scholarly journals A new approach to measure reduction intensity on cores and tools on cobbles: The Volumetric Reconstruction Method

2020 ◽  
Author(s):  
Diego Lombao ◽  
José Ramón Rabuñal ◽  
Arturo Cueva-Temprana ◽  
Marina Mosquera ◽  
Juan I Morales

Knowing to what extent lithic cores have been reduced through knapping is an important step toward understanding the technological variability of lithic assemblages and disentangling the formation processes of archaeological assemblages. In addition, it is a good complement to more developed studies of reduction intensity in retouched tools, and can provide information on raw material management or site occupation dynamics. This paper presents a new methodology for estimating the intensity of reduction in cores and tools on cobbles, the Volumetric Reconstruction Method (VRM). This method is based on a correction of the dimensions (length, width, and thickness) of each core from an assemblage. The mean values of thickness and platform thickness of the assemblage’s flakes are used as corrections for the cores’ original dimensions, after its diacritic analysis. Then, based on these new dimensions, the volume or mass of the original blank are reconstructed using the ellipsoid volume formula. The accuracy of this method was experimentally tested, reproducing a variety of possible archaeological scenarios. The experimental results demonstrate a high inferential potential of the VRM, both in estimating the original volume or mass of the original blanks, and in inferring the individual percentage of reduction for each core. The results of random resampling demonstrate the applicability of VRM to non size-biased archaeological contexts.

2021 ◽  
Author(s):  
Diego Lombao ◽  
José Ramón Rabuñal ◽  
Juan I Morales ◽  
Andreu Ollé ◽  
Eudald Carbonell ◽  
...  

Approaching the life history of artefacts is fundamental for understanding both the formation processes of archaeological assemblages and their technological variability. In this paper, we explore the variability of technological behaviours exhibited by the hominins from subunit TD6.2 at the Gran Dolina site (Atapuerca, Burgos), by combining both technological and reduction intensity analyses of the cores recovered. We used the Volumetric Reconstruction Method (VRM) to estimate the original volume of the blanks and quantify the reduction intensity of each core individually, after which we characterised the reduction distribution patterns using Weibull probability distribution functions. Our results suggest differential raw material management in terms of reduction intensity, according to the characteristics of each lithology. This could reflect a solid understanding of raw material qualities and a certain degree of planning. From a technological perspective, our results suggest continuity between knapping strategies through reduction, which seems to indicate constant adaptation to raw material constraints as well as particular knapping conditions, rather than to specific compartmentalised mental schemes.


2020 ◽  
Vol 12 (9) ◽  
Author(s):  
Diego Lombao ◽  
Arturo Cueva-Temprana ◽  
Marina Mosquera ◽  
Juan Ignacio Morales

The quality, safety, and suitability of animal fat for processing of a specific meat product is a critical issue. Increasing the human awareness about the health aspects associated with increased intake of animal fat, makes camel fat a suitable raw material for meat processing due to its excellent nutritional contribution. Therefore, the target of this study is examination of the sensory, physicochemical, fat oxidation, fatty acid profile, and other quality parameters of camel fat to evaluate the feasibility for processing of different meat products. To achieve this goal, 30 fat samples each from the hump, renal, and mesentery of Arabian male camels were investigated. The results showed that both the renal and mesenteric fat had honey color and medium-soft texture, while the hump had greyish-white color and hard texture. The sensory panel scores were significantly different between the hump and other fats. Hump fat had significantly (P<0.05) higher moisture, protein, and collagen content, while higher fat content was recorded in mesenteric fat. The fatty acid analysis showed that hump had high SFA and very low PUFA in comparison with both renal and mesenteric fat. Camel fat had high oxidation stability, and the mean values were very low in comparison with the levels of quality and acceptability. The ultrastructural analysis showed that hump fat had high elastin fibers which increase its hardness. The results indicated that both renal and mesenteric fat were more suitable for the production of various meat products than the hump.


Nanomedicine ◽  
2020 ◽  
Vol 15 (29) ◽  
pp. 2837-2850
Author(s):  
Myxuan Huynh ◽  
Ivan Kempson ◽  
Eva Bezak ◽  
Wendy Phillips

Background: The use of gold nanoparticles (AuNPs) as radiosensitizers may offer a new approach in the treatment of head and neck cancers; minimizing treatment-associated toxicities and improving patient outcomes. AuNPs promote localized dose deposition; permitting improved local control and/or dose reduction. Aim: This work aimed to address the theoretical optimization of radiation doses, fractionation and nanoparticle injection schedules to maximize therapeutic benefits. Materials & methods: Probabilistic nanoparticle sensitization factors were incorporated into the individual cell-based HYP-RT computer model of tumor growth and radiotherapy. Results: Total dose outcomes across all radiation therapy treatment regimens were found to be significantly reduced with the presence of AuNPs, with bi-weekly injections showing the most decrease. Conclusion: Outcomes suggest the need for regular AuNP administration to permit effective radiosensitization.


Author(s):  
Yuko Komuro ◽  
Yuji Ohta

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.


