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An important factor resulted from the ascension of the milk and milk-based by-products production is many effluents directly released into the environment. The main objective of this study was to evaluate the efficiency of the combination of the chemical coagulation, with ferric chloride as a coagulant, and the membrane separation processes (MSP) and reverse osmosis (RO) processes in the treatment of effluents from a powdered milk dairy industry. To evaluate the effectiveness of the integration of these mechanisms, the characterization of the effluents was carried out through Total Nitrogen (N

Studies of dairy cow longevity usually focus on the animal life after first calving, with few studies considering early life conditions and their effects on longevity. The objective was to evaluate the effect of birth conditions routinely collected by Dairy Herd Improvement agencies on offspring longevity measured as length of life and length of productive life. Lactanet provided 712,890 records on offspring born in 5,425 Quebec dairy herds between January 1999 and November 2015 for length of life, and 506,066 records on offspring born in 5,089 Quebec dairy herds between January 1999 and December 2013 for length of productive life. Offspring birth conditions used in this study were calving ease (unassisted, pull, surgery, or malpresentation), calf size (small, medium, or large), and twinning (yes or no). Observations were considered censored if the culling reason was "exported," "sold for dairy production," or "rented out" as well as if the animals were not yet culled at the time of data extraction. If offspring were not yet culled when the data were extracted, the last test-day date was considered the censoring date. Conditional inference survival trees were used in this study to analyze the effect of offspring birth conditions on offspring longevity. The hazard ratio of culling between the groups of offspring identified by the survival trees was estimated using a Cox proportional hazard model with herd-year-season as a frailty term. Five offspring groups were identified with different length of life based on their birth condition. Offspring with the highest length of life [median = 3.61 year; median absolute deviation (MAD) = 1.86] were those classified as large or medium birth size and were also the result of an unassisted calving. Small offspring as a result of a twin birth had the lowest length of life (median = 2.20 year; MAD = 1.69) and were 1.52 times more likely to be culled early in life. Six groups were identified with different length of productive life. Offspring that resulted from an unassisted or surgery calving and classified as large or medium when they were born were in the group with the highest length of productive life (median = 2.03 year; MAD = 1.63). Offspring resulting from a malpresentation or pull in a twin birth were in the group with the lowest length of productive life (median = 1.15 year; MAD = 1.11) and were 1.70 times more likely to be culled early in life. In conclusion, birth conditions of calving ease, calf size, and twinning greatly affected offspring longevity, and such information could be used for early selection of replacement candidates.

Additive manufacturing is an evolving technology for fabricating porous structures used in a broad array of applications, ranging from the aerospace industry to biomedical engineering. Porous titanium alloy (Ti6Al4V) structures play a major role in biomedical implants and are preferred over conventional solid implants because their properties can be tailored to obtain the stiffness required to avoid stress shielding and improve osteointegration. The mechanical properties of these structures are dependent on unit cell topology and overall porosity. In the present work, three open cellular configurations were studied, namely regular (square), irregular (skewed square) and fully random structures, at three different porosity levels. The samples were manufactured using the selective laser melting of spherical Ti6Al4V powder. The deviations of manufactured samples from as designed were assessed using morphological characterisations and porosity analyses. The mechanical characterisations of the samples included monotonic and cyclic tensile tests, along with conventional compression tests under monotonic and cyclic conditions. The results from the study indicate a clear deviation of thickness values from as-designed values. The effect of inclination of the strut with respect to the loading axis has been studied in compression samples. The off-axis loading in compression led to the asymmetry in the Young's modulus in compression and tension. These led to finite element modelling of structures in the elastic regime and its validation using Gibson–Ashby model for cellular structures.

