Shell Samples Research Articles

On tailoring morphing mechanics of a bistable composite cylindrical shell through elastic fibre prestressing

A bistable composite cylindrical shell is a thin-walled structure that can change shape between two stable configurations under small energy input, showing great potential to be applied to space deployable mechanics. The internal stress level within a cylindrical shell plays a vital role in determining its morphing mechanics, whilst tailoring the internal stress is tricky for traditional composite manufacturing methods. In this paper, we devise a novel biaxial elastic fibre prestressing (EFP) method to systematic design and produce prestrained carbon-based composite cylindrical shells, with tailorable bistability and morphing mechanics, as well as improved load-carrying capabilities. A biaxial fibre stretching rig was devised to apply tensions on both directions of a plain-weave carbon prepreg simultaneously; prestrained cylindrical shell samples were produced with various prestrain levels to fully evaluate the fibre prestraining effects; a finite element model was established and showed good agreement with experimental observations. The fibre prestraining mechanisms were then proposed. It is found that EFP is effective in tailoring the internal strain/stress level within a composite cylindrical shell, which in turn altering the structural morphing mechanics, and able to significantly lower the maximum tensile strain during shape-changing, thus improve the load-carrying capability. These findings are expected to facilitate structural design of the deployable composite structures and flexible mechanical hinges, by allowing further design freedoms in terms of morphing mechanics and load-carrying capability.

Reply to Comment on “Singh R, Vadlamani R, Bajpai S & Maurya AS (2024) Strontium Isotope Stratigraphy of Marine Oligocene–Miocene Sedimentary Successions of Kutch Basin, Western India. Geological Journal, 1–20. DOI: 10.1002/gj.4961”

ABSTRACTThis response addresses the comments made by Saraswati et al. on our recent publication in Geological Journal. In our study, we used a multi‐analytical screening approach, including visual, XRD and trace element analysis, to evaluate diagenetic alteration of carbonate shell samples. Contrary to the claims made by Saraswati et al. our findings are based on well‐preserved samples with minimal alteration. The Sr‐isotope data from the Khari Nadi Formation (23.07–18.09 Ma) are largely consistent with existing biostratigraphic constraints, but suggest a possible extension of the upper age limit into the Burdigalian. Our Sr‐isotope ages for the Chhasra Formation (15.11–12.29 Ma) are younger than those suggested previously, based on larger benthic foraminifers, but largely corroborate recent nannoplankton data. As a result of the new age data from Kutch, we suggest that the sedimentation rates, derived from multiple samples, increased significantly from the Oligocene to Miocene. We assert that ‘established’ ages are also subject to refinements as the rock units become amenable to new dating techniques. We welcome any criticism that is constructive, and remain open to any further data that could refine or challenge our interpretations.

RADIOCARBON CHRONOLOGY OF THE OCCUPATION OF THE SOUTHERN COAST OF NAYARIT, MEXICO

ABSTRACT Despite chronicles from the 16th century describing fertile alluvial plains and densely populated wetlands, archaeology in western Mexico has been little studied. The Directorate of Archaeological Salvage (DSA) of National Institute of Anthropology and History (INAH) has initiated a study of two sites in Costa Canuva, at the southern part of Nayarit state: Becerros and Naranjos. Thirty charcoal and shell samples were radiocarbon (14C) dated to determine occupation history. A Bayesian approach was used to build a chronological modeling from charcoal samples. Charcoal and shell samples found in the same context allowed us to calculate the ΔR values of marine offset for this period. In general, the archaeological sites of this area are divided into three major periods: Formative, Classic, and Postclassic. The 14C dating of Becerros recovered materials provided a chronological framework for the site’s occupation, from cal AD 169–1025, corroborating the ceramic studies in the sense that human settlement activities date from the Formative (300 BC–AD 600) to the Early Postclassic (AD 900–1200). Naranjos started in the Classic period and reached its occupancy peak in the Late Classic. The site’s occupation may have persisted for at least two centuries after the conquest of the Altiplano in 1521. The comparison of charcoal dates and associated shell samples from the Naranjos Unit gave a probability distribution for ΔR, that ranged from 118.5 to 199.5 with a mean value of 159 ± 4, slightly higher than other values obtained at nearby sites.

