Addition Of Various Types Research Articles

Effect of Additives and Print Orientation on the Properties of Laser Sintering-Printed Polyamide 12 Components.

3D printing, also known as additive manufacturing, is becoming increasingly popular for prototype processing in industrial practice. Laser sintering, which is a laser powder bed fusion technique, is a versatile and common 3D printing technology, which enables compact and high-quality products. Polyamide 12, a popular 3D printing material, provides reliable mechanical and thermal properties. Weaknesses in applying this technology for polyamide 12 include incomplete information regarding the application of various types of additives and different printing orientations with respect to the properties. This study aimed to investigate the influence of various additives (including carbon fiber, glass fiber, flame retardant, and aluminum powder) combined with polyamide 12, using processing of predefined powder refreshing mixture on the properties of a finished product. The thermal, surface, and mechanical properties of samples printed with five different polyamides 12-based powders at three different print orientations were investigated. It was found that the inclusion of additives decreases the tensile strength and increases the surface roughness of printed components—however, the toughness increases. The results can assist designers in selecting an appropriate material that will produce a finished part with the required properties for a given application.

AN ANALYSIS OF THE INFLUENCE OF CARBON NANOPARTICLES ADDITIVE ON SELECTED PROPERTIES OF LUBRICATING OILS

This paper presents the results of an analysis of the influence of the addition of various types of carbon nanoparticles on selected essential physical and operational properties of lubricating oils. Two selected oils, i.e. the mineral base oil without additives and the typical marine lubricating circulating oil Marinol RG 1240, were modified with the addition of shungite nanoparticles, graphite nanotubes, and C60 fullerenes. The mass fraction of modifiers was 0.2% wt for each of the additives. As part of the experimental tests, measurements were made of the impact of the above-mentioned modifiers on the change in the value of the ignition temperature of oils, the effect on the changes in the value of the dynamic viscosity coefficient in the aspect of changes of temperature and shear rate, as well as the impact on the changes in the friction coefficient and the size of the wear size scar. These tests were carried out on an EraFlash automatic apparatus for determining ignition temperature using the closed cup method, with a Haake Mars III research rheometer, and a T-02U tribometer with a four-ball head.

Review on the Revolution of Polymer Electrolytes for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) are a suitable replacement for conventional silicon solar cells due to their unique features, such as high energy conversion efficiency and cheap manufacturing cost. The liquid-state DSSCs, however, are poorly sustainable on a long-term basis because volatile liquids are used. The early intention of incorporating polymer into the liquid electrolytes was to curb the problem encountered by liquid electrolytes and enable the DSSCs to function as a long-term stability device. This work briefly reviews how the improvisation has been done on the polymer electrolytes formulation and the extent of how each element can affect the cell efficiency and long-term stability. The role of each component, such as the type of host polymer, iodide salts, nanoparticles, and organic additives that improve the performance of DSSCs, has also been highlighted. This clarified the main purpose of introducing various types of additives into electrolytes to enhance the transport properties as well as the performance of the DSSCs.

Development on Solid Polymer Electrolytes for Electrochemical Devices.

Electrochemical devices, especially energy storage, have been around for many decades. Liquid electrolytes (LEs), which are known for their volatility and flammability, are mostly used in the fabrication of the devices. Dye-sensitized solar cells (DSSCs) and quantum dot sensitized solar cells (QDSSCs) are also using electrochemical reaction to operate. Following the demand for green and safer energy sources to replace fossil energy, this has raised the research interest in solid-state electrochemical devices. Solid polymer electrolytes (SPEs) are among the candidates to replace the LEs. Hence, understanding the mechanism of ions’ transport in SPEs is crucial to achieve similar, if not better, performance to that of LEs. In this paper, the development of SPE from basic construction to electrolyte optimization, which includes polymer blending and adding various types of additives, such as plasticizers and fillers, is discussed.

