bluuebunny/crossref_metadata_2025 huggingface dataset:
Bridging the Gap between 3D Navigation and Semantic Search. The INCEPTION platform
Authors: Iadanza Ernesto , Maietti Federica , Medici Marco , Ferrari Federico , Turillazzi Beatrice , Di Giulio Roberto
Published: November 2020

The paper presents the main outcomes and future development of the INCEPTION project, “Inclusive Cultural Heritage in Europe through 3D semantic modelling”, funded by the European Commission under the Horizon 2020 Work Programme Europe in a changing world – inclusive, innovative and reflective Societies (Call Reflective-7-2014, Advanced 3D modelling for accessing and understanding European cultural assets) and completed in May 2019. In particular, the key-targeted project achievement will be presented: a specific cloud-based platform conceived to accomplish the main objectives of accessing, understanding and strengthening European Cultural Heritage by means of enriched 3D models. The need for digital data interpretation, in addition to documentation, guided the overall process of the cross-disciplinary work methodology, based on new methods and tools for 3D surveying and H-BIM modelling, new approaches and methodologies for Cultural Heritage 3D data inclusive access and exploitation by means of the Platform.
An interdisciplinary study of biodeterioration of the external marbles of Santa Maria del Fiore Cathedral, Florence (IT)
Authors: Santo AP , Agostini B , Checcucci A , Pecchioni E , Perito B
Published: November 2020

Stone-built cultural heritage exposed to urban environment represents a habitat where heterogeneous microbial communities can grow causing structural and aesthetical modifications and significant biodeterioration phenomena, the most common being colored patinas and crusts. An in-depth investigation of microbial community composition and its metabolic potential is essential to take the appropriate measures to control its growth. Conventional biocides remain the most used practical solution to control microbial growth, nevertheless, they may be dangerous for human health and the environment. The Cathedral of Santa Maria del Fiore (SMFC) is a major architectural masterpiece in Florence (IT), and its conservation is a main issue of worldwide concern. The whole edifice is externally covered with polychrome stone panels consisting of white marbles, serpentinites and red limestones. Here we report a multidisciplinary investigation on the state of conservation of SMFC white marbles which show, in some extended areas, patinas and discoloration due to microbiological growth. This work provides new details on the deterioration of SMFC marble and, for the first time, on the microbial community involved. This preliminary knowledge will be used for planning field tests with innovative low environmental impact biocides, such as essential oils, to contrast biodeterioration.
Using atmospheric pressure plasma as a tool in the cleaning of icon paintings
Authors: Stefanova M , Kamenarov Z
Published: November 2020

The removal of aged and unwanted layers from the surface of a work of art is one of the most significant operations in the conservation process, but it is also complex, risky and hard to control. The plasma cleaning procedure has been tested successfully on different materials representative in the field of cultural heritage and has proven its many advantages compared to mechanical and chemical cleaning techniques. Despite the success of atmospheric pressure plasma treatment in the cleaning of easel paintings (i.e. the removal of thin films of varnishes, resins, re-paintings or deposits) it is still a new research area. This paper presents the use of atmospheric pressure plasma (APP) for the removal of aged varnish, wax and soot from the pictorial layer of an icon painting. The case study is conducted on a 19th century wooden alms box with a painting of Saint John the Baptist and compares the influence of two different concentrations of the used gas mixture. Better cleaning result is obtained using APP Ar/O2 0.2%. The successful removal of the aged oil-resin varnish, wax and soot deposits, is assured without any mechanical and chemical modification of the underlying pictorial layer. The surface action of the plasma treatment is an important advantage compared to the use of aggressive solvents, mechanical shock, or local heating which is typical of traditional cleaning procedures. Furthermore, the non-contact treatment with plasma does not require preliminary consolidation of the treated surface, and avoids additional drawbacks. This method is a rare opportunity, especially in cases when the surface is protected by an organic material and could be neither safely, nor acceptably cleaned by the existing conventional techniques. Therefore, the use of plasma is proposed for the cleaning of icons as an alternative or complementary treatment to the existing techniques.
Learning from Objects: the use of advanced numerical methods to exploit a complete set of information from experimental data, for the Mona Lisa’s Digital-Twin
Authors: Lorenzo RIPARBELLI , Fabrice BRÉMAND , Paolo DIONISI-VICI , Jean-Christophe DUPRE , Giacomo GOLI , Franck HESSER , Delphine JULLIEN , Paola MAZZANTI , Marco TOGNI , Elisabeth RAVAUD , Luca UZIELLI , Joseph GRIL
Published: November 2020