On the applicability limits of the structurally orthotropic shell model in problems of calculating the buckling under axial compression of waffle cylindrical shells

The article considers the solution of the buckling problem of a waffle cylindrical shell under axial compression using the Euler (bifurcation) approach. Two models are used: a model based on the numerical integration method and a model based on the finite element method. The first model assumes that the stiffeners are structurally an orthotropic shell obeying the Kirchhoff-Love hypotheses, with the assumption of "smearing". The second model uses a tetrahedron element with ten nodes. The study is based on experimental data from tests of one of the waffle cylindrical shell samples under axial compression. The research results show that with an increase in the waffle shell rib thickness, a discrepancy between the calculation results of the two models is observed. With the optimal value of the k parameter, characterizing the ratio of the rib thickness to the rib pitch, equal to 0.035, such a discrepancy is estimated to be about 5%. At the same time, the calculation using the model of a structurally orthotropic shell leads to an underestimation of the critical load compared to the finite element model. This provides an estimate of the loss of stability of a waffle cylindrical shell with a safety margin. For parameter k between 0.02 and 0.05, the difference between the results from the two computational models for critical loads does not exceed 11%.

Development of Composite Adsorptive Biosorbent from \(H_3PO_4-NaOH-BaCl_2\) Modified Almond Shell: Experimental and Statistical Approach

This study aimed to use an experimental and statistical approach to develop a cost-effective composite adsorptive biosorbent from acid, base and salt-modified biomass. Almond Shell samples were washed, milled to uniform particle sizes (425 µm) and then modified with H3PO4, NaOH, and BaCl2 separately. The three active samples were combined to form a tricomposite biosorbent based on the Simple Lattice Design (SLD) under the Mixture Methodology of the Design Expert Software (11.0.1), within the ranges of 20-60%. The adsorptive capacity of each within tricomposite consisting of different percentage compositions of the modified Almond shell samples was investigated based on the Methylene Blue Number (MBN) Test. The results obtained were subjected to statistical analysis. The maximum adsorption capacity (MBN) of 896.12 mg/g was obtained from the tricomposite almond shell comprising mixture ratio of 20% (H3PO4), 20% (NaOH) and 60% BaCl2. The combination is well fitted to Linear Model () with Std. Dev. of 13.25, R² of 0.6452, Adjusted R² of 0.5565, Predicted R² of 0.4566 and Adeq Precision of 8.472 (>4). The numerical optimization of the experimental data was obtained at 0.980 desirability. The experimental values obtained were in good agreement with the predicted values from the models, with relatively small errors (0.13%) between the predicted and the actual values. This shows that the optimisation process via the SLD was very fit and reliable.

Underwater measurement of abalone shell’s size based on stereo vision

In order to cultivate superior varieties of abalone, it is necessary to accurately measure the useful trait data of them. This paper presents a novel underwater binocular system for measuring the size of abalone. The measurement process can be divided into two main stages. In the first stage, underwater images are corrected using our proposed algorithm to eliminate the impact of refraction. In the second stage, the corrected images are utilized for the 3D reconstruction of the abalone shell. The length and width can be calculated by analyzing the contour of the shell. To validate the effectiveness of our method, a set of abalone shell samples are measured with the binocular system. The average measurement errors for the length and the width are 2.02% and 2.54%, respectively.

High resolution stable isotope ratios in modern African land snails: Testing inferred environmental conditions

High-resolution sub-annual stable oxygen isotope data were measured in modern land snail shells collected from different climatic zones in Africa to search for patterns in seasonal δ18O cycles associated with specific hydroclimates, keyed to flora/biozones. Thirty-three recently dead shells were collected between 1995 and 2012, and collection localities were divided into five climate types: tropical forest, woodland savannah, bushland savannah, woodland monsoon, and arid/semi-arid. Thirteen genera are represented in the collection. Sampling covered at least one year in the life of the land snails, often multiple years. A comparison of measured data to predicted δ18O values, using local temperature and rain δ18O value, shows that predictions tend to be lower than measured values, suggesting that surface waters or snail body waters have undergone some evaporation. Predictions based on night-time temperatures (average monthly minimum T) are closer to, but still underestimate, measured values compared to day-time (maximum) temperatures in a majority of cases. The largest range in δ18O values for individual shells occurs in the bushland savannah and woodland monsoon biomes. Longer seasonal intervals of dry conditions lead to greater δ18O ranges in shells, although if the dry interval approaches 10 months in the year the amplitude is again reduced. This is in agreement with other oxygen isotope studies of high-resolution land snail shell samples, which show very high δ18O variance in strong monsoon climates.