There are many blackberry cultivars in Brazil; however, the characteristics and applications of the Cherokee cultivar have not yet been widely studied. For this reason, this research investigated the behaviour of maltodextrin (MD), gum Arabic (GA), and pectin (PEC), as carriers combined in different proportions (20% MD, 15% MD + 5% GA, 15% MD + 5% PEC), on encapsulation of Cherokee blackberry pulp extract obtained by freeze-drying. The results of moisture content (2.73-3.36%), water activity (aw) (0.11–0.15), solubility (52.40–54.11%), hygroscopicity (17.59–21.11%), colour (hue 0.24–0.32), retention of anthocyanins (51.55–60.53%), total phenolic compounds (39.72–70.73 mg GAE/100g), antioxidant activity at 25 mg/mL (77.89–80.02%), IC50 (12.26–14.53), simulated in vitro digestion and morphology were discussed. Concerning morphology, blackberry powders had irregular structures and amorphous structures. Comparatively, the best results were obtained for MD-GA. MD-GA presented the highest content of phenolic compounds (70.73 ± 1.84 mg GAE/100g) and antioxidant activity (80.02%), as well as the lowest IC50 value (12.26). In general, all powders showed an increase in phenolic compounds during in vitro digestion, because of the pH conditions and digestive enzymes present in the simulated digestive fluid. This result shows that the wall material provides protection, since the blackberry rich extract (RE) showed degradation of phenolic compounds in in vitro digestion. In this sense, freeze-drying is a suitable technique for the encapsulation of Cherokee blackberry pulp extract.

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The use of prerecorded data to remotely assess the herd welfare status is a promising approach to reduce the need for costly and time-consuming on-farm welfare assessments. Therefore, the objective of this study was to validate the Herd Status Index, an index developed based on Dairy Herd Improvement data from Canada, to remotely evaluate the welfare status of dairy herds. Herd-level prevalence of five animal-based welfare outcomes, measured once on 2 986 Quebec - Canada dairy herds between 2016 and 2019, were used to generate clusters with different welfare status using the algorithm partitioning around medoids. Dairy Herd Improvement data from 12 months prior to the welfare assessment were extracted and used to calculate the Herd Status Index. A linear model was used to carry out comparisons between clusters. Three stable clusters were found to best describe the data. Cluster two had the best overall welfare status since it had the lowest prevalence of all welfare issues while cluster three had the highest prevalence of most welfare issues, with the exception for the prevalence of neck lesions that was not different than cluster one. Cluster one had an overall intermediate welfare status. The Herd Status Index was higher (i.e., indicating a good welfare status) on cluster two compared to cluster three, but neither cluster three nor two differed to cluster one. In its current format, the Herd Status Index has a weak potential to identify herds with varying prevalence of welfare issues and it requires further improvements before it could be used to accurately assess the welfare status of the herds.

The present work investigates cellular materials that can be potentially used as a replacement of solid implants owing to their mechanical properties and biocompatibility. More specifically, titanium alloy (Ti6Al4V) cellular materials of three different topologies were considered to study the effect of the degree of irregularity. Cubic regular, cubic irregular and trabecular structures were manufactured using Laser based powder bed fusion (LB-PBF) process. The LB-PBF process had an impact on the strut thickness of the samples. Samples were subjected to micro computed tomography to understand the geometrical deviations and to use the actual geometry for finite element analysis. Mechanical properties such as Young's modulus and strength were derived from compression and tensile testing. The results indicate that the Young's modulus was between 6 and 17 GPa, which were closer to the values of human cortical bone. The finite element analysis results showed a good correlation with the tensile test results as well. Furthermore, Gibson–Ashby model is used to study the effect of cell topology on the structural behavior. The model indicated that the misalignment of nodes of cubic regular structures to form irregular structure, transformed the stretching dominated behavior of cubic structures to bending dominated behavior like trabecular structures. Finally, the regular structures appeared to be much more prone to catastrophic failure than irregular and trabecular structures. Both visual observation of experimental testing and FE analysis explained this difference as result of different modes and zones of failures.

Selective Laser Melting (SLM) is a technology that allows for the realization of metallic porous solids that cannot be produced with other methods. Nevertheless, a geometric discrepancy between the as-designed and as-built part is a well-known issue that can be critically important for biomedical metallic lattices with pore size and strut thicknesses of a few hundred microns. In practice, any geometric imperfection introduces a degree of uncertainty that can alter the mechanical properties of the as-built lattice. A quantitative relationship between the as-designed geometry and the real geometry is a very useful design tool because it makes possible to predict the final morphology of the lattice by considering the manufacturing errors: a more predictable geometry of the lattice structure means more predictable mechanical properties of the implant. In this work, we investigate the relationship between the as-designed strut thickness and the printed strut thickness for regular cubic cell lattices. The joints between the struts are filleted to reduce the stress concentration and increase fatigue resistance. The size of the unit cell is scaled to find the smallest radius which can be accurately reproduced. Moreover, we also studied the effect of the printing direction on geometrical accuracy

