scholarly journals The formation conditions of birch tar in oxygen-depleted environments

2021 ◽  
Vol 13 (6) ◽  
Author(s):  
Tabea J. Koch ◽  
Patrick Schmidt
Keyword(s):  
Temperature Interval ◽  
Production Systems ◽  
Technical Skills ◽  
Middle Palaeolithic ◽  
Dry Distillation ◽  
Narrow Temperature Interval ◽  
Glass Tubes ◽  
Formation Conditions ◽  
The Relationship ◽  
Heating Duration

AbstractBirch tar is the oldest manmade adhesive dating back to the European Middle Palaeolithic. Its study is of importance for understanding the cognitive capacities and technical skills of Neanderthals and the aceramic production systems employed in the European Palaeolithic and Mesolithic. Several methods may have been used to make birch tar, the most common proposition being dry distillation in oxygen-depleted atmospheres. One of the major impediments for our understanding of the conditions employed to make Neanderthal birch tar, and ultimately the technique used, is that it remains unknown at which temperatures exactly birch tar forms. The relationship between heating duration and tar formation is also unknown. To address these questions, we conduct a laboratory heating experiment, using sealed glass tubes and an electric furnace. We found that birch tar is only produced at a narrow temperature interval (350 °C and 400 °C). Heating times longer than 15 min have no effect on the quantity of tar produced. These findings, notwithstanding previous propositions of necessarily long heating times and larger tolerances for temperature, have important implications for our understanding of the investment in time needed for Palaeolithic birch tar making.

Preliminaries

2017 ◽  
Author(s):  
David J. Lobina
Keyword(s):  
Data Structures ◽  
Production Systems ◽  
Specific Data ◽  
Recursive Functions ◽  
Recursive Solution ◽  
Partial Recursive Functions ◽  
Recursive Structures ◽  
Recursive Data Structures ◽  
Recursive Data ◽  
The Relationship

Recursion, or the capacity of ‘self-reference’, has played a central role within mathematical approaches to understanding the nature of computation, from the general recursive functions of Alonzo Church to the partial recursive functions of Stephen C. Kleene and the production systems of Emil Post. Recursion has also played a significant role in the analysis and running of certain computational processes within computer science (viz., those with self-calls and deferred operations). Yet the relationship between the mathematical and computer versions of recursion is subtle and intricate. A recursively specified algorithm, for example, may well proceed iteratively if time and space constraints permit; but the nature of specific data structures—viz., recursive data structures—will also return a recursive solution as the most optimal process. In other words, the correspondence between recursive structures and recursive processes is not automatic; it needs to be demonstrated on a case-by-case basis.

scholarly journals 395 Impact of pig mortality on U.S. pig producers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 184-185
Author(s):  
Caleb M Shull
Keyword(s):  
Feed Efficiency ◽  
Management Practices ◽  
Production Systems ◽  
Research Priorities ◽  
Functional Approach ◽  
Production Cycle ◽  
Limiting Factor ◽  
Significant Challenge ◽  
The Relationship ◽  
Positive Step

Abstract Swine producers in the U.S. face a significant challenge. On top of the ever-changing market dynamics that lead to wide swings in profitability or loss, is an underlying issue of pig mortality that the industry must address. While significant improvements in total piglets born per litter have been achieved over the last 10 years, pig mortality has seen no improvement or has worsened (Figure 1). When expressed as a percentage of piglets born (excluding mummies), a total of 7.9% were recorded as stillborn and 13.4% died prior to weaning in 2019. Assuming a typical mortality range of 7–10% from weaning to harvest, a typical U.S. producer could expect to lose around 27–30% of all piglets born. In addition, the average producer had around 12% annual sow mortality (Figure 1). Litter size and post-weaning growth rate and feed efficiency will always factor heavily into research priorities due to the economic impact associated with those traits; however, the opportunity to drive value through reduction in pig losses across the production cycle is staggering. In defense of the industry, improving pig survival is not an easy task for a number of reasons. The sample size (i.e., number of pigs) required to do mortality research correctly is often a limiting factor for many production systems. Furthermore, a cross-functional approach is likely required to make significant improvements in mortality. Specifically, the relationship between genetics, health, and management practices warrant consideration. Recent collaboration across the industry to improve mortality is a positive step forward and this collaboration should continue moving forward.

scholarly journals Using Computer Simulation Method to Improve Throughput of Production Systems by Buffers and Workers Allocation

