Breakage Patterns Research Articles

Stringing Together Cowrie Shells in the African Archaeological Record with Special Reference to Southern Africa

Archaeological explorations of the meaning of ‘trade objects’, such as glass beads and cowrie shells, remain hampered by theoretical and methodological limitations in both their analyses and interpretations. In this paper, we develop a methodology for critically engaging in multi-scalar questions of the circulation, exchange, and value of cowrie shells in African archaeological contexts. Species, size, dorsal modifications, and depositional contexts were compared across five sites from South Africa dating between 750 and 1350 CE. These results were positioned within a review of cowries from archaeological sites in the region and compared to the documented distribution of cowries from wider African archaeological contexts. Monetaria annulus were the prevalent cowrie species in southern African archaeological contexts over the last 2000 years, with a notable absence of Monetaria moneta, prevalent at contemporaneous sites in West Africa, as well as a variety of endemic southern African species. Breakage patterns on the dorsal surface correspond to different modification techniques, such as chipping and grinding. Combined analyses of modification, use-wear, and depositional patterns show variation, revealing a diversity in the biographies of individual cowries. While a comparison of the distribution of cowries across the continent confirms the circulation of cowries through known trade routes, such as the trans-Saharan trade network and the European mercantile network, they also reveal new pathways for exchange that highlight the need for further exploration of intra African networks. Finally, the breadth of the results of this study demonstrates the value of a focus on a specific artefact to address a wide range of themes, from exchange to the archaeology of everyday life.

Zooarchaeology of Mission Santa Clara de Asìs: Bone Fragmentation, Stew Production, and Commensality

Through the analysis of faunal remains from refuse features associated with the Native Californian living quarters at Mission Santa Clara de Asìs, the article examines Indigenous diet within this colonial mission settlement. In Alta California, Native Californians from differing sociolinguistic groups were relocated to Spanish missions, creating an ever shifting pluralistic society. Within these mission settlements, Native Californians were tasked with maintaining the vast agricultural fields for which they received ingredients for two Spanish-style meals, atole and pozole. This study examines the diet of Native Californian families living within Mission Santa Clara, specifically focusing on the breakage patterns of cattle bones and the communal preparation, cooking, and consumption of these daily meals. These results illustrate change and continuity of foodway practices, expanding our understanding of mission political economies and Native Californian persistence within this colonial system.

Morphological and functional variability in triangular projectile points in the Piedmont Southeast, 1300–1600 CE

ABSTRACT Triangular arrowheads are overwhelmingly the dominant projectile point form across eastern North America from 600 to 1600 CE. Although triangular points have been studied less than earlier technologies, important research has been conducted over the last 25 years on their morphology, function, and temporal relationships. One important observation from reading these works is that there is noticeable variability within the triangular form both between and within regions. However, this variability has not been studied extensively by quantitative means. In this research, we examine a collection of 199 points from two Piedmont Siouan sites in the upper Yadkin River valley dating to 1300–1600 CE. We analyzed seven discrete attributes using discriminant function analysis and found quantitative support for the contemporaneous existence of the three forms and evidence of changes in morphology over time. We follow this with an examination of the context and breakage patterns of these types to discuss their roles in social, political, and economic activities. We then compare our results to those from other areas of eastern North America to address why such variability and changes over time may have occurred.

DEM simulation of the shear behaviour of breakable granular materials with various angularities

Particle shape is an important factor that affects particle breakage and the mechanical behaviour of granular materials. This report explored the effect of angularity on the mechanical behaviour of breakable granular materials under triaxial tests. Various angular particles are generated using the quasi-spherical polyhedron method. The angularity α is defined as the mean exterior angle of touching faces in a particle model. A breakable particle is constructed as an aggregate composed of coplanar and glued Voronoi polyhedra. After being prepared under the densest conditions, all assemblies were subjected to triaxial compression until a critical state was reached. The macroscopic characteristics, including the shear strength and dilatancy response, were investigated. Then, particle breakage characteristics, including the extent of particle breakage, breakage pattern and correlation between the particle breakage and energy input, were evaluated. Furthermore, the microscopic characteristics, including the contact force and fabric anisotropy, were examined to probe the microscopic origins of the shear strength. As α increases, the peak shear strength increases first and then remains constant, while the critical shear strength generally increases. Assemblies with larger angularity tend to cause more serious particle breakage. The relative breakage is linearly correlated with α under shear loading. Compared with unbreakable particles, the peak shear strength and the critical volumetric strain decline, and the degree of decline linearly increases with increasing α.

