Lightweight concrete as covers on floating house platforms made from expanded polystyrene system (EPS) material

Floating houses can be utilized in coastal areas as they are equipped with platforms made from expanded polystyrene system (styrofoam) and lightweight concrete covers. A lightweight concrete cover on a floating house platform made from styrofoam can improve the feasibility of housing in terms of strength, comfort and cleanliness. This research aims to obtain mixture that meet the weight and compressive strength requirements of lightweight concrete and produce them as covers on floating houses platform. The compositions of lightweight concrete materials in this research use volume ratios of 1 Pc: 2 Sand: 3 Styrofoam, 1 Pc: 1.5 Sand: 2.5 Styrofoam and 1 Pc: 1.25 Sand: 2.75 Styrofoam. The research results show that the concrete made with styrofoam qualifies as lightweight concrete with average volume weight of concrete produced between 1000-1300 kg/m3. The lightest concrete weight (1097.88 kg/m3) could be obtained from variations of mixture of 1 Pc: 1.25 Sand: 2.75 Styrofoam, The highest concrete compressive strength results were obtained from the mixture of 1 Pc: 2 Sand: 3 Styrofoam (119.26 kg/cm2). The variations of concrete mixture of 1 Pc: 2 Sand: 3 Styrofoam can be considered as lightweight concrete (≤ 1900 kg/m3).

Karakteristik Beton Mutu 16,9 MPa Mengunakan 1% Kawat Bendrat dengan Variasi Panjang

The research aimed to determine the characteristics of the 16.9 MPa, using steel fibers (bendrat wire) with lenght variations in the concrete mixture 1% by volume-weight of the concrete. This research is an explanatory research with research questions are: how significant is the difference, and what are the characteristics. The total population of each treatment is 12 specimens with a sample of 5 specimens for compressive strength and 4 specimens for split tensile strength for each given treatment which is a random sample, specifically: A (reference concrete); B, C, D, and E for concrete with length variation an expressed as L/D fiber ratio of 50; 62.5; 75 and 87.5. The concrete material meets the standard. At the level of significance 0,05 indicates that the test data are normal distribution and uniform and the characteristics of concrete between reference concrete and concrete fiber different variance values. The unit weight between the reference concrete and the fiber concrete is slightly identical. The slump value decreases with increasing L/D fiber ratio. The concrete characteristics increase up to an L/D fiber ratio of 75. It generates a compressive strength of 19.47% of the design and 16.60% of the reference concrete (17,316 MPa). The split tensile strength is 2,753 MPa (22.29% higher than the design 2,251 MPa) and 18.83% of the reference concrete (2,317 MPa). The flexural strength was 3.638 MPa (18.01% of the 3.083 MPa design) and 1.97% of the reference concrete (3.144 MPa).

Bearing Capacity Modification Of Clay In The Kedungsigit Village Using Zeolite

Clay is a type of soil with a high level of water content. These properties make clay soils have a low low bearing capacity which can have an impact on the buildings above them, such as cracked walls, raised foundations, bumpy roads and so on. The soil in Kedungsigit Village, Karangan District, Trenggalek Regency is clay and needs to be repaired to build a strong building. This study aims to modify the value of the bearing capacity of clay. Modifications were made by adding Zeolite with a percentage of 0%, 5%, 10%, 15%, and 20%. Zeolite is used because it contains mineral kristal alumina silikat which have the ability to bind grains between aggregates. Observations were made on the characteristics of clay including testing of volume weight, shear strength, and bearing capacity using the Terzaghi method. The results showed the optimum value for the addition of 15. In testing the bearing capacity of the soil using the tread foundation, the value of 32,470 t/m2 was obtained for the addition of 15% zeolite and 21,376 t/m2 for the original soil. From these results it is known that the use of zeolite can increase the value of the bearing capacity of the soil. So that these modifications can be used as an effort to improve soil in Kedungsigit village.

Flexible Films as Anode Materials Based on rGO and TiO2/MnO2 in Li-Ion Batteries Free of Non-Active Agents

Recently, to meet the growing demand for stable and flexible batteries, anodes in the form of thin films have drawn the attention of researchers. It is clear that mass production of such batteries would bring the worldwide distribution of flexible devices and wearable electronics closer. Currently, electrodes are deposited on a flexible substrate and consist of conductive and binding agents that increase the volume/weight of the electrode. Here, we propose free-standing and non-active-material-free thin films based on reduced graphene oxide (rGO), titanium dioxide (TiO2) and manganese dioxide (MnO2) as working electrodes in lithium-ion half-cells prepared via the vacuum-assisted filtration method. The electrochemical performance of the assembled half-cells exhibited good cyclic stability and a reversible capacity at lower current densities. The addition of TiO2 and MnO2 improved the capacity of the rGO film, while rGO itself provided a stable rate performance. rGO/TiO2/MnO2 film showed the highest discharge capacity (483 mAh/g at 50 mA/g). In addition, all assembled cells displayed excellent repeatability and reversibility in cyclic voltammetry measurements and good lithium-ion diffusion through the electrolyte, SEI layer and the active material itself.

