De Laval Research Articles

Design and Development of a Mini Steam Turbine for Domestic Electric-Powered Application

This work focuses on the design and development of a single stage De Laval impulse type of steam turbine connected to an AC generator for the purpose of generating electricity for domestic use. The system possesses several components such as turbine runner and blades, turbine casing, steam inlet nozzle and AC generator. The system is designed to work with a steam generator (boiler) fired by biogas, which is connected to the rotary (turbine blade) system via a nozzle. Factors such as steam pressure, temperature, velocity and mass flow rate of steam and nozzle angle are the key input variables that help in the development, construction and fabrication of the turbine wheel (blades and rotor). The developed mini steam turbine was simulated using solid works software and the von mises result obtained for maximum and minimum stresses of the turbine frame and stand unit were 2.725 × 105N/m2 and 4.447 × 101N/m2, respectively with yield strength of 2.5 × 108N/m2. Also, the von mises maximum and minimum stresses of the turbine blade were 3.522 × 107N/m2 and 7.064 × 104N/m2, respectively with a yield strength of 2.413 × 108N/m2. The developed mini-turbine is designed to withstand the working conditions based on the static simulation and analysis of results obtained.

Numerical Analysis of De Laval Nozzle under Surrounding Zone and Compressed Flow

Numerical Analysis of De Laval Nozzle under Surrounding Zone and Compressed Flow

Atomization mechanism and powder morphology in laminar flow gas atomization

Metal powders prepared by laminar flow gas atomization have the advantages of small particle size and narrow particle size distribution. At present, the research on laminar flow gas atomization mainly focuses on the influence of process parameters on atomization and powder characteristics, but the atomization mechanism of laminar flow gas atomization is still not clear. In this work, the atomization gas flow, primary and secondary breakup mechanism, and particle morphology of the laminar flow gas atomization process are systematically investigated through numerical simulation and experimental analysis. The characteristics of single-phase atomization gas flow through the De Laval nozzle are studied using the standard <i>k-ε</i> turbulence model. The flow field structure shows a “necklace”-like structure with an expansion wave cluster of oblique shock. The primary and secondary atomization mechanism are investigated using the coupled level-set and volume-of-fluid model, which is validated by solidified fragments and powders after the atomization experiment, and results of the numerical simulation also provide some important advices for the application and specific process of laminar gas atomization technology. The studies indicate that the melts at the periphery of the liquid column are mainly peeled off by filaments or ligaments, which exhibits the small dimension and pressurized melt atomization characteristics. The secondary atomization is mainly based on the disintegration of spherical droplets in the mode of Rayleigh-Taylor instability deformation and sheet-thinning breakup. The simulation results also show that increasing the gas pressure and melt superheat can effectively reduce the probability of irregular powders to occur. The AlSi10Mg powders are obtained under a pressure of 2.0 MPa in the experiment on gas atomization, and the properties of the powders are analyzed. The results show that the powders have good sphericity and flowability, and the proportion of hollow powders is very low. In addition, the mean particle size of the AlSi10Mg powders is 54.3 μm, and the yield of fine powders reaches 48.7%, which is greatly improved compared with the traditional gas atomization processes. Moreover, about 90% of the powders have particle sizes in a range of 30–100 μm, which indicates that a narrow particle size distribution can be obtained by the laminar gas atomization technology.

Les français d'ici: des discours et des usages éd. par Sandrine Hallion et Nicole Rosen

