Percentage Of Substitution Research Articles

THE USE OF FLY ASH AS A SUBSTITUTE FOR PORTLAND CEMENT IN HYDRAULIC CONCRETE

The analysis of fly ash (FA) as a substitute for Portland cement aims to corroborate its influence on the compressive and flexural strength in hydraulic concrete. The aggregates used were characterized by ASTM standards and the concrete was designed according to ACI for a f’c of 4000 psi. Dosing with FA was used in mass substitution percentages from 10% to 30%. The results at 28 days in compression are 5360 psi without replacement, 3760 psi for 10% of mass replacement, 4770 psi with 15% of mass replacement, 3810 psi with 20% of mass replacement, 3820 psi with 25% of mass replacement and 2470 psi with 30% of mass replacement. The 28-day flexural results were 660 psi without replacement, 630 psi with 10% of mass replacement, 660 psi with 15% of mass replacement, 660 psi with 20% of mass replacement, 650 psi with 25% of mass replacement and 490 psi with 30% of mass replacement. Therefore, the use of FA as a substitute for Portland Cement Structural

Engineering in Oxygen-incorporated monolayer MoS2 for Effi-cient Hydrogen Evolution

MoS2 is a promising alternative to Pt in hydrogen evolution reaction (HER) due to its low cost. To enhance the catalytic properties of the 2H MoS2 inert basal plane, we propose an approach of employing oxygen incorporated MoS2 as a catalyst for HER. Different density of oxygen substitution doped monolayer MoS2 samples (MoS1.51O0.49, MoS1.55O0.45, MoS1.67O0.33) were achieved by chemical vapor deposition method and their catalytic performance were tested. Experimentally, we demonstrate that oxygen substitution can activate the inert basal plane and the catalytic performance is dependent on the oxygen substitution percentage. Also, combining with DFT calculations, we confirm that oxygen substitution act as catalytic sites. Our work provides a strategy for enhancing of monolayer MoS2 HER activities through in situ substitution doping.

Water stable colloidal PVP coated spin crossover nanoparticles.

Stable aqueous dispersions of spin-crossover (SCO) doped [FeII(Htrz)2(trz)](BF4) nanoparticles (NPs) were prepared by using water-soluble polyvinylpyrrolidone (PVP) as protecting polymer. The metal or ligand substitution percentage regulated the ultra-small size and morphology of the NPs. At the same time, the colloidal dispersions showed a complete conversion of the LS state to the HS state of the FeII ion.

Otimização das propriedades reológicas das massas de pães com substituição de farinha de trigo por farinhas de grão inteiro de pseudocereais Andinos germinados

ABSTRACT: This study optimized the rheological parameters of doughs with partial substitution of wheat flour for blends of whole grain flours from germinated Andean pseudocereals such as quinoa (GQF), kiwicha (GKF), and cañihua (GCF) for bread production. The optimization was conducted through a Simplex-Centroid Mixture Design (SCMD) and Desirability Function (DF). Experiments were formulated using 80 to 90% wheat flour and 5 to 15% germinated pseudocereal blends. The rheological evaluation included farinograph, extensograph, and amylography analyses. Results showed that whole flour from germinated pseudocereals increases the water absorption, consistency, and extensibility of the doughs; and decreases its development time, stability, resistance to extensibility, temperature, and peak viscosity. The GQF-GKF blend developed more extensible and stable doughs, while GCF increased its consistency and was recommended for bread production. The data allowed us to obtain response surface models and the optimal substitution percentages to produce bread using GQF-GKF, GQF-GCF, and GKF-GCF blends.