On the determination of particle impact breakage in selection function

This paper presents a thorough study of particle impact breakage in selection function with a unified breakage criterion. The impact mode and breakage pattern for particulate materials are classified based on a significant review of well-established impact testers. It was found that the lack of a unified breakage criterion to determine the breakage probability disables a direct comparison of particle breakage propensity from different impact loading testers. The literature breakage models to describe the breakage probability are reviewed where the advantage and drawback of these models are scrutinized. The sourced literature breakage models are compared with the zeolite breakage datasets in a unified breakage criterion to evaluate the model performance. A novel computational modelling workflow for a milling process is proposed to provide a guidance in implementing the digital twin in milling process prediction. The breakage probability models, i.e. the selection functions are comprehensively assessed in population balance model to examine the model serviceability. The model simplicity and fidelity in the model assessment are specifically discussed and the value of digital twin in substantially reducing the experimental trials is highlighted.

Damage and fracture characteristics of rocks with different structures under high-velocity water jet impact

This paper aims to investigate the damage and fracture characteristics of rocks with different structures under water jet impact. Three types rocks including heterogeneous coal, homogeneous sandstone, and transversely isotropic shale, were selected as the impact target rock. Water-jet impingement experiments with jet velocities varying from 447 m/s to 774 m/s were conducted. The rock macro-breakage characteristics were obtained by describing the breakage patterns, measuring the erosion depth and area, and counting the cracks number. A 3D reconstruction method based on the computed tomography and digital image processing technology was proposed to visualize the internal breakage characteristics and quantitatively analyze the damage field distribution. Combined with fracture morphology from scanning electron microscope, the failure mechanisms of rocks with three structures under water jet impact were revealed. The results indicate that coal, sandstone and shale will experience different breakage patterns with the increasing jet velocity: layered transverse cracks → “十”-type crack network → splitting crack, only one spindle-shape erosion pit, surface debris spalling → layered transverse cracks → “T”-type crack network. The effects of jet velocity and rock structure on the evaluation indexes (such as erosion depth and damage area, the number and angle of transverse cracks) were investigated thoroughly. In addition, the relationships between total damage degree based on breakage volume and jet velocity, and between damage variable based on breakage area and erosion depth, were compared and discussed. The failure mechanisms of three rocks impacted by water jets are as follows: (i) the reflection and interference of stress wave combined with the pressured water wedge effect cause the layered breakage and longitudinal splitting breakage of heterogeneous coal; (ii) the grinding effect of back flow mainly accounts for the formation of spindle-shape erosion pit in homogeneous sandstone; (iii) the shock stress wave effect and bedding structure lead to the spalling of large shale block and layered breakage, and the reflected wave tensile accompanied with pressured water wedge effect cause the tensile splitting breakage.

Three‐dimensional X‐ray‐computed tomography of 3300‐ to 6000‐year‐old Citrullus seeds from Libya and Egypt compared to extant seeds throws doubts on species assignments

Societal Impact StatementThe watermelon (Citrullus lanatus subsp. vulgaris) is among the world's most important fruit crops. We here use C‐14 dating and morphometric analysis to test whether ancient seeds can be identified to species level, which would help document food expansion, innovation, and diversity in Northeastern Africa. We dated a Libyan seed to 6182–6001 calibrated years BP, making it the oldest Citrullus seed known. Morphometric analysis could not reliably assign ancient seeds to particular species, but several seeds showed breakage patterns characteristic of modern watermelon seeds cracked by human teeth. Our study contributes to the understanding of the early history of watermelon use by humans, who may have mostly snacked on the seeds, and cautions against the use of morphology alone to identify Citrullus archaeological samples.