Application of the yeast comet assay in Testing some food additives for genotoxicity by comet assay in yeast

Food additives of various types are frequently used in the food sector. Their use is justified by the need to preserve, color, or sweeten a variety of foods. Despite the fact that some additives have been demonstrated to be cytotoxic, they are nevertheless utilized in practice. The effects of monosodium glutamate (MSG), sodium benzoate (SB), and saffron on several yeast haploid knockout strains were studied in this study (YKO). We used the Comet test method to find the optimum amounts at which this set of dietary additives could cause DNA damage. Three regularly used dietary additives were found to efficiently damage DNA. We also evaluated the sensitivity of higher eukaryotic cells to the genotoxic effects of these chemicals with yeast. The comet assay exhibited a better sensitivity of yeast cells, which was undeniably confirmed. The genotypes of haploid (knockout) yeast strains were chosen based on the (Clustal Omega Multiple Sequence Alignment EMBL-EBI) alignment of human and yeast gene sequence homology.

The Role of Glass Additives in the Properties of Lime-Based Grouts

Various types of additives have been diachronically used in historic mortars, whereas their use in lime-based grouts, used for the restoration of historic structures, is rather limited. In this study, an effort was made to investigate the performance of glass additives in grouts, consisting of lime and natural pozzolan. The additives concerned glass fibers (3 and 6 mm in length), glass beads and bubbles, added in a proportion 0.3–3% w/w of binders. Five grout compositions were manufactured and their properties at fresh and hardened states were tested. From the evaluation of the results, it was asserted that glass additives influenced the grouts’ performance in a favorable way. Their fresh state and physical properties were maintained or slightly improved, while there was a significant enhancement of the long-term mechanical characteristics of the mixes. Additionally, the adhesion capability of grouts was notably increased, which is a crucial aspect indicating their efficacy.

Gypsum polymer materials in construction

The modern level of technological development involves the use of traditional materials modified with additives of various types and functional purposes, as well as composite materials allowing to obtain a product with improved properties. Expanding the area of application of products based on gypsum for facade systems involves the creation of weather-resistant, and, first of all, waterproof materials based on gypsum polymers. The purpose of the experiment, the results of which are presented in the article, was to assess the possibility of using polycondensation polymers as a component of gypsum polymer, to model the properties of the material and to evaluate its characteristics as a result of climatic and humidity influences. The modeling and optimization of gypsum polymer properties were based on statistical methods as well as methods of mathematical analysis of functions of several variables. The assessment of the water resistance of gypsum polymer samples was carried out under test conditions in an open reservoir with an almost unlimited reaction capacity of the medium. The weather resistance was checked according to the results of tests in a climatic chamber. Experiments have shown that the strength of samples with 20% modified melamine-formaldehyde resin in compression and in bending for 80 days of storage in air increases by 30% and 25%, respectively. The compressive strength is 60 MPa, and the flexural strength is 12 MPa. Gypsum polymer has high frost resistance up to 150 cycles of alternate freezing and thawing. The result of the research was the confirmation of the possibility of using polycondensation resins and the foundations of the method for selecting the composition of the gypsum polymer were developed. The results obtained can be used in the development of the technology of gypsum polymer products, and, in particular, piece products (building cladding tiles).