Additive manufacturing of industrially-relevant high-performance parts and products is today a reality, especially for metal additive manufacturing technologies. The design complexity that is now possible makes it particularly useful to improve product performance in a variety of applications. Metal additive manufacturing is especially well matured and is being used for production of end-use mission-critical parts. The next level of this development includes the use of intentionally designed porous metals - architected cellular or lattice structures. Cellular structures can be designed or tailored for specific mechanical or other performance characteristics and have numerous advantages due to their large surface area, low mass, regular repeated structure and open interconnected pore spaces. This is considered particularly useful for medical implants and for lightweight automotive and aerospace components, which are the main industry drivers at present. Architected cellular structures behave similar to open cell foams, which have found many other industrial applications to date, such as sandwich panels for impact absorption, radiators for thermal management, filters or catalyst materials, sound insulation, amongst others. The advantage of additively manufactured cellular structures is the precise control of the micro-architecture which becomes possible. The huge potential of these porous architected cellular materials manufactured by additive manufacturing is currently limited by concerns over their structural integrity. This is a valid concern, when considering the complexity of the manufacturing process, and the only recent maturation of metal additive manufacturing technologies. Many potential manufacturing errors can occur, which have so far resulted in a widely disparate set of results in the literature for these types of structures, with especially poor fatigue properties often found. These have improved over the years, matching the maturation and improvement of the metal additive manufacturing processes. As the causes of errors and effects of these on mechanical properties are now better understood, many of the underlying issues can be removed or mitigated. This makes additively manufactured cellular structures a highly valid option for disruptive new and improved industrial products. This review paper discusses the progress to date in the improvement of the fatigue performance of cellular structures manufactured by additive manufacturing, especially metal-based, providing insights and a glimpse to the future for fatigue-tolerant additively manufactured architected cellular materials.

Simple Summary The ability of farms to produce milk sustainably is closely related to dairy cow longevity, i.e., the length of productive life. However, longevity is a very complex feature that depends on all the aspects of the lifespan of a cow and there is no standard definition nor metric to measure it. Measuring longevity is important because it influences the profitability and the environmental impact of farms as well as the welfare of the animals. The objectives of this paper were to review metrics used to measure longevity and describe its status among high milk-producing countries. Increasing dairy cow longevity would imply that an animal has an early age at first calving and a long and profitable productive life. Combining age at first calving, length of productive life, and margin over all (available) costs provides a complete evaluation of longevity. This paper also shows that dairy cow longevity has decreased in most high milk-producing countries over time, which confirm the concerns voiced by the dairy industry and other stakeholders. Increasing cow longevity would reduce health costs and increase cow profitability while improving both animal welfare and quality of life, contributing to a more sustainable dairy industry. Abstract The ability of dairy farmers to keep their cows for longer could positively enhance the economic performance of the farms, reduce the environmental footprint of the milk industry, and overall help in justifying a sustainable use of animals for food production. However, there is little published on the current status of cow longevity and we hypothesized that a reason may be a lack of standardization and an over narrow focus of the longevity measure itself. The objectives of this critical literature review were: (1) to review metrics used to measure dairy cow longevity; (2) to describe the status of longevity in high milk-producing countries. Current metrics are limited to either the length of time the animal remains in the herd or if it is alive at a given time. To overcome such a limitation, dairy cow longevity should be defined as an animal having an early age at first calving and a long productive life spent in profitable milk production. Combining age at first calving, length of productive life, and margin over all costs would provide a more comprehensive evaluation of longevity by covering both early life conditions and the length of time the animal remains in the herd once it starts to contribute to the farm revenues, as well as the overall animal health and quality of life. This review confirms that dairy cow longevity has decreased in most high milk-producing countries over time and its relationship with milk yield is not straight forward. Increasing cow longevity by reducing involuntary culling would cut health costs, increase cow lifetime profitability, improve animal welfare, and could contribute towards a more sustainable dairy industry while optimizing dairy farmers’ efficiency in the overall use of resources available.