Testing of Nutmeg Shell as a Normal Concrete Material in Terms of Volume Weight and Compressive Strength Value

Normal concrete uses fine aggregate and coarse aggregate with concrete density 2200 kg/m3-2400 kg/m3 with a compressive strength of about 15-40 MPa [1]. The purpose of this study is to determine characteristics of the concrete aggregate and the compressive strength of the concrete design based on the DOE (Department of Environment) method and the SNI Standard. In this research, the use of nugmet shell was varied as follows: 0%, 0,25%, 0,50%, 0,75% and 1% of the cement weight. The results showed that the use of nutmeg shells as a normal concrete affected the specific gravity and the value compressive strength of concrete. The higher the percentage of nutmeg shells, the lower the specific gravity and compressive strength of the concrete. The average value of density to nutmeg shell concrete (NSC) 2254.72 (kg/m3) and normal concrete 2304.32 (kg/m3). The compressive strength of normal concrete is 224.2 kg/cm2 and the nutmeg shell concrete (NSC) the composition of 0.25% and 0.5% obtained by 129.6 kg/cm2 and 140.0 kg/cm2 increases the use of nutmeg shell 0.75% and 1% obtained value ​​of 117.6 kg/cm2 and 118.1 kg/cm2 decreased at the age of 28 days. The compressive strength of normal concrete 22 MPa while the maximum nutmeg shell concrete (NSC) 14 MPa, so it does not meet the quality of normal concrete in general.

Impact of agrotechnical methods on improvement of sowing qualities of F1 seeds of sunflower hybrid Fakel on hybridization plot (report I)

The studies were carried out in 2020 at the "Berezanskoye" agricultural enterprise located in the Korenovsky district of the Krasnodar region. The aim of the research was to establish the possibility of improving the sowing qualities and yielding properties of the forming F1 seeds in the hybridization plot of a simple interline hybrid of sunflower Fakel. We studied the influence of various complexes of agrotechnical methods on plants of the maternal form of sunflower: application of the fertilizers, biological preparations and protection means against diseases and pests. The after-effect of the positive impact of the preparations was investigated in 2021 in a field experiment on studying the field germination of F1 seeds of the sunflower hybrid Fakel. It was found that during the formation of F1 seeds of the hybrid Fakel at the hybridization plot, the best results in terms of seed quality were obtained using a complex of fertilizers and chemical plant protection, where the highest values of the indicators of the yield structure were noted (diameter and formation of a head, seed amount per a head, 1000 seed weight, and volume weight). This made it possible in F1 to have lower losses of field germination for the formation of a scientifically based plant density. As a result of phytoexamination of grown seeds, it was revealed that the use of protective measures at the hybridization plot during the growing season of plants of the maternal form of the hybrid Fakel made it possible to increase the percentage of formed healthy seeds. The best data on the level of field germination of seeds were obtained when using biological plant protection and microbiological fertilizers at the hybridization plot. This ensured the smallest loss of germination at the scientifically grounded plant density of the hybrid Fakel in F1.

Effect of Fullerenes Additions on Physical – Mechanical Properties of Hot-Forged Iron-Based Powder Materials

It is possible to expand the applications ranges of powder material products by enhancing the performance properties of these products in addition to their manufacturability and reliability together, it’s possible by materials structures modification. In this paper, the effect of fullerene (C60) additives to iron-based powder material has been studied. All samples produced by Hot-Forging (HF) powder materials technology. Green and HF density of the obtained samples calculated by volume / weight and Archimede’s principle, respectively. The effect of technological parameters on the microstructure of carbon steels’ samples was done by an ALTAMI MET-1M metallographic microscope. Tensile test executed by using of a universal testing machine UMM –5 and the microhardness (HV10) was measured by REICHERT hardness test machine. The results showed that the HF C60 steels’ samples had higher density and strength of 0.81 and 25%, respectively, with a good plasticity in comparison with graphite steels’ samples.