Reviewed by: Les français d'ici: des discours et des usages éd. par Sandrine Hallion et Nicole Rosen Kelle L. Marshall Hallion, Sandrine, Nicole Rosen, éd. Les français d'ici: des discours et des usages. PU de Laval, 2019. ISBN 978-2-7637-4032-4. Pp. 224 The colloquium Les français d'ici has been organized biennially since 2006 at Canadian universities in regions with a Francophone heritage and community, such as Kingston (ON), Moncton (NB), and Montréal (QC). The colloquium is meant to be a platform for the presentation and discussion of linguistic research on North American varieties of French, including both formal and functional analytical approaches. Each instantiation of the colloquium has a particular organizing theme. In 2016, Les français d'ici was held at l'Université de Saint-Boniface in Winnipeg (MB), with the theme of comparative analyses of varieties of French and the promotion of trans-Canadian perspectives. This volume contains nine of the papers presented at the 2016 meeting, the first time the colloquium was hosted in western Canada. Five of the texts feature comparative analyses in which western varieties of French or discourses on them or on their speakers are represented. In the first of these, Laurence Arrighi and Émilie Urbain present a comparative corpus analysis of written and social media discourses surrounding French in Manitoba, comparing it to their previous [End Page 254] findings on discourses of the acadianisation of Canadian varieties of French. Geneviève Bernard Barbeau discusses an analysis of tweets and media discourse associated with the hashtag #nouscomptons, emanating from Francophone regions outside of Québec—including western provinces—during the 2015 federal elections. Pierre-Don Giancarli offers a detailed comparative analysis of pronominal verbs in oral and written Acadian and Laurentian varieties of French, drawing on corpora from New Brunswick, Québec, Ontario, Manitoba, and Saskatchewan. Liliane Rodriguez discusses a topolectal analysis of lexical variation in Manitoban varieties of French, investigating adolescent speech from fifteen communities. Samantha Cook interprets the literary devices of language use and code-switching in the creation of bilingual space and identity in Jean Chicoine's novel L'ange about a Franco-Manitoban poet. The volume also includes four texts featuring variation within eastern Canadian varieties of French. Franz Meier examines data drawn from thirty-nine interviews with Québécois journalistic experts (instructors, chroniqueurs de langage, translators, and copy-editors) on their conceptions of français correct and norms for written journalism in Québec. Ingrid Neumann-Holzschuh and Julia Mitko analyze the habitual aspect expressed by morphosyntactic forms such as the conditional mood, the past of the conditional, and the verbal construction aller + infinitive, among others, in varieties of French from New Brunswick, Newfoundland, and Louisiana. Carmen LeBlanc presents an analysis of English-language borrowings in madelinot French, comparing them to borrowings in Louisiana, Québécois, and Acadian French. Finally, Wladyslaw Cichocki and Yves Perrault present an acoustical analysis of variants of the phoneme "R" in five Acadian varieties of French in New Brunswick. In short, the texts chosen for the volume highlight the continued dedication among scholars in a wide range of linguistic subfields to the study of North American varieties of French. This collection will certainly be of interest to those who follow new developments in this field or who study variation in French more broadly. Kelle L. Marshall Pepperdine University (CA) Copyright © 2021 American Association of Teachers of French

Impact of various milking equipment on incidence of mastitis in dairy herd

It was found that the lowest percentage of cows with mastitis was recorded in winter: 10.3% (P≤0.001) when milking with ‘De Laval’ equipment and 17.7% (P≤0.001) when milking with the ADM-8A unit. The highest incidence of mastitis in cows was observed in summer: 21.0% (P≤0.001) and 27.1% (P≤0.001), respectively, when milking cows at milking parlors ‘De Laval’ and ADM-8A. It was found that, when using milking equipment ADM-8A, adult cows are 2.1-1.7 times more prone to mastitis compared to cows of the 1st and 2nd calving. When milking cows with the ‘De Laval’ unit, the incidence of mastitis in adult cows is 4.3-1.1 times higher than in cows of the 1st and 2nd calving. Gentle milking mode on the ‘De Laval’ equipment allowed to increase the number of completely healthy animals to 74%, which is 9.6% more than when using the milking unit ADM-8A (64.4%), and to reduce the incidence of clinical mastitis in cows by 3.4 times. It has been established that in cows with disorders in the udder the content of somatic cells in the secretion of the udder significantly changes (with a high degree of correlation) in all periods of the functional state of the body. Thus, during subclinical mastitis r=l0.72 (P≤0.001) and udder irritation r=l0.58 (P≤0.05). At the beginning of lactation, subclinical mastitis is accompanied with significant changes in the activity of enzymes: muramidase r=l0.84 (P≤0.001), lactoperoxidase r=l0.65 (P≤0.01) and lactoferrin r=l0.66 (P≤0.01).

First-Degree Relatives Screening of Patients with Bicuspid Aortic Valve: Effectiveness and Feasibility in Pediatric Cardiology Daily Practice.

