Wall Angle Research Articles

Three-dimensional evaluation of temporomandibular joint and dental asymmetries in angle class II division 1 subdivision malocclusion

Abstract Background Management of class II division 1 subdivision malocclusion has consistently offered an important challenge for orthodontic professionals. This problem arises not only from the complexities associated with its treatment but also from the complex nature of its asymmetric characteristics. Understanding the properties of asymmetry in this particular malocclusion has significant importance. Objectives Evaluate the features of temporomandibular joint and dental asymmetries in angle class II division 1 subdivision malocclusion by using cone-beam computed tomography (CBCT). Patients and methods Forty CBCT scans of adult patients were analyzed and divided into two groups: 20 CBCT for each group skeletal and dental measurements were measured and compared among both groups to evaluate the features temporomandibular joint and dental asymmetries in class II division 1 subdivision malocclusion. Results Dental parameters were significantly different (P < 0.01) between right and left sides in maxillary sagittal position (mandibular first), maxillary and mandibular canine. A comparison of condyle and glenoid fossa concerning right, and left sides showed together significant an differences (P < 0.01) in coronal position of GFI, GlS, Poi, and posterior wall angle of the articular tubercle. Conclusion In class II division 1 subdivision malocclusion the mandibular first molar was distal and lingual in position, while the maxillary first molar was mesial in class II side. In class ii subdivision malocclusion, glenoid fossa position and condylar morphology asymmetries caused skeletal asymmetry.

Effects of toolpath on defect phenomena in the incremental forming of thin polycarbonate sheets

Incremental sheet forming has been largely investigated in the last two decades because of its versatility and cost-effectiveness, which make it viable for manufacturing highly customized parts as well as small- and medium-sized batches. This process allows for reaching greater formability compared to conventional sheet-forming processes. In contrast, it is affected by defects like twisting, which strongly influence the geometric accuracy of the formed parts. These aspects are dramatically accentuated when forming soft materials like thermoplastics. With these premises, the following research aims to investigate the effects of the toolpath strategy on the occurrence of failures and defects in the incremental sheet forming under very severe process conditions. Cone frusta with a fixed wall angle were obtained by thin polycarbonate sheets, imposing four unidirectional helical trajectory-based toolpaths, one traditional, and three stair strategies. The analysis of the forming forces, the evaluation of the worked surfaces, and the monitoring of the defectiveness highlight the advantages of a stair toolpath strategy in terms of reduced twisting and loading and high surface quality, regardless of the lubrication conditions.

Differences in bladder neck angles between female patients with overactive bladders and healthy peers.

The aim of this study was to compare the differences between angles of bladder neck in girls with overactive bladder and those in healthy ones using transabdominal ultrasonography. This study consists of 28 girls complicated with overactive bladder (Group I) and 40 healthy girls (Group II). The anteroposterior vesical wall angle (APVA), urethroposterior vesical wall angle (UPVA), urethroanterior vesical wall angle (UAVA), thickness of bladder mucosa, distance of urethral orifices, and distance between ureter and urethra orifice were measured in supine position using transabdominal ultrasonography. The results were compared between the two groups. UAVA in Group I was higher than Group II (135.2 ± 12.2 mm vs. 117.4 ± 14.0 mm; p = 0.009). UPVA was smaller in Group I than Group II (114.6 ± 19.5 mm vs. 135.3 ± 16.5 mm; p = 0.014). The distance between the ureteral orifices was 31.8 ± 8.5 mm in Group I and 17.0 ± 4.1 mm in Group II (p < 0.001). There was no statistically significant difference between groups in terms of APVA, bladder mucosa thickness, and distance between ureter and urethra orifice (p > 0.05). Bladder neck dynamics may play an important role in overactive bladder pathophysiology due to differences in UPVA, UAV, and location of ureteral orifices in this patient population.

