Shell Content Research Articles

Assessment of Physico-mechanical Properties of Natural Rubber and Modified Natural Rubber Vulcanizates with Watermelon Rind as Fillers

Natural Rubber (NR) has a relatively low tensile modulus and strength, hence the need for reinforcing fillers to increase its tensile strength, hardness and abrasion resistance. In this study, NR was deproteinized, epoxidized and depolymerized. The functional groups of the NR and the modified NR were determined using Fourier Transform Infrared (FT-IR) spectroscopy. Watermelon Rind (WR) was used as fillers to replace Carbon Black (CB) in the compounding process. The shells were collected, dried, milled and sieved to 75 µm mesh size. Powdered WR was carbonized at 250oC for 1.5 hrs to obtain Carbonized Watermelon Rind (CWR). The Uncarbonized Watermelon Rind (UWR) and CWR powder were characterized based on particle size, loss on ignition, volatile matter, moisture and ash content. The UWR and CWR were used to replace CB at 0, 50 and 100% for the NR and modified NR compounding. The physico-mechanical properties of the different vulcanizates were determined for the effect of modification on the NR. The FT-IR result of the NR samples showed the presence of O-H, C-H, C=C stretching with C=H wagging bands used as the fingerprint region of NR. The results of the physico-mechanical properties revealed that an increase in shell content in the NR decreased its tensile strength and elongation but improved the physico-mechanical properties of the modified NR. This study showed that watermelon rind can be a viable alternative source of carbon filler for improved physico-mechanical properties of modified natural rubber.

A simplified reinforcement and fracture mechanism analysis model of epoxy nanocomposites based on finite element simulation

Understanding the reinforcement and fracture mechanism of polymer matrix nanocomposites is crucial for the design of high-performance composite materials. By taking boron nitride@boronate polymer core-shell nanoparticles modified epoxy resin nanocomposites (EPNCs) as an example, a reinforcement and fracture mechanism analysis model of nanocomposites was established through the combination of experiments and simulations. Instead of the traditional programming method by using the external language, a new modeling method was introduced with the help of Digimat. The results indicated that the interface force between (within) EP matrix and nanoparticles, the shell thickness and nanoparticle content play important roles in the reinforcement and fracture of EPNCs. The bending strength increases with the raising of particle content, but decreases with the increasing of shell thickness. The simulated results were consistent with the experiments. The interface force evolves according to the order of interfaces within particles and their shell > matrix-shell > matrix interior. A proper interfacial force can make interfacial debonding and matrix failure occur at the same time, thus improving both the strength and toughness of nanocomposites. This model construction will provide theoretical guidance for nanocomposites design and the clarification of reinforcement mechanism. • Cross-examination of analytical, numerical and experimental results is conducted. • Appropriate interface, thin shell and particle content play important roles in composites reinforcement mechanism. • Finite element evaluation of core-shell nanoparticles reinforced epoxy resin composites wais established.

Analisis Karakteristik Biomassa Cangkang Kelapa Dan Kulit Mete Melalui Proses Torefaksi

In the face of the depletion of fossil fuels, alternative fuels such as biomass are needed. However, biomass has a fairly low calorific value and several other disadvantages compared to petroleum. Therefore, a new breakthrough is needed to correct these weaknesses, one of which is the Torrefaction process. The purpose of this study was to determine the effect of torrefaction of coconut shell and cashew shell biomass on the physical and chemical properties of the material. This research was conducted using coconut shells and cashew shells. The results of this study indicate that the calorific value of coconut shells and cashew shells after torrefaction is 5115,297-5147,021 cal/gr. The water content in coconut shells is 2.718% and the value of water content in cashew shells is 2.397%, the ash content of coconut shells is 6.853% and the value of cashew shell ash content is 6.600%, the value of volatile levels of coconut shells is 14.885% and the value of volatile levels of cashew shells of 14.557% and the value of fixed carbon content of coconut shell is 75.574% and the value of fixed carbon content of cashew shell is 76.447%. Keywords : Biomass, coconut shell, cashewnut shell, torrefaction