2015 ◽  
Vol 6 (4) ◽  
pp. 60-69 ◽  
Author(s):  
Sławomir Kłos ◽  
Peter Trebuna
Keyword(s):  
Computer Simulation ◽  
Production System ◽  
Production Systems ◽  
Simulation Method ◽  
System Throughput ◽  
Buffer Allocation ◽  
Simulation Experiments ◽  
Buffer Capacities ◽  
The Relationship ◽  
Support Decision Making

Abstract This paper proposes the application of computer simulation methods to support decision making regarding intermediate buffer allocations in a series-parallel production line. The simulation model of the production system is based on a real example of a manufacturing company working in the automotive industry. Simulation experiments were conducted for different allocations of buffer capacities and different numbers of employees. The production system consists of three technological operations with intermediate buffers between each operation. The technological operations are carried out using machines and every machine can be operated by one worker. Multi-work in the production system is available (one operator operates several machines). On the basis of the simulation experiments, the relationship between system throughput, buffer allocation and the number of employees is analyzed. Increasing the buffer capacity results in an increase in the average product lifespan. Therefore, in the article a new index is proposed that includes the throughput of the manufacturing system and product life span. Simulation experiments were performed for different configurations of technological operations.

The Relationship of Technical Skills and Cognitive Workload to Errors During Robotic Surgical Exercises

2021 ◽  
Author(s):  
Sidney I Roberts ◽  
Steven Yong Cen ◽  
Jessiica Nguyen ◽  
Laura C Perez ◽  
Luis G. Medina ◽  
...  
Keyword(s):  
Technical Skills ◽  
Cognitive Workload ◽  
Relationship Of ◽  
The Relationship

scholarly journals Novel Assessments of Technical and Nontechnical Cardiac Surgery Quality: Protocol for a Mixed Methods Study (Preprint)

2020 ◽  
Author(s):  
Donald Likosky ◽  
Steven J Yule ◽  
Michael R Mathis ◽  
Roger D Dias ◽  
Jason J Corso ◽  
...  
Keyword(s):  
Adverse Events ◽  
Technical Skills ◽  
Assessment Tools ◽  
Complication Rates ◽  
University Of Michigan ◽  
Electronic Health Record Data ◽  
Institutional Review ◽  
Computer Based ◽  
The University ◽  
The Relationship

BACKGROUND Of the 150,000 patients annually undergoing coronary artery bypass grafting, 35% develop complications that increase mortality 5 fold and expenditure by 50%. Differences in patient risk and operative approach explain only 2% of hospital variations in some complications. The intraoperative phase remains understudied as a source of variation, despite its complexity and amenability to improvement. OBJECTIVE The objectives of this study are to (1) investigate the relationship between peer assessments of intraoperative technical skills and nontechnical practices with risk-adjusted complication rates and (2) evaluate the feasibility of using computer-based metrics to automate the assessment of important intraoperative technical skills and nontechnical practices. METHODS This multicenter study will use video recording, established peer assessment tools, electronic health record data, registry data, and a high-dimensional computer vision approach to (1) investigate the relationship between peer assessments of surgeon technical skills and variability in risk-adjusted patient adverse events; (2) investigate the relationship between peer assessments of intraoperative team-based nontechnical practices and variability in risk-adjusted patient adverse events; and (3) use quantitative and qualitative methods to explore the feasibility of using objective, data-driven, computer-based assessments to automate the measurement of important intraoperative determinants of risk-adjusted patient adverse events. RESULTS The project has been funded by the National Heart, Lung and Blood Institute in 2019 (R01HL146619). Preliminary Institutional Review Board review has been completed at the University of Michigan by the Institutional Review Boards of the University of Michigan Medical School. CONCLUSIONS We anticipate that this project will substantially increase our ability to assess determinants of variation in complication rates by specifically studying a surgeon’s technical skills and operating room team member nontechnical practices. These findings may provide effective targets for future trials or quality improvement initiatives to enhance the quality and safety of cardiac surgical patient care. INTERNATIONAL REGISTERED REPORT PRR1-10.2196/22536

Absorptive capacity and technology: influences on innovative firms

2019 ◽  
Vol 17 (3) ◽  
pp. 250-265
Author(s):  
Angel Martinez-Sanchez ◽  
Manuela Perez-Perez ◽  
Silvia Vicente-Oliva
Keyword(s):  
Production Technology ◽  
Absorptive Capacity ◽  
Production Systems ◽  
Innovation Performance ◽  
Flexible Production ◽  
Content Type ◽  
Technology And Innovation ◽  
Production Processes ◽  
The Relationship ◽  
Agile Production