CFD Calculation of Natural Convection Heat Transmission in a Three-Dimensional Pool with Hemispherical Lower Head

The integrity of a pressure vessel (PRV) is affected by the decay heat of the molten pool in the lower head, so it is very important to study the natural convection heat transmission in the lower head. Scholars from all over the world have carried out a lot of experimental studies and calculations to determine the convection mechanism and heat transmission characteristics of the molten pool. Most of them were based on the empirical formula of convective heat transmission on the wall of a hemispherical molten pool based on two-dimensional slice experiments and simulation calculations. In this study, FLUENT 2021R1 software was used to simulate the three-dimensional convective heat transmission process of the hemispherical molten pool, and the temperature, velocity and wall heat transmission coefficients of the flow field were analyzed. The results were in good agreement with experimental data from UCLA (University of California, Los Angeles). Through research on the heat transmission of the lower head, the results showed that in the region where the wall angle was θ between approximately 72 and 90 degrees, heat transmission coefficients had larger fluctuations, and a more reasonable empirical relation was proposed. Comparing between the simulation results of CFD and the two-dimensional empirical formula, it was found that the latter one was smaller under the same θ angle condition. Finally, the convection phenomena of different external temperatures were simulated, and the main factors affecting the flow field by temperature were analyzed.

Design and Implementation of Water PH Level and Turbidity Monitoring System

Abstract: Building collapses have become a distressing and recurring issue in Nigeria, necessitating urgent action to mitigate their occurrence. This paper introduces an innovative approach to address this challenge by developing an Automated Structural Health Monitoring System (ASHMS) utilizing a mobile app. Focusing on major cities like Lagos and Abuja, the proposed system employs strategically placed sensors to gather data from various structural elements of buildings. The collected information, encompassing seismic activity, vibrations, bending moments, shear forces, and other key parameters, is wirelessly transmitted to the cloud where it can then be accessed and visualized using mobile app. The system offers real-time insights into the structural integrity of buildings and provides early warnings, thereby contributing significantly to reducing the risk of building collapses. Key findings show that when incorporated into an automated Structural Health Monitoring (SHM) system, the user's mobile app offers essential structural insights, capturing values such as a 0.5-unit vibration level, 20 units of shear force, 50 units of bending moment, and an 89-degree vertical wall angle. The app's userfriendly interface improves the effectiveness of monitoring and overseeing structural health, in line with the overarching objective of promoting safety in construction practices

Automated Structural Health Monitoring System for Mitigating Building Collapse in Nigeria: A Mobile App Approach

Abstract: Building collapses have become a distressing and recurring issue in Nigeria, necessitating urgent action to mitigate their occurrence. This paper introduces an innovative approach to address this challenge by developing an Automated Structural Health Monitoring System (ASHMS) utilizing a mobile app. Focusing on major cities like Lagos and Abuja, the proposed system employs strategically placed sensors to gather data from various structural elements of buildings. The collected information, encompassing seismic activity, vibrations, bending moments, shear forces, and other key parameters, is wirelessly transmitted to the cloud where it can then be accessed and visualized using mobile app. The system offers real-time insights into the structural integrity of buildings and provides early warnings, thereby contributing significantly to reducing the risk of building collapses. Key findings show that when incorporated into an automated Structural Health Monitoring (SHM) system, the user's mobile app offers essential structural insights, capturing values such as a 0.5-unit vibration level, 20 units of shear force, 50 units of bending moment, and an 89-degree vertical wall angle. The app's userfriendly interface improves the effectiveness of monitoring and overseeing structural health, in line with the overarching objective of promoting safety in construction practices.

Improving the local and distortional resistance of CFS trapezoidal self-supporting roof members

This paper reports the development, numerical implementation and application of a methodology to perform the multi-objective optimisation, with respect to local and distortional failures, of cold-formed steel (CFS) trapezoidal cross-section shapes used in members belonging to self-supporting roof systems and manufactured by bending the steel sheets with roll-forming machines. Initially, a brute-force approach is adopted to search for optimal unstiffened cross-section shapes of members subjected to positive (sagging) and negative (hogging) bending moments. Next, an optimisation procedure based on a Genetic Algorithm (GA) is employed to find stiffened cross-sections that (i) outperform the original (plain/unstiffened) ones, as far as the resistance against local and distortional failures is concerned, and (ii) can be fabricated with minimal additional cost, through the sole addition of small intermediate stiffeners, whose possible locations are pre-defined in accordance with a map of executable fold-line positions – the original cross-section typology, overall dimensions and wall angles are retained. The design approach adopted to estimate the member ultimate strengths is based on the Direct Strength Method (DSM), and Generalised Beam Theory (GBT) is used to calculate the elastic buckling stresses due to bending. The application and capabilities of the proposed methodology are illustrated, by means of numerical results presented in terms of cross-section families belonging to optimal Pareto Fronts – an excellent performance of the procedure was found in all cases.