The approach to wooden artefacts of historical importance, and panel paintings in particular, is a task that requires a multidisciplinary approach based on experimental observation of the artwork and advanced techniques to make these data actually useful for the knowledge and preservation of the object. This study illustrates how a series of scientific observations and instrumental analyses can be used to construct a numerical simulation that allows a deeper understanding of the physical structure and behaviour of the object itself, namely to construct a hygro-mechanical predictive model (a “Digital-Twin”) of Leonardo da Vinci’s Mona Lisa panel. Based on specific request from the Louvre Museum, a group of experts with different and complementary skills cooperated and are still cooperating to construct a complete set of experimental observation and non-invasive tests; so, the integration of the collected data made the construction of the panel’s Digital-Twin possible. This paper also specifically examines how the Digital-Twin can be used to compare two framing conditions of the panel; although the two experimental configurations are not inherently comparable, the comparison is made possible by the introduction of a technique of projection of the fields obtained as results of the two analyses, named the Projected Model Comparison (PMC), which has been developed specifically for this research.
Functional mortars for conservation of cultural heritage structures
Authors: Vucetic S , Miljevic B , Sovljanski O , van der Bergh J M , Markov S , Hirsenberger H , Tzoutzouli Malesevic M , Ranogajec J
Published: November 2020

Mortar aging and deterioration are serious problem for architectural heritage conservation. The solution might be sought in advanced functional materials which could provide repair and lasting surface protection from atmospheric pollution and microbiological corrosion. In recent years, extensive studies have been conducted on the use of bacteria with biocalcification potential for self-healing effect in cements materials, but only a few publications deal with self-healing capacity of historical lime-based mortars.

The main focus of our research was development of new bio-activated self-healing system and its application in laboratory conditions. The objects of the work were historical mortar samples from medieval Bač Fortress in Serbia and laboratory prepared and aged mortar models. Aiming to achieve high compatibility, laboratory models were prepared based on our previous results of historical mortars characterization. The bio-activated self-healing agent was made as two-component liquid system using bacterial cells of Sporosarcina pasteurii DSM 33 and nutrients. The components of the models were hydraulic lime, milled limestone, river sand, and crashed brick as aggregates, and water. Comparative characterization of historic mortars and aged models was performed by mechanical and colorimetric testing as well as examination of mutual interaction and cohesion between old and new material.

The next step was efficiency evaluation of the external bacteria-based repair healing method in/on the laboratory samples. The detailed study of the cracks of the historical samples and the prepared models, and the bacterial suspension diffusion assessment were done by comparison of the results obtained by different complementary imaging techniques (optical and scanning electron microscopy). The experiments were performed on both samples of old and new materials treated with and without bio-activated self-healing agent.

The obtained results are promising and support the development of the external bio-activated self-healing method. This solution represents functional system which could allow historical mortars and modern structures to heal themselves in the long-term, preserving their functional and aesthetic properties.
The colour of architecture. Physical-chemical analysis of polychromy on stone in a 16th century gothic Portal at the Cathedral of Santo Domingo
Authors: Prieto Vicioso Esteban , Flores Sasso Virginia , Ruiz Valero Letzai , García de Miguel José M.
Published: November 2020

Colour always played a role in the human evolutionary process and has been used as a way of expression. But the time, the lack of maintenance and abandonment, the lack of studies related to the presence of polychromy in architecture and the nineteenth-century idea of eliminating building plasters to expose stone and brick have caused many to ignore and forgotten the presence of colour in historical buildings. In most cases disappear leaving only traces of colours. For this reason the aim of this research is study the polychromy on stone of a 16th century gothic Portal in the Cathedral of Santo Domingo. Analyses were performed using non-destructive techniques as Transmission Polarized Light Microscopy (PLM), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy / Energy Dispersive Elemental Analysis X-Ray (SEM/EDX), Gas Chromatography (GC) and X-Ray Diffraction (XRD). To determinate the colour was used a CIELAB System and Munsell Colour System. In conclusion patinas yellow, ochre, red, green and blue colours; and pigmented successive layers of plaster and lime was found. Remains of these layers of polychromies are also spread throughout many areas of the Cathedral.
Integrative Applications of Microbial Biotechnology to Cultural Heritages Conservation and Promotion
Authors: Marvasi M
Published: November 2020

In the last decades a number of microbial biotechnology applications have been put into practice for the conservation of cultural heritages. Soft approaches to the bio-cleaning and bio-restoration of cultural heritage are in constant demand in addition to deep understanding of microbial bio-deterioration. Recent research has addressed this issue by different perspectives, highlighting how separate disciplines such biology, microbiology, biochemistry are taking the problem from each own view. However, in the last years the integration of these disciplines have increased the range of tools for conservation and promotion. This commentary shows recent examples of concrete exploitation of the integration of these applications in the field of cultural heritage. Current application of omics techniques and their use for restorers and conservators still rest on the assumption that this omics revolution will be – at some point, important. This commentary includes combination of evidences showing we are a step further: having used a combination of key papers in support, this perspective shows how such applications are already bringing important tools for conservators. Taken together, these sources of evidence are provocative and at the same time similarly stimulating and convincing.
B-IMPACT project: eco-friendly and non-hazardous coatings for the protection of outdoor bronzes
Authors: Masi G. , Aufray M , Balbo A , Bernardi E , Bignozzi MC , Chiavari C , Esvan J , Gartner N , Grassi V , Josse C , Kosec T , Martini C , Monticelli C , Škrlep L , Sperotto W , Švara Fabjan E , Tedesco E , Zanotto F , Robbiola L
Published: November 2020