PEMANFAATAN BAHAN LOKAL BAMBU MAYAN SEBAGAI BAHAN SUBSTITUSI ANGREGAT PADA BETON

Bamboo is a plant that can be found around us, especially in rural areas. Bamboo is an environmentally friendly building material compared to conventional building materials. In addition to being easily accessible, cheap, and lightweight, bamboo also possesses considerable strength. There have been numerous studies on the use of bamboo, but in this research, bamboo is utilized as a substitute material for coarse aggregates. The planned compressive strength is for concrete with a compressive strength of K250 (20.75MPa) with substitution proportions of 30%, 50%, and 100%, which will be compared with normal concrete. In this study, it is expected to determine the proportion of substitution of coarse aggregates in concrete using bamboo. Based on the tests conducted, ranging from testing concrete-forming materials to compressive strength tests, the compressive strength obtained for normal concrete (0%) at 28 days is 26 MPa. Meanwhile, the compressive strength for concrete with a 30% substitution proportion is 26 MPa, 50% proportion is 13 MPa, and 100% proportion is 9 MPa. Thus, it can be concluded that the greater the percentage of concrete substitution, the lower the compressive strength obtained.

Pengaruh Substitusi Tepung Mocaf pada Tepung Terigu terhadap Karakteristik Mie Basah

The purpose of this study was to determine the appropriate percentage of mocaf flour substitution for the characteristics of the resulting wet noodles. The method used in this study was RAK with five treatments and five groups. The criteria for observations made on wet noodles included testing the water content, swelling power of the noodles, testing the elasticity of the noodles and organoleptik properties (taste, aroma and texture). The results showed that best percentage of mocaf flour substitution, namely treatment B (10%) has the best swelling power, the best elasticity and has the best texture compared to other mocaf flour substitution treatments.

Sustainable Utilization of Marble Dust and Rice Husk Ash as a Partial Substitute for Fine Aggregate in Concrete

A sustainable method for partially substituting fine aggregate in concrete with marble dust and rice husk ash is described. This approach focuses on the utilization of these materials to minimize environmental impact while maintaining the integrity of the concrete structure. In this study, the fine aggregate was partially substituted with marble dust and rice husk ash. Additionally, sisal fiber was incorporated as secondary reinforcement for concrete at percentages of cement by weight. Concrete has good compressive strength but is weak in tension and bending. Thus, sisal fibers were added to enhance the mechanical properties. Sisal fibers were included at 0.1% and 0.2% of cement weight for varying percentages of mineral admixture substitution. 30% of cement was replaced with mineral admixtures, with replacement levels of 0%, 10%, 15%, 20%, and 30% of marble dust and rice husk ash. The slump cone and compaction factor tests were performed on fresh concrete mixes to determine workability. Standard cubes, cylinders, and prisms were cast to evaluate the compressive, split tensile, and flexural strengths of the hardened concrete. The results show that the replacement of cement with marble dust and rice husk ash with sisal fiber as an additional reinforcing material shows considerable improvement in tensile and flexural strength. The material properties and test results are presented graphically.

Mussel shell mortars durability: Study of aggregate replacement limit

The knowledge acquired through previous experimental phases with coating mortars with mussel shell aggregates led to conclude that irregular, flaky and hydrophobic particles of the mussel shell and the organic matter content introduce entrapped air and entrained air in the mixes. This phenomenon causes different and opposite effects on the main properties of mortars, which are in some way positive and negative (for durability), consequently, their durability cannot be easily predicted. The present work pretends to analyse the results of different durability tests, such as water vapour permeability, adhesive strength, and weathering cycles to recommend the maximum percentage of mussel shell sand used in coating mortars that guarantee the required lifespan.After an in-depth literature review, it can be said that it is not easy to predict the durability of mortars using mussel shell aggregates. This question has been hardly analysed in the existing literature and the maximum substitution percentage of conventional aggregate that can be replaced is not clear. This work aims to answer this issue by analysing different properties: water vapour permeability, adhesive strength, and weathering cycles. Mussel shell content improves the water vapour permeability of both air lime and cement mortars but worsens the adhesive strength and weathering cycle behaviour. For most applications, 25 % of mussel shell aggregate can be employed, but for some applications, 50 % or even 75 % of mussel shell aggregate is feasible and will avoid the undesirable landfilling of this waste.

