- TITLE:
THE INFLUENCE OF THE PROCESS OF FRICTION - ABRASION ON THE AIR PERMEABILITY AND APPEARANCE OF CLASSIC COTTON-TYPE SOCKS
- AUTHOR(S):
N. Cirkovic, S. Kapusi, T. Sarac, D. Trajkovic, N. Stamenkovic, J. Stepanovic, A. Ilic.
- ABSTRACT:
Socks are included in the group of everyday (indispensable) items of clothing. They should absolutely be comfortable, long-lasting and affordable. In this research were analyzed three types of socks that differ in raw material composition (mixture of Co, PA and Lycra fibers) and structure (loop density). All socks are made of knitwear in right-left interlacing. The basic characteristics of knitwear from feet, heels and toes were checked: longitudinal mass of yarn, density, loop length, surface mass, thickness. The samples were then subjected to measurements of air permeability and resistance to friction (abrasion) using methods according to ISO and EN ISO standards. After the friction process, the air permeability decreased thanks to the felting, i.e. rubbing the fibers in the structure of the knitwear, making it denser (regardless of the fact that protruding fibers fall out, they create piles of them). The visual assessment of appearance in the sock sections also changed with increasing number of friction cycles.
- DOI:
https://doi.org/10.62853/FSCJ5813
- PAGES:
65-69
- DOWNLOAD:
THE INFLUENCE OF THE PROCESS OF FRICTION - ABRASION ON THE AIR PERMEABILITY AND APPEARANCE OF CLASSIC COTTON-TYPE SOCKS
- HOW TO CITE THIS ARTICLE:
Cirkovic N., S. Kapusi, T. Sarac, D. Trajkovic, N. Stamenkovic, J. Stepanovic, A. Ilic. The influence of the process of friction - abrasion on the air permeability and appearance of classic cotton-type socks. Journal of the Technical University of Gabrovo. 67 (2023) 65-69.
- TITLE:
DETECTION OF NON-RADIOCONTRAST FRAGMENTS IN MILITARY FIELD SURGERY BY THE NOISE EMITION METHOD
- AUTHOR(S):
O. Salenko, V. Orel, B. Salenko, K. Karpenko, V. Cherniak
- ABSTRACT:
A special tool for inspecting wound canals has been developed, consisting of a flexible probe for individual use and a handle-holder with a microphone capsule, the membrane of which is directly connected to the probe and reacts to mechanical contact with an obstacle, and the capsule itself is directly connected to the oscilloscope through a signal amplifier, which has spectral signal processing chains. Functional conditioning of the controlled signals from the shape and type of the foreign object in the wound channel was revealed. The expediency of using the frequency-amplitude characteristic of noise emission as a controlled parameter has been proven. Thus, the existence of a functional conditioning of the width of the spectrum of the noise emission signal at the time of mechanical contact with a foreign object in the wound, its shape and type is shown; it was determined that the use of an oscilloscope with a spectral analysis channel allows fairly accurate identification of a nonradiocontrast foreign object in a wound.
- DOI:
https://doi.org/10.62853/KUIY9198
- PAGES:
62-64
- DOWNLOAD:
DETECTION OF NON-RADIOCONTRAST FRAGMENTS IN MILITARY FIELD SURGERY BY THE NOISE EMITION METHOD
- HOW TO CITE THIS ARTICLE:
Salenko O., V. Orel, B. Salenko, K. Karpenko, V. Cherniak. Detection of non-radiocontrast fragments in military field surgery by the noise emition method. Journal of the Technical University of Gabrovo. 67(2023) 62-64.
- TITLE:
PARAMETER SCREENING IN LONGITUDINAL TURNING OF C45E STEEL FOR SURFACE ROUGHNESS ANALYSIS
- AUTHOR(S):
M. Trifunovic, M. Madic, P. Jankovic, M. Radovanovic
- ABSTRACT:
Parameter screening refers to the identification of the most important controllable factors with respect to a given performance characteristic of a given system/process. In this study, PlackettBurman design was applied in order to identify the factors that significantly affect surface roughness in longitudinal turning of C45E steel. The experiment involved realization of geometric PlackettBurman design with eight trials and two replicates. Six turning controllable factors were considered in the design matrix (depth of cut, feed rate, cutting speed, insert nose radius, minor cutting edge angle and cooling/lubrication condition) and were varied at two levels. Analysis of the obtained results has shown that factors differently affect surface roughness and that their influences are in accordance with known theoretical knowledge. It was also observed that three factors have statistically significant impact on the machining quality, i.e., arithmetic surface roughness. These results can be considered as the first step for further experimental investigation of significant factors and their possible interactions effects.