Numerical simulation based approach for assessment of blast induced deformation pattern in slot raise excavation

The excavation of long-hole slot raises in a single lift comes with the difficulties of face jamming, insufficient face movement and boulder formation. The main reasons behind these problems are improper blast design, presence of geological discontinuities or inaccuracy in drilling. The proper blast design to get uniform breakage pattern for slot raise excavation consists of design of drilling, charging and delay parameters. This paper has discussed the numerical simulation based approach for assessment of blast induced deformation pattern in slot raise blasting. The numerical models with different variants of slot raise blast design was made for this purpose in Ansys-Explicit Dynamics. The model was given tested rock mass properties data of Rampura Agucha underground Lead–Zinc mine. The deformation pattern output for these variants were analysed. The analysis of deformation pattern suggests that the ratio of number of reamer holes and blast holes have more impact on deformation pattern. The more uniform deformation contour was observed for the cut hole blast with six reamer holes and five blast holes for the experimental site. The deformation pattern output for excavation of periphery holes were also analysed. The drilling pattern and delay timing for the slot raise blast was decided on the basis of model output. The experimental trials at the mine was taken on the basis of revised blasting pattern. The face jamming has been reduced with revised pattern. The blasting pattern has also been advantageous in reducing overall blasting cost by reducing the number of drill holes in cut portion.

Numerical investigation of rock sphere breakage upon oblique impact: effect of the contact friction coefficient and impact angle

Discrete element simulations are performed to better understand the breakage of marble spheres upon oblique impact. The influence of the contact friction coefficient and impact angle on the impact-induced breakage is considered. A modelling method for oblique impact is proposed. Detailed parameter calibration and verification of the modelling method were performed. The oblique simulations show that the laboratory breakage behaviour of marble spheres upon normal and oblique impact is well matched through the proposed modelling method. Tensile and shear breakage patterns are observed in laboratory tests and simulations and are significantly influenced by the contact friction coefficient and impact angle. The shear component of the impact velocity determines the breakage at a low impact angle and high contact friction coefficient, while the normal component dominates the breakage at a high impact angle or low contact friction coefficient. The damage ratio, contact force and fragment characteristics are also analysed. Two constants, i.e., the critical shear contact force and critical normal contact force, are obtained. Finally, a comprehensive breakage criterion for brittle particles under oblique impact is proposed. The breakage patterns of brittle particles can easily be determined through the proposed breakage criterion.

The precipitation behavior and its effect on mechanical properties of cold-rolled super-ferritic stainless steels during high-temperature annealing

The precipitation behavior, microstructure evolution and mechanical properties of a cold-rolled 27.6Cr–3.7Mo–2Ni ferritic stainless steel during high temperature annealing treatment were investigated. Experimental results demonstrated that the cold rolled microstructure was characterized by orientation-dependent heterogeneity, and many shear bands were found in the <111>//ND (normal direction) orientation grains. The elongated deformation microstructure gradually changed into equiaxed grains and three kinds of interphases including σ-phase, χ-phase and Laves phase were observed as the annealing temperature increased from 850 to 1000 °C. After annealing below 1000 °C, the σ-phase and χ-phase were observed to be located at grain boundaries, near the TiN particles as well as along with shear bands in grains, whereas the Laves phase distributed dispersedly in grains. After annealing at 1000 °C, both the σ-phase and χ-phase were almost completely dissolved, while the nanoscale Laves phases at grain boundaries were dominant. The grain boundary Laves phase precipitation at high temperature was attributed to the Nb segregation induced by cold rolling deformation. The σ-phase precipitation kinetics was calculated based the Johnson–Mehl–Avrami equation, and the fastest precipitation kinetics appeared at 850 °C with the activation energy of ~176.7 kJ·mol−1. The Vickers hardness, ultimate tensile strength and yield strength values decreased while the elongation value increased with increasing annealing temperature. The breakage pattern transformed from brittle to ductile fracture as the annealing temperature increases from 850 to 1000 °C.

Impact breakage of single pharmaceutical tablets in an air gun

Milling is commonly used for controlling the size distribution of granules in the pharmaceutical dry granulation process. A thorough understanding of the breakage of single compacts is crucial in unravelling the complex interactions that exist between different pharmaceutical feed materials and the mill process conditions. However, limited studies in the literature have examined the impact breakage of single pharmaceutical compacts. In this study, pharmaceutical powders including the microcrystalline MCC 101, MCC 102 and MCC DG were compressed at different pressures and tablets with different porosities and thicknesses were produced. Impact breakage tests were conducted in an air gun and the tablet impact velocities and breakage patterns were analysed using a Phantom ultrahigh-speed camera. It was observed that the tablet breakage rate and the amount of fines reduced as the tablet porosity decreased. In addition, thin tablets with low porosity exhibited semi-brittle fracture and less intense crack propagation while thick tablets with high porosity primarily disintegrated into fine fragments. Thus, this study provides a better understanding of the breakage behaviour of different pharmaceutical materials and can potentially be used to describe the breakage modes of compacts in the ribbon milling processes.

