Universal Dependencies (UD) je mednarodno usklajena označevalna shema za medjezikovno primerljivo oblikoslovno in skladenjsko označevanje besedil po načelih odvisnostne slovnice, ki je bila ob več ...kot 130 drugih svetovnih jezikih uspešno uporabljena tudi za označevanje besedil v slovenščini. V prispevku predstavimo rezultate nedavnih aktivnosti v povezavi s shemo UD znotraj projekta Razvoj slovenščine v digitalnem okolju, v okviru katerega smo obstoječo infrastrukturo nadgradili s prenovo in podrobno dokumentacijo označevalnih smernic UD za slovenščino, razširitvijo drevesnice SSJ-UD za pisno slovenščino z novimi povedmi iz korpusov ssj500k in ELEXIS-WSD, izdelavo testne množice iz besedil korpusa SentiCoref za spletni portal SloBENCH ter polavtomatsko pretvorbo oblikoslovnih oznak referenčnih učnih korpusov SUK in Janes-Tag. Na razširjeni drevesnici SSJ-UD je bil naučen tudi novi napovedni model za skladenjsko razčlenjevanje v orodju CLASSLA-Stanza, ki ga v prispevku v podporo nadaljnjim jezikoslovnim aplikacijam podrobneje ovrednotimo z vidika splošne natančnosti razčlenjevanja in najpogostejših tipov napak.
The effect of high-intensity ultrasonic treatment combined with bottom cooling treatment on the refinement of Al-5Cu alloy ingots was studied. The results show that ultrasonic treatment combined with ...forced cooling at the bottom of ingots has a good refining effect, and the best refining effect can be obtained at 2000 W and after 120 s. The cross-section of an ingot exhibits almost 100 % refined equiaxed grains and no porosity. The method of combining ultrasonic treatment and forced cooling at the bottom of ingots not only influences the ingot refinement, but also decreases the porosity of the ingots with an increase in the ultrasonic duration. The ultrasonic degassing effect is due to the release of hydrogen in biofilms, which expand and grow gradually; finally, they burst on the melt surface, achieving the effect of degassing.
The aim of our study was to investigate how different thermal conditions affect the transformation temperatures of two hot-work steels with high thermal conductivity. We focused on two conditions: ...soft annealing, and quenching and tempering. Soft annealing results in a ferritic steel matrix with spherical carbides, while quenching and tempering result in a fully hardened and tempered martensitic matrix with secondary and tempering carbides. We analysed samples using a simultaneous thermal analysis (STA) and differential scanning calorimetry (DSC) to determine the transformation temperatures. Controlled heating and cooling allowed us to observe the energy changes associated with the phase transformations. The equilibrium temperatures were calculated using the CALPHAD method. Our study investigated the influence of thermal conditions on different transformation temperatures, including solidus/liquidus temperatures, austenite solid transformation temperatures (A1 and A3), austenite solidification temperatures and bainite and/or martensite transformation temperatures. A DSC analysis was used to quantitatively measure the transformation temperatures and energy absorption during the endothermic processes (austenite solid transformation and melting) and to study the energy release during the exothermic processes (solidification and transformation). The results showed that soft annealing reduced the solidification interval and the solidus temperature, while energy absorption increased during melting. Conversely, quenching and tempering reduced the austenite solid transformation temperatures and energy release during solidification, including δ-ferrite solidification.
Electrochemical micromachining (ECMM) is a well know for manufacturing hard-to-cut materials, e.g., nickel-based alloys, titanium alloys and metal-matrix composites. For this reason it finds ...application in aerospace, automobile and biomedical industries. In this research Hastelloy C-276 is used as a workpiece and stainless-steel electrode coated with polytetrafluoroethylene (PTFE) to avoid stray current. The effect of process parameters such as voltage, duty cycle and electrolyte concentration on the machining speed and the surface-corrosion factor were studied. The range of 9–11 V has an impact on the machining speed. The electrolyte concentration range of 25–35 g/L shows a linear increase in the machining speed and the surface-corrosion factor is found to be highest at 1.1449 for an electrolyte concentration of 15g/L. The surface roughness depth profile depicts the values of Rz, Rt, Ra are 16.3 µm, 99.1 µm and 1.90 µm, and 15.4 µm, 50.6 µm and 1.49 µm, respectively.
Electrical discharge machining is an electro-thermal technique where the recast layer on a machined surface and the heat-affected zone (HAZ) immediately below the machined surface are prevalent. As a ...result, assessing the white layer (recast layer) in EDM is a critical task. In this research, a response-surface methodology-based comprehensive mathematical model was developed to predict the white-layer thickness (WLT) on electrical discharge machine-processed AISI A2 steel. Also, the effects of various process parameters on the WLT were presented, the optimum combination of process variables was assessed and the minimum WLT was achieved by combining low-peak current and pulse-on time with high pulse-off time.
This research focuses on enhancing water quality for concrete construction by utilizing treated wastewater from wetlands. The study employs a dual-stage treatment process involving charcoal and ...aggregate layers for primary treatment, followed by water hyacinths for secondary treatment. Investigating water hyacinths’ ability to absorb nutrients and contaminants from wastewater is a unique aspect of the study, offering a potential solution for soil and water remediation. Water hyacinths, especially stems and leaves, act as natural filters, effectively indicating heavy-metal pollution in tropical regions. The primary goal is heavy-metal removal from wastewater, allowing treated-water use in concrete production at varying proportions (20 %, 40 %, 60 %, 80 %, and 100 %). Silica fume at 15 % concentration is incorporated to enhance the concrete’s durability. Concrete specimens undergo thorough preparation and mechanical property evaluations, compared to conventional M20-grade concrete. The results reveal improvements in mechanical properties, particularly with 80 % treated wastewater in the mix. The dual-stage treatment process removes heavy metals, and the inclusion of silica fume enhances the concrete’s durability and resistance.
