Effect Of Shell Research Articles

EFFECT OF ACTIVATED CHARCOAL PECAN SHELL (Aleurites moluccanus L. Willd) WITH VARIATIONS IN SULFURIC ACID CONCENTRATION ON DECREASED COD AND BOD LEVELS OF LAUNDRY LIQUID WASTE

Pecan shells are organic waste that can be decomposed but the texture is hard enough that it takes a long time to decompose it naturally. Various efforts to utilize pecan shell waste (Aleurites moluccanus L. Willd), one of which is as a raw material for making activated charcoal. This study aims to find out how the effect of pecan shell activated charcoal (Aleurites moluccanus L. Willd) with variations in the concentration of sulfuric acid against a decrease in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) levels of laundry liquid waste, as well as the effectiveness of the concentration of sulfuric acid activators. The manufacture of pecan shell activated charcoal (Aleurites moluccanus L. Willd) as an adsorbent is carried out through two stages, namely the authoring stage and the activation stage. BOD testing is carried out by the Winkler titration method while COD is carried out by the closed reflux method. The concentration of sulfuric acid used is 0.5 N; 1.0 N; 1.5 N; 2.0 N; and 2.5 N with a soaking time of 2 hours. The results showed that the sulfuric acid activator that was most effective in reducing laundry liquid waste was at a concentration of 1.5 N with the largest decrease value for BOD, namely 955.56 mg/L (25.44 %) and for COD which was 1648.69 mg/L (18.56 %).

Application of some Plant Extracts as Biocolorants for Leather During Finishing Process

In this research, chrome-tanned bovine crust leathers were dyed during the finishing process using plant extracts: walnut shell (Juglans regia), oak bark (Quercus cortex), and onion peel (Allium cepa). In this study, the standard recipe applied by the factory was used in the leather finishing process. For this recipe, various plant extracts were used instead of pigments, and groups that did not contain pigment and any dyestuff were formed as the control groups. After these processes, color measurement analyzes were performed on Konica Minolta CM 3600d spectrophotometer. In order to investigate the effects of walnut shell (Juglans regia), oak bark (Quercus cortex), and onion peel (Allium cepa) on the other performance properties of leather, dry and wet rub fastness test according to standard method TS EN ISO 11640 (2001) was performed. The results of the study were statistically evaluated using the NCSS method (Number Cruncher Statistical System). As a result of the study, it was noticed that, depending on the extract, different colors were obtained. It was found that the dry and wet fastness of leathers treated with plant extracts improved.

Comparative analysis of the effects of waste shell aggregates on the material properties of cement mortars

This study investigates the effects of different waste shells on the material characteristics and properties of cement-based composites. The accumulation of large quantities of waste shells poses significant environmental concerns, leading to soil pollution and odors. Furthermore, the construction industry contributes to global environmental issues through high energy consumption and CO2 emissions during aggregate production. Recycling different waste shells, including cockles, oysters, and murex, after cleaning them using an ultrasonic device, and incorporating them as partial substitutes for fine aggregates, can potentially tackle both environmental challenges. The physical and mechanical properties, including freeze–thaw resistance, of mortar specimens with different types and amounts of waste shell aggregates were measured, to examine the effect of each shell aggregate on the specimens. The microstructural characteristics of the specimens were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and micro-computed tomography (micro-CT) and correlated with the material properties. The results demonstrate that mortars incorporating waste shells, with appropriate treatments such as 30% replacement and washing of the particles, exhibit compressive strength up to 90% of that observed in the normal case. Therefore, these shells can be effectively used as substitutes for fine aggregates.

Effect of the hydration shell on the red shift of the optical absorption bands of diketonate complexes

This work summarizes a spectral dataset of diketonate complexes and demonstrates the fundamental relationship between their spectral lines and the coordination nature of the metal ion.

One-step reductive amination of 5-hydroxymethylfurfural to 2,5-bis(aminomethyl)furan over a core–shell structured catalyst

2,5-Bis(aminomethyl)furan (BAF) is a diamine that is expected to have extensive applications in organic synthesis, medicine and polymer materials such as polyamides and polyimides. BAF can be prepared by one-step reductive amination of 5-hydroxymethylfurfural (HMF), one of the platform compounds for the added-valueconversion of biomass. Due to its complex structure, the one-step catalytically reductive amination of HMF to BAF in high yield is still a challenging issue. Herein, a core–shell structured catalyst (Ni@SiO2–0.2) was developed for this reaction, and the yield of BAF reached up to 99 % with aqueous ammonia as both ammonia source and solvent due to an isolation effect of the SiO2 shell. The isolation effect can prevent direct hydrogenation of HMF and self-coupling of BAF, thereby enhancing the selectivity of the reductive amination of HMF to BAF. In addition, the textural structure, acidity and acidic sites of the SiO2 shell can be tuned by adjusting the amount of TEOS during the catalyst preparation process, thus optimizing the performance of the catalyst. The characterization results also revealed that the Ni nanoparticles in the catalyst are uniformly dispersed and encapsulated within the SiO2 shell, which can decrease the charge density on the Ni surface and enhance the adsorption of ammonia and intermediates on the Ni surface, thus enhancing the catalytic activity of the catalyst.