Magneto-fluorescent core–shell Sr0.8La0.2Fe11CuO19 @ CQDs for the detection of metal ions

The fabrication of a sensor based on a core–shell structure of Sr0.8La0.2Fe11CuO19 @ CQDs was effectively achieved through the combination of high quantum yield carbon quantum dots (CQDs) with La-Cu doped M−type strontium hexaferrites (SLFCO HF). The structural, morphological, and spectroscopic information of the as-synthesized samples were characterized through X-ray diffraction (XRD), Raman spectroscopy (RS), Fourier transform infrared (FT-IR), energy dispersive X-ray (EDX), high-resolution transmission electron microscopy (HR-TEM), and UV–Vis-NIR spectroscopy. The magnetic properties were tested using a vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. HR-TEM confirmed the formation of a hexagonal core–shell sample at the nanoscale. Based on photoluminescence (PL) spectra and the CIE chromaticity map, the parent sample and core–shell structure of SLFCO/CQDs were found to have color coordinates corresponding to yellow-green emission. It was found that the core–shell sample has an increased light-absorption capacity, low photogenerated electron-hole recombination, high coercivity, small crystallite size, and showed good sensitivity towards the detection of Zn2+, Cd2+, and K+ ions. A high efficiency in detecting potassium (K+) ions with a limit of detection (LOD) of 15 ppm was observed. Moreover, the distinctive magnetism of CQDs @ SLFCO aided in the collection and recycling of the sensor.

An experimental and numerical investigation of ballistic penetration behaviors of deployable composite shells

Bistable composite shells are suitable candidates for deployable space structures due to high stiffness to weight ratio as well as large volume reduction. Nevertheless, impact performance of bistable composite shells conflicting with space debris have been rarely studied. In this paper deployable hybrid composites constructed with combinations of carbon–carbon, carbon–kevlar, kevlar–kevlar, high-energy-absorption graphene-reinforced polyurethane elastomers are developed, and their ballistic penetration behaviors are experimentally and computationally studied. The influences of ballistic velocity on the absorbed energy, the residual velocity and damage morphology of the targets are investigated in both deployed and coiled stable states. The results show that severe local damages were observed for the carbon–carbon and carbon–kevlar samples after penetration with various velocities even first cosmic velocity, and the sample of deployable hybrid composite shell yielded the best ballistic impact resistance. The total energy absorption performance of the hybrid composite structure was greatly improved by introducing graphene-reinforced polyurethane elastomers without losing the deployability. Additionally, investigation on the energy absorption capability of deployed laminated shells with various curvature radii indicated that the curvature radius had a significant effect on the anti-penetration performance.

Genotype and dietary supplementation of ginger (Zingibar officinale) rhizome powder affect egg quality traits of layer chickens

This study evaluated the effects of ginger (Z. officinale) rhizome powder on egg qualities of aged commercial and native hens using 160 Shaver Brown (SB) and Nigerian heavy ecotype native hens (HEN). Experimental groups per genotype were control group or basal diet group, and ginger rhizome powder supplemented group (20 g/kg, ginger group). For each genotype, forty (40) hens were assigned to the control group and 120 hens to the ginger group. Each experimental group had four (4) replicates containing 10 hens each for the control groups, and 30 hens each for the ginger groups. The hens were housed individually in laying cages and fed the experimental diets at 125 g/bird/day. Water was given ad libitum and photoperiod was 12 h light and darkness. 80 eggs from SB and 40 eggs from HEN control groups, and 80 eggs/genotype from the ginger groups were used to evaluate egg qualities while 10 shell samples were used to evaluate shell mineral contents for each group. In addition, within genotypes, eggs belonging to the ginger groups were grouped into egg weight and egg shape index grades and assessed for egg qualities. SB eggs had significantly (p ≤ 0.05) higher weight (EW), length (EL), diameter (ED), surface area (ESA), volume (EV), and shape index (ESI); yolk, albumen, and shell weights (YW, AW and SW); albumen height, diameter, and ratio (AH, AD, and AR); shell volume (SV), compression fracture force (SCFF), and calcium content but lower egg specific gravity (ESG), yolk ratio (YR), yolk/albumen ratio (Y/A ratio), shell Zinc, and Phosphorus contents compared to HEN eggs. Ginger groups had higher EW, EL, ESA, EV, YW, YD, YR, AH, AI, Y/A ratio, and shell Zn but lower ESG, YH and YI compared to control groups. SB-ginger group had highest (p ≤ 0.000) AD while HEN-ginger group had highest (p ≤ 0.05) shell Zinc, and Phosphorus contents. EW grades differed significantly in EW, ESA, ESG, ESI and SCFF in the two genotypes while ESI grades differed significantly in ESI and Y/A ratio in SB but in ESI, YI and Haugh unit in HEN. In conclusion, genotype, diet, genotype x diet, EW and ESI grades influenced egg quality traits. These factors are important for egg quality evaluation and genetic improvement.