Mussels Repair Shell Damage despite Limitations Imposed by Ocean Acidification

Bivalves frequently withstand shell damage that must be quickly repaired to ensure survival. While the processes that underlie larval shell development have been extensively studied within the context of ocean acidification (OA), it remains unclear whether shell repair is impacted by elevated pCO2. To better understand the stereotypical shell repair process, we monitored mussels (Mytilus edulis) with sublethal shell damage that breached the mantle cavity within both field and laboratory conditions to characterize the deposition rate, composition, and integrity of repaired shell. Results were then compared with a laboratory experiment wherein mussels (Mytilus trossulus) repaired shell damage in one of seven pCO2 treatments (400–2500 µatm). Shell repair proceeded through distinct stages; an organic membrane first covered the damaged area (days 1–15), followed by the deposition of calcite crystals (days 22–43) and aragonite tablets (days 51–69). OA did not impact the ability of mussels to close drill holes, nor the microstructure, composition, or integrity of end-point repaired shell after 10 weeks, as measured by µCT and SEM imaging, energy-dispersive X-ray (EDX) analysis, and mechanical testing. However, significant interactions between pCO2, the length of exposure to treatment conditions, the strength and inorganic content of shell, and the physiological condition of mussels within OA treatments were observed. These results suggest that while OA does not prevent adult mussels from repairing or mineralizing shell, both OA and shell damage may elicit stress responses that impose energetic constraints on mussel physiology.

Cell Type, Compression Performance, and Thermal Performance of Rigid Polyurethane Foam: Effects of Egg Shell Content and Size

Cell Type, Compression Performance, and Thermal Performance of Rigid Polyurethane Foam: Effects of Egg Shell Content and Size

Fischer-Trospch to olefins over hydrophobic FeMnOx@SiO2 catalysts: The effect of SiO2 shell content

Selective conversion of syngas to olefins has aroused extensive attention while some challenges still existed such as high CO2 selectivity. Herein, a series of hydrophobic FeMnOx@SiO2-y-(CH3)3 (y represents SiO2 weight percent of the catalyst) catalysts with various SiO2 shell content were synthesized for Fischer-Tropsch to olefins (FTO). During the activation process, high hydrophobic SiO2-coating content catalysts suppressed the reduction/carburization of iron species to iron carbide. During FTO reaction, iron carbide of low hydrophobic SiO2-coating content catalysts was re-oxidized while it was stabilized for high hydrophobic SiO2-coating content catalysts. The trade-off among CO2, CH4 selectivity and SiO2-coating content was reflected as an increasing trend relationship, while olefins selectivity exhibited a decreasing trend. Additionally, a desirable hydrophobic SiO2-coating (8.2 wt%) catalyst apparently suppressed CO2 formation (4.7 C%) with high olefins selectivity (54.6 C%) at CO conversion of 50.7%. This study provides an efficient approach to inhibit CO2 formation of Fe-based FTO catalyst.

Architecture of outer shell and inner blocklets of rice starch granule is related to starch granule-associated proteins

Waxy, low-amylose and high-amylose rice starches were chosen to separate inner blocklets and outer shell from their granules under incomplete gelatinization. Isolated outer shells and swollen or merged inner blocklets, based on morphological structure of broken granules, were used as a probe to study the mechanism of differences between outer and inner blocklets formation, through molecular characteristics and starch granule-associated proteins (SGAPs) analyses. On the basis of molecular composition, it was concluded that shorter branched-chain amylopectin and some amylose chains were involved in the formation of inner blocklets (shells). While the stronger interaction occurred among outer blocklets (shell), those are composed of longer branched-chains amylopectin and few amylose molecules. SGAPs types and content of inner shells (blocklets) were higher than outer shell (blocklets). SGAPs not only interacted with amylose chains but also with amylopectin chains. The enzymatic machinery for biosynthesis, such as starch branching enzyme, plays a critical role in blocklet architecture.

The Effect of Drying Time of Pearl Shells (Pinctada penguin) on Nutrition and Mineral Quality in the Strait of Buton

Pearl shells were one of the mineral sources for ruminant and non-ruminant animal feed. Several studies on pearl shells present results of different nutritional and mineral content caused by several factors, including the geographical location of an area and the processing process. The purpose of this study was to determine the effect of different drying times on the quality of the Nutrient and Mineral content of the Pinctada penguin shells in the Buton Strait. The research design used was a completely randomized design with four treatments and four replications, each replication consisting of 400 grams of Pinctada penguin. The research sample was dried at 1200C for 15, 30, and 45 minutes for each treatment. Then an analysis was carried out to see the levels of calcium (Ca), Iron (Fe), Zinc (Zn), Protein, Fat, Phosphorus (P), Potassium (K), and Iodine (I). The research data were analyzed using analysis of variance (ANOVA) based on RAL using the SPSS standard. If the treatment has a significant effect, further tests are carried out with the Duncan Multiple Range Test.

