Gloss and Modelling Studies of Stone Polishing, Using Linear Polishing Machines With Rotating Heads

The ornamental stone industry has always played an important role in the world economy, particularly in building construction. Polishing the slabs to increase its gloss, is an important processing operation to enhance the beauty and richness of these natural materials. Many industrial polishing machines rely on rotating heads movement along zigzag trajectories, eroding the surface as stochastically as possible, to avoid scratches and other visual defects caused by paths too symmetric. The displacement of the polishing head after a single zigzag movement and after a single rotation have been used to quantify the polishing process as these two parameters are related with the final stone gloss and are a measure of the efficiency of the polishing process. Applying experimental and new computer simulation techniques, we studied the influence of these two tool displacement parameters on the final stone gloss, and acquired insight into the accuracy of the simulation techniques that were applied here for the first time. We concluded that: 1) a clear correlation can be established between experimental and simulation data; 2) the two displacement parameters represent an effective way to control the quality and efficiency of the polishing process; 3) there is a limit for the gloss acquired through polishing processes, so polishing above a given threshold decreases the efficiency without increasing the quality.

Controlled growth and ordering of poorly-crystalline calcium-silicate-hydrate nanosheets

Optimising the mesoscale structure of calcium-silicate-hydrate (C-S-H) is critical to achieving durable and sustainable infrastructure using Portland cement concrete. However, control of its intricate formation process, which comprises spatially disordered growth of poorly-crystalline sheets, remains a challenge. Here, through combination of experimental and computer simulation techniques, we report a promising mechanism to control this complex growth process and thereby optimise the C-S-H nanostructure. The pivotal step was utilizing graphene oxide (GO) to restrain the inherent spatial deformations of the C-S-H sheets and guide their concurrent 2D growth and layer-by-layer ordering. Accordingly, we designed a layered GO–C-S-H composite that exhibits 1–2 orders of magnitude improvement in strength and durability compared with C-S-H formed without control. Our findings open a window for nano-engineering of cements and other complex layered materials for ceramic, pharmaceutical and energy applications.

Marginally compact phase and ordered ground states in a model polymer with side spheres

We present the results of a quantitative study of the phase behavior of a model polymer chain with side spheres using two independent computer simulation techniques. We find that the mere addition of side spheres results in key modifications of standard polymer behavior. One obtains a novel marginally compact phase at low temperatures, the structures in this phase are reduced in dimensionality and are ordered, they include strands assembled into sheets and a variety of helices, and at least one of the transitions on lowering the temperature to access these ordered states is found to be first order. Our model serves to partially bridge conventional polymer phases with biomolecular phases.

Surgical Workflow Simulation for the Design and Assessment of Operating Room Setups in Orthopedic Surgery

Background The design and internal layout of modern operating rooms are influencing the team’s collaboration and communication, ergonomics, as well as intraoperative hygiene substantially. Nevertheless, there is no objective method for the assessment and design of the personnel and table positions for different surgical disciplines and intervention types available. The aim of this work is to establish an improved OR setup for common procedures in arthroplasty. Methods With the help of computer simulation techniques, a method for the objective design and assessment of enhanced OR setups was developed. In this work, new OR setups were designed, analyzed in a computer simulation environment and evaluated in the actual intraoperative setting. Results The implementation of improved OR setups reduces the instrument handover time between the surgeon and the scrub nurse, the travel paths of the OR team as well as shortens the procedure duration. Additionally, the ergonomics of the OR staff were improved. Conclusion The developed simulation method was intraoperatively evaluated and proved its benefit for the design and optimization of OR setups for different surgical intervention types. As a clinical result, enhanced setups for total knee arthroplasty and total hip arthroplasty surgeries were established in daily clinical routine and the OR efficiency was improved.