Bicuspid aortic valve (BAV) is the most common congenital heart disease. Since heritability is suspected, actual guidelines recommend to perform an echocardiographic assessment for first-degree relatives (FDR) of patient with BAV. This study aimed to assess the effectiveness and the feasibility of the current guidelines for the screening of FDR of patient with BAV in a pediatric cardiology daily practice. Consecutive patients with BAV and their FDR were prospectively included from January 2015 to March 2018 at Centre Hospitalier Universitaire de Laval, Quebec City (Canada). Data were retrospectively collected and analyzed. A total of 713 FDR of 213 consecutives index cases [median age: 11 (6-20) years] were studied. Up to 32 (6.6%) FDR had a BAV and 26 (5.4%) had an aortic valve dysfunction. A total of 14 (2.9%) FDR had an ascending aorta dilatation according to Z-score including 6 (1.2%) patients with an ascending aorta ≥ 45mm. No statistically significant differences regarding BAV, aortic valve dysfunction and ascending aorta dilatation prevalence were identified between generations. Screening was done in 482 (67.6%), prescribed but not done in 134 (19%), not prescribed in 92 (13%) and declined in 5 (1%) FDR. The prevalence of BAV in FDR was similar to prospective adult studies and supports actual guidelines in pediatric cardiology practice. Ascending aorta dilatation was rare in our young population. Exhaustiveness and additional burden to implement current guidelines remain a challenge in daily practice.

Inflammation's Epigenetic Footprint in Hematopoietic Stem Cells.

Immune memory was thought to be unique to cells of the adaptive immune system. In this issue of Cell Stem Cell, de Laval etal. (2020) describe persistent epigenetic modifications in hematopoietic stem cells following an inflammatory insult with LPS as a mechanism by which immune memory may be established.

Stellar rotation effects on the stellar winds

The purpose of this paper is to give detailed systematic considerations to clarify and provide insights and a qualitative guide into the role of the azimuthal wind flow in the stellar-rotation braking mechanism. For this purpose, we make use of the Weber-Davis [Astrophys. J. 148, 217 (1967)] magnetohydrodynamic (MHD) version of Parker's [Astrophys. J. 128, 664 (1958)] stellar wind model. For the case when the magnetic field is primarily radial (as that near the surface of a star), the Weber-Davis [Astrophys. J. 148, 217 (1967)] “slow” magnetosonic critical point becomes Parker's [Astrophys. J. 128, 664 (1958)] sonic critical point, and the azimuthal wind flow can be approximated by corotation. Stellar rotation is shown to cause the sonic critical point to occur lower in the corona, and so the stellar wind experiences a stronger “afterburner” (as in an aircraft jet engine) action in the corona. Our results show that stellar rotation leads to considerably enhanced stellar wind acceleration even for moderate rotators like the sun. On the other hand, the stellar wind is shown to experience an immensely enhanced acceleration in a narrow shell near the star for strong rotators. This is underscored by the sonic critical point occurring considerably lower in the corona for strong rotators, hence supporting a huge afterburner action in the corona for such stars. For strong rotators, this sonic critical point is shown to be determined only by the basic stellar parameters such as mass M and angular velocity Ω∗, which signify the dominance of centrifugal and magnetic drivings in accelerating the stellar wind for such stars. Stellar rotation causes the physical throat section of the effective “de Laval” nozzle associated with the stellar wind flow to become narrower and the nozzle to also have a larger flare, indicative of an enhanced flow acceleration. The de Laval nozzle analogy does not, however, comply with the density drop in the stellar wind correctly. Thus, stellar rotation leads to tenuous and faster stellar wind flows without changes in the mass flux and hence enables protostars and strong rotators to lose their angular momentum quickly.