Numerical simulation and geometric optimization of a desalination system using solar energy using two-phase mixing method with alumina nanoparticles

This research paper presents 2D numerical simulations of a single-slope solar desalination system from a nanomaterial science perspective, utilizing the two-phase mixture method. Alumina nanoparticles with a volume percentage of 0.1 % are introduced into the water storage tank for thermal analysis. The system features a trapezoid-shaped glass wall to harness solar energy. Key variables studied encompass ambient temperature, glass wall angle, front wall height, glass wall temperature, and air temperature inside the system. Temperature and velocity contours within the system are obtained through numerical simulations. To enrich the analysis, artificial intelligence techniques and response surface methodology are employed to examine the maximum and minimum temperatures. The results indicate that, at medium ambient temperatures, the lowest maximum air temperature inside the desalination system occurs at a front wall height of 0.2 m and a glass angle of 45°. Additionally, the lowest air temperature is observed at an ambient temperature of 10 °C and a front wall height of 0.05 m, corresponding to a glass angle of 27.5°. On the other hand, the highest maximum air temperature is recorded at a front wall height of 0.125 m, with a glass angle of 45° and an ambient temperature of 55 °C. Increasing the ambient temperature from 10 °C to 55 °C for a wall height of 0.2 m leads to a 26.81 °C rise in the air temperature inside the system, equivalent to a 9 % increase. The findings provide valuable insights for optimizing the design and performance of single-slope solar desalination systems integrated with alumina nanoparticles from the perspective of nanomaterial science.

Nanotomographic Analysis of Orthodontic Molar Tubes for Direct Bonding

(1) Background: The most important part of an orthodontic attachment (bracket or tube) is the tube or slot for the insertion of the orthodontic wire. Aligning teeth along the archwire according to angular values preadjusted in the bracket slots (or tubes) requires a very precise size accordance between the archwires and slots. The aim of this study was to perform a nanotomographic analysis of the geometric features of molar tubes for direct bonding in terms of their dimensions and angles of their inner walls and analyze the presence of metallurgic imperfections. (2) Methods: Orthodontic tubes (n = 100) for upper right first molars from five different manufacturers (3M-Victory Series, Adenta-Bond Sing, Dentaurum-Ortho Cast M, GC-L LP, and ORMCO-Accent), 20 tubes each, were subjected to nanotomographic analysis. Measurements of the inner channel of the tubes, angles between the walls, and analysis of metallurgic imperfections were performed using high-resolution computed tomography. (3) Results: height measurements differed by 4–14% from ideal values declared by manufacturers, whereas the angles ranged from reducing by a maximum 1% comparing to values declared (hypodivergent walls) to increasing by a maximum 4.5% (divergent walls). (4) Conclusions: 1. The sizes of channels measured were slightly larger than those declared by manufacturers. 2. Slight deviations in wall parallelism and angles between the walls were found. 3. Some tubes were characterized by manufacturing defects of the metal. 4. Efforts should be made to further improve the production process of orthodontic attachments.