Application of protective coatings is the most widely used conservation treatment for outdoor bronzes. Eco-friendly and non-hazardous coatings are currently needed for conservation of outdoor bronze monuments. To fulfil this need, the M-ERA.NET European research project B-IMPACT (Bronze-IMproved non-hazardous PAtina CoaTings) aimed at assessing the protectiveness of innovative coatings for historical and modern bronze monuments exposed outdoors.

In this project, two bronze substrates (historical Cu-Sn-Zn-Pb and modern Cu-Si-Mn alloys) were artificially patinated, by acid rain solution using dropping test and by “liver of sulphur” procedure (K2S aqueous solution) to obtain black patina, respectively. Subsequently, the application of several newly developed protective coatings was carried out and their performance was investigated by preliminary electrochemical tests. In the following steps of the work, the assessment of the best-performing coatings was carried out and their performance was compared to Incralac, one of the most widely used protective coatings in conservation practice. A multi-analytical approach was adopted, considering artificial ageing (carried out in representative conditions, including exposure to rain runoff, stagnant rain and UV radiation) and metal release, as well as visual aspect (so as to include aesthetical impact among the coating selection parameters) and morphological and structural evolution of the coated surfaces due to simulated outdoor exposure. Lastly, also the health impact of selected coatings was assessed by occupational hazard tests. The removability and re-applicability of the best-performing coatings were also assessed. The best alternatives to the conventional Incralac exhibited were: (i) fluoroacrylate blended with methacryloxy-propyl-trimethoxy-silane (FA-MS) applied on patinated Cu-Sn-Zn-Pb bronze and (ii) 3-mercapto-propyl-trimethoxysilane (PropS-SH) applied on patinated Cu-Si-Mn bronze.
The STORM experience (the importance of preparedness in natural disaster facing)
Authors: Boi S , Capua MC , Perossini F
Published: November 2020

STORM project was the best opportunity to cope with the challenge of merging computer and communication technologies with human and cultural oriented practices in conservation and restoration. The result of this powerful synergy between these two approaches (technology and CH needs) in view of mitigating effects on cultural heritage, is expected to enormously increase the mitigation of the damages created by climate change disasters. The main question, coming from the experience gained, is how we can capitalize the acquired expertise in the future. This will probably be done using strategies which could rely on local financial support and the possibility to have advanced regulations provided by local authorities. Communication between different actors will play a major role in the future achievements: the project faced a big challenge in establishing good communication among different competences so to say that now, after a three year project, it should be great to start a new experience counting on the level of friendship and communication achieved during the STORM project. But communication is also the key element of emergency management. The recent event which affected the Notre Dame Cathedral (Paris, 15/04/2019), was a matter of discussion between STORM partners and during those discussion we concluded that probably the proper preparedness was not in place. Preparedness could have dramatically reduced the reaction time and the effectiveness of intervention after a disaster. As a final though we are convinced that new professions could grow from the project experience, starting from cultural heritage experts such as conservators, restorers, archaeologists, architects, art historian involving specific branches of engineering; that could create new job opportunities for all those people provided that they will receive the proper education and practice experience..
Through the Looking Glass. Cultural Heritage Custodians to Populate the Mirrorworld
Authors: Hazan Dr. Susan
Published: November 2020

This contribution is a wake-up call to custodians of cultural heritage to get ready and prepare for the next platform – the 3D and 4D experiences of the nascent Mirrorworld. Built upon the first generations of online experience, the sprawling communication platform of the World Wide Web, and driven by the ubiquitous reach of social networks and online gaming, the Mirrorworld will breach the glass ceiling of 2D experiences to draw us into a fully functioning 3D environment. Public institutions that manage cultural heritage for visitors, such as galleries, libraries, archives and museums (GLAMS), are ideally placed to seed the spatial communications network that will drive the new platform. Despite the formidable challenges to be surmounted, it is up to custodians of cultural heritage to become proactive in building the Mirrorworld rather than to wait for third party actors to advance commercial interests with imitation culture, simulated histories, or made-up stories. As gatekeepers of cultural artefacts, GLAMs have the capability, the experience, and even the responsibility to tell their stories forcefully, accurately and in fully-functioning 4D.
STORM integrated solution: a toolkit of collaborative and decision-making services and tools
Authors: Giunta Gabriele , Gugliandolo Emilia , Li Calsi Giuseppe , Bicchierai Irene , Brancati Francesco
Published: November 2020

