scholarly journals AMS Radiocarbon Dating of Paleolithic-Aged Charcoal from Europe and the Mediterranean Rim Using ABOx-SC

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 839-846 ◽  
Author(s):  
F Brock ◽  
T F G Higham
Keyword(s):  
South Africa ◽  
Failure Rate ◽  
Radiocarbon Dating ◽  
Sample Pretreatment ◽  
Combustion Method ◽  
High Failure Rate ◽  
Acid Base ◽  
Ams Radiocarbon Dating ◽  
The Mediterranean

Radiocarbon dating of charcoal >25–30 kyr can be problematic due to contamination from exogeneous carbon and the variable effectiveness of 14C pretreatments to remove it. Bird et al. (1999) developed the ABOx-SC (acid-base-oxidation-stepped combustion) method for removing contaminants from older charcoal samples, which involves a harsher treatment than traditional acid-base-acid (ABA) pretreatments. This method has been shown to considerably improve the reliability of dating old charcoal from sites in Australia, South Africa, Brazil, and Malaysia (Bird et al. 1999, 2003; Turney et al. 2001; Santos et al. 2003; Higham et al. 2009a). Here, we apply the technique to material from 5 Paleolithic sites from Europe and the Mediterranean Rim. For 2 of the sites (Kebara Cave, Israel and Taramsa Hill, Egypt), the ABOx-SC and ABA methods produced similar dates. However, in the case of 1 site, the Grotta di Fumane in Italy, ABOx-SC pretreatment produced significantly older results from those of ABA methods, requiring substantial reinterpretation of the archaeological sequence of the site. The rigorous nature of the technique resulted in a high failure rate for sample pretreatment, and insufficient material survived the pretreatment for dating from Grotte des Pigeons, Morocco or Gorham's Cave, Gibraltar.

Drivers of restaurant efficiency in South Africa: a stochastic frontier approach

2018 ◽  
Vol 12 (4) ◽  
pp. 407-419 ◽  
Author(s):  
Oswald Mhlanga
Keyword(s):  
South Africa ◽  
Failure Rate ◽  
Stochastic Frontier ◽  
Stochastic Approach ◽  
High Failure Rate ◽  
Content Type ◽  
Cost Frontier ◽  
Secondary Sources ◽  
Food And Beverage ◽  
Structural Drivers

Purpose Restaurants in South Africa have a notoriously high failure rate. This study aims to identify drivers of restaurant efficiency in South Africa. Design/methodology/approach A stochastic cost frontier function with three inputs (i.e. labour, food and beverage and materials) and one output as the total revenue is specified and used to estimate restaurant efficiency. An extensive data collection using primary and secondary sources enabled the researcher to gather data from 42 restaurants, for the year 2016, on a variety of parameters. Findings The findings show that on average restaurants were operating at 77%, with the most and least efficient restaurants operating at a 97 and a 43% efficiency level, respectively. From the study, it is clear that two structural drivers, namely, “location” and “operation type”, and two executional drivers, namely, “restaurant type” and “revenue per available seat hour”, significantly impacted (p < 0.05) on restaurant efficiency in South Africa. Research limitations/implications Despite the importance of this study, it is not free of limitations. First, the research was based on efficiency drivers for restaurants situated in a specific South African province. Caution is therefore required when generalising the findings of this study to restaurants in other geographic areas, as a replication of this study in other geographic areas might reveal varying levels of efficiency. Second, the measurement of restaurant efficiency was limited to five efficiency drivers. Even though these efficiency drivers were included in other studies as well, there could be other relevant efficiency drivers that are likely to influence restaurant efficiency. Practical implications To improve efficiency, restaurateurs should first concentrate on the drivers that can be changed in the short term (executional drivers) and then later focus on the drivers that require long-term planning (structural drivers). Restaurateurs should understand the use of RevPASH strategies to manipulate demand during peak and off-peak periods. Furthermore, restaurants should be able to change the table mix to optimise table configuration. Changing a restaurant’s table configuration during peak times increases efficiency. Originality/value This paper is a first attempt to identify drivers of operational efficiency using a stochastic approach in the restaurant industry in South Africa. As restaurants in South Africa have a high failure rate, the results could assist restaurateurs in managing more successful entities.