Review of Models for Estimating and Predicting the Amount of Energy Produced by Solar Energy Systems

Energy production based on renewable sources is a fundamental aspect of society’s sustainable development. The involvement of renewable energy sources in the implementation of modern energy systems can significantly reduce the amount of harmful emissions into the atmosphere and provide greater flexibility of energy infrastructure. The first step in determining the feasibility of involving a particular energy source in the overall energy system of the region is a preliminary assessment of the energy potential to determine the possible percentage of substitution of traditional energy. To solve this problem, it is necessary to use the models of energy supply, which are currently presented in a wide variety. In this regard, this paper proposes to consider various models for estimating the solar energy potential, which can be divided into empirical models and models based on the application of modern intelligent data analysis technologies. Such models are based on many different climatic and geographical indicators, such as: longitude of sunshine, ambient temperature, serial number of the day of the current year, amount of precipitation, average and maximum values of wind speed and so on. The paper analyzed the existing models for estimating the amount of energy, which can be used in the system designed to determine the most optimal configuration of the energy system based on the use of various conversion technologies most relevant to the case under study, and also serve as the basis for creating digital twins designed to model and optimize the operation of the projected energy complex

Impact of recycled concrete aggregates on the strength and durability properties of pervious concrete

An investigation was designed to assess the performance of pervious concrete prepared with fly ash (FA) and recycled concrete aggregates (RCA) in place of Portland cement (PC) and natural aggregates (NA). The percentage of NA replacement with RCA was varied (0%, 50% and 100%), while the percentage of FA substitution was fixed at 10%. Various fresh (workability and consistency), mechanical (compressive strength, split tensile and shear strength), durability (abrasion resistance, freeze–thaw resistance, flexure and acid resistance) and microstructural properties of the pervious concretes were evaluated after different curing periods. The findings showed that the incorporation of RCA at different levels and partial substitution of FA was desirable pervious concrete used for structural and pavement construction purposes. The incorporation of 10% FA in addition to higher levels of RCA was found to be particularly beneficial in refining the microstructure of pervious concrete. A homogenous microstructure with dense and layered calcium silicate hydrate and calcium hydroxide was observed for the mix made with 10% FA and 100% RCA.

Effects of replacing dietary fishmeal with zymolytic black soldier fly larvae on the growth performance of the mud crab (scylla paramamosain) larvae

Black soldier fly have been shown to be one of the optimal alternatives to fishmeal, but there are few reports on the effects of zymolytic black soldier fly larvae (ZBSFL) on the growth and digestion of crustaceans. An 8-week feeding trial was conducted to evaluate the effects of different replacement levels of ZBFLS on growth performance, body composition, and digestive enzyme activity of the mud crab larvae. Four diets were formulated by replacing fishmeal with 0%, 5%, 10% and 15% ZBSFL in the basal diet. Crab larvae were randomly divided into four groups of three replicates each and fed twice daily. The results showed that the SR of crab larvae was higher than that of the no-substitution group when the substitution rate reached 5% (P < 0.05). There was no significant change in SR when the substitution rate was further increased. Weight growth rate and Specific growth rate were similar, both highest at 10% substitution ratio. The crude protein content of whole crab larvae gradually increased as the proportion of FM substituted by ZBSFL increased. The lipid content of whole crab larvae in the 5% substitution ratio group was significantly higher than that in all other groups (P < 0.05). Meanwhile. The activities of amylase, protease and lipase gradually increased. In this experiment, when the percentage of ZBSFL substitution for FM reached 10%, its growth performance was optimal, with higher SR, less negative effects and more balanced indicators in all aspects. When the substitution rate was further increased, it might increase the digestive burden of the crab and negatively affect its growth.