The current world is increasingly supported by a knowledge-based economy, where technological, economic, political, social and cultural changes modify the nature of human relationships. The Information and Communication Technologies (ICTs) revolution along with the spread of different and faster channels have become important driver to disseminate knowledge and information. In this changing landscape, knowledge is considered one of the most valuable assets able to generate growth and competitive advantage. Knowledge sharing plays a central role specifically during emergency, allowing the access to and the availability of critical information regarding risks and disasters. Lack of information complicates the efficient management of catastrophes and weakens the decision-making processes. For these reasons, it is fundamental to develop an infrastructure able to manage knowledge and, most specifically, to increase economic and social values fostering knowledge creation and sharing, to use innovation to perform better, to be updated and to enhance sustainability. In such complex situations, the STORM project aims at building a collaborative and dynamic environment allowing the actors to interact with each other and to join their efforts towards highest levels of cooperation and coordinated decision making approaches. Making fast and efficient decisions requires supporting tools allowing a prompt situational picture and critical information sharing based on effective use and coordination of resources, people, and information, where information and knowledge are distributed. In the context of the STORM project, the proposed tools and services enabled by IT technologies enhance collaboration, co-ordination and to support decision making amongst stakeholders, providing, at any moment, a clear situational picture. Existing knowledge (e.g. best practice, guidelines, lessons learned, procedures and processes, etc.) related to natural disaster risks and impacts can help teams of experts in making decisions and sharing new knowledge (e.g. from the situational picture, risk assessment and data analytics) for a prompt and more effective recovery. As a main benefit, the involved actors will be aware about the formulation and selection of risk reduction measures based on available risk information and stakeholders’ needs, speeding up response time where the right people with the relevant skills and disaster events are identified in a more timely manner.
A preliminary approach on point cloud reconstruction of bronze statues through oriented photogrammetry: the “Principe Ellenistico” case
Authors: Bici M. , Gherardini F. , Campana F. , Leali F.
Published: November 2020

Close-Range Photogrammetry is a widespread and efficient technique in the 3D acquisition of artefacts, particularly in fields like Cultural Heritage. Despite this wide usage, also due to a convenient quality/cost ratio, it shows some limitations due to light conditions as well as the artefact surface finishing. In this paper, we would like to report the assessment of a photogrammetry approach to 3D capture metal reflective surfaces, such as bronze, which is a widely used material in ancient statues. To this aim, we propose a photogrammetry workflow based on systematic steps capable of overcome some of the main issues of reflective surfaces. To validate this approach, the developed 3D model is compared to a more accurate model of the same artefact, obtained with a 3D scanner. As a case study, we selected the Principe Ellenistico, an ancient bronze statue conserved in the Museo Nazionale Romano (Rome, Italy), of which a photogrammetric model is firstly developed and then compared to the scanned one.
Condition monitoring of rolling element bearings: benchmarking of data-driven methods
Authors: Iunusova E , Szipka K , Archenti A
Published: November 2020

Condition-based maintenance (CBM) is a maintenance strategy used to gain updated information about equipment condition and is today considered a natural part of the engineering field. The replacement of the traditional scheduled maintenance strategy in favor of CBM has the potential to significantly improve the safety of the system operating in harsh environments of the operation and increase in productivity by prolonging the life of an asset and preventing costly breakdowns. For many years CBM remained the subject of vigorous research and discussions. Increasing the automation level and the number of sensors in industries allowed obtaining and collecting data in large amounts. The current level of computational power allows us to process and analyse this massive amount of data, which has given a new leap in the development of industrial analytics. Rather than in the case of classical knowledge-based modelling tools, data-driven methods propose modelling and forecasting frameworks based on data analysis. Consequently, the transition to the data-driven modelling gave a leap in CBM research and has recently drawn increasing attention, providing new case studies, algorithms, and results. However, technical challenges remain. Despite great flexibility and good forecasting performances, there are several limitations of data-driven algorithms. This paper provides an overview of the data-driven failure algorithms for rolling element bearings monitoring. Bearings have played a pivotal role in industrial machinery to operate with high effciency and safety. They are considered to be one of the most common machine elements of precision rotating machinery. A benchmarking of various predictive and descriptive algorithms was performed. The analysis was carried out on a dataset from the run-to-failure experiments on bearings from NASAs Data Repository. This paper also summarizes the current trends and highlights the limitations with respect to traditional knowledge-based modelling. Special attention is paid to identifying research gaps and promising research directions.
Computational Framework Concerning the Formulation of Maximum Work Principle used in Plasticity, Materials Forming and Tribology as a Consequence of a Variational Optimization Problem Defined From the Constructal Law
Authors: Gavrus Adinel
Published: November 2020