Electrical discharge machining (EDM) is much preferred in modern precision-manufacturing industries owing to its ability to machine any metal regardless of its hardness. However, its constraint is ...that the selected metal should be an electrically conductive material. For the present investigation, an Inconel 718 alloy was selected for EDM, using a TiB2-Cu electrode made with powder metallurgy. Input factors, namely, the pulse current (Ip), pulse-on time (Ton) and gap voltage (Gv) were selected and their output responses were the surface roughness (SR) and material-removal rate (MRR). For the response surface, the Box Behnken technique was preferred when designing the experiments (DoE). An ANOVA test was performed to understand the influence of the selected input factors on the SR and MRR. The RSM integrated with a grey relational analysis (GRA) revealed that the optimal input parameters for better machining characteristics were: Ip = 10 A, Ton = 40 µs and Gv = 50 V. Besides, the results also showed that the pulse current more significantly influenced the output responses than the other parameters. Moreover, an increase in the gap voltage caused surface irregularities on the machined surface. Surface morphology of the machined surfaces was analysed through SEM and EDAX. Moreover, a certain amount of tool-material transfer was noted with the EDAX analysis.
The high-temperature oxidation behaviour of chromium-molybdenum-vanadium alloyed hot-work tool steel was investigated. High-temperature oxidation was investigated in two conditions: soft annealed, ...and quenched and tempered. The samples were oxidised in a chamber furnace and in an instrument for simultaneous thermal analysis, for 100 h in the temperature range between 400 °C and 700 °C. Metallographic analysis (optical and scanning electron microscopy) was performed to study the microstructural changes in the steel and the oxide layer. Oxidation kinetics were analysed by thermogravimetric analysis, and equations were derived from the results. The kinetics can be described by three mathematical functions, namely: exponential, parabolic and cubic. However, which function best describes the kinetics depends on the oxidation temperature and the thermal condition of the steel. Quenched and tempered samples were shown to oxidise less, resulting in a slower oxidation rate.
Izhodišča: Sagitalna orientacija medenice je pomemben element sagitalnega ravnovesja, kvantitativno pa jo lahko opredelimo na podlagi merjenja geometrijskih parametrov medenice, in sicer naklona ...križnične končne ploskve (SS), nagiba medenice (PT) in naklona medenice (PI). V tem članku predstavljamo rezultate popolnoma samodejnega računalniško podprtega merjenja parametrov sagitalne orientacije medenice na podlagi rentgenskih slik ter testiramo hipotezo, da ni statistično pomembnih razlik med dobljenimi in referenčnimi ročnimi meritvami.Metode: Samodejno računalniško podprto merjenje parametrov sagitalne orientacije medenice temelji na najnovejših tehnologijah iz področja obdelave in analize medicinskih slik, in sicer na konvolucijskih nevronskih mrežah kot posebni obliki tehnik globokega učenja. Na podlagi teh tehnologij se v sagitalni rentgenski sliki medenice najprej samodejno določijo območja zanimanja (križnična končna ploskev ter kolčni sklepni glavi), nato pa se znotraj teh območij določijo značilne točke, in sicer anteriorni rob, središče in posteriorni rob križnične končne ploskve, na katere se kasneje prilega premica, ter središči obeh kolčnih sklepnih glav s pripadajočo sredinsko točko, ki predstavlja os medenice. Na podlagi osi medenice ter premice vzdolž križnične končne ploskve in njenega središča lahko končno izračunamo SS, PT in PI.Rezultati: Merjenje je bilo retrospektivno opravljeno na sagitalnih rentgenskih slikah medenice 38 oseb (15 moških in 23 žensk; povprečna starost 71,1 let). Statistična analiza referenčnih ročnih in samodejnih računalniško podprtih meritev parametrov sagitalne orientacije medenice je pokazala na relativno dobro ujemanje in majhno odstopanje. Za SS, PT in PI je bila povprečna absolutna razlika (standardni odklon) namreč 5,2º (3,8º), 2,2º (2,0º) in 5,1º (4,4º), korelacijski koeficient 0,73, 0,94 in 0,82 (p < 10-6), ničelna hipoteza pa je bila na podlagi parnega t-testa vedno potrjena (p > 0,05).Zaključek: Rezultati so pokazali, da ni statistično pomembnih razlik med referenčnimi ročnimi ter samodejnimi računalniško podprtimi meritvami parametrov sagitalne orientacije medenice. Poleg tega so odstopanja od referenčnih ročnih meritev znotraj ponovljivosti in zanesljivosti samega ročnega določanja teh parametrov, zato je z samodejnim računalniško podprtim merjenjem mogoče natančno določiti parametre sagitalne orientacije medenice. Vsekakor pa pregleda in potrjevanja tako izmerjenih vrednosti ne smemo popolnoma opustiti, saj so lahko odstopanja v določenih primerih precej velika, predvsem zaradi naravne biološke variabilnosti človeške anatomije ter lastnosti rentgenskega slikanja.
Due to the creation of a significant temperature gradient, electrical discharge machining (EDM) causes localized, high thermal stress in a tiny heat-affected zone. This thermally developed stress ...leads to fatigue life and strength decrement, micro-cracks and probably catastrophic failure. On AISI A2 steel, a mathematical model based on finite-element analysis was constructed to estimate the temperature field and associated thermal stresses. In this present research work, the heat-flux distribution in a single spark during EDM is considered to be Gaussian distributed. The model first calculates the temperature distribution, and then uses this temperature field to determine the thermal stresses. It was observed that the stresses surpass the workpiece material’s yield strength near the center of the spark and this gradually weakens as the distance from the center increases.
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