Contribution of invasive bivalves (Dreissena spp.) to element distribution: phase interaction, regional and seasonal comparison in a large shallow lake

After introduction, the invasive bivalve dreissenids became key species in the biota of Lake Balaton, the largest shallow lake in Central Europe. The contribution of dreissenid soft tissue and shell, as biotic phases, in element distribution and its interaction with the water and upper sediment phases were examined in two basins with different trophic conditions in spring and autumn. Six metals (Ba, Cu, Fe, Mn, Pb, Zn) were detected in all investigated phases. In general, metals were abundant in the water and soft tissue in the eastern basin in spring, and in the sediment and shells in the western basin in autumn. This might be associated with the more urbanized surroundings in the eastern, and the enhanced organic matter production in the western basin. High relative shares of Ba, Cu, Mn, and Pb were associated with the water and shell samples, whereas high shares of Fe and Zn were noted in the soft mussel tissue and sediments. Results suggest that dynamics of metal uptake by dreissenids depend on the seasonal change in metabolic activity. Shell metal content is less changeable; shells might absorb metals from both the soft tissue and water phases. Metallothionein peptides, the scavengers of intracellular metals, were determined to be biomarkers of the bulk contaminants rather than only metals. The present study shows that invasive bivalves, with high abundance, filtering activity, and storing capacity can significantly contribute to element distribution in the shoreline of a shallow lake ecosystem.

In-situ preparation of Nb2O5 coated Si nanoparticles with pseudocapacitive effect for high-rate lithium ion batteries

Lithium-ion batteries with the merits of no memory effect, cycle stability, and proven technology have attracted greatly attention as an energy storage system in daily life. However, the anode of commercial lithium-ion batteries is layered graphite, delivering an unsatisfied capacity of 372 mAh g−1. In this work, Si nanoparticles were in-situ coated with Nb2O5 with core–shell structure via a simple hydrothermal method. The effect of the content of Nb2O5 shell on the Si core was investigated. As a result, [email protected]2O5 composite (SN-1) exhibits high capacity (2383 mAh g−1) and stable cycle life as anode materials for lithium-ion batteries. Even rate current improves to 5C, the SN-1 composite anode still delivers a high capacity (1221 mAh g−1). Such a superior electrochemical performance are attributed to the fact that Nb2O5 is evenly coated on the surface of the Si nanoparticles, acting as a stress buffer layer and surface stabilization layer, ensuring rapid ion diffusion. Meanwhile, Pseudocapacitance contribution is vital for enhanced lithium storage. Therefore, the cycling stability of the electrodes is further improved. These superior electrochemical properties make the method of in-situ coating Si particles hold promising potential for energy storage systems.

Формальная оболочка источника права и проблемы толкования её нормативного содержания (с позиций Ганса Кельзена и современной немецкой теоретической юриспруденции)

The article is devoted to the problem of interpretation of objective law by clarifying the content of legal norms, as well as determining the design features of the external forms of their expression. Questions of interpretation of law are considered from the point of view of the normative approach to law, reflected in the doctrine of “pure law” (“reine Rechtslehre”) by Hans Kelsen. The author determines the methodological and regulatory significance of the distinction between legal norms and legal texts in the analysis of formal sources of law. Particular attention is paid to the consolidation of the main methods (modes) of legal regulation in the rules of law and the importance of their determination in the process of interpreting law. The author establishes that the practical interpretation of the content of legal norms is carried out in two main ways: by interpreting the elements of the formal shell of legal norms (elements of the organization of the legal text as a formal source of law) and by interpreting the elements of the internal content of this formal shell. The fundamental difference between legal norms and legal texts in the issue of regulating social relations is associated with the distinction between methods for interpreting their content. In this sense the significance of the difference between "norms-prescriptions" and "norms-judgments" in the concept of Hans Kelsen is emphasized. The article provides examples from modern German theoretical and legal literature, substantiating the need to distinguish between legal norms and legal texts within the framework of normativism. The approaches of Karl Larenz, Bernd Rüthers, Christian Fischer, Axel Birk and Thomas Westing to the definition of the language form of the rule of law - the so-called “bearer of a legal norm” (Rechtsnormträger), the most important types of legal sentences (Rechtssätze) as carriers of legal norms are specified. The article uses authentic scientific texts in German and for the first time the author's translation of a number of such texts into Russian was made. Conclusions are drawn about the importance of delimiting the interpretation of the content of a legal norm from the organization's interpretation of the external means of its expression; about the difference between the prescriptive and descriptive nature of legal regulation, which determines the key difference between legal positivism and non-positivist concepts of understanding law; on the significance of Kelsen's idea of Stufenbau der Rechtsordnung in interpreting the content of individual legal norms.