The inverse search determination of the strain-energy-density (SED) control radius R1 devised in Benedetti et al. Int J Fatigue 2019;126:306-318 and based on the knowledge of the notch fatigue factor estimated using an optimal V-notch specimen geometry is here reformulated to take into account the statistical properties of the input fatigue properties. It was found that R1 exhibits a non-symmetric probability density function that is well represented by a skew-normal distribution. The uncertainty in R1 can be attributed to the uncertainty in the inverse search procedure and to the material variability in notch sensitivity. By applying the devised procedure to real experimental data, it was found that the former contribution is preponderant in the assessment of very sharp notches, while the latter dictates the fatigue strength of blunt notches, especially in the case of intrinsically flawed materials, such as those additively manufactured.

Pitting is frequently encountered in machine elements, such as bearings, cams and gears, containing parts in relative sliding-rolling motion. Most of investigations on rolling contact fatigue have been carried out by means of numerical/analytical models in the frame of LFEM, but the interpretation of the numerical results is still controversial. The SIFs history is highly non-proportional and the intensity of the peaks is not expected to cause propagation, since they do not exceed the fatigue threshold usually found for long cracks in steels and cast irons. To shed light on this issue, this work is intended to reproduce experimentally the SIF-cycles, estimated by our previous model of RCF crack, by using an alternative non-standard procedure. The novel experimental apparatus is based on the exploitation of a kinked edge crack subjected to a compressive load distributed through the thickness. Changing the load position and intensity permits to induce different values and ratios of SIFs. It has been found that lubricant is strictly necessary to trigger crack propagation, which can be in form either of coplanar extension followed by branching or of branching only. Coplanar extension occurs when mode II SIF range exceeds a certain threshold, well below the typical fatigue threshold. Empirical evidences are in accordance with the tendency of the RCF cracks to do coplanar extension and to branch into the bulk material and toward the surface. Coplanar extension is more pronounced in the interior of the sample, while branching occurs only at the edges. The results indicate that our previous modelling of RCF crack is likely to underestimate the effective SIFs. Thus this work would open the way to improve the actual understanding and modelling of RCF.