Preparation and characterisation of black conversion coating of Cr(NO3)3–CoCl2–NiCl2 of Zn–Ni alloy electroplated on 2024 aluminium alloy surface

AbstractTo meet the application requirements of electronic connectors, a trivalent chromium process (TCP) conversion coating was prepared on the Zn–Ni alloy plating of 2024 aluminium alloy. The composition of the TCP solution was as follows: 45 g/L Cr(NO3)3, 14 g/L CoCl2, 1.3 g/L NiCl2, 10 g/L citric acid, 10 g/L succinic acid and 1 g/L sodium dodecyl sulphate. The properties of TCP were characterised by a range of techniques, including macroscopic observations, scanning electron microscope, energy‐dispersive X‐ray spectrometer, three‐dimensional (3D) morphometry, electrochemical impedance spectroscopy, polarisation curves and conductivity tests. The TCP prepared in this experiment exhibits a uniform black colour and bright appearance, predominantly composed of Zn, Ni, O, Cr and Co. The TCP enhances the impedance of Zn–Ni alloys, reduces the corrosion current to 1.99 × 10−5 A/cm2 and maintains a flatter surface 3D morphology and less surface roughness following electrochemical testing. It has better corrosion resistance. Following the preparation of the TCP on a suitably sized shell sample, the shell resistance was 1.2 mVDC with good electrical conductivity, which meets the requirements for electrical connector applications.

Evaluation of quasi-static and dynamic compressive properties of Ti-6Al-4 V functionally graded shell lattices with minimal surfaces

Functionally graded shell (FGS) lattices have recently captivated enormous research interest in engineering applications for their outstanding mechanical and energy-absorbing performances. This paper designs FGS lattices featuring I-WP triply periodic minimal surfaces using implicit functions. FGS and uniform shell (US) samples made of Ti-6Al-4 V powder are manufactured utilizing laser powder bed fusion technology. Quasi-static compression and drop-weight impact experiments are conducted to evaluate the mechanical and energy-absorbing performances as well as deformation mechanism of FGS and US samples. The results demonstrate that the deformation modes of the samples under both loading conditions are similar, which is basically attributed to the drop-weight impact velocities being lower than the critical speeds calculated by the rigid-power-law hardening (RPLH) model. Additionally, the effects of loading velocity on the deformation mechanisms of US and FGS lattices are simulated, and homogenization, transition, and shock deformation models are predicted by the RPLH model. The FGS sample exhibits distinct layer-by-layer failures and eliminates the abrupt shear band under dynamic and quasi-static loadings. Compared to the quasi-static results, a notable strain rate hardening effect is observed under the dynamic condition, mainly due to the hardening of the row material. Consequently, the elastic modulus, yield strength, compression strength, and cumulative energy absorption of the US sample under drop-weight impact loading improved by 18.74 %, 56.52 %, 45.31 %, and 6.62 %, respectively. However, the FGS sample shows less sensitivity to strain rate owing to the layer-by-layer deformation mechanism, and their elastic modulus, yield strength, compression strength, and cumulative energy absorption only increased by 11.84 %, 34.72 %, 36.85 %, and 3.86 %, respectively. The FGS lattices exhibit a low peak stress during the compression process, which is favorable for industrial applications in crashworthiness and energy absorption.