2021 ◽  
Vol 13 (4) ◽  
pp. 2059
Author(s):  
Angel Paniagua

Rural differentiation processes have formed the backbone of rural studies. Owing to the strength of rural–urban and local–global relationships, the theoretical approaches to rural restructuring in the Anglo-Saxon world and new rurality in Latin America only have a limited capacity to explain contemporary global phenomena of rural spaces. Due to this, transverse theoretical and methodological approaches have emerged to explain social, environmental and spatial (rural) processes. Here, a new approach is proposed called the individual–global field, based on the individual–global binary category to substitute the traditional relevance of the locality–community–globality association This new approach tries to reinvigorate rural geography in a more flexible way, based on minor theory, to adapt to all the phenomena that can occur globally. In any case, various spatial planes are proposed, dominated by specific socioeconomic processes on which the rural individual would move.


2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Marcell Virág ◽  
Tamas Leiner ◽  
Mate Rottler ◽  
Klementina Ocskay ◽  
Zsolt Molnar

Hemodynamic optimization remains the cornerstone of resuscitation in the treatment of sepsis and septic shock. Delay or inadequate management will inevitably lead to hypoperfusion, tissue hypoxia or edema, and fluid overload, leading eventually to multiple organ failure, seriously affecting outcomes. According to a large international survey (FENICE study), physicians frequently use inadequate indices to guide fluid management in intensive care units. Goal-directed and “restrictive” infusion strategies have been recommended by guidelines over “liberal” approaches for several years. Unfortunately, these “fixed regimen” treatment protocols neglect the patient’s individual needs, and what is shown to be beneficial for a given population may not be so for the individual patient. However, applying multimodal, contextualized, and personalized management could potentially overcome this problem. The aim of this review was to give an insight into the pathophysiological rationale and clinical application of this relatively new approach in the hemodynamic management of septic patients.


2000 ◽  
Vol 174 ◽  
pp. 40-45
Author(s):  
D. I. Makarov ◽  
I. D. Karachentsev

AbstractA new approach is suggested which makes use of the individual properties of galaxies, for the identification of small galaxy groups in the Local Supercluster. The criterion is based on the assumption of closed orbits of the companions around the dominating group member within a zero velocity sphere.The criterion is applied to a sample of 6321 nearby galaxies with radial velocities V0 ≤ 3000 km s−1. These 3472 galaxies have been assigned to 839 groups that include 55% of the sample considered. For the groups identified by the new algorithm (with k ≥ 5 members) the median velocity dispersion is 86 km s−1, the median harmonic radius is 247 kpc, the median crossing time is 0.08(1/H), and the median virial-mass-to-light ratio is 56 M⊙/L⊙.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 670
Author(s):  
Jaroslav Legemza ◽  
Róbert Findorák ◽  
Branislav Buľko ◽  
Jaroslav Briančin

This article deals with material research of selected types of quartz and quartzites in order to determine the priority of their use in the production of ferrosilicon and pure silicon, respectively. The highest quality quartzes and quartzites are commonly used in metallurgy, but not all types of these silicon raw materials are suitable for the production of ferrosilicon and pure silicon, despite their similar chemical composition. Behavior differences can be observed in the process conditions of heating and carbothermic production of ferrosilicon and silicon. These differences depend, in particular, on the nature and content of impurities, and the granularity (lumpiness) and microstructure of individual grains. The research focused primarily on determining the physicochemical and metallurgical properties of silicon raw materials. An integral part of the research was also the creation of a new methodology for determining the reducibility of quartzes (or quartzites), which could be used for real industrial processes and should be very reliable. The results of the laboratory experiments and evaluation of the physicochemical and metallurgical properties of the individual quartzes (or quartzites) are presented in the discussion. Based on comparison of the tested samples’ properties, their priority of use was determined. This research revealed the highest quality in quartzite from Sweden (Dalbo deposit) and Ukraine (Ovruč deposit) and quartz from Slovakia (Švedlár deposit). The use of these raw materials in industrial conditions is expected to result in the achievement of better production parameters, such as higher yield and product quality and lower electricity consumption.


Author(s):  
Zezhong C. Chen ◽  
Xujing Yang

Extensive research on G1 biarcs fitting to free-form curves (i.e., Bezier, B-spline, and NURBS curves) has been conducted in the past decades for various purposes, including CNC contouring to make smooth, accurate profile features such as pockets, islands, and sides. However, all the proposed approaches only focused on the approximation errors and the biarc number, not on the radius of the individual fitting arc; so it could be smaller than the cutting tool, which would cause gouging during machining. This work, based on the tool radius pre-determined by the minimum size of the concavities of the design profile, proposes a new approach to approximating the profile with a G1 biarc curve in order to make smooth, accurate, and non-gouged profile features using CNC contouring. The significant new contribution of this work is a new mechanism that ensures all the concave arcs of the fitting curve are larger than the pre-determined tool and the fitting errors meet the specified tolerance. This approach can promote the use of G1 biarc tool paths in the manufacturing industry to make high precision profile features.


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