Peningkatan Kapasitas Petani Cokelat Desa Randualas Kecamatan Kare Kabupaten Madiun Melalui Edukasi Kualitas Kemasan Produk Cokelat

<p align="justify"><em><strong>Increasing the Capacity of Chocolate Farmers in Randualas Village Kare District Madiun Regency through Education of Chocolate Product Packaging Quality.</strong></em> Cocoa is one of the largest commodities from Madiun Regency. Cocoa has the potential to be developed into processed chocolate products that will become typical souvenirs of Madiun Regency. The cocoa farmers in Randualas Village, Kare District, Madiun Regency have received counseling on the processing of cocoa beans into ready-to-consume chocolate products. However, the chocolate product was wraped in only an HDPE plastic layer which was less attractive to consumers, so it is necessary to improve the quality of the chocolate packaging. This community empowerment aims to increase the ability of cocoa farmers (partners) to package chocolate products properly and attractively so it will further increase the economic value of their chocolate product. The activities are education and counseling about the importance of packaging for chocolate products and how to design good and attractive packaging. Monitoring and evaluation were also carried out by filling out questionnaires by participants regarding the level of understanding of the material before and after being presented. The result showed that the partners understand the importance of packaging in food products in general and packaging for chocolate products in particular. It was evidenced that after counseling, up to 50% of participants understand the importance of packaging in the food packaging process and 50% of participants understand the criteria for good packaging for chocolate products.</p>

Hybrid Welding of Metal-Polymer Composites with a Non- Conducting Polymer Layer

Metal-polymer composites (MPCs) are becoming increasingly popular primarily because of their high strength-to-weight ratio. Metal-polymer composites consist of three layers, i.e. two external metallic sheets (linings) and the core made of plastic. The presence of the internal plastic layer makes MPCs impossible to join using conventional welding processes, which significantly limits their usability. One of the solutions to the problem involves the use of hybrid methods, e.g. ultrasonic method-aided resistance welding. The research work discussed in the article involved the development of a prototype test rig and a technology enabling the joining of the Litecor® composite with steel DP600. The joining process consisted of two stages. The first stage involved the removal of the non-conducting layer of polymer from the welding area and the making of an appropriate electric contact for resistance welding. The second stage was the classical resistance spot welding process. The development of the concept posed a challenge as it was necessary to develop an appropriate acoustic waveguide for high-power ultrasonic waves which, at the same time, could transfer loads in the form of electrode force as well as provide appropriate electric and thermal conductivity without compromising acoustic parameters during the welding process. The development of the test rig was followed by the performance of numerous tests aimed to identify the appropriate window of process parameters. Test joints were subjected to macrographic, strength, ultrasonic and topographic tests.

Overmoulding of Additively Manufactured Titanium Inserts Using Polyoxymethylene (POM)—Evaluation of Bond Quality as a Function of Process Parameters

Due to their process-induced porous surfaces, additively manufactured structures are not optimized for applications in which friction is a key factor. To improve the frictional properties of additively manufactured titanium inserts of various thicknesses, two tribologically optimized POM materials, which differ in terms of filler composition and contents, were used to overmould the inserts. The titanium inserts were manufactured in two different building directions, resulting in a variation in surface roughness. The main challenge with respect to overmoulding is to maintain an even, thin plastic layer on the titanium insert. In order to evaluate the adhesion between plastic and metal, the interface is examined by optical microscopy and assessment of the peeling resistance. The peeling test shows that the overmoulded titanium inserts with a higher surface roughness are characterized by a higher peeling resistance. It is further revealed that the POM material with a special filler concept shows superior peeling resistance.

Development of Resistance Spot Welding Processes of Metal–Plastic Composites

Metal–plastic composites (MPCs) are gaining importance mainly due to high strength to weight ratio. They consist of three layers, two outer metallic cover sheets, and a plastic core. The presence of that inner plastic layer makes them rather unsuitable for joining by means of any conventional welding processes, which significantly reduces the application range of MPC. In this work, three various resistance spot welding (RSW)-based concepts were developed to overcome that limitation and join Litecor to DP600 steel. In all cases, a dedicated initial stage was implemented to RSW, which was aimed at removing the non-conductive polymer layer from the welding zone and creating the proper electrical contact for the resistance welding. These were, namely: (i) shunt current-assisted RSW; (ii) induction heating-assisted RSW; and (iii) ultrasonic-assisted RSW. The development of each concept was supported by finite element modeling, which was focused on setting the proper process parameters for polymer layer removal. Finally, the macro- and microstructure of exemplary RSW joints are shown and the most common spot weld features as well as the further development possibilities are discussed.