Le Carnet Pour Lui-Même ed. by François Dumont

Reviewed by: Le Carnet Pour Lui-Même ed. by François Dumont Douglas L. Boudreau Dumont, François, éd. Le carnet pour lui-même. PU de Laval, 2019. ISBN 978-2-920949-77-5. Pp. 202. In this collection, the writer's notebook, or carnet, is considered as a literary genre in its own right and not merely as a rough draft or proving ground for ideas to be used in future works. The first four articles consider the degree to which Roman emperor Marcus Aurelius, eleventh-century Japanese writer Sei Shōnagon, Michel de Montaigne, and Joseph Joubert may be read as carnettistes avant la lettre. The next several articles study more recent authors who published works labeled as carnets or cahiers during their lifetime, or whose personal notebooks became posthumously [End Page 219] available to the public as published works or in archives. These are Julien Gracq, Henri Thomas, Henry Bauchau, Aimé Césaire, Austrian Peter Handke, André Major, and Pierre Issenhuth. The last article in the issue looks at the overlap between the carnet and digital publishing formats such as blogs. The exploration of the carnet as a genre is enhanced by the chronological presentation of the articles, the works explored in the first four chapters appreciable as precursors to the carnet proprement dit. It is notable, for example, that Montaigne's comparison of his Essais to marginal grotesques is evoked in several of the articles to describe the kind of writing typically found in carnets. The carnet is revealed to be a genre of notable diversity. Some incorporate images and others do not. Some display genuinely spontaneous writing and in others the apparent artlessness is in fact the result of careful refining and curating of earlier writing. Despite this variety, there are common threads that run throughout this issue and which may define the carnet as a genre. The informality, real or apparent, of the carnet is shown to be part of its appeal and so, too, is the implied intimacy of the genre. The contributors note that this artlessness and spontaneity are reinforced by the form of the notebook as an object, bound blank pages upon which one is encouraged to scribble, and by its portability. The contributors place the informal qualities of the carnet in contrast to genres such as novels and poetry, in which the more formal or artistic use of language is seen as creating an undesirable distance between writing and lived experience. The articles on Major and Issenhuth highlight this aspect, which calls to mind the idea of vécrire from Jacques Godbout's Salut Galarneau!, notable in this context as a novel written in the form of two cahiers. The articles argue that acts of writing, editing, and rewriting that occur in a carnet contribute to an intriguing blurring of the line between writer and reader. The individual articles of this collection are fairly concise but meaty and thought-provoking. Some of the articles are more easily accessible to non-specialists than others, but the collection as a whole reveals the carnet as a genre ripe for further exploration. Taken altogether, this is a fascinating contribution to the field of French letters and should be of interest to a wide range of scholars. Douglas L. Boudreau Mercyhurst University (PA) Copyright © 2020 American Association of Teachers of French

190 ASAS-EAAP Exchange Speaker Talk: Beyond stainless steel and milk pumps: precision technology in the milking equipment world

Abstract What do you think of when you hear the words: milking equipment? Do you think of the different brands? Boumatic, DeLaval, GEA or Lely? Do you think of parlours, parallels or rotaries? Do you think of teat cups, liners or rubber hosing? Do you think of teat dips and cleaners? If you think of mostly hardware – I can’t blame you. If I look at DeLaval, the company I work for, it has a 136-year history of offering dairy producers revolutionary innovations. In 1878, Gustaf de Laval patented the cream separator, which was the basis for forming our company in 1883. (That was even before Old MacDonald’s farm.) DeLaval has since made other significant improvements in animal health and welfare, milk production, food safety and labor efficiency with technologies like: the vacuum operated milking machine (1917); a commercial rotary (1930); animal identification systems (1978); variable speed vacuum pumps (1977); milking robots (late 1990s); an on-farm lab called Herd Navigator; Clover-shaped liners (2013); a teat spray robot (2015); a body condition score camera (2015); and our latest robot, the VMSTM V300 (2018). DeLaval has been pushing the Brave New World for many years. Today, we have a software program called DelProTM Farm Manager – a powerful data management tool providing valuable information and analysis. It enables the dairy producer to make efficient daily actions and for advisors to monitor and provide profitable and sustainable management actions. As animal scientists, what is your role in this? One avenue is to consider working with the data to provide relevant summaries on what the information is telling us. You can have a role in influencing management changes for dairy farms for the future. While not all farms have access to this data and information, your research projects can help dairy farmers wanting to make improvements to their operations. Producers need non-bias, third party sources they can reference. The dairy farming world is changing; we all need to keep up. Make sure the research that you decide upon fits into this rapid pace.

Effect of evolocumab on lipoprotein apheresis requirement and lipid levels: Results of the randomized, controlled, open-label DE LAVAL study

Lipoprotein apheresis (LA) can effectively lower lipoproteins but is an invasive procedure. The objective of this study was to evaluate whether evolocumab can reduce LA requirement in patients undergoing chronic LA. Patients on regular weekly or every-2-week LA and moderate- to high-intensity statin (if tolerated) with pre-LA low-density lipoprotein cholesterol (LDL-C) levels ≥2.6mmol/L (100mg/dL) to ≤4.9mmol/L (190mg/dL) were randomized to continue the same LA frequency, or discontinue LA and receive evolocumab 140mg every-2-weeks subcutaneously for 6weeks. At week 6, all patients received only open-label evolocumab for 18weeks. The primary endpoint was LA avoidance at the end of 6weeks based on achieving pre-LA LDL-C <2.6mmol/L at week4. Thirty-nine patients (mean [SD] age 62 [10] years, 59% male, 82% with familial hypercholesterolemia) were randomized (evolocumab, n=19; LA, n=20). At the end of 6weeks, more patients receiving evolocumab avoided LA than those receiving LA (84% vs 10%; treatment difference, 74% [95% CI: 45, 87]; P<.0001). Thirty patients (77%) did not require LA at 24weeks. Evolocumab reduced pre-LA LDL-C by 50% from the baseline to week 4 compared with a 3% increase in the LA arm. Pre-LA LDL-C <1.8mmol/L (70mg/dL) was achieved by 10 patients (53%) receiving evolocumab and none receiving LA (week 4). Safety was comparable between arms. Evolocumab treatment significantly reduced LA requirement in patients undergoing chronic LA. In addition, >50% of patients achieved LDL-C <1.8mmol/L on evolocumab alone, demonstrating that in patients with pre-LA LDL-C ≤4.9mmol/L, evolocumab may replace LA.