Optimizing the SPIF parameters for enhancing microhardness and surface quality in Inconel 625 superalloy components

Inconel 625, a high-strength superalloy with excellent corrosion resistance, discovers wide applications in critical sectors such as aerospace, nuclear, marine, and petrochemical. Single-Point Incremental Forming (SPIF) has appeared as an adequate fabricating process for shaping superalloy components. This work used a systematic approach, implementing Response Surface Methodology (RSM) to explore the influence of SPIF process variables, including tool nose diameter, step size, tool spindle speed, and wall angle, on microhardness (MH) and surface roughness (SR). The experimental results have been analyzed to determine the influencing process variables and their optimal settings, which simultaneously enhance MH and reduce SR of Inconel 625 superalloy truncated cones using analysis of variance and the desirability function analysis approach. The most significant parameters that influence MH and SR were TND and SS, respectively. The development of quadratic models for MH and SR has been completed successfully. The maximum MH of 486.8 HV and minimum SR of 0.432 µm have been obtained at the optimal parametric setting of TND = 15 mm, SS = 0.4 mm, TSS = 900 rpm, and WA = 57.5° with the desirability values for MH, SR and combined are 0.832, 0.933, 0.881 respectively. The F-value of the MH model = 109.18 and SR Model = 78.24 implies that both models are significant and both models have excellent prediction strength. The percentage error between predicted and actual values of MH and SR in confirmation run results is less than 5 %.

Feasibility Study of Single-Point Incremental Forming for Discontinuous-Fiber CFRP Using Oil-Bath Heating

Although, three-dimensional printing has several advantages, however there are currently many limitations. In particular, printed products using composite materials such as fiber-reinforced plastic have yet to achieve the same mechanical properties as those obtained from conventional manufacturing methods. In addition, fabricating thin plates or thin shell shapes with sufficient strength is challenging. Incremental forming enables high-mix, low-volume production of thin sheets. This method applies incremental deformation to thin sheets, the desired shape is obtained by accumulating the deformation, and no dies are required. Carbon-fiber-reinforced plastic (CFRP) materials have high specific strength. Discontinuous-fiber CFRP is capable of large plastic deformation under appropriate conditions due to the discontinuity of the reinforcement, and its mechanical properties are nearly isotropic due to the random fiber arrangement. The authors focused on this property and studied the application of single-point incremental forming to discontinuous carbon-fiber-reinforced polyamides. In this study, the workpiece was formed by heating it locally to a deformable temperature by the frictional heat between the rotating tool and the workpiece. The forming experiment was also conducted in an oil bath to keep the entire material at a suitable forming temperature. The results showed that the spindle speed affected forming results even in an oil bath and that heating using an oil bath suppressed deviations from the sine law for thickness and wall angle due to elastic deformation.

Complexity upgrade and triggering mechanism of mixed-wettability: Comparative study of CO2 displacement in different phases

Complex pore structures and wettability affect CO2 storage in underground reservoirs. Revealing the flow law of CO2 in complex reservoirs is crucial for evaluating storage stability and security. Considering the complexity of the pore structure and wettability of rock, a complex mixed-wettability characterization method based on a complex pore structure is proposed. Matrix numerical models for two-dimensional heterogeneous complex mixed-wettability rock were developed to simulate CO2 displacement in different phases. A comparative study found that, under single-phase wettability, the weaker the wettability, the better the effect of gaseous CO2 displacement. Moreover, the stronger the wettability, the better the displacement effect of ScCO2. The wetting phase of CO2 was transformed from the non-wetting phase. At the late stage of gaseous CO2 displacement, when the contact angles were 30° and 60°, the displaced water phase was absorbed back into the matrix owing to imbibition, resulting in the formation of a peak in the displacement efficiency curve. Compared to that at a contact angle of 60°, the displacement efficiency at a contact angle of 30° decreased more significantly after the peaks, while the suck-back phenomenon did not occur when the contact angle was 90°. Under mixed-wettability conditions, the flow law of CO2 in different phases is directly affected by the contact angle of the pore walls. The displacement efficiencies of gaseous CO2 and ScCO2 increased by 9.58% and 17.96%, respectively, owing to the dual driving force caused by imbibition. The complexity of mixed-wettability is upgraded by providing pore walls with different proportions of contact angles (six types). The flow law of different phases of CO2 showed that, the higher the proportion of walls with small contact angles (3:2:1), the worse the displacement effect of gaseous CO2 and the better the displacement effect of ScCO2. Compared with single-phase wettability and mixed-wettability, the displacement efficiency of gaseous CO2 and ScCO2 under complex mixed-wettability decreased by 4.26%, 1.00% and 20.41%, 3.37%, respectively. Therefore, ignoring complex mixed-wettability often leads to a higher displacement efficiency.