Surgical Workflow Simulation for the Design and Assessment of Operating Room Setups in Orthopedic Surgery

Background The design and internal layout of modern operating rooms are influencing the team’s collaboration and communication, ergonomics, as well as intraoperative hygiene substantially. Nevertheless, there is no objective method for the assessment and design of the personnel and table positions for different surgical disciplines and intervention types available. The aim of this work is to establish an improved OR setup for common procedures in arthroplasty. Methods With the help of computer simulation techniques, a method for the objective design and assessment of enhanced OR setups was developed. In this work, new OR setups were designed, analyzed in a computer simulation environment and evaluated in the actual intraoperative setting. Results The implementation of improved OR setups reduces the instrument handover time between the surgeon and the scrub nurse, the travel paths of the OR team as well as shortens the procedure duration. Additionally, the ergonomics of the OR staff were improved. Conclusion The developed simulation method was intraoperatively evaluated and proved its benefit for the design and optimization of OR setups for different surgical intervention types. As a clinical result, enhanced setups for total knee arthroplasty and total hip arthroplasty surgeries were established in daily clinical routine and the OR efficiency was improved.

Surgical Workflow Simulation for the Design and Assessment of Operating Room Setups in Orthopedic Surgery

Background: The design and internal layout of modern operating rooms are influencing the team’s collaboration and communication, ergonomics, as well as intraoperative hygiene substantially. Nevertheless, there is no objective method for the assessment and design of the personnel and table positions for different surgical disciplines and intervention types available. The aim of this work is to establish an improved OR setup for common procedures in arthroplasty. Methods: With the help of computer simulation techniques, a method for the objective design and assessment of enhanced OR setups was developed. In this work, new OR setups were designed, analyzed in a computer simulation environment and evaluated in the actual intraoperative setting. Results: The implementation of improved OR setups reduces the instrument handover time between the surgeon and the scrub nurse, the travel paths of the OR team as well as shortens the procedure duration. Additionally, the ergonomics of the OR staff were improved. Conclusion: The developed simulation method was intraoperatively evaluated and proved its benefit for the design and optimization of OR setups for different surgical intervention types. As a clinical result, enhanced setups for total knee arthroplasty and total hip arthroplasty surgeries were established in daily clinical routine and the OR efficiency was improved.

Surgical Workflow Simulation for the Design and Assessment of Operating Room Setups in Orthopedic Surgery

Background The design and internal layout of modern operating rooms are influencing the team’s collaboration and communication, ergonomics, as well as intraoperative hygiene substantially. Nevertheless, there is no objective method for the assessment and design of the personnel and table positions for different surgical disciplines and intervention types available. The aim of this work is to establish an optimal OR setup for common procedures in arthroplasty.Methods With the help of computer simulation techniques, a method for the objective design and assessment of optimal OR setups was developed. In this work, new OR setups were designed, analyzed in a computer simulation environment and evaluated in the actual intraoperative setting.Results It was shown that the implementation of an optimized OR setup reduces the intraoperative instrument handover time between the surgeon and the scrub nurse, the travel paths of the OR team as well as shorten the procedure duration. Additionally, the ergonomics of the OR staff could be improved.Conclusion The developed simulation method was intraoperatively evaluated and proved its benefit for the design and optimization of OR setups for different surgical intervention types. As a clinical result, optimized setups for total knee arthroplasty and total hip arthroplasty surgeries were established in daily clinical routine and the OR efficiency was improved.

Designing the functional garments for people with physical disabilities or kyphosis by using computer simulation techniques

The two-fold purpose of this study is to document the current challenges of the 3D scanning and computer simulation techniques in developing functional garments for people with physical disabilities or postural disorder kyphosis. The first part of the study investigates the health problems of the wheelchair users and presents the possibilities of developing functional pants from the perspective of protection and health needs. The second part of the study investigates the usefulness of the newly developed methodology for elementary surfaces evaluation, named CASP (Curvature, Acceleration, Symmetry, Proportionality), in the process of designing the well-fitted bodice for wheelchair users suffering from the postural disorder kyphosis. The relationships between the health problems, human body postures, kyphosis, 3D scanning, CASP evaluation and treated garments were considered in the prototyping process. The obtained research results regarding the functional pants for wheelchair users and the well-fitted bodice for a kyphosis body are valuable also for a wider population of those who are forced to a sitting posture during a day and are confronted with similar health problems as paraplegics or are affected by the kyphosis.