Aerosol Deposition as a Promising Technique to Fabricating a Thin-Film Solid Electrolyte of Solid Oxide Fuel Cells

In present work we developed and tested model anode-supported planar solid oxide fuel cells. We used commercially available 2-layered (current-collector and functional) anode supports. Thin-film electrolyte layer based on 8 mol.% yttria-stabilized zirconia (YSZ) was produced by aerosol deposition method using converging-diverging (de Laval) type nozzle. To provide the fabrication of pinhole-free gas-tight thin-film electrolyte coatings, the pre-treatment procedure of initial powders was developed. The optimal operating parameters of the deposition modes of the YSZ solid electrolyte of different thicknesses are determined. Morphology analysis of the obtained thin-film coatings showed that the application of these modes provides the fabrication of thin-film YSZ layer with thickness of a few microns possessed good adhesion to the anode support, gas tightness and uniformity thickness.

Numerical assessment of miniaturized cold spray nozzle for additive manufacturing

Purpose Application of cold spray technology may exhibit significant benefits for the additive manufacturing process, particularly for producing intricate objects. To ascertain the feasibility of such an application, this paper aims to present a numerical investigation of the effect of scaling down a convergent-divergent (de Laval) nozzle, which is typically used in the cold spray industry, on the compressible flow parameters and thermal characteristics. Design/methodology/approach The Navier–Stokes equations and energy equation governing compressible flow are numerically solved using a finite volume method with a coupled solver. The conjugate heat transfer technique is used to couple fluid and solid heat transfer domains and predict the local heat transfer coefficient between the solid and fluid. The use of various RANS turbulence models has also been investigated to quantify the effect of the turbulence model on the simulation. Findings The numerical results reveal that the flow and thermal characteristics are altered as the convergent-divergent nozzle is scaled down. The static pressure and temperature profiles at any section in the nozzle are shifted toward higher values, while the Mach number profile at any section in the nozzle is shifted toward a lower Mach number. The turbulent kinetic energy at the nozzle exit increases with the scaling down of the nozzle geometry. This study also provides convincing evidence that the adiabatic approach is still suitable even though the temperature of the nozzle wall is extremely high, as required for industrial application. Results indicate that it is feasible to use the available capabilities of the cold spray technology for additive manufacturing after scaling down the nozzle. Originality/value The idea of adopting cold spray technology for additive manufacturing is new and innovative. To develop this idea into a viable commercial product, a thorough understanding of the flow physics within a cold spray nozzle is required. The simulation results discussed in this paper demonstrate the effect that scaling down of a convergent-divergent nozzle has on the flow characteristics in the nozzle.

Modeling Multiphase Effects in CO2 Compressors at Subcritical Inlet Conditions

An advanced numerical framework to model CO2 compressors over a wide range of subcritical conditions is presented in this paper. Thermodynamic and transport properties are obtained through a table look-up procedure with specialized features for subcritical conditions. Phase change is triggered by the difference between the local values of pressure and saturation pressure, and both vaporization and condensation can be modeled. Rigorous validation of the framework is presented for condensation in high pressure CO2 using test data in a De Laval nozzle. The comparisons between computations and test data include: condensation onset locations, Wilson line, and nozzle pressure profiles as a function of inlet pressures. The framework is applied to the Sandia compressor that has been modeled over broad range of conditions spanning the saturation dome including: near critical inlet conditions (305.4 K, and 7.843 MPa), pure liquid inlet conditions (at 295 K), pure vapor inlet conditions (at 302 K), and two-phase inlet conditions (at 290 K). Multiphase effects ranging from cavitation at the liquid line to condensation at the vapor line have been simulated. The role of real fluid effects in enhancing multiphase effects at elevated temperatures closer to the critical point has been identified. The performance of the compressor has been compared with test data; the computational fluid dynamics (CFD) results also show that the head-flow coefficient curve collapses with relatively minor scatter, similar to the test data, when the flow coefficient is defined on the impeller exit meridional velocity.