Effects of cellulose fibers on the properties of asphalt mixtures

• Mechanical properties were more sensitive to CF addition methods than volumetric. • CF orientation and distribution may affect the variation in measured properties. • No unique CF-asphalt mixture met all the required properties. • The determination of optimum CF content was inconclusive. Various types of additives have been used in asphalt pavement industry to improve the performance. Among these additives, fibers have received increasing attention to achieve the desired improvement. This investigation aims to evaluate the effect of applying dry and wet methods separately to introduce the cellulose fibers (CF) into the local hot mix asphalt (HMA). The evaluation was carried out by measuring the volumetric and mechanical proprieties of conventional (control) and CF-asphalt mixtures. This study also aims to examine the possibility of using the cellulose fiber as a sustainable material in the local asphalt pavement industry. The effect of variations in cellulose fibers content; 2.5%, 5.0%, 7.5%, and 10.0% by the weight of asphalt cement, aggregate source (Al-Nibaay and Al-Suddor aggregates), and two methods (wet and dry) for adding cellulose fibers to asphalt mixtures are evaluated. Marshall methodology and indirect tensile strength test (ITS) were applied to investigate the effects of these variables. The results of this study showed that the difference in mechanical properties of the fiber-reinforced asphalt mixtures was more sensitive to CF application methods in these mixtures than the difference in volumetric properties. In addition, the wet method improved most properties of Al-Nibaay aggregate asphalt mixtures while the dry method improved most properties of Al-Suddor aggregate asphalt mixtures. Determination of optimum CF content was found inconclusive due to the wide variation in the measured properties. CF can be recommended as a promising sustainable additive to improve the properties of local asphalt pavement. However, further investigation remains necessary to precisely determine the optimum CF content in parallel with the optimum asphalt content and it is also important to assess the resistance of CF-asphalt mixtures to moisture damage and aging.

Surface modification of carbonyl iron with organosilicon block copolymer performed by wet ball milling

The paper shows the possibility of producing plate-like carbonyl iron particles covered with a surface layer modified with a poly(dimethylsiloxane) – poly(phenylsilsesquioxane) block copolymer by means of wet ball milling. At the initial stages, the milling is accompanied with the formation of an intermediate layer enriched with rigid poly(phenylsilsesquioxane) blocks followed by the copolymer precipitation. Long-term milling leads to the complete decomposition of the polymer on the surface with the formation of silicon oxycarbide and silicon carbide, with the shape of the particles being changed from plate-like to stone-like. Mechanochemical treatment goes also with dehydrogenation/hydrogenation of the milling medium followed by the formation of alkyl derivatives in the liquid and carbides in the particles as well as oxidation of the medium with the formation of ester groups. Other additives of various types (sodium dodecyl sulfate, stearic acid, N-phenylanthranilic acid) introduced into the block copolymer solution under milling facilitates the formation of multicomponent modifying layers. The most of modifying organic layers formed under wet ball milling have been shown to exhibit anticorrosive properties. The particles covered with as-modified layers may be used as magnetic fillers for microwave materials.

Mechanochemical synthesis of the NiSn, CuSn bimetallic and NiCuSn trimetallic nanocomposites using various types of additives

Ni-Cu-Sn nanocomposite was prepared for the first time, in the mechanochemical way complementing with the investigation of milled Cu-Sn and Ni-Sn systems using grinding additives. Several chemicals were examined like NaCl, PVP, CTAB, SDS, oleylamine, n-heptane, ethylene and polyethylene glycol. X-ray diffractometry attested the varying effects of the additives on the quality and quantity of the milling end-products: in several cases complete or partial mechanical alloying occurred, while in some instances, the segregation of the starting materials were also observed verified by spatially-resolved energy dispersive X-ray analysis. Dynamic light scattering measurements revealed the efficacy of additive amounts used on particle size reduction and size distribution of the milled bimetallic and trimetallic solids. For the Ni-Cu-Sn nanocomposites, the average solvodynamic diameters varied in the range 180–700 ​nm with 0.21–0.48 polydispersity values. The application of CTAB and PVP resulted in aggregated nanoparticles under 100 ​nm size in significant amounts verified by the transmission electron microscopy images. The analysis of the surface plasmon resonance bands of the nanocomposites indicated the presence of the Cu(I) oxide phase, while the calculated textural parameters increased up to 5 and 24 ​m2/g and 0.01–0.05 ​cm3/g specific surface area and total pore volume values, respectively, compared to the 0.8 ​m2/g and 0.002 ​cm3/g of the milling in the absence of additives.