Enhanced sequestration of Pb2+ and Cu2+ by Artemia cyst shell supported nano-Mg composite and the potential photocatalytic performance of carbonized exhausted-adsorbent

This study reported a new strategy for enhanced Pb2+ and Cu2+ sequestration by Artemia cyst shell (shell) supported nano-Mg from aqueous solutions and the carbonated exhausted-adsorbents sequenced potential application in photo-catalyst, which obtained two expected results. One is that the immobilization of nano-Mg onto Artemia cyst shell (shell-Mg) can greatly strengthen the adsorption effect of the neat cyst shell on Pb2+ and Cu2+. The adsorption capacities of shell-Mg for both metal ions reached to 622.01 and 313.91 mg/g, which was 10–15 and 30–50 times that of the neat shell respectively. And shell-Mg has strong selectivity, which was approximately 2–4 times that of shell. The shell-Mg can be used to retrieve Pb2+ and Cu2+ from aqueous solutions efficiently. Another is that the carbonated exhausted-adsorbents (C-shell-Mg-Pb and C-shell-Mg-Cu) showed their potential photocatalytic degradation effects on congo red under pH = 4 condition, the decolorization rate reached to 61.19% and 80.39% respectively. Reuse of exhausted adsorbents can avoid the secondary pollution caused by the regeneration, extend the utilization value of exhausted adsorbents, and provide a new viewpoint for the reuse of spent bio-nanomaterial adsorbents.

Preparation of Ba0.65Bi0.07Sr0.245TiO3 relaxor ferroelectric ceramics with high energy storage capability by coating powders with ZnO

A chemical coating method to form a core-shell structure was applied to produce ZnO@Ba0.65Bi0.07Sr0.245TiO3(ZnO@BBST) relaxing ferroelectric ceramics with high energy storage density. The ZnO@BBST ceramic grain was refined and the structure is dense. Simultaneously, the relaxor behavior of ZnO@BBST was improved due to the synergistic effect of ZnO shell and internal BBST. Ultimately, under the electric field of 320 kV/cm, a energy storage density of 1.91 J/cm3 and an energy storage efficiency of 82 % are obtained in 2 wt% ZnO@BBST, together with fast discharge characteristics(τ0.9<1.25 μs) and excellent cycle stability (up to 1 × 105 times). ZnO@BBST ceramics have its unique advantages in the field of ceramic capacitors.

Effects of Crab Shell Waste as Feed on Growth Performance and Colouration of Siamese Fighting Fish (Betta splendens)

Betta splendens, Siamese fighting fish exhibit behavior, coloration, and morphology that make them popular aquarium fish in aquaculture. Coloration for this fish requires high-quality feeds rich in carotenoids. Crab shells, mostly dumped as agro-waste by the seafood industry contain carotenoids and protein that can be an alternative for carotenoids in fish feed. The objectives of this study were to analyze the proximate composition and carotenoid content in feed and determine the effect of crab shells as feedstuff on the growth performance and coloration of Betta splendens. A 40-day feeding trial using 45 tails of B. splendens with an average body weight, of 0.25 g was conducted by using five feed treatments namely TC (0% crab shell), T1 (25% crab shell), T2 (50% crab shell), T3 (75% crab shell) and T4 (100% crab shell) respectively. Sampling was done weekly. Analysis done were proximate composition and extraction of carotenoid while growth performance parameters such as body weight gain (BWG), specific growth rate (SGR), feed intake (FI), and feed conversion ratio (FCR) were also taken. Skin coloration and water quality data were collected every 10 days. All data were analyzed using One-Way ANOVA via SPSS. Results showed protein content for T1 (22.40±0.29) was slightly higher compared to all treatments. Carotenoid content in crab shells was lower compared to krill. Body weight from T1 (25% crab shell) showed a significant increase among all treatments. All treatments show no changes in coloration. In conclusion, T1 (25% crab shell waste) is the best treatment as it has a high protein content that improves body weight gain without any significant effect on coloration in all treatments.