- DOI:
https://doi.org/10.62853/FVOS5135
- PAGES:
57-61
- DOWNLOAD:
PARAMETER SCREENING IN LONGITUDINAL TURNING OF C45E STEEL FOR SURFACE ROUGHNESS ANALYSIS
- HOW TO CITE THIS ARTICLE:
Trifunovic M., M. Madic, P. Jankovic, M. Radovanovic. Parameter screening in longitudinal turning of C45E steel for surface roughness analysis. Journal of the Technical University of Gabrovo. 67 (2023) 57-61.
- TITLE:
ELIMINATION OF THE DEFECTIVE LAYER AND STRESS CONCENTRATORS DURING MICROMACHINING OF HOLES IN THIN SHEET BLANKS OF METAL CELLULAR PANELS
- AUTHOR(S):
O. Salenko, V. Cholodny, W. Alnusirat, H. Habuzyan
- ABSTRACT:
Thin-sheet blanks made of aluminum (in particular, AMg2-N), titanium (VT-15, VT-19) or stainless (12X17) alloys are widely used in the production of honeycomb panels in the aviation and space industries. Foil (thickness 0.025-0.055 mm) is used for the production of fillers for cellular sandwich panels; it is pre-perforated with holes of 0.05-0.18 mm and laid out in a corrugated box with adhesive strips. The possibility of making holes by the laser jet method is considered, as it precedes the occurrence of mechanical damage and thermal defects of the surface adjacent to the treatment zone. It is shown that the Water Jet Guided Laser (WJGL) is an effective and efficient method of obtaining profile holes in the fillers of cellular panels and in the panels themselves, which is characterized by high productivity and allows obtaining holes without thermal and mechanical defects. The method can be used both for foil fillers and for metal panels made of stainless steel up to 1.5 mm thick.
- DOI:
https://doi.org/10.62853/NSUK6396
- PAGES:
54-56
- DOWNLOAD:
ELIMINATION OF THE DEFECTIVE LAYER AND STRESS CONCENTRATORS DURING MICROMACHINING OF HOLES IN THIN SHEET BLANKS OF METAL CELLULAR PANELS
- HOW TO CITE THIS ARTICLE:
Salenko O., V. Cholodny, W. Alnusirat, H. Habuzyan. Elimination of the defective layer and stress concentrators during micromachining of holes in thin sheet blanks of metal cellular panels. Journal of the Technical University of Gabrovo. 67 (2023) 54-56.
- TITLE:
DEVELOPMENT OF A HIGH CAPACITY THREE HEADED COIL-SPOOL WINDING MACHINE
- AUTHOR(S):
B. Avci, S. Kavak, F. Dalmis, S. Yimaz, I. Dalmis
- ABSTRACT:
Cable packaging machines are machines that can automatically wrap long and thin materials such as wires, cables and pipes into regular packages. These machines play an important role in cable production and save time and labour in the production process. There are many types of cable packaging machines and they have different features, but in general, all of them ensure that the materials are wrapped in the correct size, tightly packed and transported quickly. In the machine designed and manufactured in this study, cables are packed in perforated spool, slotted spool and coil form. The system consists of 7 sections as unloader, traverse unit, dancer, cable winding heads, spool feeding, pliers group and main control panel. In the designed and manufactured machine, the number of cable winding heads was increased to 3 for the first time and the lost time during the cable winding process was minimized. In the research, the performance of the designed and manufactured machine was tested. As a result of the experiments, it was determined that the machine winds 10-12 coils/min at a cable length of 16,5-25 m and 4,5-5 spools/min at a cable length of 100 m.
- DOI:
https://doi.org/10.62853/QUPA2451
- PAGES:
49-53
- DOWNLOAD:
DEVELOPMENT OF A HIGH CAPACITY THREE HEADED COIL-SPOOL WINDING MACHINE
- HOW TO CITE THIS ARTICLE:
Avci B., S. Kavak, F. Dalmis, S. Yimaz, I. Dalmis. Development of a high capacity three headed coil-spool windings machine. Journal of the Technical University of Gabrovo. 67 (2023) 49-53.