Numerical investigation of LDL nanoparticle collision in coronary artery grafts with porous wall and different implantation angles and two state of inlet velocity.

This study aimed to reduce the risk of graft occlusion by evaluating the two-phase flow of blood and LDL nanoparticles in coronary artery grafts. The study considered blood as an incompressible Newtonian fluid, with the addition of LDL nanoparticles, and the artery wall as a porous medium. Two scenarios were compared, with constant inlet velocity (CIV) and other with pulsatile inlet velocity (PIV), with LDL nanoparticles experiencing drag, wall-induced lift, and induced Saffman lift forces, or drag force only. The study also evaluated the concentration polarization of LDLs (CP of LDLs) near the walls, by considering the artery wall with and without permeation. To model LDL nanoparticles, the study randomly injected 100, 500, and 1000 nanoparticles in three release states at each time step, using different geometries. Numerical simulations were performed using COMSOL software, and the results were presented as relative collision of nanoparticles to the walls in tables, diagrams, and shear stress contours. The study found that a graft implantation angle of 15° had the most desirable conditions compared to larger angles, in terms of nanoparticle collision with surfaces and occlusion. The nanoparticle release modes behaved similarly in terms of collision with the surfaces. A difference was observed between CIV and PIV. Saffman lift and wall-induced lift forces having no effect, possibly due to the assumption of a porous artery wall and perpendicular outlet flow. In case of permeable artery walls, relative collision of particles with the graft wall was larger, suggesting the effect of CP of LDLs.

A New Approach to Multi-Stage Incremental Forming Method

Producing vertical edged parts in sheet metal forming methods can cause tears on the sheet. The incremental forming method can allow sheet forming without tears. Forming can be done multi-stage to prevent this tear. Incremental forming method can be used in prototype production. The most important advantages of incremental forming method are that it is fast and inexpensive. In this study, we applied multi-stage forming to the two-point incremental forming-rolling blank holder method. Thus, we have developed a new way: the multi-stage, two-point incremental forming-rolling blank holder method. Parts with vertical edges are produced, and the wall thickness distribution is examined. The work material is a DC04 sheet with a thickness of 0.98 mm. The workpiece is axially symmetrical with a wall angle of 90°. The effect of four different parameters were researched: increment, feed rate, clamping pressure, and angle increment. Three different levels were determined for each parameter. The wall thickness distribution of the parts obtained from the experiments was measured.

Distal phalanx radiographic grading features in long‐toe, underrun heel in Egypt Baladi donkeys (Equus asinus)

SummaryBackgroundLong‐toe, underrun heel conformation is a term referring to a long toe, collapsed frog and atrophied heels in equids, including donkeys. However, data on the radiological evaluation and classification of the long‐toe, underrun heel conformation in the donkey are relatively limited.ObjectivesThe present study aimed to determine the relationship between the dorsal hoof wall angle and the radiological angular and linear features of the distal phalanx in long‐toe, underrun heel conformation in Egypt Baladi donkeys.Study designPost‐mortem collected feet.MethodsForty‐seven front hooves with long‐toe, underrun heels from cadavers were radiographically examined. Lateromedial radiometric parameters included dorsal hoof wall angle, heel angle, distal phalanx angle, distal phalanx solar border angle, coronet angle, axis of the distal phalanx angle, proximal palmar cortex angle, distal phalanx to ground distance, distal phalanx to frog distance, distal phalanx to toe distance, foot length and hoof balance%. Long‐toe, underrun heel cadaver feet were classified into four groups according to the dorsal hoof wall angle (DHWA).ResultsThe DHWA of the first group was less than 58.25°–54° (&lt;58.25°:54°), the second group was less than 54°–52° (&lt;54°:52°), the third group was less than 52°–47° (&lt;52°:47°), and the fourth group was less than 47° (&lt;47°). From the first to the fourth groups DHWA, heel angle (HA), distal phalanx solar border angle (P3BA), distal phalanx angle (P3A), axis of the distal phalanx angle (LP3A), proximal palmar cortex angle (PPCA), distal phalanx to frog distance (P3F) and foot length (FL) were decreased, while the coronet angle (CA), distal phalanx to toe distance (P3T) and hoof balance (HB) percentages were increased. Statistical analysis revealed strong and moderate correlations between DHWA and HA, P3A, P3BA, LP3A, PPCA, P3G, P3F and P3T.Main limitationCadaver feet were collected from different yards and body sizes, the collection of radiographic parameters without trimming and the lack of a record of the work history of these donkeys.ConclusionThis study will assist veterinarians in evaluating the long‐toe, underrun heel conformation during hoof trimming.