This research work proposes a fundamental application of the Constructal Theory developed by Prof. Adrian BEJAN of Duke University (USA) to prove on a mathematical point of view the “Principle” of Maximum Work, used by the theory of plasticity, material forming and tribology, as a consequence of the global solution defining a constrained variational optimization problem. According to the first and second law of thermodynamics, the principal law of Constructal Theory try to complete them with a quantitative prediction of the natural tendency of any finite size system to evolve towards an optimal space-time configuration minimizing the losses and the entropy generation simultaneously with a required maximum of the global entropy. In this sense, regarding a material plastic deformation characterising the forming processes, among all possible and admissible flow undergoing well-specified boundary conditions and loadings, the real one is the one who minimizes the sum of the dissipated power of volume deformation and surfaces friction. Thus, all the mechanical variables defining the real mechanical state (velocities, stresses, strain and strain rate) are those ones which minimize the total dissipated power. A variational minimization problem under a lot of defined constraints is then obtained. Using the Principle of Virtual Powers it can be shown finally that the “Principle” of Maximum Work, used particularly in metals plasticity, is obtained as a consequence of a minimization problem under constraints based on the Constructal Theory. This generalizes its application to any type of continuous media (metals, polymers, fluid, mushy state) and allows proving an equivalent form for the friction stresses occurring on contact interfaces. The convexity properties of both the plastic and the friction potential together with their normal rule properties can be also proven using the proposed mathematical framework. It is concluded that only the rheological and tribological flow laws associated with a potential become to satisfy the second thermodynamics principle completed with the Constructal Law. Analytical computations concerning plane and cylindrical crushing show the feasibility of the proposed minimization problem formulation to define material flow giving accurate approximate solutions. In order to valid the whole presented theory, comparisons are made using classical analyses based on the upper and lower bound theorems (obtained as consequences of the proposed optimization variational problem), the well-known slices method and a finite element modelling (FEM). A second application concerning the anisotropic formulation of a Coulomb friction law from a quadratic convex tribologic potential will be presented to define contact evolution during rectilinear sliding of a circular pion on a plane laminated thick plate surface along different orientations.
Numerical analysis of hydroforming process control using variable blankholder force
Authors: Paunoiu V , Maier C , Iacob I , Marinescu V
Published: November 2020

Hydroforming was developed to provide a cost effective means to produce relatively small quantities of drawn parts or parts with asymmetrical or irregular contours that are difficult to obtain by conventional stamping. This paper presents a study of hydroforming process with variable blankholder force in order to assure the parts quality. The main idea is to decompose the blankholder function of the elementary zone of the part contour corresponding to the linear and curvilinear zone. For each zone different blankholder force is applied in correlation with the hydrostatic pressure. A numerical analysis using finite element modelisation is performed considering different sets of blankholder forces and hydrostatic pressures, as process parameters. An optimum is determined in order to avoid parts defects (thickness reduction, wrinkles, fracture) for such types of parts.
Influence of some process input factors on the main dimensions of the grooves generated during the ball vibroburnishing
Authors: Nagit G , Dodun O , Slatineanu L , Ripanu M , Mihalache A , Hrituc A
Published: November 2020

The ball vibroburnishing is a processing method based on the plastic deformation of the workpiece surface layer, as a result of a vibration movement achieved by the ball pressed with a known force on the workpiece surface. The surface obtained by ball vibroburnishing includes grooves with different directions and partially overlapped. To know better the influence exerted by the ball vibroburnishing conditions on the main dimensional characteristics of the grooves, an experimental research was designed and materialized. As the process input factors, the diameter of the ball, the force, and the workpiece rotation speed were used. The depth and width of the groves generated by the moving balls on the workpiece surface layer were measured. By mathematical processing of the experimental results, empirical mathematical models were determined. These models highlight the intensity of the influence exerted by the ball vibroburnishing process input factors on the main dimensions of the grooves.
Experimental investigation and regression modelling to improve machinability in CNC turning of CALMAX® tool steel rods
Authors: Vaxevanidis N M , Fountas N A , Papantoniou I , Manolakos D E
Published: November 2020

This paper studies the effect of cutting conditions (spindle speed - rpm; feed rate - mm/rev and depth of cut - mm) on main cutting force and surface roughness during CNC turning of the commercial tool steel CALMAX® by Uddeholm (Sweden). Experiments have been designed using the Central composite design (CCD) approach. The experimental design involved twenty base runs with eight cube points, four center points in the cube, six axial points and two center points in axial direction. Statistical analysis to examine the effect of cutting conditions on the responses of main cutting force and surface roughness included ANOVA under the scope of generating a full quadratic model for predicting the responses. Finally, a feed-forward back-propagation neural network was applied to predict the responses of cutting force and surface roughness. It was found that regression models corresponding to the responses as well as the neural network developed can efficiently explain much of the variation in terms of main cutting force and surface roughness and thereby they may be implemented to practical applications either for predicting actual machinability parameter values or for setting up objective functions to be evaluated by intelligent algorithms for process optimization.
Influence of aluminium alloys relative positioning on dissimilar friction stir lap welds properties
Authors: Sabari S , Galvão I , Leitão C , Rodrigues D M
Published: November 2020