Dynamically vulcanized blends of UHM-EPDM and polypropylene: Role of nano-fillers improving thermal and rheological properties

The effect of the addition of various types of nano-fillers on the viscoelastic properties of the dynamically vulcanized ultra-high molecular weight EPDM (UHM-EPDM)/Polypropylene (PP) was studied in details. The authors have studied the molten state viscoelastic properties at 180 °C by dynamic strain sweep (SS) and also stress relaxation (SR) through Rubber process Analyzer (RPA). The results of the SS and SR indicates that due the addition of the nano-silica to the blends resulting higher Storage modulus (Gʹ) and slower rate of relaxation than the pristine blend and nano-clay added blends. In the parallel plate rheometer frequency sweep study (FS), authors have noticed that nano-silica added blends are showing similar trends like SS study (in RPA) and all the blends are following pseudoplastic type flow behaviour. In the Cole-Cole plot, it is found that there is no semi-circular nature of the ηʹʹ vs ηʹ curve, and it indicates the immiscibility of the blends. In the thermal characterization, it is observed that there is a change in temperature in the thermal degradation study (TGA) about ̴ 5 °C and as the nano-filler amount are increasing the degradation temperature also improving. This special type of UHM-EPDM based TPVs exhibit superior physico-mechanical properties over conventional EPDM based TPVs and in presence of nano-fillers, they show even better physical properties. These newly developed TPVNs can be applied in aesthetic seals/strips, smaller injection moulded parts and 2K-moulds with PP in automotive.

Growth optimization of Saccharomyces cerevisiae and Rhizopus oligosporus during fermentation to produce tempeh with high β-glucan content

Abstract. Rizal S, Murhadi, Kustyawati ME, Hasanudin U. 2020. Growth optimization of Saccharomyces cerevisiae and Rhizopus oligosporus during fermentation to produce tempeh with high β-glucan content. Biodiversitas 21: 2667-2673. Saccharomyces cerevisiae grows and produces β-glucan during fermentation in tempeh production. The content of β-glucan in tempeh is influenced by the growth of S. cerevisiae throughout fermentation. The purpose of this study was to determine the effects of different types and concentrations of carbon sources on yeast growth, fungi growth, and β-glucan content in tempeh inoculated using Rhizopus oligosporus and S. cerevisiae. This study used a Factorial Randomized Complete Block Design (RCBD) with two factors and three replications. The first factor was the types of carbon sources, tapioca and wheat flour; the second factor was the concentrations of carbon source, 0.0%, 2.5%, 5.0%, 7.5% and 10.0% (w/w). Tempeh produced was investigated for yeast number, fungi number, β-glucan content, and pH value. The obtained data were tested using Tukey's Honestly Significance Difference (HSD) test. The results showed that the addition of various types and concentrations of carbon source significantly influenced the increase in yeast number, fungi number, β-glucan content, and pH in tempeh. The growth of yeast, fungi, and β-glucan content increased along with the increment of carbon source concentration. The amounts of yeast, fungi, and β-glucans in tempeh added with tapioca were higher compared to tempeh with wheat flour. The addition of 10% tapioca produced the highest amount of yeast with 9.505 Log CFU/g and the highest β-glucan content with 0.707% (w/w).

Characteristics of Nata De Taro from “Beneng” Taro Starch Waste with Addition of Various Types of Carbon and Isolated Soy Protein

Abstract The research aims to characterize nata of “Beneng” taro starch waste with addition of various types of carbon and several concentration of Isolated Soy Protein (ISP). The experimental design used was a complete randomized group design with ISP concentrations of 1%, 1.5%, and 2%. “Beneng” taro waste was heated, added with 2% vinegar, then treated with a carbon source of sucrose and glucose 5% and a nitrogen source from the ISP at concentrations of 1%, 1.5%, and 2% and fermented for 13 days. The results showed the combination of glucose with 1% ISP gave the best results and yield of 44.28%, 0.984 cm of thickness was not significantly different from the addition of ZA with a yield of 43.77%, thickness of 1.016 cm. Nata fiber content tends to be higher in the treatment with ZA addition compared to ISP, although it is not significantly different. The value of the white level is getting higher or the nata become brighter in the glucose treatment with ISP and significantly different from other treatments. The addition of ISP has the potential as an alternative for substitution of ZA and tends to increase the brightness of nata color. Keywords : “Beneng” taro, fermentation, isolated soy protein, nata