Influence of multi-stage processing and mechano-chemical treatments on the hydration and microstructure properties of recycled aggregate concrete

On account of the shortage of naturally occurring coarse aggregate, recycled aggregate (RA) made from crushed concrete debris is now used in the construction industry. With this rise in the utilisation of recycled aggregate in the construction sector, there has been extensive research into ways to improve its quality. The significant fraction of mortar remains that are left on the RA surface is the primary factor that affects its quality. Concrete made from RA loses strength and mechanical performance due to the attached mortar's increased porosity and water absorption values and the frailer transition region between the new mortar and aggregates. In order to minimise the old cement fractions and increase the quality, this paper studies the effect of concrete incorporating multi-stage processed RA from demolished concrete waste, followed by treatment with mechanical abrasion and sodium silicate immersion. The recycled aggregates were produced through multi-stage jaw crushing, followed by utilising natural aggregate, recycled aggregate, and recycled aggregate obtained after mechanical abrasion, followed by sodium silicate treatment for concrete mix design at various substitution percentages as coarse aggregates. The experimental investigation further progresses with the evaluation of mechanical and durability properties of concrete mixes, which is additionally followed by microstructural studies such as scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Thermogravimetry-differential thermal analysis (TG-DTA). The outcomes demonstrate that two-stage treatment, such as mechanical abrasion followed by sodium silicate immersion, yields superior-quality RA. Recycled aggregate concrete (RAC) made with these treated aggregates illustrated an increase in workability and density with respect to an untreated RAC mix. Furthermore, comparable strengths in compression, flexure, and tension are found in treated RAC mixes, particularly at 35% replacement levels, with respect to concrete mixes comprised of natural aggregates. A similar trend is detected in the chloride penetration tests and water sorptivity tests. In addition, the microstructural investigation confirmed the formation of additional calcium silicate hydrate for treated RAC mixes, particularly for the 35% substituted RA mix. On the basis of the results, it is suggested that multi-stage jaw crushing followed by treatment through mechanical abrasion and sodium silicate can potentially enhance the mechanical, microstructural, and durability performance of RAC.

Influence Substitution of Tabas Stone Waste which Coated Polyester Resin to Concrete Compressive Strength

The need for the use of concrete raw materials is increasing in line with the increase in the use of concrete in construction. The availability of concrete raw materials is dominated by the exploitation of natural resources, namely components of cement, sand and crushed stone or gravel. If the availability of this material is exploited in excess, it will have an impact on environmental damage. On the other hand, many stone crafts for decoration and building ornaments in Bali also utilize tabas stone which is also exploited from nature, where the processed rock leaves a lot of waste that is disposed of without any wise processing actions. Tabas stone waste management is expected to maximize the utilization of natural resources and also reduce environmental pollution caused by the disposal of tabas stone waste that is not managed properly. This research is expected to provide an alternative to maximize the use of tabas waste as a partial substitution of crushed stone or gravel as coarse aggregate in concrete mixtures. The porous structure of tabas stone and the high level of water absorption in the concrete mix can reduce the compressive strength of the concrete. Steps to reduce water absorption in tabas stone are carried out by maximally closing the pores using a polyester resin coating. The study was carried out by making normal concrete mixture objects according to SNI 03-2834-2000. The percentage of substitution of crushed stone with waste stone that is coated with polyester resin is 0%, 25%, 50%, 75%, 100% of the required weight of coarse aggregate. The compressive strength of the concrete will be tested at the age of 7 and 28 days using a cylindrical specimen measuring 150x300mm. Test results in the laboratory showed that the coating of tabas stone using polyester resin was able to reduce the level of water absorption from 9.96% to 3.24% or 67.5% compared to tabas stone that was not coated with polyester resin. The optimum compressive strength of coarse aggregate substitution using tabas was obtained at variations of 50% crushed stone 50% tabas stone at the age of 7 days and 28 days, respectively, reaching 15.06 MPa and 21.55 MPa.

Stabilization and valorization of tomato byproduct: A case study for the bakery industry.