Investigation of coherent Fourier scatterometry as a calibration tool for determination of steep side wall angle and height of a nanostructure

Nanostructures with steep side wall angles (swa) play a pivotal role in various technological applications. Accurate characterization of these nanostructures is crucial for optimizing their performance. In this study, we propose a far-field detection method based on coherent Fourier scatterometry (CFS) for accurate quantification of steep swa and heights in cliff-like nanostructures. Our approach introduces a parameter termed ‘visibility’, derived from the unique far-field signatures of cliff-like nanostructures. This parameter serves as a quantitative metric for the calibration of swa and heights. The heightened sensitivity of our method is demonstrated, particularly when the incident polarization is perpendicular to the invariant direction of the nanostructure for swa calibration, while both polarization states exhibit sensitivity to height calibration. Furthermore, a comprehensive sensitivity analysis reveals the stable nature of our method, showcasing that even with fluctuations of ±10 nm in the position of the nanostructure, the resulting swa remains stable within a range of ±0.5∘ . The exponential variation of the visibility parameter with edge roundness is observed, with fluctuations in edge roundness within 10 nm resulting in swa variations within 1.7∘ for both polarization states. In experimental validations, our results demonstrate reasonable agreement between CFS-derived and AFM measurements. The AFM data for swa ( 77.99∘±1.37∘ ) and height (148.35 nm ±2.11 nm) are corroborated with CFS-derived value of swa ( 77.75∘±3.61∘ , 78.36∘±3.89∘ ) and height (149.42 nm ±1.66 nm, 150.05 nm ±1.04 nm) obtained from calibration curves for TM and TE incident beams, respectively. Overall, our findings underscore CFS as a potential and reliable tool for nanostructure characterization, offering precise measurements that are pivotal for advancing nanotechnology.

Study on Wave Overtopping Discharge Affected by Guiding Wall Angle of Wave Dragon Device Using FLOW-3D Software

The Wave Energy Converters (WECs) have become the main attraction in producing electricity by converting the wave's energy to electricity. The focus of the WECs is the overtopping of the wave. The higher of overtopping water collected in the basin, the higher the power produced. Producing the higher overtopping also requires higher wave flow rate entry. In the Wave Dragon system, the rate of wave flow entering the reservoir is influenced by the guiding wall (reflector) angles and wave height. Hence, most overtopping concepts have tried to increase the water addition into the pool studying their geometrical parameter, mainly on the guiding wall of Wave Dragon. The unknown effect of the guiding wall angles on the overtopping and effect of the wave characteristic remained. Thus, this study aims to investigate the appropriate guiding wall angle on the influence of different wave heights affecting the performance of the Wave Dragon unit. Then, using FLOW 3D software to apply different guiding wall angles and wave characteristics to the device parameters for investigation. The numerical result highlights that the higher overtopping discharge is obtained during the upper limit of wave height and guiding wall angle. Besides, percentage different between the simulations model and experimental observation, was found at 15%. The result of this study will be beneficial to the industry related to wave potential energy, especially Wave Dragon, and it will also help them improve their device performance.