Numerical study on the mechanical behavior of ultrahigh performance concrete using a three‐phase discrete element model

AbstractThis paper deals with numerical analysis on the mechanical behavior of ultrahigh performance concrete (UHPC) under uniaxial compression. For the modeling of the mechanical behavior of UHPC, the mesh‐free discrete element method was applied. To calibrate the model parameters and validate the numerical simulation results, a set of experimental investigations including mechanical tests, microscopy and tomography analysis, were performed. The scanning electron microscopy and polarized light microscopy were used to examine cross sections of UHPC as well as to characterize interfacial transition zone and aggregate in detail. X‐ray microtomography analysis was used to obtain information about the nonspherical shape of aggregate and to generate a realistic structural model. Simulation results have shown that the developed model predict stiffness reliably, strength, and breakage pattern of UHPC and shows good agreement with experimental results. Finally, the model has been applied to analyze the main crack initiation in static failure and to investigate the influence of different parameters such as aggregate content as well as aggregate and binder stiffness on the mechanical behavior of UHPC.

Genome plasticity in Paramecium bursaria revealed by population genomics

BackgroundCiliates are an ancient and diverse eukaryotic group found in various environments. A unique feature of ciliates is their nuclear dimorphism, by which two types of nuclei, the diploid germline micronucleus (MIC) and polyploidy somatic macronucleus (MAC), are present in the same cytoplasm and serve different functions. During each sexual cycle, ciliates develop a new macronucleus in which newly fused genomes are extensively rearranged to generate functional minichromosomes. Interestingly, each ciliate species seems to have its way of processing genomes, providing a diversity of resources for studying genome plasticity and its regulation. Here, we sequenced and analyzed the macronuclear genome of different strains of Paramecium bursaria, a highly divergent species of the genus Paramecium which can stably establish endosymbioses with green algae.ResultsWe assembled a high-quality macronuclear genome of P. bursaria and further refined genome annotation by comparing population genomic data. We identified several species-specific expansions in protein families and gene lineages that are potentially associated with endosymbiosis. Moreover, we observed an intensive chromosome breakage pattern that occurred during or shortly after sexual reproduction and contributed to highly variable gene dosage throughout the genome. However, patterns of copy number variation were highly correlated among genetically divergent strains, suggesting that copy number is adjusted by some regulatory mechanisms or natural selection. Further analysis showed that genes with low copy number variation among populations tended to function in basic cellular pathways, whereas highly variable genes were enriched in environmental response pathways.ConclusionsWe report programmed DNA rearrangements in the P. bursaria macronuclear genome that allow cells to adjust gene copy number globally according to individual gene functions. Our results suggest that large-scale gene copy number variation may represent an ancient mechanism for cells to adapt to different environments.

From owl prey to human food: taphonomy of archaeological small mammal remains from the late Holocene wetlands of arid environments in Central Western Argentina

The present study analyses small mammal bone and tooth accumulations recovered in three open-air archaeological sites from northern Mendoza (Argentina) in the central Monte Desert, one of the most arid rangelands of South America. The sites, with radiocarbon dates between ca. 2100 and 400 years BP, are located on the margins of a now-extinct swamp that formed a more widespread wetland environment in the past. In order to recognize the agents responsible for such bone and tooth accumulations, a taphonomic analysis was conducted evaluating relative abundances of skeletal elements, breakage patterns, digestive corrosion, signs of anthropic activity and post-depositional processes. The taphonomic analysis allowed the detection of owls and humans as the agents responsible for small mammal accumulations. On the one hand, the low proportion and degree of digested diagnostic elements, among other taphonomic processes, suggest owl pellet-derived small mammal assemblages. On the other hand, the thermo-altered elements detected, some showing a differential burning pattern, the abundance of large-sized and gregarious small mammals and the identification of cut-marks on a caviid femur shaft are possibly due to human exploitation/consumption of small mammals.