Worldwide, tomato production is estimated at 180 million tons per year, which generates a byproduct with highly variable characteristics and volumes. According to the principles of the circular economy, a semi-industrial method for the integral use of the tomato byproduct as an ingredient in the bakery industry is proposed. Using two different dehydration processes (convection or freeze-drying), a tomato byproduct formed by peels and seeds was stabilized and ground into flours that were used as ingredients in focaccia-type flatbread elaboration through a wheat flour partial substitution trial (from 0% to 20% w/w). Based on the kinetics of convection drying and remaining lycopene content results, conditioning of the byproduct at 60°C was proposed. The higher the percentage of substitution, the greater the firmness of the flatbread. However, the cutting force was maximum with 15% replacement. The flatbreads with 5%-15% replacement were rated positively according to consumer acceptance studies. Substitution of up to 15% tomato byproduct is suggested for the formulation, as the higher the byproduct flour content, the lower the volume, the higher the firmness, and reddish-brown tones. Realistically, for the industrial setting, this processing proposal reached the whole food chain, from field to fork. PRACTICAL APPLICATION: Based on the circular economy and considering the whole food chain, a case study is proposed to prove the usefulness of tomato byproduct flour implementation in bakery with consumers' acceptance. Once the tomato byproduct was dehydrated by convection drying and ground, the flour was used to make focaccia-type flatbread. Up to 15% of tomato byproduct flour addition was accepted by consumers. Considering the tons of tomato byproducts generated worldwide and the overall bakery possibilities, this case shows industrial steps toward sustainable food production practices.

Functional End-Use of Hemp Seed Waste: Technological, Qualitative, Nutritional, and Sensorial Characterization of Fortified Bread

Due to its multipurpose usability, short production cycle, and low capital requirement in cultivation, hemp represents an excellent material applicable to the Sustainable Development Goals (SDGs) defined by the United Nations Organization as a strategy “to achieve a future better and more sustainable for all”. Hemp seeds represent the only edible part of Cannabis sativa and have a distinctly different nutritional composition from other representative foods such as rice and wheat (high protein content, low carbohydrate content, polyunsaturated fatty acids, dietary fiber, and gluten-free). Hemp seeds are mainly used for the production of oil; the waste obtained after extraction, reduced to a fine powder and rich in bioactive components, is added to durum wheat flour and used for the preparation of fortified bread. The aim of this study was to use varying percentages of hemp seed flour for bread production and determine the impact of fortification on texture, organoleptic characteristics, crumb color, changes in crumb texture, total polyphenols, the scavenging activity of free radicals, and amino acid content. The solid residue remaining after oil extraction from hemp seeds (generally discarded as waste or added to feed) was triturated and sieved to 0.530 mm (Hemp 1) or 0.236 mm (Hemp 2). Samples of fortified bread were obtained by replacing variable percentages of durum wheat semolina with the two hemp flours (5%, 7.5%, and 10%). The total phenolic content of the fortified bread was between 0.73 and 1.73 mg GAE/g, and the antiradical activity was between 1.17 and 3.18 mmol TEAC/100 g on the basis of the growing fortification. A comparison of Ciclope semolina bread with hemp flour-enriched bread showed a large increase in amino acid content in the fortified samples. In particular, bread enriched with 10% hemp flour 2 showed a higher content of glutamic acid, tyrosine, proline, and essential amino acids such as leucine and isoleucine compared to other samples with the same percentage of substitution. The amount of hemp seed flour influenced the color of the crumb by increasing the yellow index from 18.24 (100% Ciclope) to 21.33 (bread with 5% hemp flour 2). The results of the sensory analysis were very good, demonstrating the high acceptability of fortified breads at higher percentages.

