of forming in seasonally frozen ground are commonly referred to as earth hummocks (e.g., North America), thúfur (e.g., Greenland and Iceland) and pounus (Fennoscandia). Over the past few decades there has been a consistent interest to study earth hummocks from a variety of environmental settings. This review summarizes the current knowledge of earth hummocks, highlighting aspects on the external and internal morphology, and thermal characteristics, which may assist to explain hummock formation. Several hypotheses have been proposed for the genesis of earth hummocks, including the ‘cryoexpulsion’ of clasts, hydrostatic and cryostatic pressure, cellular circulation, and differential frost heave. These hypotheses are critically evaluated and some research gaps identified. It emerges that considerable advances have been made towards an improved understanding of earth hummock development, modification and disintegration. Much progress has been made in the application of earth hummock studies to a variety of environmental research approaches such as palaeoenvironmental reconstructions and assessing their impact on hillslope drainage.

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