Presence of 236U,237Np and 239,240Pu in shells from the coast of the south of China

This study reports first results on uranium (236U), neptunium (237Np) and plutonium (239Pu and 240Pu) isotopes in shell samples (i.e. oyster, clam and scallop shells) from the coast of the South of China. The 240Pu/239Pu and 236U/238U atom ratios are used for source identification, and the 237Np/239Pu, 237Np/236U and 236U/239Pu non-isotopic atom ratios to study the relative bioaccumulation of Np, Pu and U during the shell formation. The obtained concentration levels are in the 104-106 atoms g−1 range in every case. Clear regional differences are observed in the case of the 240Pu/239Pu atom ratio, with average values lower along the coast of East China Sea (average 0.227 ± 0.120, n = 5) compared to the South China Sea (average 0.258 ± 0.018, n = 7), showing a possible influence of the Pu released at the Pacific Proving Ground nuclear test site. 236U/238U ( × 10−8) atom ratios range from 0.046 ± 0.009 to 0.524 ± 0.135, in agreement with the expected levels in surface seawater from the China Sea. 237Np/239Pu (average 4.1 ± 2.6, n = 13) and 237Np/236U ratios (average 14 ± 10, n = 13) in the oyster shells are clearly enhanced compared to the estimated one in the surface seawater, pointing out higher bioaccumulation of Np compared to Pu and U.

An experimental batch study on separation of palm kernel and palm shell with salt solution

Abstract The effectiveness of the palm kernel separation process is of paramount significance, as it directly influences the quantity of palm kernels obtained. This efficiency forms the core of the decision-making process when considering how to best use palm kernel shells, which are a byproduct of the palm oil industry. These versatile shells have various applications, including their role as a fuel source, their use in producing activated carbon, and their utility as an alternative material in lightweight concrete. The primary aim of this investigation is to examine and enhance the efficiency of this innovative segregation technique, with a specific focus on identifying the optimal conditions for achieving effective segregation, particularly the ideal concentration of salt (NaCl) in a batch process. The research methodology comprises a wellstructured series of steps designed to systematically evaluate the segregation process. In the initial stages, samples of palm kernel and shell were collected from a local palm oil industry and meticulously prepared for experimentation. Subsequently, salt solutions with varying saturation percentage of salt solution beetwen 12 g/L and 380 g/L were prepared. As the samples were immersed in the solution, the denser palm kernel shells settled at the base, whereas the lighter palm kernels rised to the top, simplifying the separation of these two elements. The highest level of segregation efficiency was achieved at the 380 g/L of Consentration of salt solution. This suggested method offers advantages, including the capability to achieve a 100% separation of palm kernel and palm kernel shell.

LOAD-LOADING CAPACITY AND CRACK FORMATION OF REINFORCED CONCRETE CYLINDRICAL SHELL WHEN CHANGING ITS THICKNESS

The results of experimental studies of long cylindrical shells with the aim of determining their stress-strain state, load-bearing capacity and crack resistance when the thickness of the shell changes are described. A special stand was developed by the authors to implement the task. 4 models of a cylindrical shell made of reinforced concrete (samples RC1-RC4) were manufactured and tested. The thickness of the samples was 45, 50, 55, 60 mm, and the cross-sectional dimensions of the side elements were changed accordingly. The distributed load (vertical) was applied in four strips, each 13 cm wide, and only the body of the shell, i.e. the side members were not loaded. The shell hinges from the corners on 100x100mm plates. Inside each side element are two reinforcing rods with a diameter of 10 mm. In order to obtain a complete and reliable picture of the deformation of the shell surface, 4 hour-type indicators are attached to each of the three zones located between the load chains. In addition to indicators, strain gauges were pasted on the shell, which were used to monitor deformations on the upper and lower surfaces. The loading process ended when the tested shell lost its ability to resist the external load. The magnitude of the load corresponding to this moment was taken as the bearing capacity of the shell. Simultaneously with the shell samples, control samples of prisms and cubes were made to determine the physical and mechanical characteristics of concrete. Graphs of the dependence of the relative deformation on the load were constructed. The bearing capacity of the shells and the load at which the first crack formed were determined. By the time of loss of bearing capacity, cracks with the same initial opening width of 0.05 mm had formed in all shells. The final crack opening width, as well as the load-bearing capacity, slightly increased with increasing shell thickness. However, the load at the beginning of crack formation turned out to be the largest for the two average values of the shell thickness – 50 and 55 mm. The general pattern of cracking of all samples is almost the same. The test methodology and the developed stand are universal in nature and will be used for further research.