Very thin sheets of heat treatable (AA6082-T6) and non-heat treatable (AA5754-H22) aluminium alloys were used to produce dissimilar joints by friction stir lap welding. Joint strength and mechanical heterogeneity were assessed by performing lap tensile-shear and microhardness testing, respectively. Optical microscopy was used to analyse the weld morphology. Welding machine outputs, such as torque and axial force, were analysed in order to capture differences in the alloys strength during dissimilar welding. From the process outputs analysis, it was concluded that higher Z-Forces were necessary while positioning the AA5754 alloy at the top of lap configuration, indicating that this alloy offered higher resistance to the tool stirring than the AA6082 alloy. These results were associated with the flow softening of the AA6082 alloy during welding, which was explained using finite element analysis to illustrate the welding thermal cycles and the precipitation behaviour of this alloy. The lap welds defect formation was also related to the base materials plastic properties at high temperatures, which was inferred from process outputs data analysis. Based on the results it was shown that the lap welds defects might be supressed by a proper positioning the dissimilar base materials in the lap joint.
Using open source software CNC controllers and modular multi-axis mechanical structure as integrated teaching environment for CAD/CAM/CAE training
Authors: Breaz R E , Racz S G , Girjob C E , Tera M , Biriş C
Published: November 2020

Open source CNC controllers, such as Linux CNC are used more and more because they are open source projects and consequently are available for free. Moreover, these controllers are highly customizable, and their capabilities are close to the commercial solutions. The paper presents how using Linux CNC controller and a modular structure of a multi-axis CNC machine-tools, built by a commercial company, an integrated environment for training students in implementing CAM techniques was developed. Aside the CNC controller and the machine-tool, a CAM software package was used for programming complex machining operations. The kinematic model of the machine was built, for the user to be able to simulate, in a realistic way the multi-axes machining operations. The integrated teaching environment enable the users to be trained in CNC programming for three to five axes machining operations. Advanced programming strategies, such as tool center point management (TCPM) can also be tested.
Tribological Performance of Graphene and Graphene Oxide Films as Solid Lubricant Layers on Tool Steel Surfaces
Authors: Píška M , Sedlácek J , Foksová V , Sliwková P
Published: November 2020

Some high productive processes induce a use of effective cooling and lubricating for forming and cutting tools today. Apart of various fluids, foams, oils and emulsions with EP (extreme pressures) additives some very effective means based on graphene or graphene oxide show excellent performance in their solid phase. In this study, a very effective way to enhance the tribological performance of graphene layers on tool steel surfaces is studied. The solid lubricants based on graphene and graphene oxide flakes showed a very good thermal stability, low coefficient of friction and high wear resistance. However, some technological conditions and topographies of surfaces for their successful applications should be made in advance as prerequisites. The research work deals with a high productive forming of metals and improving the mechanical and functional properties of special products. It contributes to finding the optimal internal varnishes, testing their resistance to stress and chemical resistance to the components, understanding all relevant mechanical properties especially of graphene (friction properties, adhesion and abrasion resistance). This research and development is concerned with a production of thin walled products, which will provide future customers with a more durable and safe products and also would have better properties compared to similar products already available on the market.
A Python and Java software approach for 2.5 axes, self-adaptive stretch forming process and IoT solution
Authors: Grigoras C C , Chirita B , Brabie G
Published: November 2020

Stretch forming is a metal forming process that implies bending and stretching a sheet of metal over a die, with the sheet being plastically deformed into the desired shape. The purpose is to obtain large parts. One of the main aspects is that the metal sheet is locked into position by gripping jaws. A hydraulic ram is raised into the metal sheet, therefore increasing the tensile forces. This process is used to draw intro shape materials like aluminium, magnesium, titanium alloys, stainless steel, Inconel. These materials have in common the fact that they have poor formability or the elastic spring-back has unacceptable values. Taking this into consideration, the nature of the materials along with the fact that the metal sheet can crack, due to excessive strain, we propose a self-adaptive stretch forming process. Underlining this process is the stress-strain curve, that has three inputs: force, sample section area and strain. For each of these factors, our method uses a particular approach, as in a Python-based software and Android-based IoT solution, that uses stress and strain data. Furthermore, it controls, in real-time the hydraulic press to the point at which the material is stretch close to its ultimate yield strength.
Aging mechanism and surface properties of Silica fluoropolymer coating and its application
Authors: Huang Hongpu , Guo Hong , Qu Jia , Feng Yefeng
Published: November 2020