Damage to silo bags by mammals in agroecosystems: a contribution for mitigating human–wildlife conflicts

Abstract ContextDamage to harvest storage systems by mammals and associated postharvest losses generate human–wildlife conflicts. Silo bags have been widely adopted worldwide as a type of temporary harvest storage for agricultural crops. The basis of silo-bag technology is the hermetic condition of the plastic lining. Breaks in this silo-bag lining by mammals generate damage of stored content and are a serious concern for farmers, who generally take actions against wildlife with consequent impacts on the environment. AimsWe described the incidence and intensity of breaks in silo-bag linings by different mammal groups (armadillos, canids and rodents) in agroecosystems of central Argentina, and we analysed the influence of extrinsic and intrinsic factors on patterns of breakage of silo bags, and propose management options based on cultural methods tending to prevent damage and reduce human–wildlife conflicts. MethodsSampling was conducted during the austral summer and winter of 2018, at three sites in the Pampas of Argentina. At each site, we chose farms that were using at least one silo bag, described silo-bag characteristics, and recorded the number of breaks in silo bags generated by mammals. Key resultsWe sampled a total of 306 silo bags from 38 farms. Damage incidence by mammals comprised 49% of silo bags sampled. Statistical analyses (GLMMs) revealed that damage intensity generally increased with storage time. Seasonality played a key role, with breakage being higher during summer for armadillos, when they are most active, and in winter for rodents, when they are most abundant. Damage by armadillos exhibited geographic variation and also decreased significantly with increasing distance to the nearest plot edge in which the silo bag was placed. Damage by rodents was higher for bags containing grains rather than forage. ConclusionsDamage to silo bags by mammals was affected by both extrinsic (seasonal and geographical) and intrinsic (stored content, storage time and distance to nearest edge) factors; however, these effects varied according to the mammal group considered. ImplicationsRelocation of silo bags away from plot edges could significantly reduce damage by armadillos, the most harmful mammals to silo bags.

Time-constrained demolition of a concrete cofferdam using controlled blasting

A concrete cofferdam of a hydropower project in India had to be demolished within a limited time period due to impoundment of river water. The cofferdam was trapezoidal at bottom and middle, rectangular at the top and abutted to one of the spillway piers. Two more spillway piers, spillway gates and a dam were very close to it. The length and height of cofferdam were 62 m and 24 m, respectively. For demolition of cofferdam, a new controlled blasting technique was developed after conducting test blasts at different locations. Two test blasts with varying blast designs and charging patterns were conducted at the farthest end of cofferdam which was free from other structures. Two more test blasts were conducted near the abutted portion with a very light explosive charge per hole fired in delayed sequence using half-second electric detonators. Results of the test blasts, particularly ground vibrations, throw of blasted materials and breakage patterns were analysed critically. Based on the results, a cautious blasting zone was determined near the abutted portion and controlled blasting patterns were designed. The formation of a zone of disturbance from cautious blasts at the abutted end for every concrete lift significantly reduced the magnitudes of vibration waves for successive blasting operations in remaining portion of that lift. The use of half-second delay detonators helped in segregating the vibration waves from the holes fired in different delays. The demolition work completed safely within the time limit using cautious blasting technique and systematic sequencing of blasts.

Patterns and Implications of Early Syndesmotic Screw Failure in Rotational Ankle Fractures.

The purpose of this study was to identify characteristic patterns of syndesmotic screw (SS) failure, and any effects on clinical outcome. A retrospective study was performed using a consecutive series of patients treated with open reduction and internal fixation with trans-syndesmotic screws for unstable ankle fractures with syndesmotic injury between 2015 and 2017. Patient demographics, fracture characteristics and classification, rates and patterns of trans-syndesmotic screw breakage, and backout were analyzed. Functional outcome was assessed using passive range of motion (ROM) and Maryland Foot Score (MFS). A total of 113 patients (67%) had intact screws and 56 patients (33%) demonstrated either screw breakage or backout. Patients with SS failure were younger (P = .002) and predominantly male (P = .045). Fracture classification and energy level of injury were not associated with screw failure. Nine screws (11%) demonstrated backout (2 also broke) and 56 other screws broke. There was no association between the number of screws or cortices of purchase and screw failure. There was a trend toward a higher proportion of screw removal (20%) in this failed SS group compared with the intact SS group (12%) (P = .25), but with similar ankle ROM and MFS (P > .07). Syndesmotic screw breakage was common in younger, male patients. Despite similarities in ankle range of motion and clinical outcome scores to patients with intact screws, there was a trend towards more frequent screw removal. This information can be used to counsel patients pre- and postoperatively regarding the potential for screw failure and subsequent implant removal. Level III, retrospective case-control study.