Local Heat Dissipation and Elasticity of Suspended Silicon Nanowires Revealed by Dual Scanning Electron and Thermal Microscopies.

A novel combined setup, with a scanning thermal microscope (SThM) embedded in a scanning electron microscope (SEM), is used to characterize a suspended silicon rough nanowire (NW), which is epitaxially clamped at both sides and therefore monolithically integrated in a microfabricated device. The rough nature of the NW surface, which prohibits vacuum-SThM due to loose contact for heat dissipation, is circumvented by decorating the NW with periodic platinum dots. Reproducible approaches over these dots, enabled by the live feedback image provided by the SEM, yield a strong improvement in thermal contact resistance and a higher accuracy in its estimation. The results-thermal resistance at the tip-sample contact of 188±3.7K µW-1 and thermal conductivity of the NW of 13.7±1.6W m-1 K-1-are obtained by performing a series of approach curves on the dots. Noteworthy, the technique allows measuring elastic properties at the same time-the moment of inertia of the NW is found to be (6.1±1.0) × 10-30m4-which permits to correlate the respective effects of the rough shell on heat dissipation and on the NW stiffness. The work highlights the capabilities of the dual SThM/SEM instrument, in particular the interest of systematic approach curves with well-positioned and monitored tip motion.

Scrutinizing the protein hydration shell from molecular dynamics simulations against consensus small-angle scattering data

Biological macromolecules in solution are surrounded by a hydration shell, whose structure differs from the structure of bulk solvent. While the importance of the hydration shell for numerous biological functions is widely acknowledged, it remains unknown how the hydration shell is regulated by macromolecular shape and surface composition, mainly because a quantitative probe of the hydration shell structure has been missing. We show that small-angle scattering in solution using X-rays (SAXS) or neutrons (SANS) provide a protein-specific probe of the protein hydration shell that enables quantitative comparison with molecular simulations. Using explicit-solvent SAXS/SANS predictions, we derived the effect of the hydration shell on the radii of gyration Rg of five proteins using 18 combinations of protein force field and water model. By comparing computed Rg values from SAXS relative to SANS in D2O with consensus SAXS/SANS data from a recent worldwide community effort, we found that several but not all force fields yield a hydration shell contrast in remarkable agreement with experiments. The hydration shell contrast captured by Rg values depends strongly on protein charge and geometric shape, thus providing a protein-specific footprint of protein–water interactions and a novel observable for scrutinizing atomistic hydration shell models against experimental data.

Effect of shell spacing on mechanical behavior of multi-span soil-steel composite structure

This study analyses the effect of lateral shells on central shell at a different spacing in a multi-span soil-steel composite structure subjected to quasi-static moving loads. The displacements and internal forces of the central shell during consecutive truck passages over the structure are investigated by finite element (FE) analysis. Field measurements from a site in Niemcza, Poland, are used to calibrate input parameters. Next, the simulations for different spacing between the shells are investigated. The backfill soil is modeled as elastic-perfectly plastic, while the shells and sheet piles are linear elastic. The non-linear contact zone between the shell and the soil backfill is assumed to reflect an elastic-plastic constitutive model. The analysis reveals that both vertical and horizontal displacements increase significantly when the ratio of shell spacing to span length is less than 0.5. Maximum stress occurs when the shells are placed adjacent to each other, i.e., without spacing. The stress is almost doubled in this position compared to the reference case—a single-span structure. The shifting of extreme deflections and stress is observed in the direction of truck movement. Nevertheless, the influence of lateral shells on the central shell's performance under moving loads is nearly negligible when the spacing-to-span ratio exceeds 0.5.

Characterizing the effects of liner and fiber-reinforced resin composite shell on fracture energy in type-III high-pressure composite tanks

Characterizing the effects of liner and fiber-reinforced resin composite shell on fracture energy in type-III high-pressure composite tanks

Potential of walnut shell flour as a binder in briquette production from industrial and garden wastes

Briquettes as a product of biomass compaction is considered a renewable product for replacing fossil fuels. Briquettes can be produced from several sources using the development of technology. In this study, the effect of walnut shells as an organic binder on the properties of biofuel briquettes made of industrial and garden wastes was investigated. Cylindrical briquettes from walnut shell flour with weight ratios of 5%, 10%, 15%, 20%, and 25% were prepared from industrial sawdust and ground garden residue with a weight ratio of 50/50. Briquettes were compacted under a temperature of 170 °C and pressure of 150 kg/cm2 for 30 s. Results indicated that the chemical analyses of compounds, compaction ratio, and density of the briquettes containing different proportions of walnut shells were not significantly different. The lowest fixed carbon was measured for briquettes containing 5% of walnut shell, and increasing the ratio of walnut shell significantly increased the compressive strength of the resulting briquette.