The Hidden Life of Monuments: Reflections from the Lost Stories Project

The Hidden Life of Monuments: Reflections from the Lost Stories Project Ronald Rudin (bio) SINCE 2012 I HAVE BEEN WORKING WITH historians, educators, artists, and filmmakers to develop the Lost Stories Project, which seeks from the public little-known stories from the Canadian past, gives these stories to artists who transform them into inexpensive pieces of public art on appropriate sites, and documents the artists’ creative process through the production of short films.1 When I came up with the concept for the project it was largely in the context of my own research over the past 15 years, which had explored the public representation of the past in both Quebec and Atlantic Canada with a particular emphasis upon the backstory that is usually impossible for the casual observer to perceive. In the case of Quebec, I examined the public memory of Samuel de Champlain and Mgr. François de Laval, generally viewed as the founding fathers of French-speaking Quebec: one the secular father (responsible for the settlement at Quebec City) and the other the religious founder (the first Roman Catholic bishop of Quebec).2 In regards to Atlantic Canada, I focused my attention on efforts in the early 21st century to commemorate both the founding moment for Acadians – the attempt to establish a permanent settlement on Île Ste-Croix in 1604 (so four years before Quebec City) – and their moment of trauma – the deportation of the Acadians between 1755 and 1763, or what they call “le grand dérangement.”3 I learned from these projects what others have also observed: namely, that public remembrance of the past – through such tools as the construction of [End Page 111] monuments – is really as much – maybe more – about the people who had the power to erect them than they were about the individuals being honoured. This point was convincingly made by Kirk Savage in his Monument Wars, which explores the commemorative landscape on the National Mall in Washington. Savage paid particular attention to the Washington Monument, the huge obelisk completed in the 1880s that bears no iconography that would directly link it to the first president of the United States. From Savage’s perspective, however, there was nothing odd about this situation because “this was indeed a ‘modern monument’ that had nothing to do with George Washington and his agrarian world. It was a monument to technocratic wisdom and bureaucratic efficiency, seemingly accessible to a democratic people yet remote from their experience and understanding.”4 But while there is a large scholarly literature that tries to tease out why and how some individuals are commemorated in public space (and others are not), sometimes this is simply not possible due to a lack of sources. In my own research, for instance, I was unable to find the minutes of the committee responsible for creating Quebec City’s monument in honour of Champlain, which was unveiled in 1898 only metres from the Château Frontenac. One report indicated that those minutes had been sealed inside the monument’s pedestal.5 More broadly, Savage has pointed to the challenges of such research since the archives provide only “a scattered record. Sometimes monument committees are very proud of themselves, and they publish their proceedings and then there are more records and archives. Other times they’re just lost entirely.”6 In this context, I imagined that Lost Stories could provide a solution since I would be able to watch the entire process unfold. What I could not have imagined in 2012, however, was that monuments were about to take centre stage in heated public debates across the globe, mostly prompted by demands for the removal of structures connected with now-disgraced individuals or deeds. By and large, these debates have only reinforced my sense of the pertinence of Lost Stories. As we will see in the following section of this short essay, the controversies surrounding such monuments as those dedicated to Confederate heroes in the American South have dealt only superficially with these structures and have largely ignored the context in which they were erected in the first place. Then, in the subsequent sections, I [End Page 112] will return to Lost Stories to discuss...

A comparative review on cold gas dynamic spraying processes and technologies

Cold gas dynamic spraying (CGDS) is a relatively new technology of cold spraying techniques that uses converging-diverging (De Laval) nozzle at a supersonic velocity to accelerate different solid powders towards a substrate where it plastically deforms on the substrate. This deformation results in adhesion to the surface. Several materials with viable deposition capability have been processed through cold spraying, including metals, ceramics, composite materials, and polymers, thereby creating a wide range of opportunities towards harnessing various properties. CGDS is one of the innovative cold spraying processes with fast-growing scientific interests and industrial applications in the field of aerospace, automotive and biotechnology, over the past years. Cold gas spraying with a wide range of materials offers corrosion protection and results in increases in mechanical durability and wear resistance. It creates components with different thermal and electrical conductivities than that substrates would yield, or produces coatings on the substrate components as thermal insulators and high fatigue-strength coatings, and for clearance control, restoration and repairing, or prostheses with improved wear, and produces components with attractive appearances. This review extensively exploits the latest developments in the experimental analysis of CGDS processes. Cold gas dynamic spraying system, coating formation and deposit development, description of process parameter and principles, are summarized. Industrial applications and prospectives of CGDS in future research are also commented.