Milk is rich in nutrients, but several factors in the production system interfere with its quality. The objective of this study was to analyze the composition and microbiological quality of raw milk stored in community tanks from the municipality of Aricanduva – Minas Gerais. Samples were collected from eight community tanks at different properties. The milk composition and temperature were analyzed using the digital milk analyzer. The total count of aerobic mesophilic microorganisms was performed at the Laboratory of Science and Technology of Products of Animal Origin, Department of Animal Science, Federal University of Vales do Jequitinhonha and Mucuri, Diamantina – Minas Gerais. The data obtained were compared to the values established by Normative Instruction (IN) n° 76, by means of Student's t-test and Wilcoxon's non-parametric test at the level of 5% of significance. The average levels of fat (3.55 g/100g), protein (3.00 g/100g), lactose (4.45 g/100g) and total solids (11.76 g/100g) were within the standards minimum required. The content of defatted solids (8.21 g/100g) was the limiting factor to the compliance with IN76, with an average value lower than that established (8.40 g/100g). The temperature of the milk was higher than the standard required by the legislation and the count of mesophilic microorganisms did not differ from the legislation. It is concluded that the composition of raw milk stored in community tanks in the municipality of Aricanduva – Minas Gerais, compared to IN 76, did not fully met the legislation in all evaluated parameters. La leche es rica en nutrientes, pero varios factores del sistema de producción interfieren con su calidad. El objetivo fue analizar la composición y calidad microbiológica de la leche cruda almacenada en tanques comunitarios en el municipio de Aricanduva MG. Se recolectaron muestras por duplicado de ocho tanques comunitarios en diferentes propiedades. Los análisis de composición y temperatura de la leche se realizaron utilizando un analizador de leche digital. El recuento total de microorganismos aeróbicos mesófilos se realizó en el Laboratorio de Ciencia y Tecnología de Productos de Origen Animal, Departamento de Ciencia Animal, Universidad Federal de Vales do Jequitinhonha y Mucuri, Diamantina MG. Los datos obtenidos se contrastaron con los valores establecidos por la Instrucción Normativa (IN) No. 76, utilizando las pruebas t de Student y Wilcoxon a un nivel de significancia del 5%. Los contenidos medios de grasa (3,55 g / 100 g), proteína (3,00 g / 100 g), lactosa (4,45 g / 100 g) y sólidos totales (11,76 g / 100 g) estuvieron dentro de los estándares mínimos requeridos. El contenido de sólidos desgrasados (8.21 g / 100g) fue el factor limitante para cumplir con la IN76, con un valor promedio menor al establecido (8.40 g / 100g). La temperatura de la leche fue más alta que el estándar requerido por la legislación y el recuento de microorganismos mesófilos no difirió de la legislación. Se concluye que la composición de la leche cruda almacenada en tanques comunitarios en el municipio de Aricanduva MG, en comparación con la EN 76, no cumplió con la legislación en todos los parámetros evaluados y su calidad microbiológica se vio comprometida, ya que las temperaturas estuvieron por encima del valor recomendado por legislación. O leite é rico em nutrientes, porém vários fatores do sistema de produção interferem em sua qualidade. Objetivou-se analisar a composição e qualidade microbiológica do leite cru armazenado em tanques comunitários no município de Aricanduva MG. Foram coletadas amostras em duplicatas de oito tanques comunitários em diferentes propriedades. As análises de composição e temperatura do leite foram realizadas através do analisador de leite digital. A contagem total de microrganismos aeróbios mesófilos foi realizada no Laboratório de Ciência e Tecnologia de Produtos de Origem Animal do Departamento de Zootecnia, da Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina MG. Os dados obtidos foram contrastados aos valores estabelecidos pela Instrução Normativa (IN) n° 76, por meio dos testes t de Student e Wilcoxon ao nível de 5% de significância. Os teores médios de gordura (3,55 g/100g), proteína (3,00 g/100g), lactose (4,45 g/100g) e sólidos totais (11,76 g/100g) encontraram-se dentro dos padrões mínimos exigidos. O teor de sólidos desengordurados (8,21 g/100g) foi o fator limitante ao atendimento à IN76, com valor médio menor que o estabelecido (8,40 g/100g). A temperatura do leite foi maior que o padrão exigido pela legislação e a contagem de microrganismos mesófilos não diferiu da legislação. Conclui-se que a composição do leite cru armazenado em tanques comunitários no município de Aricanduva MG, comparada à IN 76, não atendeu a legislação em todos os parâmetros avaliados e a sua qualidade microbiológica estava comprometida, uma vez que as temperaturas estavam acima do valor preconizado pela legislação.

Pitting is one of the causes of failure for mechanical components subjected to rolling contact fatigue. In the present article, a FE model is described in which a 2D half-space with an edge crack is affected by a travelling contact load produced by a cylindrical body. The contact load is not approximated by an analytical pressure distribution but the actual mating bodies are modelled. The presence of lubricant between the mating bodies and inside the crack is taken into account and its effect on the crack is simulated via hydrostatic elements. The lubricant is assumed to be entrapped into the crack by the external body when the latter covers the crack mouth, that is, the crack is sealed by the contact area and not by the contact between the crack faces (fluid entrapment mechanism). The pressure of the fluid is calculated via an iterative procedure by assuming that its volume stays constant inside the crack. Comparisons between this model and the alternative fluid pressurization mechanism have been made. The effects of the coplanar extension are investigated. The outcomes suggest that the fluid pressures inside the crack produced by the fluid entrapment mechanism tend to those of the fluid pressurization mechanisms as the crack becomes short.

Cellular materials are characterized by a complex interconnected structure of struts or plates and shells, which make up the cells edges and faces. Their structure can be advantageously engineered in order to tailor their properties according to the specific application. This aspect makes them particularly attractive for the manufacturing of bone prosthetics, where the elastic modulus of the implant should match that of the bone in order to avoid loosening due to the stress shielding phenomenon. In this regard, the ability to design a component with the desired mechanical response is crucial. For this reason, the present paper evaluates the stiffness of 2D cellular structures with variously arranged square cells. Specifically, two spatial arrangements are considered: the former one is a regular square cell honeycomb, while in the latter the square cells are staggered by a prescribed offset of half of the cell wall length. An analytical model based on classical beam theory is proposed to identify the effect of stretching and bending actions on the stiffness of a single cell by applying the periodic boundary conditions. The theoretical beam model is fitted on the results from a 2D Finite Elements model based on plane elements via an extensive parametric analysis. In this way, semi-analytical formulas are proposed to calculate the stiffness in large domains of the geometric parameters: wall thickness to edge length ratio in the interval [0.04,0.20] and fillet radius to edge length ratio in the interval [0,0.15].