PREPARATION OF WOOD, CHARCOAL AND BONE COLLAGEN MICRO SAMPLES USING AUTOMAT FOR AMS RADIOCARBON DATING

2019 ◽  
Vol 186 (2-3) ◽  
pp. 433-436 ◽  
Author(s):  
Pavel Simek ◽  
Natálie Megisová ◽  
Július Bemš
Keyword(s):  
Radiocarbon Dating ◽  
Wood Charcoal ◽  
Bone Collagen ◽  
Peristaltic Pump ◽  
Acid Base ◽  
Ams Radiocarbon Dating ◽  
Switching Valve ◽  
Computer Controlled

Abstract For the pretreatment of wood, charcoal and collagen from bone micro samples using the Acid–Base–Acid (ABA) method, we have assembled an automated computer-controlled unit in our laboratory CRL. The sample is placed in a glass single-necked cuvette. The machine consists of prepared solutions which are guided through capillaries, switching valve and peristaltic pump into the cuvette with the sample according to the currently selected program. The automat can be used for the pretreatment of charcoal, wood and also collagen from bones.

Radiocarbon Dating of Bones at the LARA Laboratory in Bern, Switzerland

Radiocarbon ◽  
2016 ◽  
Vol 59 (3) ◽  
pp. 831-842 ◽  
Author(s):  
Sönke Szidat ◽  
Edith Vogel ◽  
Regula Gubler ◽  
Sandra Lösch
Keyword(s):  
Acid Treatment ◽  
Radiocarbon Dating ◽  
Sample Pretreatment ◽  
Bulk Sediment ◽  
Acid Base ◽  
The Holocene ◽  
Plant Remains ◽  
University Of Bern ◽  
The University

AbstractThe Laboratory for the Analysis of Radiocarbon with AMS (LARA) was established at the University of Bern in 2013. Since then, the quality of sample preparation and radiocarbon measurement procedures have been validated for different materials such as plant remains, macrofossils, bulk sediment, charcoals, and wood. This article presents the optimization of sample pretreatment of bones based on protocols described in the literature. The extraction of collagen was performed with an acid-base-acid treatment, gelatinization, coarse filtration, lyophilization, and graphitization. Dating results were validated as satisfactory for the Holocene by investigation of 36 individual samples previously dated by other 14C laboratories including VIRI/SIRI materials and from well-known archaeological contexts. An additional blank contribution for bone treatment was determined by comparison with the preparation of other sample materials. The cases of two outliers from the Holocene were studied in detail.

scholarly journals Brand Naming Behavior Defining SMMEs in eThekwini

2018 ◽  
Vol 9 (6) ◽  
pp. 6-16
Author(s):  
Lindiwe N. Kunene ◽  
Maxwell Phiri
Keyword(s):  
South Africa ◽  
Failure Rate ◽  
Brand Equity ◽  
High Failure Rate ◽  
Research Outcomes ◽  
Branding Strategies ◽  
Brand Strategies

Branding is an integral part to the success of any and every business. Appropriate brand strategies contribute to brand equity of the organization leading to increased turnover and profits of positive turnover for organizations. Application of properly planned brand naming processes could save SMMEs and reduce the high failure rate experienced by this sector, in South Africa currently. Branding helps businesses to define who they are and guides their overall strategy. Branding strategies begin with the brand naming process. There are scientifically proven models that govern this process which have been used by successful businesses, globally. This study sought to find the current brand naming processes as implemented by SMMEs in the eThekwini Municipality area in Durban, South Africa. This was the first step in developing a model for brand naming for SMMEs in eThekwini. The study therefore used descriptive-exploratory ethos to conduct the research, guided by the epistemological, ontological and axiological assumptions. Demographic dimensions, ownership of the brand naming process, traits in the naming process and brand naming strategies considered were used to reach conclusions that define these entities in eThekwini. Research outcomes found that a lack of resources and knowledge were the main impediments distorting appropriate brand naming processes. 