TAKING INTO ACCOUNT PSYCHOPHYSIOLOGICAL FACTORS WHEN RECONSTRUCTING -FACADES OF SCHOOLS WITH INNOVATIVE AIR-CLEANING PANELS

Introduction. The spatial and aesthetic requirements for the use of air purification architectural and construction technologies in the reconstruction of school buildings facades are considered. The relevance of the use of such innovative technologies is their use for educational buildings located in the immediate vicinity of roads of different categories, where the concentration of air pollutants from vehicles is high enough. The scientific novelty of the research iscontained in the study of psychophysiological conditions of perception of school buildings facades covered with air purification panels, depending on the methods and scale of the surrounding buildings. The purpose and objectives of the study. The purpose of the article is justification of the necessity and possibility of using innovative air purification panels in the reconstruction of school buildings facades. The attention is paid to the analysis of psychophysiological features of perception of objects located in the conditions of historically developed environment with various restrictions of planning structure. The interrelations and regularities in the perception ofair purification facade slabs with the change of visual impressions during movement were revealed. The possibilities of using micro — and large-relief facade structures depending on the height (number of floors) of the surrounding buildings are considered. Materials and methods. There were used graphic-analytical, field and computer simulation techniques in the use of innovative air pollution control boards of school buildings.Introduction. The spatial and aesthetic requirements for the use of air purification architectural and construction technologies in the reconstruction of school buildings facades are considered. The relevance of the use of such innovative technologies is their use for educational buildings located in the immediate vicinity of roads of different categories, where the concentration of air pollutants from vehicles is high enough. The scientific novelty of the research iscontained in the study of psychophysiological conditions of perception of school buildings facades covered with air purification panels, depending on the methods and scale of the surrounding buildings. The purpose and objectives of the study. The purpose of the article is justification of the necessity and possibility of using innovative air purification panels in the reconstruction of school buildings facades. The attention is paid to the analysis of psychophysiological features of perception of objects located in the conditions of historically developed environment with various restrictions of planning structure. The interrelations and regularities in the perception ofair purification facade slabs with the change of visual impressions during movement were revealed. The possibilities of using micro — and large-relief facade structures depending on the height (number of floors) of the surrounding buildings are considered. Materials and methods. There were used graphic-analytical, field and computer simulation techniques in the use of innovative air pollution control boards of school buildings. Results. The most applicable scales and compositional solutions of ecological modules taking into account the picked up structure recommended for finishing of facades of schools in areas with preferential low — and average building are established. Conclusions. The use of facade air purification panels will contribute not only to the improvement of the environment, but also will improve its architectural quality. Results. The most applicable scales and compositional solutions of ecological modules taking into account the picked up structure recommended for finishing of facades of schools in areas with preferential low — and average building are established. Conclusions. The use of facade air purification panels will contribute not only to the improvement of the environment, but also will improve its architectural quality.

Deformation of a Red Blood Cell in a Narrow Rectangular Microchannel

The deformability of a red blood cell (RBC) is one of the most important biological parameters affecting blood flow, both in large arteries and in the microcirculation, and hence it can be used to quantify the cell state. Despite numerous studies on the mechanical properties of RBCs, including cell rigidity, much is still unknown about the relationship between deformability and the configuration of flowing cells, especially in a confined rectangular channel. Recent computer simulation techniques have successfully been used to investigate the detailed behavior of RBCs in a channel, but the dynamics of a translating RBC in a narrow rectangular microchannel have not yet been fully understood. In this study, we numerically investigated the behavior of RBCs flowing at different velocities in a narrow rectangular microchannel that mimicked a microfluidic device. The problem is characterized by the capillary number C a , which is the ratio between the fluid viscous force and the membrane elastic force. We found that confined RBCs in a narrow rectangular microchannel maintained a nearly unchanged biconcave shape at low C a , then assumed an asymmetrical slipper shape at moderate C a , and finally attained a symmetrical parachute shape at high C a . Once a RBC deformed into one of these shapes, it was maintained as the final stable configurations. Since the slipper shape was only found at moderate C a , measuring configurations of flowing cells will be helpful to quantify the cell state.