Development and validation of BLRI Mastitis Test Kit at Bangladesh Livestock Research Institute Regional Station, Sirajganj.

Objective:The objective of this study was to develop a low-cost kit for the detection of subclinical mastitis (SCM) and to check its validity, reproducibility, and efficacy at the field level.Materials and Methods:A total of 550 quarter milk samples from crossbred dairy cows were collected, of which 400 milk samples were used to validate the newly developed BLRI mastitis test (BMT) kit to justify its efficacy as an individual test kit in detecting SCM based on somatic cell count (SCC) by direct microscopic count (DMC). The efficacy of the newly developed BMT was compared with the California Mastitis Test (CMT) kit. Another 150 milk samples were subjected to SCC determined by DMC and DCC (De Laval cell counter®) categorized by CMT and BMT scores.Results:A SCM test kit, namely, BMT kit was successfully developed in this study. The percentage accuracy of CMT and BMT were 76.75% and 75.75%; sensitivity 69.36% and 67.56%; specificity 85.95% and 85.85%; positive predictive value 86.03% and 85.71%; negative predictive value 69.23% and 68%, respectively. A p value of 0.001 was found for both CMT and BMT. However, CMT and BMT had no significant difference in sensitivity (p = 0.778). Average SCCs (cells/ml) determined by DCC and DMC, respectively, were mostly corresponded to the SCC ranges of both CMT and BMT scores.Conclusion:The newly developed BMT kit is an independent, cheap, farmer-friendly, first country made, and reliable SCM diagnostic test kit that can be used at field condition.

Evaluation of 3 esterase tests for the diagnosis of subclinical mastitis at dry-off and freshening in dairy cattle

Subclinical mastitis (SCM) and intramammary infection (IMI) increase esterase activity in the glandular secretions of dairy cattle. Our objective was to evaluate the clinical performance of 3 commercially available esterase tests for diagnosing SCM and IMI. Foremilk samples were collected from 380 quarters (96 cows) at dry-off and from 329 quarters (83 cows) within 4 to 7 d after calving. Quarter somatic cell count (SCC) was measured using the reference method (DeLaval cell counter; De Laval International AB, Tumba, Sweden) with SCM defined as SCC >200,000 cells/mL. Bacterial culture of foremilk samples was used to diagnose IMI based on the growth of ≥100 cfu/mL. The SCC was estimated using 3 PortaSCC tests (PortaCheck, Moorestown, NJ) from the measured esterase activity and the California Mastitis Test (CMT). Clinical performance was evaluated using logistic regression to determine the area under the receiver operating characteristic curve (AUC) and identify test sensitivity (Se) and specificity (Sp) at the optimal cut-point for diagnosing SCM and IMI. Test agreement was also evaluated using the kappa coefficient (κ) and weighted κ. The PortaSCC color test was the best-performing PortaSCC test for diagnosing SCM at dry-off (AUC = 0.90, Se = 0.91, Sp = 0.81, κ = 0.71) and at freshening (AUC = 0.86, Se = 0.74, Sp = 0.95, κ = 0.72), at an optimal cut-point of ≥250,000 cells/mL but required 45 min to produce a result. For comparison, the CMT required 2 min to produce a result and a CMT score of trace or higher was superior to the PortaSCC color test for diagnosing SCM at dry-off (AUC = 0.95, Se = 0.95, Sp = 0.86, κ = 0.81) and freshening (AUC = 0.88, Se = 0.79, Sp = 0.95, κ = 0.76). The PortaSCC quick test was the best-performing PortaSCC test for diagnosing IMI at dry-off (AUC = 0.81, Se = 0.81, Sp = 0.78 κ = 0.40) and required 5 min to produce a result, whereas the PortaSCC color test was the best performing PortaSCC test for diagnosing IMI at freshening (AUC = 0.80, Se = 0.75, Sp = 0.79 κ = 0.38). For comparison, the CMT was inferior to the PortaSCC quick test for diagnosing IMI at dry-off (AUC = 0.73, Se = 0.76, Sp = 0.60, κ = 0.20) but was equivalent to the PortaSCC color test at freshening (AUC = 0.79, Se = 0.58, Sp = 0.93, κ = 0.50). The PortaSCC color and quick tests and CMT were considered good tests for diagnosing SCM and IMI because clinically useful tests typically have an AUC >0.80 and κ >0.6. Based on the test sensitivity, cost, and analysis time, there does not appear to be a persuasive reason to select the PortaSCC tests over the traditional CMT for diagnosing SCM and IMI.