EVALUATION OF SELECTED TECHNICAL PROPERTIES OF BITUMEN BINDERS MODIFIED WITH SBS COPOLYMER AND CRUMB RUBBER

Good quality bitumen used in the production of bitumen-aggregate mixtures is a binder with high stiffness and elasticity at high operating temperatures occurring in summer and adequate flexibility during exposure to sub-zero temperatures. Currently, one of the best technological solutions to improve the viscoelasticity of bitumen and the resistance to ageing is their modification with various types of additives. The paper presents the results of penetration tests as a function of temperature, softening point (ring and ball method) and strain energy at various temperatures of road bitumen modified with SBS (styrene-butadiene-styrene) copolymer, crumb rubber and simultaneous bitumen modification with SBS copolymer and crumb rubber. The obtained results allowed to assess temperature sensitivity, resistance to changes in selected technical properties of the tested binders as a result of technological ageing process with RTFOT (Roler Thin Film Oven Tester) method and to evaluate changes in their technical properties in relation to the 50/70 base bitumen. Multivariate analysis of variance (MANOVA) was used to analyse the impact of the modification type on the test results of technical properties (significance of the impact of the considered factors on the level of technical properties).

Assessment of the Mechanical Parameters of Resin Composites with the Addition of Various Types of Fibres.

The article describes tests of epoxy mortars after the addition of fibres. The fibres were a substitute for sand in the amount of 0, 1, 2, 3, 4 and 5% by volume, respectively. Three types of mortar were obtained, containing polypropylene, glass and carbon fibres, respectively. Statistical analyses (ANOVA) were carried out to assess the impact of fibre content on the mechanical properties of mortars. Brittle fracture toughness was also tested using the Cracked Straight Through Brazilian Disc method. The addition of each type of fibre improved the assessed parameters. Based on the obtained research results, and also due to availability and price, the most advantageous seems to be the production of composites containing the addition of polypropylene fibres.

Durability of mortars modified with the addition of amorphous aluminum silicate and silica fume

In modern concrete technology, the use of various types of additives and admixtures is standard. They not only affect the mechanical properties of cement composites but also significantly facilitate the formation of a concrete mix. The paper presents the effect of the content of silica fume (SF) and an amorphous aluminum silicate (AAS) on selected properties of cement mortars, such as flexural and compressive strength, water absorption, freeze–thaw resistance, and shrinkage. The dynamics of strength development, determined after 7, 28, and 90 days of maturing of test samples, are also presented in the paper. Mortars modified with the addition of amorphous aluminum silicate in amounts of 5% and 10% of the cement mass exhibited increased flexural strength within the range of 25–30% in comparison with standard mortar and mortar modified with the addition of SF of the same amount. In the case of compressive strength, both additives resulted in similar increases in the strength within the whole maturation period. The freeze–thaw resistance tests showed that the mortars with the addition of AAS were the most resistant to variable freezing and thawing cycles, in relation both to the control mortar and to the mortar modified by SF. The application of AAS resulted in a significant reduction of shrinkage strain (by more than twice) in comparison with mortars prepared with the analogous amount of silica fume.

Leidenfrost phenomenon during quenching in aqueous solutions: effect of evaporation-induced concentration gradients.