Advancing highly selective low-temperature ammonia oxidation: Hydrophobic silicalite-1 shell confining silver nanoparticles on Cu/ZSM-5 core

A judiciously devised core–shell NH3-SCO catalyst featuring a Cu/ZSM-5 core enveloped by an Ag/silicalite-1 shell (Cu/ZSM-5@Ag/S-1) was rationally constructed. Integrating the silicalite-1 shell effectively suppresses the migration of Ag into Cu/ZSM-5 core, conserving the active Cu2+ sites for the catalytical conversion of byproducts NOx. Concurrently, the shell averts the formation of positively charged Ag species, facilitating the generation of abundant Ag0 nanoparticles encapsulated in the S-1 shell. Comprehensive characterizations reveal abundant Ag0 species within the core–shell Cu/ZSM-5@Ag/S-1 catalyst, boosting O2 activation and NH3 dehydrogenation and thereby contributing to superior low-temperature activity in NH3-SCO reactions. Furthermore, the hydrophobic S-1 shell effectively reinforces the hydrothermal stability of the core–shell Cu/ZSM-5@Ag/S-1. DRIFTS coupled with DFT studies elucidate that the core–shell sample follows the imide mechanism, while the shell-free sample adheres to the hydrazine mechanism. This work advances our understanding of catalyst design and presents a promising solution with practical implications for ammonia oxidation processes.

Detection of gunshot residue by flash-pulse and long-pulse infrared thermography

Detection of gunshot residues (GSR) in a bullet hole area is one of the forensic investigations aiding in the reconstruction of crime scenes. Traditionally, chromogenic methods based on chemical exposure or microscopic/spectroscopic methods are used for this purpose. In this study, we explore the applicability of active excitation infrared thermography methods for GSR detection in the bullet hole area on fabric samples. A standard 9 mm full metal jacket ammunition with a nickel-plated shell and natural cotton fabric samples were used for experiments in this study. The applicability of active thermography methods based on two different light/heat excitation sources to detect the GSR was investigated. Flash-pulse and long-pulse thermography were compared through an experimental investigation. We evaluated the effectiveness of various thermographic data processing methods, including background subtraction, temperature derivative analysis, Fourier transform phase analysis, principal component analysis, and higher-order statistics for GSR evaluation. Our findings demonstrate that flash-pulse thermography and kurtosis analysis yield the highest contrast-to-noise ratio (CNR) and produce sharp, clear images of GSR, making it the optimal method for thermographic GSR detection. Our study indicates that even though the GSR particles are tiny, they can produce sufficient contrast to be detected by the thermographic methods if appropriate experimental and post-processing procedures are used. Thus, these methods could complement GSR detection as they are non-destructive and offer rapid inspection.

الخصائص الفيزيوكيميائية للكيتوزان المستخلص من قشور الجمبري المصطادة على طول الساحل الليبي

This study aims to assess the possibility of extracting chitosan extracted from shrimp collected from the Libyan coast, to study some of its physiochemical properties, and to classify it compared to those extracted from imported shrimp available in the Libyan market in Tripoli. The physical and chemical properties of chitosan were studied including fat-binding capacity (FBC), water-binding capacity (WBC), throughput, solubility, moisture content, ash, protein, lipid, and degree of deacetylation of chitosan. The results showed that the moisture content was 28.025% in the untreated shrimp shells. The chitin sample contained 10.166% of moisture, compared to 2.677% only in the chitosan sample. Fresh local shrimp shells contained 4.70% ash, whereas the ash content in the imported sample was 53.62%. The extracted chitin and chitosan samples recorded 0.45% and 2.05% ash content, respectively. Local shrimp shells contained 28% of protein. 4.16% protein content was found in chitin extract from locally collected shrimp shells, against 0.098% in extracts from imported shrimp shells. Moreover, local shrimp shell samples contained 0.668% of fat, against 5.86% fat content in imported samples. Chitin and chitosan extracted from local shrimp shells contained 0.74% and 2.50% fat, respectively. Chitosan extracted from imported shrimp shells had a fat content of 7.307%. Fresh shrimp yielded 14.04% of chitosan, with a 0.329% the chitosan extracts from the local shrimp shells, compared to 8.5% extracts from the imported shrimp shells. A deacetylation score of 9.944 was found in chitosan extracted from both local and imported chimpanzees. The solubility of chitosan extracted from domestic shrimp shells was 0.329%, against an 8.5% solubility of chitosan extracted from imported shells. The solubility of locally extracted chitosan is, therefore, comparatively weaker. The water-binding capacity (WBC) of chitosan extracted from local and imported shrimp shells were found to be 485.6% and 483.2%, respectively. The ability of chitosan extracted from local shrimp shells showed a fat binding capacity (FBC) of 611% against a capacity of 764% of imported chitosan. Although this study succeeded in extracting chitin and chitosan from local and imported shrimp shells using chemical treatment, chitosan production was significantly poor, compared to previous studies. Keywords: Fat binding capacity, Fresh shrimp, Physiochemical properties, Solubility of chitosan