ASSESSMENT OF FORECAST ACCURACY DANGEROUS PROPERTIES OF COAL LAYERS BY THE DEGREE OF METAMORPHISM OF SOLID FOSSIL COALS

In the normative base of Ukraine for the safe mining of coal seams, only five indicators of the degree of metamorphism are used to predict the manifestation of their hazardous properties during mining operations: mass release of volatile substances during thermal decomposition of coal without air (Vdaf) access to characterize coal; volumetric yield of volatile substances daf V V to establish the distinctive properties of anthracites; logarithm of electrical resistivity (lg); the thickness of the plastic layer (y) and the grade of coal (M) for predicting the outburst hazard of seams. When developing regulatory documents, it was assumed that these criteria for assessing the degree of coal metamorphism remain constant within one mine field. Their values, as mining operations show, are influenced by the location of the coal sampling site in relation to the distance from relatively large geological disturbances or the boundaries of the gas weathering zone. In most cases, the boundaries of mine fields are usually relatively large geological faults. The proximity of the locations of coal sampling points to them influences the obtained results of evaluating the properties of mine layers. Аdjusting indicators (Vdaf, daf V V , lg, y ,M) for individual mines on the possible impact of geological disturbances, the depth of the mining robot and the distance from the zone of gas weathering, according to the requirements of regulatory documents. For this reason, it is of scientific and practical interest to establish the possible ranges of change in the indicators of the degree of metamorphism of coal within the same mine layer. The results of research in this direction are relevant, as they are necessary to improve the regulatory framework for the safe mining of coal mines. A possible change within a separate mine field was considered using the example of the indicator Vdaf as the most studied at present. According to a specially developed methodology, the analysis involved data on 2193 mines from different coal basins. Most of them belong to the mines of the Donetsk basin (1773). The rest of the basins account for information on 460 mine layers, including data on 46 mine layers for the Lvov-Volyn basin.

Laser-Assisted 3D Printing of Carbon Fibre Reinforced Plastic Parts With Sandwiching Fibres Between Plastic Layers

A laser-assisted 3D printing process of carbon fibre reinforced plastic parts with sandwiching fibres between plastic layers was developed to improve the bond strength of the fibres to the plastic layers. In this process, the bunded carbon fibres were placed on the 3D-printed lower layer, then the upper plastic layer was deposited on the fibres, and the two layers with sandwiching the fibres were laser-heated. The heating temperature at the interface between the fibres and the plastic layer was changed by the colour of the plastic layer because of the transmittance and absorption of laser beam, and the translucent layer was most appropriate. Not only the strength but also the rigidity of the 3D-printed carbon fibre reinforced plastic part was improved by laser heating. Carbon fibre reinforced plastic parts having closed cross-section was manufactured, and strengthened by optimisation sandwiched fibre orientation. A tailored part locally reinforced by carbon fibres was 3D-printed.

Plastic Flow in a Thin Layer: the Theory, Formulations of the Boundary- Value Problems and the Applications

Two-dimensional, averaged over the thickness of the layer, mathematical theory of the spreading of a plastic layer on the plane has been studied. General and simplified mathematical formulations of boundary value problem were presented. The problem of plastic stretching of a strip by forces applied on its “clamped” ends was investigated. The analysis of various modes of the process was carried out, which are determined by both the total compression force of the ends and the total tensile force. Mathematical analogy between the process of the free spreading of a plastic layer on the plane and the process of heat transfer was studied. For known forms of a domain occupied by a thin plastic layer at the initial time and for a given law of convergence of the plates, the evolution of the boundary of a plastic layer spreading was described. The exact particular solutions of the aforementioned problem was obtained.

ON THE INFLUENCE OF MINERAL IMPURITIES ON THE MANIFESTATION OF DANGEROUS PROPERTIES OF COAL SEAMS

Purpose: to establish a possible correspondence between metamorphic processes with artificial thermal destruction of coals and their ashing in order to identify the components of mineral impurities that can affect the manifestation of the hazardous properties of coal mine seams. Methodology is based on a comparison of metamorphic processes that took place at a certain temperature mode in the bowels of the Earth and the production of artificial coals and their ashing. Results: The research made it possible to reveal the important role of mineral impurities in the formation of the hazardous properties of coal seams. This is due to both the significant possible content of mineral impurities in fossil coals, and the simultaneous presence of the main components that determine the hazardous properties of coal seams (carbon, hydrogen, sulfur, oxygen and moisture), both in the organic and in the mineral parts of fossil coals. To improve the regulatory framework for the safe conduct of mining operations, it is necessary to take into account features of the properties of fossil coals due to the presence of mineral impurities in them. In modern regulatory documents on the safe conduct of mining operations, in general, several indicators are used without proper scientific justification: the mass yield of volatiles during the thermal decomposition of coal, the volumetric yield of volatile substances, the thickness of the plastic layer and the logarithm of the electrical resistivity of anthracites. Their values are related to the dry ash-free mass of organic matter only. This excludes consideration of the influence of mineral impurities on the manifestation of the hazardous properties of coal mine seams during mining operations. In many cases, the content of moisture and sulfur is a criterion for the manifestation of hazardous properties of coal seams. They belong to the integral components of both organic and mineral constituents of fossil coals. The share of mineral impurities in the coals of individual coal seams can be more than 40%. The presence of oxygen, hydrogen, sulfur and moisture in mineral impurities significantly affects the manifestation of the hazardous properties of coal seams during mining. The content of mineral impurities in fossil coals in engineering calculations can be determined on the basis of the ash content of coals according to known empirical relationships, corrected for the content of total sulfur and, in some cases, carbon dioxide. Scientific novelty: the significant influence of mineral impurities in fossil coals on the manifestation of hazardous properties of coal seams during mining operations has been proved. Practical value: the results obtained allow substantiating the methodology for the combined use of the composition of organic and mineral components of fossil coals for a reliable forecast of the manifestation of hazardous properties of coal seams and improving the regulatory framework for their safe mining.