The hydrothermal aging cycles experiment was carried out on synthetic Silica fluoropolymer coating (SiO2-FP). The hydrothermal aging mechanism, surface properties and protective efficacy on sandstones was studied. For comparison, the same study was conducted for commercial protective material acrylic resin Paraloid B72 (PB72). The hydrothermal aging mechanism was studied by Fourier infrared spectroscopy attenuated total reflection technique (ATR-FTIR) and x-ray photoelectron spectroscopy (XPS) technology. The surface properties were characterized by field emission scanning electron microscope (SEM), the CR-400 color difference meter, static contact angle and GMT6503 Electronic universal Tensile machine. The capillary water absorption, water absorption by complete immersion (CI) and water vapor permeability were measured to evaluate the protective efficacy on sandstones after treatment. The results of ATR-FTIR and XPS indicated that part of the ester groups in PB72 was hydrolysed and the chemical structure of SiO2-FP was not changed but only microphase separation occurred after 360 h of aging. After 360 h of aging, the PB72 film had obvious change and the SiO2-FP film only shown a minor change; the color change of PB72 film was very obvious and the color change of SiO2-FP film was within the acceptable range; the PB72 film changed from hydrophobic to hydrophilic and the SiO2-FP film still retained high hydrophobicity (119.3°); the SiO2-FP had a higher adhesive strength than PB72 at the end of aging. Compared with PB72, the SiO2-FP can obviously reduce the capillary water absorption and had a higher protective efficiency (97.25%), much lower soakage capacity (0.60%), higher water vapor permeability (267.0 ± 2) and less influence on the water vapor permeability. All the results demonstrated that the SiO2-FP has much better anti-aging ability and longer durability under hydrothermal condition. The SiO2-FP can provide adequate protection for sandstones. The SiO2-FP can be used as a suitable protective coating on sandstones.
One-Loop order effects from one extra universal dimension on λϕ
4 theory
Authors: López-Osorio M A , Martínez-Pascual E , Nápoles-Cañedo G I , Toscano J J
Published: November 2020

The self-interacting λ
ϕ
4 scalar field theory is the prototype in the study of basic renormalisation issues in quantum field theories. In this paper we explore the one-loop order divergent impact to this theory from one universal extra dimension,

S

1

/

Z

2

, to the self-energy, four point vertex and the beta function. Such effects come as an infinite number of UV divergences corresponding to an infinite superposition of excited KK particles around the loop. We show that dimensional regularisation is adequate enough to control all of them in terms of the product of the one dimensional inhomogeneous Epstein zeta function times the gamma function. From the analytical properties of these functions, the UV divergences are extracted and the counterterms defined; the latter turn out to be of canonical dimension four at the Lagrangian level. We use both, the MS-scheme and a mass-dependent subtraction scheme to remove divergences. Only the latter manifestly satisfy the decoupling theorem.
Differential effects of land use on nutrient concentrations in streams of Pennsylvania
Authors: Clune John W , Crawford J Kent , Chappell William T , Boyer Elizabeth W
Published: November 2020

Nutrient pollution of surface waters is a widespread problem, calling for regional assessments of water quality conditions. In this study, we quantified long-term median nutrient concentrations of total nitrogen (TN) and total phosphorus (TP) in streams and rivers of Pennsylvania and explored relationships between stream nutrient concentrations and the land use of their watersheds. Our analysis is based on a synthesis of monitoring data from multiple agencies that included records of nutrient concentrations observed between 2000–2019. Across the state, stream nutrient concentrations observed in predominantly undeveloped areas (e.g., forests, shrubs, and grasslands) have median concentration values of 0.42 mg l−1 for TN and 0.011 mg l−1 for TP, reflecting background concentrations for minimally impacted watersheds. Median stream concentrations of TN in agricultural areas are about eleven times higher than in undeveloped areas; and are about five times higher in developed areas than in undeveloped areas. Median stream concentrations of TP in developed areas have about eight times higher concentrations than undeveloped areas; and are about four times higher in agricultural areas than in undeveloped areas. Concentrations of TN and TP increased substantially as the combined percentage of agricultural and developed land use increased. Fragmented data storage practices (e.g. incomplete metadata, ambiguous site names, and missing coordinates) and inconsistencies in monitoring protocols (e.g., differences in constituents measured, parameter names, and measurement methods) made leveraging the secondary use of multiple sources of data challenging. Nonetheless, our integrated dataset is robust, represents the best data available, and provides a new window into the nutrient status of Pennsylvania’s surface waters. The long-term median nutrient concentrations reveal the magnitude of variability in TN and TP concentrations across the state’s diverse environmental settings of land use, physiography, and geology. This information is useful for interpreting additional monitoring data, informing evaluation of water quality conditions, and guiding watershed management.
Extended connectivity interaction features: improving binding affinity prediction through chemical description
Authors: Sánchez-Cruz Norberto , Medina-Franco José L , Mestres Jordi , Barril Xavier
Published: November 2020

Motivation

Machine-learning scoring functions (SFs) have been found to outperform standard SFs for binding affinity prediction of protein–ligand complexes. A plethora of reports focus on the implementation of increasingly complex algorithms, while the chemical description of the system has not been fully exploited.