Mechanical Properties and Energy Absorption of Integrated AlSi10Mg Shell Structures with BCC Lattice Infill

Shell-infill structures comprise an exterior solid shell and an interior lattice infill, whose closed features yield superior comprehensive mechanical performance and light weight. Additive manufacturing (AM) can ensure the fabrication of complex structures. Although the mechanical behaviors of lattice structures have been extensively studied, the corresponding mechanical performances of integrated-manufactured shell structures with lattice infills should be systematically investigated due to the coupling effect of the exterior shell and lattice infill. This study investigated the mechanical properties and energy absorption of AlSi10Mg shell structures with a body-centered cubic lattice infill fabricated by AM. Quasi-static compressive experiments and corresponding finite element analysis were conducted to investigate the mechanical behavior. In addition, two different finite element modeling methods were compared to determine the appropriate modeling strategy in terms of deformation behavior. A study of different parameters, including lattice diameters and shell thicknesses, was conducted to identify their effect on mechanical performance. The results demonstrate the mechanical advantages of shell-infill structures, in which the exterior shell strengthens the lattice infill by up to 2.3 times in terms of the effective Young’s modulus. Increasing the infill strut diameter can improve the specific energy absorption by up to 1.6 times.

Confined Ni nanoparticles in N-doped carbon nanotubes for excellent pH-universal industrial-level electrocatalytic CO2 reduction and Zn-CO2 battery

Electrocatalytic reduction of CO2 (ECR) offers a promising approach to curbed carbon emissions and complete carbon cycles. However, the inevitable creation of carbonates and limited CO2 utilization efficiency in neutral or alkaline electrolytes result in low energy efficiency, carbon losses and its widespread commercial utilization. The advancement of CO2 reduction under acidic conditions offers a promising approach for their commercial utilization, but the inhibition of hydrogen evolution reaction and the corrosion of catalysts are still challenging. Herein, Ni nanoparticles (NPs) wrapped in N-doped carbon nanotubes (NixNC-a) are successfully prepared by a facile mixed-heating and freeze-drying method. Ni100NC-a achieves a high Faraday efficiency (FE) of near 100 % for CO under pH-universal conditions, coupled with a promising current density of CO (>100 mA cm−2). Especially in acidic conditions, Ni100NC-a exhibits an exceptional ECR performance with the high FECO of 97.4 % at −1.44 V and the turnover frequency (TOF) of 11 k h−1 at −1.74 V with a current density of 288.24 mA cm−2. This excellent performance is attributed to the synergistic effect of Ni NPs and N-doped carbon shells, which protects Ni NPs from etching, promotes CO2 adsorption and regulates local pH. Moreover, Ni100NC-a could drive the reversible Zn-CO2 battery with a high power-density of 4.68 mW cm−2 and a superior stability (98 h). This study presents a promising candidate for efficient pH-universal CO2 electroreduction and Zn-CO2 battery.

Chitooligosaccharide modified pesticide-loaded polyurethane microcapsules to mitigate drought stress in wheat

To cope with global climate change and ensure food security, the development of functional pesticide carriers suitable for application on plants under drought stress is an important research direction. Herein, polyurethane microcapsules loading prothioconazole (PUMC@PRO) were synthesized using interfacial polymerization. Subsequently, chitooligosaccharide (COS) and glutaraldehyde (GA) were incorporated to prepare microcapsules with cross-linked network containing Schiff bases (PUMC-COS@PRO). Results demonstrated that the fitting degree of the release curve of PUMC-COS@PRO to the zero-order release kinetic model can reach up to 0.99. Due to the synergistic effect of the microcapsule shell and cross-linked network structure containing Schiff base (C=N), the half-life of PUMC-COS@PRO is 6.6 h in UV, which is approximately 28 times that of commercial microemulsion. After the introduction of COS with biologically activity, the EC50 can decrease significantly to as low as 1.612 μg/mL. In the growth promotion test, the PUMC-COS@PRO suspension exhibited the most growth promotion rate of 16.74 % on wheat stem length. Under simulated drought stress conditions, the growth promotion rates of the PUMC-COS@PRO suspension for wheat coleoptiles and radicles can achieve 22.46 % and 59.77 %, respectively. Therefore, this study provided a promising functionalized pesticide carrier for crops under drought stress in agricultural production.