Effect of contact angle on the pressure needed for a liquid to permeate a cylindrical pore

Effective separation of two immiscible liquids with filters requires a difference in the pressures to permeate between the two liquids, and setting the applied pressure between these two pressures. To help design such filters, we present an equation that enables the calculation of the pressure for a liquid phase to permeate through a smooth pore in the shape of a truncated cone as a function of (a) the contact angle of the liquid on the filters and (b) the angle of the pore wall. The equation was derived by considering the interfacial energy required to push a liquid meniscus from the top of the pore to the bottom, and then to exceed the maximum curvature required at the exit. This equation was tested experimentally by adding a hydrostatic head with water on the 3D-printed filters of acrylate polymer while systematically varying the pore radii and contact angle with water. Experimental results showed an increased pressure to permeate with higher contact angles while the equation predicted the opposite. We hypothesized that the reason for the disagreement was the assumption of a smooth pore. For a liquid on a rough pore wall, the curvature of the meniscus is not solely determined from the microscopic contact angle and the pore wall angle, but the liquid would adopt a lower curvature meniscus. Therefore, the developed equation was modified after reflecting the lower curvature, which showed much better agreement with the experimental results. The remaining discrepancy from the theory was attributed to the pressure fluctuation from the fluid flow occurring while adding water.

A scoring system for grading corkscrew claws in dairy cattle

Corkscrew claw (CC) in dairy cattle is increasingly reported in dairy herds. CC is a progressive deformity of the claw capsule with uncertain aetiology and pathogenesis. Genetics and specific environmental factors are suspected of contributing to the development of this irreversible condition. CC has been found in lame cows; however, the cause and effect has not been established. To perform analysis of risk factors, treatment and pathogenesis, a definition of severity scores is called for. The aim of this study was to measure and analyse CC characteristics from photos of cows’ feet to describe and evaluate a scoring system for CC. Width of the visible part of the axial wall, degree of contact between the toe and the floor and angle of the distal part of the abaxial wall as a proxy for the deviation of the abaxial wall was measured from 393 pictures of CC. Based on the measurements on the claws, the parameter “width of the axial wall” was chosen to define the scores. The parameter was divided into three intervals to define either mild CC 0.3–2.0 cm, moderate CC 2.1–3.5 cm or severe CC>3.5 cm and correlation between the parameters; level of contact between the toe and the floor and the angle of the distal abaxial wall was evaluated.There was a significant positive linear correlation between width of the axial wall and angle of the distal part of the abaxial wall (r=0.91), the wider the axial wall, the more the abaxial wall deviated in the distal part. As the width of the axial wall increased the toe increasingly lost contact with the floor, this association was significant for mild CC and moderate CC but not for severe CC. The Interobserver agreement of the CC Scoring system was tested by 30 claw trimmers each scoring 32 cadaver feet and by 2 trained observers on 28 photos of feet using Cohen´s weighted kappa and showed substantial to almost perfect agreement between untrained and trained observers, respectively.

Numerical analysis of 3D hydrodynamics and performance of an array of oscillating water column wave energy converters integrated into a vertical breakwater

Performance and hydrodynamics of an array of Oscillating Water Column (OWC) Wave Energy Converter (WEC) integrated into a vertical breakwater is studied. The FLUENT® software, in which the numerical model is based on the Reynolds-Averaged Navier-Stokes equations and the Volume of Fluid method for free surface flow modeling, is used in a 3D numerical wave tank. Three vertical breakwater configurations subject to the action of incident regular waves with periods from 6 to 12 s are studied: normal breakwater, with vertical walls parallel to the direction along the breakwater length; and two novel breakwater geometries, partially and fully convergent breakwaters, whose converging vertical walls are inclined θ in relation to this direction. Different spacing S from 0 to 20 m between the array of OWC devices and two converging wall angles θ, 30 and 45°, are investigated. Firstly, analysis of the influence of S for the normal breakwater shows that the vertical wall concentrates naturally a higher quantity of the incident wave energy inside OWC chamber devices and, consequently, increases their efficiencies. This effect is intensified as the spacing S increases. Secondly, analyses of the partially and fully convergent breakwaters allow concluding that these novel geometries, which direct an amount of incident wave energy into the OWC chamber, increase significantly the efficiency of the array of the OWC devices at the range of the wave periods. The highest performance of OWC device is obtained by the fully convergent breakwater with S = 20 m and θ = 45°, once 10 OWC devices inserted in a breakwater 300 m long have the same efficiency of 20 OWC devices inserted into the normal breakwater.