Analysis of Mechanical Performance of Cementitious Materials with Spent Garnets as Fine Grain Aggregate Partial Replacement

The present research aims to simultaneously have positive contribution in two environmental issues identified on global scale, but also locally, in Romania: the waste generation due to industrial processes, on one hand, and on the other hand, the exhaustible natural resources constant increasing demand and consumption, in the construction industry as well. The use of abrasive waterjet (AWJ) sand in specific industries, for material processing purpose, represents an advantageous and efficient methodology, with increased domain of applicability and experiencing a significant development and improvement in the last years; still, besides the numerous benefits of the AWJ cutting and material processing techniques, they also generate collateral by-products, mostly converted into wastes: the abrasive materials (Garnet Sands) used during the AWJ cutting generate a sludge, generally unutilized and randomly deserted into damps (Spent Garnets, SG). In the same time, the construction industry and the corresponding mortar and concrete production segments, present accelerated growth, associated with global population fast increase (mainly in urban poles) and also with the industrial drive. The population growth and the industry expansion demand the corresponding infrastructure, civil, industrial, agrozootechnical, road and energetic, etc., leading to related request for building materials, concrete and natural resource consumption, like aggregates. This was the context which induced the idea of potentially valorizing the SG industrial by-products, generated by the local AWJ cutting industry, into construction materials, namely fine grain aggregates substitution in mortar and concrete. In order to evaluate the waste compatibility to a typical composition of cementitious material, a regular mortar was developed, considered the Reference (R) and further partial substitution of the usual sand was performed, by using the Spent Garnet wastes generated by two local companies. The substitution percentage was established in accordance to the previous studies in the topic, and ranged from 10 to 50% with respect to the sand quantity in the Reference mix. The mechanical performance of the mortars was analyzed at specific ages, in order to establish the viability of the substitution: 7day-testing, 14-day testing, 28 day-testing. The first results of the experimental study, focused on mechanical and physical characteristics of the mixes, are clearly encouraging, leading to the conclusion that SG by-products could be efficiently integrated in concrete and mortar mixes, as partial replacement of the regular sand; thus, the study opens the path to a sustainable, preventive solution for industrial waste generation and natural resources consumption as well. The potential use of SG as aggregate partial replacement in pavement eco-blocks is also considered, as future direction of research.

Bond strength analysis of post-installed rebar with chemical adhesive in concrete mixed with marble powder and glass fiber

This study investigates the impact of marble powder as a part of fine aggregate and the addition of glass fiber on the bond strength of concrete and deformed high-strength post-installed steel rebars using the epoxy chemical as an adhesive. Five marble dust powder (MDP) substitution percentages (i.e. 0%, 10%, 20%, 30%, and 35%) and the addition of glass fiber (i.e. 0.5%, 1%, and 1.5%) were used. The performance of deformed high-strength post-installed rebars in conventional concrete and concrete modified with 35% marble powder and 1% glass fiber was examined here utilizing pull-out tests on a total of 96 specimens. To examine the bond behaviors of deformed high-strength post-installed rebars at the epoxy–conventional concrete interface and epoxy-modified concrete with MDP and glass fiber interface, test criteria included concrete compressive strength, anchorage depth of rebar into concrete, rebar diameter, and concrete cover to rebar diameter ratio. For post-installed high-strength deformed rebar, bond stress–slip relationships were determined, examined, and subsequently compared with prior work and readily available codes. It was found that none of the specimens exhibited pull-out failure and that the majority of them displayed concrete splitting, concrete rapture, or rebar rapture failure. This suggests that epoxy resins are particularly successful as bonding agents to retrofit concrete structures at the steel–concrete contact. A closed-form equation for predicting the bond strength for post-installed high-strength deformed rebar was also created using regression analyses on the experimental data. With a significant coefficient of determination (R2 = 0.85) the observed predicted bond strengths and the test data were quite similar.