Gd2O3-based contrasting agents for photon-counting computed tomography: Effect of structure, composition, and particle size

New contrast agents (CAs) for photon-counting computed tomography (PCCT) were synthesized, including Gd2O3@SiO2 core-shell structures and surface-modified Gd2O3–SiO2–C3H6NH2 nanoparticles. Their composition and structure were assessed by IR spectroscopy, scanning electron microscopy, X-ray phase analysis, and thermogravimetric analysis. The X-ray attenuation of synthesized particles Gd2O3@SiO2 with a size of 150–200 nm and Gd2O3–SiO2–C3H6NH2 with a size of 200–300 nm, as well as the sample of Gd2O3 with a particle size of 300–500 nm in gelatine dispersion, was investigated in phantom studies by PCCT. Energy-specific X-ray attenuation properties of all CA types correlated with their Gd concentrations. Gd2O3 demonstrated higher X-ray attenuation compared to Gd2O3@SiO2 and Gd2O3–SiO2–C3H6NH2 at the same concentrations of Gd, which can be explained by the effect of the SiO2 shells.

Tribological performances of polytetrafluoroethylene/Kevlar fabric liner reinforced by oil-containing microcapsules

The wear depth of polytetrafluoroethylene (PTFE)/Kevlar fabric liner is directly related to the service life of self-lubricating spherical plain bearings. Herein, two kinds of oil-containing microcapsules were applied to improve the wear properties of PTFE/Kevlar fabric liner at various temperatures. The addition of microcapsules successfully reduced the wear and COF simultaneously, which was owing to the synergistic effect of hard shell and liquid lubricants core. The hard shell enhanced the mechanical strength of PTFE, while the released lubricants made up the shortcoming due to the incomplete PTFE lubricating film, and inhibited the abrasive wear of SiO2 debris. The present work suggested that the addition of oil-containing microcapsules was an effective method to enhance the tribological performances of PTFE/Kevlar fabric liner.

A Polyelectrolyte Colloidal Brush Based on Cellulose: Perspectives for Future Applications.

This feature article is devoted to the evaluation of different techniques for producing colloidal polyelectrolyte brushes (CPEBs) based on cellulose nanofibers modified with grafted polyacrylates. The paper also reviews the potential applications of these CPEBs in designing electrode materials and as reinforcing additives. Additionally, we discuss our own perspectives on investigating composites with CPEBs. Herein, polyacrylic acid (PAA) was grafted onto the surface of cellulose nanofibers (CNFs) employing a "grafting from" approach. The effect of the PAA shell on the morphological structure of a composite with polypyrrole (PPy) was investigated. The performance of as-obtained CNF-PAA/PPy as organic electrode material for supercapacitors was examined. Furthermore, this research highlights the ability of CNF-PAA filler to act as an additional crosslinker forming a physical sub-network due to the hydrogen bond interaction inside chemically crosslinked polyacrylamide (PAAm) hydrogels. The enhancement of the mechanical properties of the material with a concomitant decrease in its swelling ratio compared to a pristine PAAm hydrogel was observed. The findings were compared with the recent theoretical foundation pertaining to other similar materials.

Thermally-driven contraction asymmetric yolk-shell MnSe@C microsphere with boosted dielectric behaviors and microwave absorption

The conventional selective template etching method to fabricate yolk-shell microwave absorbers is inconvenient and inefficient, so the thermally-driven contraction strategy was used to prepare asymmetric yolk-shell MnSe@C microsphere microwave absorbers via self-template directed transformation. The self-templated oriented transformation enables compositional customization and enhances the template utilization. The confinement effect of the carbon shell is crucial for realizing the thermally-driven contraction strategy and contributes to the strong conduction loss to MnSe@C. On the other hand, the enhanced polarization loss benefits from the abundant heterogeneous interfaces and defects in the asymmetric yolk-shell MnSe@C microspheres. The rich cavities in the yolk-shell structure not only facilitate optimal impedance matching, but also promote the enhancement of multiple reflection loss (RL). As a result, the asymmetric yolk-shell MnSe@C microspheres obtain excellent microwave absorption performance, the minimum RL (RLmin) and the maximum effective absorption bandwidth (EAB) reaching –54.4 dB and 5.1 GHz, respectively, at a thickness of 1.9 mm. The successful obtainment of the asymmetric yolk-shell MnSe@C microspheres paves the way for the convenient synthesis of the yolk-shell transition-metal selenides (TMSs) microwave absorbers.