Estimation of quality for steel wire ropes according

Life and work dependability of steel wire ropes depend also on their quality. Test results of the steel wire ropes for pull, bend and torque are used for determination of their work capacity by safety factors and standards. To estimate the quality of steel wire ropes a factor of unequal pull steel wires, which we evaluated for sixty nine operating steel wire ropes made in various countries, can be calculated. The tests revealed that producers of steel wire ropes use for their products steel wires with unequal properties, so that results of the calculation is more disperse especially for bend and torque. Our results this type of steel wire ropes to have no guarantee of long life in comparison with present standards

Structural, ecological and biogeographical attributes of European vegetation alliances

The first comprehensive phytosociological classification of all vegetation types in Europe (EuroVegChecklist; Applied Vegetation Science, 2016, 19, 3–264) contained brief descriptions of each type. However, these descriptions were not standardized and mentioned only the most distinct features of each vegetation type. The practical application of the vegetation classification system could be enhanced if users had the option to select sets of vegetation types based on various combinations of structural, ecological, and biogeographical attributes. Based on a literature review and expert knowledge, we created a new database that assigns standardized categorical attributes of 12 variables to each of the 1106 alliances dominated by vascular plants defined in EuroVegChecklist. These variables include dominant life form, phenological optimum, substrate moisture, substrate reaction, salinity, nutrient status, soil organic matter, vegetation region, elevational vegetation belt, azonality, successional status and naturalness. The new database has the potential to enhance the usefulness of phytosociological classification for researchers and practitioners and to help understand this classification to non-specialists

EUNIS Habitat Classification: Expert system, characteristic species combinations and distribution maps of European habitats

Aim: The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation‐plot records to the habitats of the EUNIS system, use it to classify a European vegetation‐plot database, and compile statistically‐derived characteristic species combinations and distribution maps for these habitats. Location: Europe. Methods: We developed the classification expert system EUNIS‐ESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each habitat was formally defined as a formula in a computer language combining algebraic and set‐theoretic concepts with formal logical operators. We applied this expert system to classify 1,261,373 vegetation plots from the European Vegetation Archive (EVA) and other databases. Then we determined diagnostic, constant and dominant species for each habitat by calculating species‐to‐habitat fidelity and constancy (occurrence frequency) in the classified data set. Finally, we mapped the plot locations for each habitat. Results: Formal definitions were developed for 199 habitats at Level 3 of the EUNIS hierarchy, including 25 coastal, 18 wetland, 55 grassland, 43 shrubland, 46 forest and 12 man‐made habitats. The expert system classified 1,125,121 vegetation plots to these habitat groups and 73,188 to other habitats, while 63,064 plots remained unclassified or were classified to more than one habitat. Data on each habitat were summarized in factsheets containing habitat description, distribution map, corresponding syntaxa and characteristic species combination. Conclusions: EUNIS habitats were characterized for the first time in terms of their species composition and distribution, based on a classification of a European database of vegetation plots using the newly developed electronic expert system EUNIS‐ESy. The data provided and the expert system have considerable potential for future use in European nature conservation planning, monitoring and assessment