Fully dense titanium alloy implants have long been used for the replacement and stabilization of damaged bone tissue. Nevertheless, they can cause stress shielding which brings to a loss of bone mass. Additive manufacturing (AM) allows obtaining highly porous cellular structures with a wide range of cell morphologies to tune the mechanical properties to match that of the patient’s bone. In this work, the fully reversed fatigue strength of cellular specimens produced by Selective Laser Melting (SLM) of Ti-6Al-4V alloy was measured. Their structures are determined by cubic cells packed in six different ways and their elastic modulus is roughly 3GPa to match that of trabecular bone. Part of the specimens was left as sintered and part treated by Hot Isostatic Pressing (HIP). The fatigue resistance of such AM parts can be affected by surface morphology, geometrical accuracy as well as internal defects. Micro X-ray computed tomography (CT) was used in this work to compare the geometry of the produced specimens with the CAD model and to carry out residual stress measurements using the Plasma FIB-SEM-DIC micro-hole drilling method.

Porous structures have great potential in the biomedical field because, compared to traditional fully dense implants, prostheses with a porous structure show reduced stress shielding and improved osseo-integration. Selective Laser Melting (SLM) made possible to obtain metallic cellular materials with highly complex structures characterized by a wide range of cell morphologies that allow to finely tune the mechanical properties of the implant. Nevertheless, there are still several issues to address: among others, detrimental residual stresses and the discrepancy between the as-designed and the manufactured geometry. Micro X-ray computed tomography (µCT) combined with the Finite Elements (FE) method permits to carry out in-depth investigations on the effect of the number and severity of defects on the mechanical properties. In the current study, the results of fatigue and quasi-static tests were compared with FE calculations based on the as-designed geometry and on the as-built geometry reconstructed from µCT scans. Both the elastic modulus and the fatigue resistance resulted strongly correlated with the number and severity of defects. Moreover, predictions of the mechanical properties based only on the as-designed geometry were shown not to be accurate. The importance of considering the limitations in accuracy of the manufacturing technique when designing load bearing lattice structures was highlighted.

Laser Powder Bed Fusion (L-PBF) provides ample freedom to fabricate lattice materials with tailored micro-architecture. Nevertheless, small-scale structures often suffer from a wide range of morphological defects, which impact the macro-scale mechanical properties. In this work, prominent morphological factors including geometric irregularities (surface notches and cross-section deviation), node geometry and printing direction are assessed for four batches of L-PBF Ti-6Al-4 V cubic lattice specimens, and their fatigue behavior compared. The results show that smoothing the strut fillets at their node remarkably improves the S-N curves and that the printing direction impacts both the fatigue strength and the failure behavior.

Mediale patellaluxatie is een veel voorkomende aandoening bij de hond. Het komt het vaakst voor bij kleine honden maar grote hondenrassen kunnen zeker ook aangetast zijn. De meest voorkomende oorzaak van patellaluxatie is van congenitale oorsprong. Een traumatische oorzaak is zeldzaam. De origine van deze aandoening ligt in een verplaatsing van de krachten van het quadricepsmechanisme die tot misvorming van de femur, tibia en patella kan leiden. Therapeutische en chirurgische opties voor mediale patellaluxatie zijn reeds veelvuldig beschreven. In dit artikel wordt een samenvatting gegeven van de verschillende behandelingsopties en hun mogelijke complicaties.

Pitting is one of the causes of failure for mechanical components subjected to rolling contact fatigue. In the present article, a FE model is described in which a 2D half-space with an edge crack is affected by a travelling contact load produced by a cylindrical body. The contact load is not approximated as usual by an analytical pressure distribution but the actual mating body is modelled. The presence of lubricant between the mating bodies and inside the crack is taken into account and its effect on the crack is modelled via hydrostatic elements. The lubricant is assumed to be entrapped into the crack by the external body when the latter covers the crack mouth, that is, the crack is sealed by the contact area and not by the contact between the crack faces (fluid entrapment mechanism). The pressure of the fluid is calculated via an iterative procedure by assuming that its volume stays constant inside the crack. Comparisons between this model and the alternative fluid pressurization mechanism have been made. The outcomes suggest that the fluid pressures inside the crack produced by the fluid entrapment mechanism tend to those of the fluid pressurization mechanisms as the crack becomes short.

