β-Cyclodextrin-Calcium Complex Intercalated Hydrotalcites as Efficient Catalyst for Transesterification of Glycerol

β-cyclodextrin derivative intercalated MgAl-hydrotalcites (β-CD-Ca/LDH) was synthesized to convert glycerol into high value-added glycerol carbonate(GC) by transesterification of dimethyl carbonate (DMC) and glycerol in this paper. β-cyclodextrin-metal complexes and β-CD-Ca/LDH was characterized by XRD, FT-IR, SEM, XPS and nitrogen adsorption-desorption. The enrichment of organic reactants in the hydrophobic cavity of β-cyclodextrin improved the collision probability of reactants. The intercalation of β-cyclodextrin-calcium complex (β-CD-Ca) increased the pore size and basic strength of catalyst. The experiment results showed that the glycerol conversion was 93.7% and the GC yield was 91.8% catalyzed by β-CD-Ca/LDH when the molar ratio of DMC and glycerol was 3:1, the catalyst dosage was 4 wt.%, the reaction temperature was 75 °C and the reaction time was 100 min while the glycerol conversion was 49.4% and the GC yield was 48.6% catalyzed by MgAl-LDH under the same conditions.

Use of kaolin as a potential low-cost adsorbent for the removal of reactive blue BF-5G dye

The objective of this work was to use kaolin as an adsorbent for synthetic effluent, based on the reactive blue dye BF-5G. Several analytical techniques were used to investigate the material's crystallinity, morphology, specific surface area and fundamental functional group of kaolin. In sequence, different pH values were studied using a finite bath system. In investigating the influence of pH, the adsorbent used showed superior performance at a pH value equal to 1. From this optimal value, kinetic studies were carried out with the ideal conditions of pH, concentration and adsorbents (pH = 1, C0 = 50 mg/L and kaolin used as adsorbent). The adsorption percentage is maximum at pH 1 and decreases with the basic strength of the dye solution.

Study of the Ca2Fe2O5 Perovskite Synthesis from Waste Sources and Application as Heterogeneous Catalyst For Biodiesel Production

The use of chicken eggshells and ferrous metal waste were evaluated as feedstock for the synthesis of Ca2Fe2O5 perovskite. The solid Ca2Fe2O5 obtained was applied as heterogeneous catalyst in the transesterification reaction of soybean oil with methanol for biodiesel production. The calcium ferrite (Ca2Fe2O5) obtained from waste materials was formed at temperatures above 898 K and its basic force was very similar to that one presented in the same structure obtained using high-purity reagents. The formation of the Ca2Fe2O5/CaO system occurred for both catalysts at higher temperatures. The catalysts Ca2Fe2O5lab and Ca2Fe2O5res presented the same basic strength, 0.469 and 0.473 mmol/g, respectively. This fact indicates that both cata- lysts have similar structures even though they were prepared with very different origins of reagents. Besides that, the residual Ca2Fe2O5 perovskite showed a good catalytic performance in the transesterification reaction. The transesterification reaction led to yields of biodiesel greater than 80 %, at 333 K, methanol to oil molar ratio of 3:1 and 10 h of batch reaction.

Design of Vehicle Lifting Equipment Using Progressive Methods

The main objective of this article is to analyse the structural design of tire lifting equipment for tire services. To gain a better insight into the problem, several steps must be taken. The first step is to conduct a market analysis, which involves identifying all available equipment. Several types of lifting devices were distinguished within the development process, which differ from each other in terms of design and power supply. The type of structure and power unit represent the second steps in the design process. This is a critical aspect of the design since the forces necessary to move the system change as a result of these attributes. The design itself is the last step in the device’s design. Passenger cars differ from each other by their weight, which is limited to 3.5 tons. Based on the weight, basic strength calculation and dimensioning of the lifting device are carried out. Based on the calculations, the scissor lift device is selected. The lower frame, scissor legs, ramp, mechanical lock, and scissors drive mechanism are five main components of the device. This type of structure is best used with a hydraulic drive unit, which is calculated in the article.