White-opaque flowable composite liner as a depth marker in composite restorations prevents tooth substance loss in filling removal: a randomized double-blinded in vitro study

Objectives Removal of esthetic restorations leads to loss of tooth structure and the extent of the loss is difficult to estimate due to exact-shade matching. This randomized double-blinded in vitro study aimed examining the influence of a white-opaque flowable composite depth marker as an optical removal aid for tooth substance preservation and shortened restoration removal time. Materials and methods Class II cavities (n = 100) in extracted healthy mandibular molars (n = 50, two runs) were prepared, filled, and the restoration removed. Tooth weight and volume (before and after) and removal time were measured and remnants visually documented. An optimal tooth shade-matched flowable composite liner was used as control. Results Tooth structure loss was significantly lower using a white-opaque liner. Mean values for volume/weight loss were 0.037 ± 0.030 g and 0.016 ± 0.005 cm3 (p < 0.01) for white-opaque liner; 0.067 ± 0.000 g and 0.028 ± 0.003 cm3 (p < 0.01) for tooth-colored composite. Removal time and number of pulp chamber perforations showed no significant differences (p = 0.80). Conclusions Within the limitations of this randomized double-blinded in vitro study, the use of a white-opaque flowable liner as a depth marker may provide the practitioner a visual aid in the replacement of a composite restoration and may protect against tooth structure loss. Clinical relevance When restoration replacement is indicated, removal of esthetic restorations often causes tooth structure loss due to difficult optical color matching. Using a white-opaque flowable liner as a depth marker clinically aids in restoration removal and protects against tooth structure loss.

The Effect of Composting Campus Litter Granules and Inorganic Fertilizers on the Improvement of Soil Physical Properties and Corn Yield (Zea mays L.) In Inceptisol

The addition of organic matter is done to overcome the problems that occur in acid soils such as inceptisols. The aim of the research was to develop organic fertilizer enriched in granular form from campus litter compost to improve soil physical properties and maize yield in Inceptisols. The treatments consisted of: no fertilizer (KGSK1), 8 t ha-1 granule compost (KGSK2), inorganic fertilizer (Urea, SP-36, and KCl) recommended dose (KGSK3), inorganic fertilizer + 8 t ha- granule compost (KGSK4 ), x dose of inorganic fertilizer + compost granule (8 t ha-1) (KGSK5), 2 times dose of inorganic fertilizer + compost granule 8 t ha-1 (KGSK6), x dose of inorganic fertilizer + compost granule 12 t ha- 1 (KGSK7) and 2 times the dose of inorganic fertilizer + compost 4 t ha (KGSK8). The study was designed using a randomized block design with three replications. The results of the study found that the provision of enriched campus litter granules, either applied singly or in combination with inorganic fertilizers, had a significant effect on improving soil physical properties, namely soil volume weight, soil specific gravity, soil porosity, fast drainage pores, slow drainage pores, water pores. available, and unavailable pore water were 0.90 g cm-3, 2.30 g cm-3, 7.77%, 23.54%, 8.83%, 11.62%, and 249.17%, and the yield of dry shelled corn was 7.85 tons ha- 1.Keywords: Granular compost, Corn, Inceptisol, inorganic fertilizer

PROSPECTS FOR THE USE OF STRUCTURAL MATERIAL BASED ON LOW-VALUE SOFT HARDWOOD WOOD FOR BRIDGES ON HARVESTING ROADS

Russia has significant reserves of low-value soft deciduous wood (birch, aspen, alder, poplar), which are practically not processed, the wood rots in the forest and in the lower warehouses. Wood is a good and widespread building material. Due to the significant strength, low volume weight, ease of processing, ease of manufacturing and assembly of structures, wood has long been used for the construction of bridges. At present, despite the widespread use of reinforced concrete bridges, in the forest-rich northern and eastern regions of Russia, wooden bridges can be very useful on logging roads. But wooden bridges have a number of significant drawbacks: they have a short service life, are subject to rot, are not fire-resistant, and do not meet the requirements for passing modern loads. In order to ensure the safe and uninterrupted transport of timber on logging roads, special attention should be paid to the construction material for the construction of bridges. The proposed construction material is based on low-value soft hardwood, has high performance characteristics. To improve the performance of the wood, it is necessary to impregnate it-giving it the desired properties and compress it-thereby increasing the density, hardness and strength. We have developed a technology that combines three main technological operations of wood modification: impregnation, pressing and drying, while allowing us to obtain a structural material with increased performance characteristics, suitable for the manufacture of load-bearing supports, as well as beams of wooden bridges on logging roads.