Results

Herein, we introduce Extended Connectivity Interaction Features (ECIF) to describe protein–ligand complexes and build machine-learning SFs with improved predictions of binding affinity. ECIF are a set of protein−ligand atom-type pair counts that take into account each atom’s connectivity to describe it and thus define the pair types. ECIF were used to build different machine-learning models to predict protein–ligand affinities (pKd/pKi). The models were evaluated in terms of ‘scoring power’ on the Comparative Assessment of Scoring Functions 2016. The best models built on ECIF achieved Pearson correlation coefficients of 0.857 when used on its own, and 0.866 when used in combination with ligand descriptors, demonstrating ECIF descriptive power.

Availability and implementation

Data and code to reproduce all the results are freely available at https://github.com/DIFACQUIM/ECIF.

Supplementary information

Supplementary data are available at Bioinformatics online.
The Carceral City: Confinement and Order in Hong Kong’s Forbidden Enclave
Authors: Fraser Alistair , Schliehe Anna
Published: November 2020

Once feted, Hong Kong has recently become a centre of civil unrest. In this paper, we situate these emergent politics through a case study of corruption and everyday life in Kowloon Walled City, a mainland Chinese enclave in British Hong Kong, which developed notoriety as a freestanding grey economy. Drawing from oral testimonies of police officers, triad members and local residents, we excavate the lived experience of confinement within this contested space. These accounts reconstruct the Walled City as a ‘quasi-carceral’ site of enclosure, a zone of colonial exceptionalism and a hybrid cultural space. Through this case study, we historicize current debates in carceral geography, humanize recent interventions in urban scholarship and analyse the shifting politics at the frontier of Chinese expansionism.
Social Workers during COVID-19: Do Coping Strategies Differentially Mediate the Relationship between Job Demand and Psychological Distress?
Authors: Ben-Ezra Menachem , Hamama-Raz Yaira
Published: November 2020

The consequences of the coronavirus disease of 2019 (COVID-19) pandemic have raised many challenges in the social services workforce. The current study aimed to examine the associations between job demands, coping strategies (i.e. emotion-focused coping and problem-focused coping) and psychological distress exhibited by social workers during the COVID-19 pandemic. In addition, the mediating role of different coping strategies was investigated for the associations revealed. The participants were 615 social workers, working in various organisations and with diverse populations in Israel. Each completed a validated self-report questionnaire. Results revealed that job demands were significantly associated with higher psychological distress, and that coping strategies, especially emotion-focused coping was associated with higher psychological distress and with job demands. In addition, emotion-focused coping strategies were found to mediate the association between job demands and psychological distress, especially ventilation of emotion beyond other strategies, which relate to emotion-focused coping. These findings are discussed with relation to a stress and coping theory, suggesting that in social work practice there is a need for intervention measures to improve social workers’ coping strategies during crises such as the COVID-19 pandemic.
Dilemma of the differential diagnosis of hilar cholangiocarcinoma and benign diseases: a single-center retrospective study
Authors: Pang Liwei , Hu Shangzhi , Dai Wanlin , Wu Shuodong , Kong Jing
Published: November 2020

Hilar cholangiocarcinoma (HCCA), which lacks specific clinical manifestations, remains very difficult to distinguish from benign disease. This distinction is further complicated by the complex hilar anatomy. We conducted the present study to evaluate the differential diagnosis of these conditions. Sixty-five patients underwent resection surgery for suspected HCCA between January 2011 and October 2018. Institutional Review Board of Shengjing hospital agreed this study and all participants sign an informed consent document prior to participation in a research study. Following a postoperative pathology analysis, all patients were divided into two groups: malignant group (54 patients with HCCA) and benign group (11 cases with benign lesions). Compared with the benign group, the malignant group had a significantly higher median age and serum CA19-9, CEA, ALT, BILT and BILD levels (P < 0.05). In contrast, the groups did not differ significantly in terms of the sex distribution, clinical manifestations, serum levels of AST and ALKP, and imaging findings. In a receiver operating characteristic curve analysis, we identified a CA19-9 cutoff point of 233.15 U/ml for the differential diagnosis and CEA cutoff point of 2.98 ng/ml for the differential diagnosis. The differential diagnosis of HCCA and benign hilar lesions remains difficult. However, we found that patients with HCCA tended to have an older age at onset and higher serum levels of CA19-9, CEA, BILT, ALT and BILD. Furthermore, patients with a serum CA19-9 level >233.15 U/ml and CEA level >2.98 ng/ml are more likely to have malignant disease.