Mechanical Properties of Gangue Cement Stabilized Road Foundation Mixture

In this study, coal gangue was used to replace the four single-graded natural gravels of 0~5 mm, 5~10 mm, 10~20 mm, and 20~26.5 mm to design the mix ratio and to study the influence in particle size changes of coal gangue on the mechanical properties of the mixture. The research results show that: The maximum dry density of the mixture with coal gangue is lower than the density of the natural crushed stone water-stable mixture, and the optimal moisture content is higher than that of natural crushed stone water-stable mixture; coal gangue aggregate is mixed with cement stabilized in the crushed stone mixture, and the 7d and 28d unconfined compressive strength, splitting strength, and compression rebound modulus values of the mixture are all reduced, which has a degrading effect on the mechanical properties of the mixture; however, both can attain high speed, which is the basic strength requirements for expressways, including first-class highways.

Pucuk Rebung Motif on Kain Tapis in Pepadun Community, Lampung, Indonesia

Each ethnic group in Indonesia has its own traditional fabric. The fabric contains meaning and is functioned in accordance with customary rules. Lampung as a province in Indonesia has traditional fabrics found in the Sabitain (coastal) and Pepadun (inland) communitys. Kain Tapis is a traditional fabric from Pepadun community, has a variety of motifs and functions. The diversity of Kain Tapis motifs is very interesting to be researched especially on pucuk rebung motif as the dominant motif found in Kain Tapis. Data obtained from the literature and interview, the results of the analysis of literature obtained the motif of pucuk rebung have aload of meanings of basic strength and meaning related to its function, so that its use is regulated by custom, used only for women, and should not be used by sutan and penyimbang titles are also only used by the Abung clan.

STUDY OF THE FEATURES OF STRENGTH CALCULATION OF CULTIVATOR WORKING BODIES EQUIPPED WITH POINTED LEGS

The materials of this article are devoted to research on determining the main strength characteristics of the pointed leg working body, the main difference between which and the traditionally used ones is the variable angle of crumbling. The purpose of this article was to determine the basic strength characteristics in typical cross sections ploskorezy Lancet paws, as well as identifying the degree of influence of cross-sectional dimensions of racks for efficiency. the features include the study of changes in the stress state occurring in the paw working organ in its characteristic sections, and as a consequence, the effect of these changes on the rigid rack. Modeling of working bodies and the most important working conditions, as well as calculations were performed using the "APM Win Machine" package. As a result of the conducted research, it was found that large stresses are obtained at the place of attachment of the paw to the rack and reach 193.4 MPa, and with a decrease in the cross-sectional area of the rack, its strength characteristics correspondingly decreased to a value of 85.3 MPa.

MODERN LAMINATE COMPOSITE DESIGNED FOR AIRCRAFT CONSTRUCTION

The article presents modern laminate composites designed for aircraft structural elements based on ECC e461 symmetric fabric and Interglas 02037 symmetric fabric with MGS L285/H285 resin. These composites differ in the weave used and the type of fabric. The article presents basic strength parameters of the composite obtained as a result of stand tests. The results of compressive strength tests of the material samples are presented. It was shown that the weave of the fabric significantly affects the strength parameters of the composite. The change of the weave caused the increase in strength by more than 65%. The possibilities of application of this material on selected structural elements of aircraft such as: propeller blade plating, masts, shavings, pylons.

Statistic-Driven Proton Transfer Affecting Nanoscopic Organization in an Ethylammonium Nitrate Ionic Liquid and 1,4-Diaminobutane Binary Mixture: A Steamy Pizza Model

Herein, we report on the theoretical and experimental investigation of the chemical equilibrium in a Ethylammonium Nitrate (EAN)/1,4-Diaminobutane (DAB) binary mixture displaying a significant excess of the latter component (namely, a 1:9 mole ratio). Both the neutral compounds, i.e., ethylamine (EtNH2) and DAB, present very similar chemical properties, especially concerning their basic strength, resulting in a continuous jump of the proton from the ethylammonium to the diamine (and vice-versa). Due to the significant excess of DAB, the proton is (statistically) expected to be bound to one of its nitrogen atoms, leading to the formation of a new (ternary) mixture containing DAB (ca. 80%), ethylamine (ca. 10%) and 4-amino-1-butylammonium nitrate (ABAN, ca. 10%). This is probed by means of SAXS measurements, showing LqE (low q excess) that increases over time. This feature tends to stabilize after approximately one day. When the measurement is repeated after one year, the LqE feature shows an increased intensity. Based on the results of our simulations, we suggest that this phenomenon is likely due to partial ethylamine evaporation, pushing the equilibrium toward the formation of ABAN.