Traditional implants made of bulk titanium are much stiffer than human bone and this mismatch can induce stress shielding. Although more complex to produce and with less predictable properties compared to bulk implants, implants with a highly porous structure can be produced to match the bone stiffness and at the same time favor bone ingrowth and regeneration. This paper presents the results of the mechanical and dimensional characterization of different regular cubic open-cell cellular structures produced by Selective Laser Melting (SLM) of Ti6Al4V alloy, all with the same nominal elastic modulus of 3 GPa that matches that of human trabecular bone. The main objective of this research was to determine which structure has the best fatigue resistance through fully reversed fatigue tests on cellular specimens. The quality of the manufacturing process and the discrepancy between the actual measured cell parameters and the nominal CAD values were assessed through an extensive metrological analysis. The results of the metrological assessment allowed us to discuss the effect of manufacturing defects (porosity, surface roughness and geometrical inaccuracies) on the mechanical properties. Half of the specimens was subjected to a stress relief thermal treatment while the other half to Hot Isostatic Pressing (HIP), and we compared the effect of the treatments on porosity and on the mechanical properties. Fatigue strength seems to be highly dependent on the surface irregularities and notches introduced during the manufacturing process. In fully reversed fatigue tests, the high performances of stretching dominated structures compared to bending dominated structures are not found. In fact, with thicker struts, such structures proved to be more resistant, even if bending actions were present.

Metallic lattice biomaterials can be very complex structures that are often impossible to be fabricated with other manufacturing technologies than additive manufacturing (AM). Residual stresses and geometric defects such as severe notches and distorted struts are inevitably introduced into the printed structures and these can affect the mechanical and biological properties. Micro X-ray Computed Tomography (µCT) has been proven to be a very powerful tool for accurately measuring the mismatch between the as-designed CAD model and the SLM structure. In this work, selective laser melting (SLM) Ti6Al4V lattices were measured using a metrological µCT system to identify and classify the geometrical distortions introduced by the printing process. The µCT measurements have also been used to build Finite Element (FE) models based on beam elements that make possible a quantification of the effect of these defects on the elastic modulus of the lattice by comparison with FE models based on the ideal geometry. Moreover, solid FE models of the junctions between the struts have been built by importing the CT data in Ansys® to calculate the stress concentrations caused by the severe notches.

In deze casuistiek wordt het voorkomen van een recente aandoening van de processus coronoideus medialis (medial coronoid disease, MCD) bij een elf jaar oude Labrador retriever beschreven. Voordat de hond werd aangeboden, liep hij reeds zes maanden mank op de linkervoorpoot. Radiografisch was er slechts een beperkte pathologie zichtbaar en via computertomografie werd een discrete fissuur van de mediale processus coronoideus aangetoond. Artroscopisch kon een letsel van de processus coronoideus medialis bevestigd worden, zichtbaar als chondromalacie. De behandeling bestond uit het artroscopisch verwijderen van het afwijkende kraakbeen en subchondrale been. Ondanks de geslaagde ingreep had de hond blijvend nood aan fysiotherapie om comfortabel te kunnen lopen. MCD is een ontwikkelingsstoornis die vooral jonge honden van grote rassen aantast. De hond in deze casereport was echter al elf jaar oud. Nochtans was de duur van de mankheid vrij kort en kon er via beeldvorming en artroscopie geen chronisch probleem aangetoond worden. In de literatuur is weinig informatie beschikbaar over de etiologie, het voorkomen en het behandelingsresultaat van MCD bij oude honden.

In navolging van de humane geneeskunde is de interesse in stamceltherapie ook in de diergeneeskunde sterk toegenomen. Door de toenemende media-aandacht is stamceltherapie voor velen zelfs een bekende term geworden. In de diergeneeskunde is de toepassing van stamceltherapie voornamelijk gericht op orthopedische aandoeningen bij paarden en honden, aangezien klassieke medicamenteuze en chirurgische therapieën voor vele bot-, kraakbeen- en ligamenteuze aandoeningen vaak niet resulteren in een volledig functioneel herstel...