Nanobubbles: A Novel Targeted Drug Delivery System

Nanobubbles are nanometer size bubbles having different constituents of varying physicochemical characteristic for the inner core and outer shell. Nanobubbles are mainly fabricated to improve the stability, bioavailability and improve the biodistribution of the delivered drug to the specific targeted site. Their small sizes bubbles allow the possibility of extravasation from blood vessels into the surrounding tissues and ultrasound-targeted site-specific release with minimal invasiveness. Nanobubbles are developing as important contrast agents for imaging and carriers for drug delivery at targeted region. Sonication is the primary method for preparation of nanobubbles followed by thin-layer evaporation, high shear emulsification, mechanical agitation and coacervation or coalescence. With exposure to ultrasound/extracorporeal shock waves, the drug is liberated from the nanobubbles into the target cells. This review paper is an effort to reveal the different formulation development techniques briefly and varying shell and core content for developing nanobubbles.

Research on Quantitative Determination of the Cocoa Shell Content in Cocoa Powder Products by UPLC-Q-TOF MS/MS

Research on Quantitative Determination of the Cocoa Shell Content in Cocoa Powder Products by UPLC-Q-TOF MS/MS

Mechanical, Thermal and Hydric Behavior of the Bio-sourced Compressed Earth Block (B-CEB) Added to Peanut Shells Powder

Bio-sourced compressed earth blocks (B-CEB) were manufactured with raw soil material and peanut shells powder to produce building material with feeble environmental impact and better mechanical and hydric performances. The objective of this work is to add value to two local natural raw materials namely earth and peanut shell in the production of B-CEB with low thermal conductivity, better water resistance, and better mechanical strength. Mineralogical studies (by XRD, DTA-TG), chemical and geotechnical studies (Atterberg limits, particle size distribution) carried out on this clay have shown that it is composed of kaolinite (40 wt.%), muscovite (8 wt.%), quartz (34 wt.%), and goethite (10 wt.%). It is a sandy-silty clay of medium plasticity containing no swelling minerals. Its particles are mainly clay (50 wt%), silt (32 wt%), fine and coarse sand (18 wt%). The clay raw material used in this study is referenced BAM. The peanut shells powder, used in range of 10 to 40 wt.% to improve the raw soil, mainly contains the cellulose type I. The apparent density of B-CEB decreases when the peanut shells content increases. By contrast, the porosity increases and was greatly affect by the addition of peanut shells powder. With 20 wt.% of peanut shells powder the porosity of B-CEB increase about 67% compared to the porosity of the reference (untreated B-CEB). Mechanical properties were enhanced with peanut shell content between 15 to 25 wt.% and reached the maximum with 20 wt.%. The B-CEB becomes more ductile when the peanut shells content increases. All the elaborated B-CEB, except the B40, are in the category of the construction of load-bearing wall which is characterized by the strength higher than 4 MPa. With 15 to 30 wt.% of peanut shells powder, the resistance of B-CEB to rain erosion was enhanced. With 30 wt.% of peanut shells powder, thermal conductivity was reduced by about 43% compared with untreated B-CEB. Given the improvement of different properties, the peanut shells powder can be used in the range of 15 to 25 wt.% to stabilize the B-CEB for the construction of habitats with better durability and thermal comfort.

Pengaruh Pupuk Organik Dari Cangkang Telur Ayam terhadap Pertumbuhan Tanaman Pala (Miristica fragrans Houtt) di Kota Ternate

Chicken egg shell is one of the wastes that can be recycled and is very easy to find in everyday life because it is the basic ingredient of various foods and cakes that can be used as a product so that it can reduce and protect the environment from waste. Dried egg shells contain about 95% calcium carbonate with a weight of 5.5 grams. Calcium carbonate (CaCO3) in agriculture is used to accelerate the growth process in plants and as a plant pest control. The high calcium carbonate content of chicken egg shells can be used as a source of nutrients for plants, one of which is the Myristica fragrans Houtt plant. The objectives are 1). Analyzing the effect of organic fertilizer from chicken egg shells on the growth of Miristica fragrans Houtt. 2). Analyzing the levels of organic fertilizer from chicken egg shells that have the most effect in accelerating the growth of Miristica fragrans Houtt plants. The type in this research is quantitative research with experimental methods. This study used a randomized block design (RAK) consisting of 8 treatments and 5 replications. The research results are 1). There was a significant effect of organic fertilizer from chicken egg shells on the growth of Miristica fragrans Houtt plants for plant height, while the number of leaves, leaf length and leaf width had no significant effect. 2). The level of organic fertilizer from chicken egg shells that had the most effect on plant height, number of leaves, leaf length and leaf width of the Myristica fragrans Houtt plant was 25 grams.