The minimum temperature limit for a sustained vapor film on a hot surface defines the well-known Leidenfrost temperature (LFT). LFT for pure fluids is typically a strong function of the surface tension. However, the effect of surface tension on LFT of aqueous additive solutions is confusing with many complicated trends. For example, despite an insignificant increase of ≈1 mN m-1 in surface tension, a substantial increase in LFT of ≈50 °C with aqueous salt and sugar solutions has been reported in comparison to pure water. Conversely, no appreciable change in LFT (within ±2 °C) is observed despite a substantial drop of up to ≈30 mN m-1 in surface tension upon varying the concentration of surfactant additives in aqueous solutions. Here, we perform simultaneous thermal, visual, and acoustic characterization of pool quenching experiments with aqueous solutions of salt, sugar, surfactant, and ionic liquids. We model the evaporation-induced increase in the concentration of the non-volatile additives at the liquid-vapor interface using Fick's second law of diffusion. We show that the localized concentration buildup of additives at the liquid-vapor interface dramatically alters the surface tension values in comparison to the typical equilibrium values estimated otherwise. We use these modified surface tension values to correlate the diverse set of experimental LFT data reported in our work and in the literature using a unified framework. We believe that these clarifications regarding the Leidenfrost mechanism will encourage the use of additives in various applications, specifically those where surface modification strategies may not be practically feasible.

Mechanical properties of hybrid fiber reinforced concrete and a nondestructive evaluation

AbstractConcrete is the most important building material of our century. Concrete, which works under compression, is a brittle material with a low tensile strength. The addition of various types of fibers to concrete increases its ductility. Basically, the use of fibers is intended to increase crack control and ductility. Today, the use of various fibers is becoming widespread. It may be necessary from time to time to reassess and evaluate newly completed reinforced concrete buildings or those buildings still under construction as well as those in existence for years. The concrete strength of a building can be determined by using non-destructive methods or by taking cores. It is an inevitable necessity that the number of cores be limited because taking cores may lead to a weakening of the structural members. The aim of this study is to compare the mechanical properties of concrete with steel fiber, polypropylene fiber and with both in combination and to investigate the effects of using these fibers on the mechanical properties of concrete. Another objective of the study is to compare concrete compressive strength as determined by the destructive method with that determined by a non-destructive method.

Thermodynamic Control of Amorphous Precursor Phases for Calcium Carbonate via Additive Ions

Calcium carbonate is an earth-abundant biomineral that exists in a variety of marine environments, including corals, shells of mollusks, sea urchins, and so forth. Particularly, amorphous calcium carbonate (ACC) phases have increasingly received scientific attention because their local order in the short range can affect the subsequent pathways for phase transition. In this regard, various types of additives have been employed to tailor the local structures and stability of ACC; however, their precise roles in controlling the phase transition pathways are still unclear. To address this ambiguity problem, the effects of additive ions on the structure and stability of amorphous precursor phases were theoretically traced using molecular dynamics simulation. Starting from the nucleation cluster in aqueous solution, the hydrated and anhydrous forms of ACC were systematically examined by varying the hydration levels and molar compositions of additive ions (e.g., Mg2+, Fe2+, Sr2+, and Ba2+). Our results revealed that each ion can exert promoting or inhibiting effect by tuning the local structures and stability of amorphous precursor phases depending on their hydrophilicity and ionic radii. Moreover, our findings suggested that the thermodynamic spontaneity of the overall phase transition process can be determined by the balance between two opposing factors—endothermic dehydration and exothermic crystallization.

The Effect of Various Types of Natural Sweeteners in Agar with Rice Bran Addition on Organoleptic and Physicochemical Characteristics

Abstract— This research was conducted in two stages, first stage, looking for the best concentration of natural sweetener with organoleptic. Second stage analyzed the physicochemical characteristics using the best concentration of first stage. This research was carried out using a Completely Randomized Design, with various natural sweeteners consisting 6 levels, namely: stevia sweetener (0.05%, 0.75%, 0.10%), sorghum sugar (10%, 15%, 20%), corn sugar (10%, 15%, 20%), coconut sugar (14%, 15%, 16%), palm sugar (7.5%, 10%, 12.5%), and honey (15%, 25%, 35%) and 3 replications so that 18 experimental units. The addition of various types of natural sweeteners significantly affected the hedonic test (taste and overall acceptance), water content, pH, total dissolved solids, total sugar, and color but did not significantly affect the hedonic quality test (texture), hedonic test (texture and color), crude fiber content, syneresis and gel hardness.
 Keywords— Agar, Natural Sweeteners, Rice Bran