Profound physiological changes occur in the body of a dairy cow during the transition period. Most of the metabolic disorders and infectious diseases are diagnosed during this time compromising the lactation overall success. Even though it has been proposed methods to evaluate the transition programme in multiparous dairy cows, the same has not been observed for dairy heifers. The present paper aimed at determining which Dairy Herd Improvement (DHI) metrics have the largest impact on first test day milk yield (FT_MILK) of primiparous dairy cows as well as building and comparing predictive models of FT_MILK from animals in this category. We used information from the first test day of 3267 Holstein primiparous dairy cows collected between 2014 and 2017. Data were split into training (n = 2345) and validation (n = 780) data set that were used to estimate model parameters and to evaluate the models, respectively. Variables associated to FT_MILK were identified using regularized regression via elastic net. Three types of models were evaluated: multivariate linear regression (MLR), random forest (RF), and artificial neural network (ANN). The resulting models were evaluated based on six fit-statistics and 10-fold cross validation. In addition, Pearson correlation coefficient and Lin's concordance correlation coefficient were calculated between predicted and observed values, as well as the comparison between observed and predicted median FT_MILK. Statistical significance was declared at an error level α

RESUMO – Os processos que utilizam lipases sao especialmente atraentes em funcao das diferentes aplicacoes. A enzimas imobilizadas possibilita uma maior estabilidade e a producao de biocatalisadores com aplicacoes industriais. O poliuretano permite o reuso da enzima reduzindo os custos de producao alem de facilidade no processo. O presente trabalho teve como objetivo a imobilizacao da lipase Candida antarctica B (Novozyme) em espuma flexivel de PU de densidades diferente (D18 e D30), avaliando a capacidade de reuso na sintese do etiloleato. Para a avaliacao do processo de reutilizacao, apos cada reacao da quantificacao da atividade de esterificacao, o excedente do produto da reacao de esterificacao era retirado. Em seguida uma nova quantidade de solucao padrao – 5mL (acido oleico:etanol) era adicionado ao imobilizado e era realizado uma nova reacao e assim sucessivamente ate o imobilizado atingir 50% da sua atividade residual inicial. A quantificacao da atividade de esterificacao foi realizada por titulometria. Ao final do estudo foi observado um total de 6 e 4 reciclos com atividade residual de 50 % para os imobilizados em espuma flexivel de PUD18 e D30 respectivamente. Para a enzima livre o numero de reciclos foram 4, porem, com atividade enzimatica menor que 20%.

RESUMO – As lipases podem ser eficientemente aprisionadas nos poros de silicatos hidrofobicos obtidos pelo processo sol-gel. Este metodo e simples e barato, em que uma mistura de um precursor da silica e hidrolisada por iniciadores da reacao de polimerizacao na presenca da enzima. Aditivos, tais como polietilenoglicol (PEG), aumentam a eficiencia deste tipo de imobilizacao da lipase. A principal area de aplicacao destes biocatalisadores heterogeneos diz respeito esterificacao ou transesterificacao em solventes orgânicos. Para a imobilizacao, o percursor da silica tetraetilortosilicato (TEOS) foi dissolvido em alcool etilico absoluto, e testados os tres diferentes iniciadores da reacao de polimerizacao: acido (HCl), basico (HBr) e nucleofilico (NH4OH). As determinacoes das atividades de esterificacao foram realizadas na sintese de oleato de etila na solucao enzimatica (enzima livre) e nos xerogeis imobilizados armazenados em temperatura ambiente e refrigeracao. Os resultados dos ensaios de estabilidade confirmaram a tendencia do processo de imobilizacao de enzimas, ou seja, a imobilizacao conferiu uma maior estabilidade da enzima imobilizada comparada com a enzima livre. No estudo foi possivel verificar, tambem, que a presenca de aditivo PEG influenciou no aumento do numero de ciclos e os suportes mantiveram-se estaveis por mais tempo armazenada em refrigerador quando se utilizou os iniciadores da reacao de polimerizacao nucleofilico e basico.