A. Irekti, M. Oualit, H. Siahmed, D. Buncianu and F. Zibouche
Lignin is the second most abundant natural polymer. Due to the high content of carbon and hydrogen (C-H, C-C, C=O), it can be used as a potential dispersant for cement matrix. The objective of this study is to extract lignin from date palm and study its effect in the form of black liquor (BL) on the rheological and physic-mechanical properties of the cements and concrete. The lignin in black liquor form represents approximately 30 wt% dry weight of date palm. It is a heteropolymer composed primarily of methoxylated phenylpropylene alcohol monomeric units interconnected by a variety of stable carbon-carbon and carbon-oxygen-carbon (ether and esters) linkages. The results found show the positive effect on the workability of cement and concrete and confirms its dispersion effect by improving compressive strength of concrete during the early and the later ages of hydration.
This is a study of a medical injection factory-Babylon carried out in order to achieve proper mechanical and morphological properties, PP has been injection molded by using cold runner injection molding machine with temperature variation (198, 200, 203……220°C) for ten samples. The physical and mechanical properties of PP product were examined. It has been found that the Shore hardness decreases linearly with injection molding temperature increasing. The tensile strength has a similar behavior to the hardness. However, it has been found that the MIF (Melt Index Flow) rates increases with the increase of injection molding temperature. The density of PP has been found for both virgin PP and the samples, it has been found that the density decreases with increasing operation temperature. FTIR (Fourier Transmission Infrared) spectra were taken for both samples with high and low operation temperature. Besides the SEM (Scanning Electronic Microscopy) test shows the difference in the morphology of the product surface and the PP product at high and low operation temperature. Moreover, for all these properties, the PP product exhibits good mechanical properties (hardness, tensile strength, density) for the samples produced at temperature lower than 207°C. While the physical properties such as MIF improved with injection temperature increasing, additionally, the SEM images show that the sample produced in low temperature have surface damage.
Katarína Stachová, Zdenko Stacho, Zuzana Papulová and Marek Jemala
The need for adaptation to rapid changes in the business environment, both on the part of employees and employers, implies dealing with new challenges, acquisition of new knowledge and skills and assumption of new roles and responsibilities. The base for companies is the availability of qualified human resources, which is ensured by the human resource management department mainly through an effective process of employee selection. The paper is oriented at the analysis of the current state of focus of organizations operating in Slovakia on systematicity and complexity of the selection process, the existence of an effective internal labor market and the regularity of development of used selection tools in the context of technological progress and changes in labor market requirements in regions of Slovakia. Results of the survey on (n = 343) enterprises show a positive trend, an increase of more than 10 percent in the orientation towards improvement of the process of employee selection, but on the other side it also confirm an increase in disparities between individual regions of Slovakia, some regions (Eastern Slovakia) progress much slower than the developed ones (Bratislava).
The article presents the results regarding the elimination of constraints in the production process of a power equipment subassembly, a boiler chamber, together with an analysis of the benefits resulting from this, both financial and non-financial. The significance of bottlenecks in the production process, ways of its identification and limitations - in general - are presented. The article is a case-study of an attempt to eliminate the bottleneck in the production process of the boiler chamber, which turned out to be the process of drilling and marking-off, and work stations representing these processes. In order to eliminate the limitation, it was decided to replace the existing tracing and drilling work with a numerically controlled device - a boring machine moved from the liquidated department.. As a result, labor-intensive, manual chambers marking-off and the process of drilling holes with a smaller diameter drill have been eliminated. A number of benefits has been demonstrated resulting from the elimination of the bottleneck in the process, first of all, it was possible to reduce the duration of the marking-off and drilling operations and reduce the costs of the boiler chamber production process.
The article characterizes the impact test method using Drop-Tower Impact Test with the registration of the value of force and energy of breaking. Based on sources, the possibilities and scope of the current application of this method were determined and the current state of knowledge on the results of these tests was reviewed. In order to determine the possibility of using the method in impact tests of high strength steel joints, investigations of hybrid PTA - GMA welding conditions on impact strength of joints of MART S1300QL steel were carried out. In particular, the influence of t8/5 cooling time on the impact strength of welded joints by the Drop - Tower Impact Test method was determined. It has been shown that the use of dropping machine with computer-based registration of breaking force and energy values was possible in the case of impact strength testing of UHSS welded joints and enabled precise analysis of the energy distribution dynamics absorbed by the tested.
Renata Nováková, Jana Šujanová and Natália Nováková
The National Quality Programme of the Slovak Republic for 2017-2021 strongly emphasises the primary objectives and priorities of the Quality Improvement Strategy. This should be one of the main priorities of the Slovak Government in the upcoming period. The Quality Improvement Strategy should, in general, lead to an improvement in the quality of life. The aim of the paper is to point out the opportunities for improvement by applying indicators aimed at defining the excellence of organisations within the national economy of the Slovak Republic.
The construction industry in India is the second most important contributor to its gross domestic product. However, high rate of accidents and fatalities have tarnished the image of industry in India. Although the industry contributes significantly to the Indian economy, safety management is the primary concern alongside with frequent workplace accidents. The role of safety management is vital to improve safety performance of an organization. The functions of safety management include planning, organizing, staffing, directing, controlling and coordinating safety activities with an aim to minimize accidents/injuries. Safety trainings, employee participation, compliance of safety procedures and motivational schemes are part of safety management which influences the overall safety performance. Several metrics were developed to measure the safety performance of an organization but not a single measure will reflect the overall performance. The present study considered parameters pertaining to the safety management which have influence on the safety performance of a construction organization in India. The parameters are analyzed by formulating a goal programming model. The results of the study suggests that much improvement is needed in the area of safety trainings and the revised targets were established.
Presented paper concentrate on problems connected with the role of operation manager within industrial company. Operation management concentrate many activities in today’s industrial corporation and because of that the role of it’s manager is very important. He should to have many skills described in this paper. We analysed responsibilities of the operation manager, his basic operational skills and also give some examples of duties and responsibilities of good operation manager on the example of food industry. This example can give some remarks about practical skills needed in operation management in particular enterprise.
J. Górka, M. Przybyła, M. Szmul, A. Chudzio and D. Ładak
The article presents problems accompanying the industrial TIG welding (142) of a heat exchanger perforated bottom made of steel clad with titanium B265 grade 1 with tubes made of titanium B338 grade 2. Research-related tests involved the making of test plates containing simulated imperfections formed during orbital welding. The above-named imperfections resulted from insufficient gas shielding during the welding process, the improper positioning of the tungsten electrode (excessively large or overly small circumference, around which the orbital welding process was performed), an excessive electrode travel rate being the consequence of an improperly set welding programme as well as excessively high welding current. Initial tests enabled the development of the orbital TIG welding of titanium tubes with the perforated bottom made of titanium-clad steel, satisfying acceptance criteria applied during commissioning.
The paper concentrates on the issues of applying smart technologies in the manufacturing processes. The author includes in it brief descriptions of the smart technologies that contributed to the emergence of Industry 4.0 concept. Additionally, based on reports and surveys conducted on a global scale regarding the application of intelligent technologies, the author analyses the current state of implementing these technologies in manufacturing processes and provides forecasts regarding the adoption of the solutions based on Artificial Intelligence in global enterprises in the near future.