A REVIEW OF WASTE MANAGEMENT IN THE EU COUNTRIES AND THE EXPERIENCE OF ITS ENERGY USE

The article is devoted to the review of waste management in the EU countries and the study of the practices of their energy use. The amount and sources of waste generation in the EU countries and the current trends in its management are analyzed. Special attention is paid to the analysis of production and collection of organic (food) waste by the population; evaluated the top 5 best European models of their collection (open container; door-to-door collection; open container on the street, accessible only to owners; collection of household waste divided into two streams «wet/dry»; composting directly on the territory of their generation). The door-to-door model has shown the highest efficiency when implemented by the households in most European countries in most cases. Two main directions of organic waste management were analyzed: composting and anaerobic fermentation with biogas production. These directions of waste use correspond to the principles of the circular economy and help to use the available potential of waste. Anaerobic digestion of waste is preferred to the composting because it produces both energy resources (biogas, which can be purified to biomethane and also converted into electrical and thermal energy) and biofertilizers (digestate). The experience of individual European countries in the energy use of the organic fraction of municipal solid waste (hereinafter referred to as MSW) is presented. It is substantiated that the use of waste of various origins (households, enterprises, municipal wastewater, etc.) for the production of biogas is actively developing in European countries; both the number of manufacturing enterprises and their production capacities are growing. A trend towards an increase in the production of biomethane – purified biogas, which has a wider application then biogas – has been noted. The production of biomethane and biogas in relation to the total gas consumption in the sixteen largest European countries is analyzed, the largest percentage of substitution as of 2021 is noted in Denmark – 5% of natural gas was replaced by biogas, 19% – by biomethane. It has been confirmed that European countries are intensifying the production of energy carriers from waste in order to reduce dependence on buying natural gas from russia. An increase in energy independence on russian energy resources is expected to accelerate as a reaction to hostilities in Ukraine.

Comparative Evaluation of the Powder and Tableting Properties of Regular and Direct Compression Hypromellose from Different Vendors.

Hypromellose, a widely used polymer in the pharmaceutical industry, is available in several grades, depending on the percentage of substitution of the methoxyl and hydroxypropyl groups and molecular weight, and in various functional forms (e.g., suitable for direct compression tableting). These differences can affect their physicomechanical properties, and so this study aims to characterise the particle size and mechanical properties of HPMC K100M polymer grades from four different vendors. Eight polymers (CR and DC grades) were analysed using scanning electron microscopy (SEM) and light microscopy automated image analysis particle characterisation to examine the powder's particle morphology and particle size distribution. Bulk density, tapped density, and true density of the materials were also analysed. Flow was determined using a shear cell tester. Flat-faced polymer compacts were made at five different compression forces and the mechanical properties of the compacts were evaluated to give an indication of the powder's capacity to form a tablet with desirable strength under specific pressures. The results indicated that the CR grades of the polymers displayed a smaller particle size and better mechanical properties compared to the DC grade HPMC K100M polymers. The DC grades, however, had better flow properties than their CR counterparts. The results also suggested some similarities and differences between some of the polymers from the different vendors despite the similarity in substitution level, reminding the user that care and consideration should be given when substitution is required.

Review of Estimating and Predicting Models of the Wind Energy Amount

Obtaining wind energy for the production of electric energy plays a key role in overcoming the problems associated with climate change and the dwindling reserves of traditional types of energy resources. The purpose of this work is to analyze current methods of energy estimation and forecasting, to consider the main classifications of forecasts and methods used in their construction and to review the main types of mathematical distributions used to calculate the speed and power of wind flow, depending on specific geographical conditions. In recent years, there has been an increase in the capacity of modern wind generators, which has significantly improved the efficiency of wind energy parks. The initial stage in determining the feasibility of involving a particular energy source in the overall energy system of the region is a preliminary assessment of the energy potential, allowing one to determine the possible percentage of substitution of traditional energy. To solve such a problem, it is necessary to use models of energy supply. Evaluation of wind as a resource creates certain difficulties in modeling because this resource is stochastic and variable. In this regard, this paper proposes to consider various models for estimating wind energy potential, which can be classified into empirical models and models based on the application of modern intelligent data analysis technologies. The paper presents an analysis of the existing models for estimating the amount of energy, which can be used in a system designed to determine the most optimal configuration of the energy system based on the use of different conversion technologies most relevant to the case under study, and it also serves as the basis for creating digital twins designed to model and optimize the operation of the projected energy complex.