Distribution maps of vegetation alliances in Europe

Aim: The first comprehensive checklist of European phytosociological alliances, orders and classes (EuroVegChecklist) was published by Mucina et al. (2016, Applied Vegetation Science, 19 (Suppl. 1), 3–264). However, this checklist did not contain detailed information on the distribution of individual vegetation types. Here we provide the first maps of all alliances in Europe. Location: Europe, Greenland, Canary Islands, Madeira, Azores, Cyprus and the Caucasus countries. Methods: We collected data on the occurrence of phytosociological alliances in European countries and regions from literature and vegetation-plot databases. We interpreted and complemented these data using the expert knowledge of an international team of vegetation scientists and matched all the previously reported alliance names and concepts with those of the EuroVegChecklist. We then mapped the occurrence of the EuroVegChecklist alliances in 82 territorial units corresponding to countries, large islands, archipelagos and peninsulas. We subdivided the mainland parts of large or biogeographically heterogeneous countries based on the European biogeographical regions. Specialized alliances of coastal habitats were mapped only for the coastal section of each territorial unit. Results: Distribution maps were prepared for 1,105 alliances of vascular-plant dominated vegetation reported in the EuroVegChecklist. For each territorial unit, three levels of occurrence probability were plotted on the maps: (a) verified occurrence; (b) uncertain occurrence; and (c) absence. The maps of individual alliances were complemented by summary maps of the number of alliances and the alliance–area relationship. Distribution data are also provided in a spreadsheet. Conclusions: The new map series represents the first attempt to characterize the distribution of all vegetation types at the alliance level across Europe. There are still many knowledge gaps, partly due to a lack of data for some regions and partly due to uncertainties in the definition of some alliances. The maps presented here provide a basis for future research aimed at filling these gaps

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Behavior of Rotary Ultrasonic Machining of Ceramic Materials at a Wide Range of Cutting Speeds

The paper deals with the behavior of the rotary ultrasonic machining process at different cutting speeds of ceramic materials. This process is relatively new; therefore, there are gaps in information about its behavior at near-critical parameters. We adjusted cutting speeds 10 times lower and 10 times higher than the recommended one. The observed parameters were machine load, tool wear, and surface roughness. Alumina and zirconia ceramics were used as materials. The results will help with the optimization of the cutting parameters of the rotary ultrasonic machining process

THE CAUSES OF THE DAMAGE TO THE BEARING ROPE – THE FAILUREANALYSIS

In our laboratory we quite often experience problems with the operation of steel ropes. There is a range of causes related with lifetime problems of ropes. These problems are related with poor quality of input material used for wire production, mixing of different wire strengths in the rope construction, improper roping of the rope into the hoist system, improper rope operation, improper rope design for a particular type of operation as well as unfair practices of vendors. The subject of the article is the analysis of the rope showing the combination of a large number of the above factors leading to the damage of the rope. During the operation of the cargo cableway, the hauling ropes were damaged in a very short time. The Z wires from the surface layer of the rope started to release from the rope. Subsequently the wires were unwinding from the layer, they were creating visible protuberant waves, they were braking and dropping out from the rope. The hauling rope had to be replaced. Than the samples were taken from the rope in order to find out the cause of the rope damage. Mechanical, metallographic and fractographic measurements were performed on the rope. The metallographic and fractographic measurements revealed the material defects of the wires of the rope caused during manufacturing of the Z wires from the surface layer of the hauling rope. The mechanical tests revealed differences in the tensile strength grade the operator required compering to the tensile strength grade the vendor declared. The above mentioned problems unambiguously show that it is appropriate to introduce a mechanical control of the rope properties in advance to its deployment. Checks must be performed by an independent testing laboratory. This procedure overprices inputs needed for the rope replacement. On the other hand it can reduce the costs when a poor quality rope is deployed. Some of our customers have already adopted this approach. It helped to the increase in the safety of the operation of the mechanisms and it eliminated the problems with exchange and climes on bad quality ropes

Simulation of the contact wires in ropes and its influence on the durability of the steel wire ropes