Experimental Studies of Moisture Transport in Grain Material and Individual Grain

The issue of moisture transfer in the total mass of the material and in a single grain is discussed taking into account the biological characteristics of the endosperm cells of the grain. Experimental studies of this process have been performed. The results of the oscillating mode with laying have been analyzed. It was found that during the time of laying, the moisture content of the grain shell increases significantly and the moisture content of the core decreases slightly, and during the implementation of the laying after the heating period, a larger amount of moisture moves from the core into the shell than after the cooling period.

A review on the physical & chemical properties of sea sand to be used a replacement to fine aggregate in concrete

Sea sand is a widely available form of sand on comparing with the river sand. Sea sand is not used widely because it may contain chloride, sea shells in large numbers and other harmful chemicals like Fe2O3, V2O5, Cr2O3, Ga2O3, Br2O and Re2O7. The usage of sea- sand may either address the concrete’s existing problems in strength and durability or can be an excellent replacement material to river sand which is in great danger due to excessive excavation in almost all countries around the world. A large number of individual works have been done worldwide on sea sand as partial/full replacement of fine aggregates in concrete and this paper is aimed and compiling all the works and give an in depth understanding about how this material can be effectively utilized in concrete. The present work focuses on compiling and reporting various works on the general material properties of sea- sand, effect of chloride content in strength and workability, effect of rainfall on the chloride content, alkali – aggregate reaction. It also consists and understanding of the likely dangerous chemical components, effect of shell content on workability and strength, effect of size and uniformity of sea sand in concrete. Effect on compressive strength due to grading of the sea sand’s, curing with sea water and using washed the sea sand before use have also been reported. From the report it can be concluded that by understanding the material properties of sea- sand, it can be effectively utilized as fine aggregate in concrete.

Extrusion of wheat semolina and cocoa shells

Extrusion of wheat semolina and milled cocoa shells using a single screw extruder Brabender 20DN was carried out. Full factorial experiment 23 was used to investigate the effect of the quantity of cocoa shells, moisture of the material and temperature of the matrix on the density and expansion index of extrudates. Feed screw speed and screw speed were fixed at 30 and 200 rpm, respectively. Compression ratio of the screw was 4:1. Expansion index values range between 2.0 and 3.36 and a density between 0.099 and 0.223 g/cm3. The increase in moisture content and quantity of cocoa shells leads to a decrease expansion index, while density of extrudates an increase.

Sediment shell-content diminishes current-driven sand ripple development and migration

Abstract. Shells and shell fragments are biogenic structures that are widespread throughout natural sandy shelf seas and whose presence can affect the bed roughness and erodibility of the seabed. An important and direct consequence is the effect on the formation and movement of small bedforms such as sand ripples. We experimentally measured ripple formation and the migration of a mixture of natural sand with increasing volumes of shell material in a racetrack flume. Our experiments reveal the impacts of shells on ripple development in sandy sediment, providing information that was previously lacking. Shells expedite the onset of sediment transport while simultaneously reducing ripple dimensions and slowing down their migration rates. Moreover, increasing shell content enhances near-bed flow velocity due to the reduction of bed friction that is partly caused by a decrease in average ripple size and occurrence. This, in essence, limits the rate and magnitude of bed load transport. Given the large influence of shell content on sediment dynamics as well as the high shell concentrations found naturally in the sediments of shallow seas, a significant control from shells on the morphodynamics of sandy marine habitats is expected.

Effect of crushed cockle shell as partial fine aggregate replacement on workability and strength of lightweight concrete

Dumping of cockle shell waste by cockle trade emits stinking smell and pollutes the environment. This study investigates the workability and compressive strength of lightweight concrete containing crushed cockle shell as fine aggregate substitution. Four concrete mixes were prepared by integrating diverse content of crushed cockle shell as partial fine aggregate substitution by weight of sand. Workability and compressive strength of concrete were determined via slump test and compressive strength test. Concrete mix become less workable as larger content of crushed cockle shell is integrated. Utilization of crushed cockle shell up to 10% enhances the concrete’s compressive strength.