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Environmental and Social Assessment of SHPP Ilovac - Expertise
No full textM103 - The expertise is done for Deloitte Consulting co. The investor was EIB (European Investment Bank)
Environmental and Social Assessment of SHPP Komalj - Expertise
No full textM103 - The expertise is done for Deloitte Consulting co. The investor was EIB (European Investment Bank)
Expertise on Environmental and Social Assessment of 12 SHPPs in Western Balkans - Final report
No full textM103 - The expertise is done for Deloitte Consulting co. The investor was EIB (European Investment Bank)
Environmental and Social Assessment of SHPP Brza voda 2 - Expertise
No full textM103 - The expertise is done for Deloitte Consulting co. The investor was EIB (European Investment Bank)
Environmental and Social Assessment of SHPP Tearce Bistrica 2 – Expertise
No full textM103 - The expertise is done for Deloitte Consulting co. The investor was EIB (European Investment Bank)
Hydrogen production by thermal cracking of natural gas - test facility
No full textHydrogen is an energy carrier which makes a decisive contribution for future energy transition. Over 90% of H2 is produced currently from primary fossil fuels with high CO2 emissions. Methane cracking is intensively developing, as the storage or using of solid carbon is easier and more attractive than carbon capture and storage. The process without catalysts is simpler, but requires higher temperatures. Main objective of the test was to show the viability for industrial applications. The test facility consists of two columns (for reversible operation) filled with pebble-bed and a connecting horizontal part. The cracking process takes place at the highest temperature zone, which is the upper pebble-bed and the connecting pipe. The required reaction energy is supplied by adding oxygen to burn small amount of H2. Sensible heat of product gas is stored in the pebble-bed and cold gas goes out. The product gas is further cooled and the condensate flows in a drain vessel. The capacity of the facility was 2-4 m3STP per hour of CH4, with corresponding residence time between 0.5-2 seconds. To compare the quality of those results, the H2 yield was evaluated. The highest yields have been achieved at temperature above 1500°C, with a maximum value of 94.9%, what is considerably better than results achieved in other test facilities for cracking using catalysts (yield 78% at 1175°C). The comparison shows important advantages of high temperature processes without catalyst. The cracking process at 1500°C is a simpler and more effective way to reach industrialization of that technology
Travel time model for multiple-deep shuttle-based storage and retrieval systems
No full textThe paper presents an analytical model for travel time evaluation in double-deep, triple-deep, quadruple-deep and fivefold-deep tier-captive shuttle-based storage and retrieval system (SBS/RS). Under the assumption of the deepest location rule for the storage process and the nearest neighbour rule for the retrieval process, the expressions for single-command and dual-command cycle times of the shuttle vehicle and elevator are developed, from which the SBS/RS performance can be estimated. The model based on the probability theory enables the evaluation of all individual times that make up the cycle times and assessment of the average number of totes relocated during a retrieval process. Special attention is devoted to the modelling of the relocation of totes which block access to the requested tote during the retrieval process. The validity of the analytical model is examined via the developed simulation model. The given case study shows that the proposed analytical travel time model results match the results of the simulation model. The presented modelling strategy could be applied to bigger system racking depths following the same modelling logic
Failure analysis of welded joint with multiple defects by extended Finite Element Method and Engineering Critical Analysis
No full textFailure analysis of welded joint with multiple defects was performed taking into account the effect of all defects, not just a dominant one. Four cases of multiple defects in welded joint under the uniaxial tensile loading were investigated using extended Finite Element Method. Two-dimensional Finite Element Models were made according to the tensile specimens with initial crack located in a critical area of welded joint. For each multiple defects case, numerical simulation was performed with three initial crack depth. Engineering Critical Analysis was made using Failure Assessment Diagrams for each defect that was determined as critical for its welded joint case. Numerical simulation showed that the geometry of the most prominent one from a point of view of structural integrity. It was concluded that the vertical misalignment in combination with a secondary defect, had the most adverse effect which can lead to failure of welded structure
Compressive and flexural mechanical responses of components obtained through mSLA vat photopolymerization technology
No full textIn recent years, Additive Manufacturing (AM) has become an increasingly popular method in industrial
applications for fabricating components with complex geometries, offering several benefits over traditional
(subtractive) manufacturing methods. Among all available AM technologies, ‘‘vat photopolymerization’’ is still
a reliable approach for manufacturing high-resolution components at relatively small costs. This particular
AM technology is based on the photopolymerization process where 3D objects are created by light-induced
solidification and it has been broadly developed and used in the past decades. Depending on the employed
light source there are three different subtypes of this technology, namely: SLA, DLP, and mSLA. Among all
three listed, the Masked Stereolithography Apparatus (mSLA) technology has emerged as a promising approach
due to the much simpler AM machine construction compared to the other two. However, the mechanical
properties of mSLA components have not been studied extensively, hence there is a lack of knowledge of
how AM process parameters and post-processing treatments affect the final mechanical properties of mSLA
components. This work presents an experimental investigation of the compressive and flexural mechanical
responses of components produced through this relatively new AM technology. A series of static and cyclic
tests were conducted with varying layer thickness and post-curing times. It is demonstrated that a thorough
optimization of the mentioned variables is required to obtain parts with the desired mechanical properties
Integrated Process Planning and Scheduling of Production Systems Based on Mountain Gazelle Optimizer
Get PDFThe mass customization paradigm, in conjunction with high market demands, puts a
significant burden on contemporary production systems to output a larger quantity of
diversified parts. Consequently, production systems need to achieve even higher flexibility
levels through physical and functional reconfigurability. One way of achieving these high levels
of flexibility is by utilizing optimization of both scheduling and process planning. In this paper,
the authors propose to solve an NP-hard integrated process planning and scheduling
optimization problem with transportation constraints regarding one mobile robot. The proposed
production environment includes four types of flexibilities (process, sequence, machine, and
tool) that can be leveraged to optimize the entire manufacturing schedule. Three metaheuristic
optimization algorithms are compared on the nine-problem benchmark based on the makespan
metric. The proposed Mountain Gazelle Optimizer (MGO) is compared to the whale
optimization algorithm and particle swarm optimization algorithm. The experimental results
show that MGO achieves most best results, while it is highly comparable on the average best
results