Purpose The purpose of this paper is to analyze the relationship between agile production (flexible production technology) and absorptive capacity. Design/methodology/approach We use a database of 1,864 Spanish industrial firms from the Survey of Business Strategies (the largest Spanish database of its kind). Our theoretical approach is based on the resource-based view and the dynamic capabilities perspective. The methodology includes descriptive statistics analysis and lineal regression with moderator effect. Findings High-agile firms with greater absorptive capacity are more innovative and better performers than low-agile firms. Absorptive capacity moderates the relationship between flexible production technology and innovation performance. Research limitations/implications This is a cross-sectional study, which may limit the establishment of causal relationships. We give evidence to the importance of studying absorptive capacity in the agile production implementation process. Practical implications There are several managerial implications. First, agile production systems should be integrated into the firm’s innovation system because the continuous improvement of agile production has to be reinforced by the outputs of external knowledge and in-house innovation activities. Second firms that use external sources of knowledge to improve production processes could leverage that benefit better, not only in Operations but also in innovation performance. The adoption of flexible production technology cannot be kept apart from the firm´s organizational learning processes based on external knowledge. Our results also support the contribution of clusters of collaborative firms to improve their production processes throughout absorptive capacity and thus the implementation of agile production systems. Originality/value This is the first study, to the best of our knowledge, has involved the role of absorptive capacity, as an internal capability/competence, to influence the relationship between agility/flexible technology and innovation performance.

scholarly journals The Relationship Between Physical Fitness Qualities and Sport-Specific Technical Skills in Female, Team-Based Ball Players: A Systematic Review

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jessica B. Farley ◽  
Joshua Stein ◽  
Justin W. L. Keogh ◽  
Carl T. Woods ◽  
Nikki Milne
Keyword(s):  
Systematic Review ◽  
Physical Fitness ◽  
Technical Skills ◽  
The Relationship

Is there a relationship between the behaviour of beef cattle and emissions of methane and ammonia from feedlot systems?

2009 ◽  
Vol 2009 ◽  
pp. 101-101
Author(s):  
S Muir ◽  
M Bai ◽  
Z Loh ◽  
J Hill ◽  
D Chen ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Production Systems ◽  
Animal Behaviour ◽  
Rapid Decline ◽  
Data Sets ◽  
Northern Australia ◽  
Grazing Cattle ◽  
Early Afternoon ◽  
The Relationship ◽  
Animal Production Systems

Associations between animal behaviour and emissions of methane (CH4) and ammonia (NH3) have been noted in studies of grazing cattle (Lockyer, 1997) and feedlot confined cattle (Harper et al., 1999, Flesch et al., 2007). Methane emissions have been predicted as being greatest during bouts of rumination (Harper et al., 1999) whereas the emissions of the indirect greenhouse gas ammonia tends to be low early in the morning but increasing rapidly in the early afternoon after which a rapid decline until sunset (Flesch et al., 2007). With the exception of Harper et al., (1999) there are few complete data sets that examine the interaction between animal behaviour and greenhouse gas emissions from intensive animal production systems. The current study aimed to investigate the relationship between animal behaviour and emissions of CH4 and NH3 in a beef feedlot system in northern Australia.

The evaluation of dual-purpose groundnut (Arachis hypogaea) varieties for fodder and seed production at Shika, Nigeria

2001 ◽  
Vol 136 (1) ◽  
pp. 75-79 ◽  
Author(s):  
A. T. OMOKANYE ◽  
O. S. ONIFADE ◽  
P. E. OLORUNJU ◽  
A. M. ADAMU ◽  
R. J. TANKO ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Crude Protein ◽  
Production Systems ◽  
Forage Yield ◽  
Dual Purpose ◽  
Whole Plant ◽  
Seed Yields ◽  
The Relationship ◽  
Forage Yields

At Shika in a subhumid environment of Nigeria, a 3-year study was carried out to select newly developed groundnut varieties for use in crop–livestock production systems. The study examined 11 groundnut varieties. Emergence time, plant stands at full emergence, forage and seed yields and yield components were examined. Whole plant samples were analysed for crude protein (CP) content. Varieties ICGV 87123 gave the lowest forage yield and cultivar M517-80I, the highest, with seven varieties recording forage yields above 5 t/ha. The CP content of forage was lowest (14·8%) for variety M576-80I and highest (21·6%) for variety M554-76. Mean seed yield (over 3 years) varied significantly from 0·73 to 1·68 t/ha. Only two varieties had mean seed yield >1 t/ha. The relationship between seed and forage yields was positive and significant (r = 0·529, P < 0·006). Varieties RMP 12, 88-80I and M517–80 were most promising for both forage and seed production.

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