FACTORS OF INFLUENCE ON THE MORBIDITY BY MASTITIS OF COWS

Diseases of mastitis of dairy livestock cause significant economic losses, exceeding losses from all non-communicable diseases combined. It leads to a sharp decline in milk production or interruption of lactation, premature culling of milking premature culling of dairy herd, large material costs. In addition, the problem of mastitis is of social importance, because when eating milk containing pathogenic microorganisms or their toxins, people, especially children, also have serious illnesses.&#x0D; The aim of the research is to determine the factors affecting the level of cow damage with mastitis.&#x0D; The research was conducted in 2014–2016 on dairy farms in Donetsk region. Average milk yield per cow per year in the farms was at the level of 4000–5055 kg of milk. Before the beginning of the experiment, a structural analysis of the dairy herds was carried out on the farms, taking into account the age of the cows, the physiological state, the stage of lactation, productivity and pedigree composition.&#x0D; Diagnosis of subclinical mastitis in milk cows was carried out by mastidinovoy breakdown on control plates. The dependence of the number of hidden mastitis on such indicators as milk yield, lactation stage, elements of technology of keeping, age of animals and season of the year was taken into account.&#x0D; Research methods: experimental, supplemented by analytical studies, measurements, calculations and observations.&#x0D; It is showed that the structure of the herd of enterpriceses AgroPromservice, Bogoyavlinske, VostokAgro and Rossiya is approximately. It was found that with two-time milking their number was 20.5%, for two-time milking with milking it was 23.9%, and with three-time milking a day it was 17.6%.&#x0D; Influence of disinfection of the nipples of the mammary gland after milking with the drug "De Laval" "Dipal-concentrate" showed that with a double treatment the incidence of mastitis was 26.4%; When disinfectiont of the nipples of the breast after milking once a day, this indicator increases by 5.3%.&#x0D; Analysis of the disinfection of the teat with iodine and glycerin after each milking showed that the incidence of mammary gland hidden mastitis is reduced from 39.3% to 30.8%, that is, 8.5%.&#x0D; It was revealed that the incidence in the summer and winter periods ranged from 14.6 to 23.9%, in the spring and autumn periods from 19.5 to 36.9%.&#x0D; Studies have shown that the number of mammary gland diseases depends on the age of the animals, in particular, in primiparous animals it was less than in older cows.&#x0D; The most resistant to the disease are low-productive animals with a productivity of 3000 kg of milk and less for lactation (the number of diseases was 2.6–9.0%). With the increase in milk productivity from 4000–5500 kg of milk and more the number of diseases increases to 13.9–50.8%.&#x0D; Analysis of the presence of subclinical mastitis in farms, depending on the lactation stage of cows, indicates that the greatest number of hidden mastitis occurs in the second or fourth months of lactation, at 10–11 months of lactation and significantly decreases in the middle of lactation.&#x0D; Thus, the factors influencing the level of cow damage with mastitis were determined: milk productivity, lactation stage, milking and maintenance technology, animal age and season of year. The most influential factors are the productivity of animals and the technology of milking and keeping animals.

Patient scheduling based on a service-time prediction model: a data-driven study for a radiotherapy center.

With the growth of the population, access to medical care is in high demand, and queues are becoming longer. The situation is more critical when it concerns serious diseases such as cancer. The primary problem is inefficient management of patients rather than a lack of resources. In this work, we collaborate with the Centre Intégré de Cancérologie de Laval (CICL). We present a data-driven study based on a nonblock approach to patient appointment scheduling. We use data mining and regression methods to develop a prediction model for radiotherapy treatment duration. The best model is constructed by a classification and regression tree; its accuracy is 84%. Based on the predicted duration, we design new workday divisions, which are evaluated with various patient sequencing rules. The results show that with our approach, 40 additional patients are treated daily in the cancer center, and a considerable improvement is noticed in patient waiting times and technologist overtime.