Jedným z dôležitých prvkov používaných v doprave sú laná. Patria medzi časti dopravných systémov, ktoré sú vysoko efektívne a zároveň patria aj k najstarším dopravným častiam používaných ľudstvom. Pri premiestňovaní bremien boli ľuďmi najskôr používané textilné laná alebo laná vyrobené z medených drôtov, od 19. storočia sú používané laná vyrobené z oceľových drôtov. Najväčšie uplatnenie lán je v baníctve pri ťažbe rúd a uhlia, ďalšími oblasťami uplatnenia sú zvislá alebo vodorovná doprava osôb a bremien pomocou žeriavov, výťahov, vlekov a lanoviek. V mnohých prípadoch sú laná nasadené v extrémne namáhaných systémoch z pohľadu zaťaženia lana alebo z pohľadu prostredia ako sú tepelné prevádzky, banské korozívne prostredie apod.. V blízkosti lán sa vždy pohybujú ľudia, buď sú lanom dopravovaní alebo pracujú pod bremenami zavesenými na lanách. Z uvedených dôvodov je lano z pohľadu bezpečnosti radené medzi určené výrobky, preto je potrebné pred uvedením lana do prevádzky alebo na trh vykonať skúšky lana predpísané normami a vykonať posúdenie zhody a certifikáciu lana. Napriek správne vykonaným skúškam na základe, ktorých lano bolo certifikované nemusí predmetné lano v prevádzke dosiahnuť požadovanú životnosť. Veľký vplyv na životnosť lana v prevádzke má jeho interakcia so zariadením, na ktorom je lano nasadené, spôsob zaťaženia lana a starostlivosť o lano počas jeho prevádzky. Okrem tohto pôsobenia na životnosť lana vplýva aj jeho správna konštrukcia, na ktorú je v tomto príspevku poukázané. Správnosť konštrukcie je posudzovaná nielen z pohľadu na pevnostné a deformačné vlastnosti drôtov, z ktorých je lano vyrobené, ale aj z pohľadu ich zabudovania do konštrukcie lana. Veľmi dôležitým prvkom pre životnosť oceľového lana, ktorý vie výrobca najviac ovplyvniť, sú správne zvolené priemery drôtov a uhly vinutí drôtov pre lano s presne určenými prevádzkovými podmienkami.Ropes rank among the most important components used for transportation. They belong to components of transport systems which are highly effective and at the same time they are the oldest transport components used by mankind. At first textile or copper wire ropes were used by people for transfer of burdens, while steel ropes have been used since nineteenth century. Mining industry is the biggest area of their application mainly for hoisting of are or coal, additional areas of application are vertical or horizontal transportation of mining personnel and burdens by means of cranes, hoists, rope haulage equipment and aerial ropeways. In many cases the ropes are installed in extremely loaded systems in view of rope loading magnitude or of environmental load in high temperature or corrosive environment mine workings etc. Workers are always moving in vicinity of ropes, either when being transported by rope haulage or when they work below burdens suspended on rope. For the above-mentioned reasons the rope is classified in view of safety into specified products, therefore it is necessary prior to putting of rope into operation or bringing it to market to perform testing of rope prescribed by standards and to assess its conformity and certification. However, in spite of correctly performed tests on the basis of which a rope has been certified, the rope might not reach required service life. A big influence on service life of rope has its interaction with the equipment for which it is applied, the way in which a load acts on rope as well as the maintenance of rope during its operation. In addition to these effects the service life of rope is affected by proper rope design as it is mentioned in final part of the paper. Adequacy of rope design is assessed not only from the point of view of strength and deformation characteristics of wires of which the rope is made, but also from the point of view of the way in which the wires are assembled within frame of rope design. As the most important element for service life of steel rope which can be in a maximum extent affected by rope manufacturer the properly designed wire diameters and wire coiling angles can be considered which are adapted to exactly defined rope service conditions

The kinematic approach to edge-chipping in rotary ultrasonic machining of Al

Rotary ultrasonic machining (RUM) is useful in the machining of difficult-to-cut materials such as Al2O3. However, the edge-chipping occurs in the machined surface because of the brittleness of ceramics.The origin of edge-chipping is clear in general and several methods to its reduction have been published, briefly described in the article. The article brings new, kinematics based view on the edge-chippingorigin and a method of its reduction. Theoretical equations were deduced based on the grit´s trajectory characterized by machining variables of the processes. The equations have been employed in a full factorial experiment and experimental results fit the theoretical assumption satisfyingly. The edge–chipping was reduced by supposed method significantly