The Biology of Mediterranean-Type Ecosystems

2018 ◽  
Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Invasive Species ◽  
Habitat Loss ◽  
Endemic Species ◽  
Geographic Area ◽  
Cutting Edge ◽  
Wide Range ◽  
The Mediterranean ◽  
Mediterranean Type Ecosystems

The world’s mediterranean-type climate regions (including areas within the Mediterranean, South Africa, Australia, California, and Chile) have long been of interest to biologists by virtue of their extraordinary biodiversity and the appearance of evolutionary convergence between these disparate regions. Comparisons between mediterranean-type climate regions have provided important insights into questions at the cutting edge of ecological, ecophysiological and evolutionary research. These regions, dominated by evergreen shrubland communities, contain many rare and endemic species. Their mild climate makes them appealing places to live and visit and this has resulted in numerous threats to the species and communities that occupy them. Threats include a wide range of factors such as habitat loss due to development and agriculture, disturbance, invasive species, and climate change. As a result, they continue to attract far more attention than their limited geographic area might suggest. This book provides a concise but comprehensive introduction to mediterranean-type ecosystems. As with other books in the Biology of Habitats Series, the emphasis in this book is on the organisms that dominate these regions although their management, conservation, and restoration are also considered.

SUITABILITY OF ACID-SOLUBLE AND ACID-INSOLUBLE LEATHER FRACTIONS IN RADIOCARBON DATING

Radiocarbon ◽  
2020 ◽  
pp. 1-8
Author(s):  
Alyssa M Tate ◽  
Brittany Hundman ◽  
Jonathan Heile
Keyword(s):  
Radiocarbon Dating ◽  
Insoluble Fraction ◽  
Economic Life ◽  
Chemical Pretreatment ◽  
Acid Base ◽  
The Past ◽  
Acid Soluble Collagen ◽  
Method Of Production ◽  
Insight Into

ABSTRACT Leather has been produced by a variety of methods throughout human history, providing researchers unique insight into multiple facets of social and economic life in the past. Archaeologically recovered leather is often fragile and poorly preserved, leading to the use of various conservation and restoration efforts that may include the application of fats, oils, or waxes. Such additives introduce exogenous carbon to the leather, contaminating the specimen. These contaminants, in addition to those accumulated during interment, must be removed through chemical pretreatment prior to radiocarbon (14C) dating to ensure accurate dating. DirectAMS utilizes organic solvents, acid-base-acid (ABA) and gelatinization for all leather samples. Collagen yield from leather samples is variable due to the method of production and the quality of preservation. However, evaluating the acid-soluble collagen fraction, when available, provides the most accurate 14C dates for leather samples. In instances where gelatinization does not yield sufficient material, the resulting acid-insoluble fraction may be dated. Here we examine the effectiveness of the combined organic solvent and ABA pretreatment with gelatinization for leather samples, as well as the suitability of the acid-insoluble fraction for 14C dating.

AMS Radiocarbon Dating of the Type Plainview and Firstview (Paleoindian) Assemblages: The Agony and the Ecstasy

1999 ◽  
Vol 64 (3) ◽  
pp. 444-454 ◽  
Author(s):  
Vance T. Holliday ◽  
Eileen Johnson ◽  
Thomas W. Stafford
Keyword(s):  
Amino Acids ◽  
Great Plains ◽  
Radiocarbon Dating ◽  
Southern Plains ◽  
Ams Radiocarbon Dating ◽  
Tight Cluster ◽  
Bison Antiquus

Plainview and Firstview are two of the principal post-Folsom Paleoindian artifact assemblages on the Great Plains, but good radiometric age control for these artifact styles is relatively poor, due in part to lack of reliable age control on the type collections. This study reports the results of AMS-radiocarbon dating of specific amino acids from Bison antiquus bone associated with the type Plainview and Firstview assemblages from the Plainview and Olsen-Chubbuck sites, respectively. Seven samples of bone and teeth from Plainview produced a surprisingly wide array of ages. As a result, the age of the bone bed and the type Plainview collection remain uncertain, but it is most likely ≥ 10,000 B.P. (but late or post-Folsom) given the dating and stratigraphic relationships at Plainview and other sites. Seven samples of bone from Olsen-Chubbuck yielded a tight cluster of ages averaging ca 9400 B.P., fitting well with other dated Firstview features on the Southern Plains. These results show that much better age control from more sites is needed in order to understand the Paleoindian record. AMS-radiocarbon dating of specific amino acids from bone has revolutionized such issues of chronology in archaeology, but like any other method, it can provide confusing results and must be used in conjunction with other chronometric data.

High failure rate of cementless threaded acetabular cups:A radiographic and histologic study in the goat

1996 ◽  
Vol 67 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Jon D Bruijn ◽  
Jan L Seelen ◽  
Roel W Veldhuizen ◽  
Rob M Feenstra ◽  
Frans P Bernoski ◽  
...  
Keyword(s):  
Failure Rate ◽  
High Failure Rate ◽  
Histologic Study
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