Radioactivity from oil and gas produced water accumulated in freshwater mussels

Legacy disposal of oil and gas produced water (OGPW) to surface water has led to radium contamination in streambed sediment creating a long-term radium source. Increased radium activities pose a potential health hazard to benthic organisms, such as freshwater mussels, as radium is capable of bioaccumulation. This project quantifies the impact of OGPW disposal on adult freshwater mussels, Eurynia dilatata, which were examined along the Allegheny River adjacent to a centralized waste treatment facility (CWT) that historically treated and then discharged OGPW. Radium isotopes (226Ra and 228Ra) were measured in streambed sediment, mussel soft tissue, and mussel hard shell collected upstream, at the outfall, 0.5 km downstream, and 5 km downstream of the CWT. Total radium activity was significantly higher (p < 0.05) in mussel tissue (mean = 3.44 ± 0.95 pCi/g), sediment (mean = 1.45 ± 0.19 pCi/g), and hard shell (mean = 0.34 ± 0.11 pCi/g) samples 0.5 km downstream than background samples collected upstream (mean = 1.27 ± 0.24; 0.91 ± 0.09; 0.10 ± 0.02 pCi/g respectively). Mussel shells displayed increased 226Ra activities up to 5 km downstream of the original discharge. Downstream soft tissue and hard shell 87Sr/86Sr ratios, as well as hard shell metal/calcium (e.g., Na/Ca; K/Ca; Mg/Ca) and 228Ra/226Ra ratios demonstrated trends towards values characteristic of Marcellus OGPW. Combined, this study demonstrates multiple lines of evidence for radium retention and bioaccumulation in freshwater mussels resulting from exposure to Marcellus OGPW.

Evaluation of the Bioenergy Potential of Blends (Green Coconut Shells and Fish Scales) as a Feedstock in Thermochemical Processes for Clean Energy Production

Brazil is among the world’s largest producers of green coconut, which contributes to inappropriate disposal and socioenvironmental impacts. Concomitantly, some of its coastal cities produce a great diversity of fish and large amounts of solid waste. This paper reports on the use of samples of fish scales (100FS) and green coconut shells (100GCS) and their mixtures in 75%FS:25%GCS (B25), 50%FS:50%GCS (B50), and 25%FS:75%GCS (B75) proportions and quantification of their Higher Heating Values (HHV) and Lower Heating Values (LHV), and Ultimate (UA) and Proximate Analyses (PA). Their thermal behavior was investigated by thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC), whereas scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transformed infrared (FTIR) were employed for analyses of their physicochemical and morphostructural properties. When compared to in natura samples, SEM images of the blends detected a structural disorder and a highly fibrous structure with an elongated chain and surface roughness. HHV were superior in samples with 100GCS (16.64 MJ kg−1), B75 (15.80 MJ kg−1), and B50 (14.98 MJ kg−1), and lower in B25 (14.16 MJ kg−1) and 100FS (13.03 MJ kg−1), with acceptable values for different biomasses. TG/DTG and DSC curves showed similarities among the samples, with the detection of their main thermoconversion stages. According to the data, the samples can be applied as renewable energy sources to mitigate socioecological illnesses and social vulnerabilities resulting from the archaic and inadequate management of solid waste.