Taphonomy and palaeoecology of deep-water chemosymbiotic bivalves from the Eocene of Outer Eastern Carpathians, Ukraine

The paper reports rare occurrence of deep-water solemyid and lucinid bivalves from Cenozoic sequences of Outer Eastern Carpathians, Ukraine. The studied bivalves occur in the Eocene Pasichna Formation, represented by deep-water marls and pelagic limestones intercalated with thin-bedded calcareous sandstones yielding material re-deposited from shallow water. This find offered a chance to study the unaltered shell breakage pattern of these deep-burrowing solemyid bivalves buried in situ by turbidites. The breakage includes arcuate breaks representing likely syn-vivo damage related to active burrowing of the animal while telescopic breaks are most likely post-mortem distortions produced by the load of the heavy sediment covering sea bottom after a turbiditic event. Taxonomic study indicates that both solemyid and lucinid bivalves from the Eocene of the Pasichna Formation are most similar to deep-water members of their respective clades, known from roughly coeval deposits from the Tethys. The available evidence indicates that bivalves in question lived on the deep-sea muddy bottom, influenced by turbidite deposits, and were buried by them syn-vivo or early post-mortem. This is in contrast to the great majority of molluskan faunas from the Carpathian Paleogene, reworked during transport downbasin from shallow-marine settings by mass gravity flows. The detailed study of the occurrence mode of deep-water bivalves in the Carpathian part of the Tethys during the Paleogene, influenced by frequent build-up of oxygen-depleted waters, offers implications for the evolutionary histories of both groups in question. For both solemyids and lucinids, adaptations to oxygen-depleted environments are primordial, and are carried from the Silurian until today, as supported by the presented fossil and actualistic evidence. This is in contrast to their histories in high-redox potential environments, with solemyids known from cold seeps from the Devonian onwards and lucinid seep record only from the Jurassic onwards.

Fuel pellet breakage in pneumatic transport and durability tests

Wood pellets for biofuel utilization are fragile and produce fines and dust when handled. Impact resistances of pellets were obtained by using tumbling box tester, ligno tester and rotary impact tester. The samples were sieved after each of the ten consecutive runs to generate a breakage vector of particle size classes: 0–1.00, 1.00–2.36, 2.36–3.15, 3.15–4.75 and > 4.75 mm. Similarly, a full-scale pneumatic blow wood pellets degradation experiment was conducted. The pellets were blown at different delivery pressures from 0.3 to 1 bars.The breakage patterns disclosed two independent mechanisms when analysed by multivariate modelling: surface breakage by the tumbling box and volume breakage by the rotary impact tester. The combination of these testers can describe the full outcome space for the pneumatic tests and it is possible to predict generation of fines and dust during pneumatic loading of wood pellets from a silo. The most severe damages corresponded to more than 10 times 500 revolutions in a tumbling box and 8 consecutive impacts at almost 20 m/s in the rotary tester. Furthermore, these results provided insights into pellet breakage mechanisms, evaluation of pneumatic pipe designs and construction of bench testing devices that purify the effect of surface vesus volume breakage.

Considerations on formation mechanisms of emitting species of organic and C-containing inorganic compounds in CO2 atmosphere using laser-induced breakdown spectroscopy as a strategy for detection of molecular solids

Detection of organic matter in CO2 atmosphere at low pressure using laser-induced breakdown spectroscopy is an arduous and complex task due to different carbon-related sources that may participate in the emission signals. This research focuses on assessing the effect of a CO2 surrounding atmosphere at 7 mbar on the formation of emitting species in laser-induced plasmas of C-containing compounds and on identifying three possible sources of carbon species: the organic compound, the inorganic matrix, and the atmosphere. Four organic compounds (adenine, glycine, pyrene and urea) were chosen due to their different molecular structures and chemical composition for the study. The influence of their molecular structure on the intensity of molecular (C2 and CN) and atomic (C, H, N and O) emissions were explored. They were used as dopants at different concentrations in inorganic matrices such as CaCO3 and CaSO4.2H2O. In order to understand the breakage pattern of the organic molecules, the study was also carried out in air (7 mbar). Differences in relative intensities of emitting species as a function of both the chemical structure and the tested surrounding atmosphere were observed. Larger intensities were observed in CO2 atmosphere compared to air. This finding confirms the contribution of the CO2 on formation routes of atomic C (I) and diatomic carbon C2, even in non‑carbon compounds such as CaSO4.2H2O. The plasma emission threshold fluence of organic molecules in the inorganic matrices was also established. Lower threshold values for C-emitting species, in the case of carbonate matrix, were measured in presence of CO2 ambient gas.