Survey of damage mechanisms on PVD coated HSS hobs used in Swedish gear manufacturing industry

Gear hobbing is widely used for production of cylindrical gears in the Swedish transmission industry. The hob, usually consisting of a homogenous HSS (High Speed Steel) body coated with a ceramic PVD (Physical Vapour Deposition) coating, is designed for regrinding and recoating several times without affecting its cutting geometries. Efficient usage of the tool, considering production costs and gear quality, requires reconditioning before wear starts to affect the gear quality negatively and certainly before tool wear renders reconditioning impossible. Hobs of today generally lack in reliability, making it difficult to judge when they have to be taken out for reconditioning. This work presents a survey of wear as observed on today’s state of the art hobs used by Swedish gear manufactures. It aims to identify damage mechanisms and the common problems in order to enable future production of more reliable hobs. The tools were temporarily borrowed from the production and the analyses were made non-destructively using optical microscopes. This was complemented by destructive cross- sectional analysis on two of the hobs.  Wear was most commonly located on the rake faces and the cutting edges of the cutting teeth. It mainly propagates by discrete fractures which appear to originate at local defects in the coating or at the interface. High intrinsic stress in the coating likely promotes coating spallation and accelerates the wear of the cutting edge

Effects of early castration on carcass composition, yield and quality characteristics of meat from young reindeer (Rangifer tarandus tarandus) bulls and steers

Thirty male reindeer; n=16 bulls (control treatment) and n=14 steers (castrated males) were used to evaluate the effects of early castration on carcass yield and meat quality attributes. The reindeer were castrated at 2 and 13 months of age, and then slaughtered at 2 and 3 years of age. Live weights and carcass weights were significantly highest in the 3 year old bulls and steers. Dressing percentage did not differ between the 2 and 3 year old reindeer steers castrated at 2 months; however these values were higher than for 2 year old steers castrated at 13 months. Meat ultimate pH values (measured in the striploin; LD) were significantly highest in 2 year old steers castrated at 13 months and their corresponding control group of 2 year old bulls, indicating low muscle glycogen stores at slaughter. Castration had an effect on fat content with 3 year old steers having a higher fat content than bulls. No significant differences were found in any sensory attribute when the trained panel compared the meat from 2 year old reindeer bulls and steers. Abstract in Swedish / Sammanfattning:Effekter av tidig kastrering på slaktkroppssammansättning, styckningsutbyte och köttkvalitet hos unga renarTrettio hanrenar; n=16 tjurar (kontrolldjur) och n=14 kastrater (härkar) ingick i denna studie för att utvärdera effekterna av tidig kastrering på slaktkroppssammansättning och köttkvalitetsparametrar. Renarna kastrerades vid 2 respektive 13 månaders ålder och slaktades sedan när de var antingen 2 eller 3 år gamla. Levandevikt och slaktkroppsvikt var högst för 3 år gamla tjurar och härkar. Slaktutbytet skiljde sig inte mellan 2 och 3 år gamla härkar som kastrerats vid 2 månaders ålder, men deras slaktutbyte var högre än för de 2-åriga härkarna som kastrerats vid 13 månaders ålder. Köttets pH-värde (mätt i ytterfilén) var signifikant högst hos de 2-åriga härkarna som kastrerats vid 13 månaders ålder och deras tillhörande kontrollgrupp av 2-åriga tjurar, vilket tydde på låga nivåer av muskelglykogen vid slakt. Kastrering hade en signifikant effekt på fettinnehållet i slaktkropparna hos de 3-åriga renarna, med de högsta fetthalterna hos härkarna. Inga skillnader i ätkvalitet rapporterades när kött från 2-åriga rentjurar och härkar jämfördes

What is the burden of illness in patients with reflux disease in South Africa?

Objectives: To describe the impact of heartburn on patients’ Health-Related Quality of Life (HRQL) in South Africa.Design: Survey of patient-reported outcomes and physician-assessed symptoms. Setting: South African, major referral gastroenterology clinic. Subjects: Consecutive patients with predominant symptoms of heartburn.Outcome measures:Patients completed the Afrikaans versions of the Gastrointestinal Symptom Rating Scale (GSRS), the Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD) and the Short Form Health-36 (SF-36). Physician-assessed frequency and severity of heartburn during the previous 7 days were also recorded.Results: 125 patients with symptoms of heartburn (age: M=46.0 [±12 years]; females= 74%, 87% mixed race) completed the Afrikaans translation of GSRS, the QOLRAD and the Short-Form-36 (SF-36). Patients were bothered most by symptoms of reflux (mean GSRS score of 4.9, on a scale of 1 [not bothered] to 7 [very bothered]), indigestion (4.0) and abdominal pain (4.0). As a result of their symptoms, importantreflux related aspects of life, such as problems with food and drink (3.5), emotional distress (3.6), impaired vitality (3.7), sleep disturbance (3.8) and impaired physical/social functioning (4.3) were experienced (QOLRAD scores where 1 represents the most severe impact on daily functioning and 7 no impact). Overall HRQL measured by the SF-36 was poor across all domains and was significantly lower compared to the UK general population. Conclusions: There is consistentevidence that GERD symptoms substantially impair all aspects of HRQL in this mixed race South African population referred to this central clinic

Assessment of the Food-Swallowing Process Using Bolus Visualisation and Manometry Simultaneously in a Device that Models Human Swallowing

The characteristics of the flows of boluses with different consistencies, i.e. different rheological properties, through the pharynx have not been fully elucidated. The results obtained using a novel in vitro device, the Gothenburg Throat, which allows simultaneous bolus flow visualisation and manometry assessments in the pharynx geometry, are presented, to explain the dependence of bolus flow on bolus consistency. Four different bolus consistencies of a commercial food thickener, 0.5, 1, 1.5 and 2\ua0Pa\ua0s (at a shear rate of 50\ua0s −1 )—corresponding to a range from low honey-thick to pudding-thick consistencies on the National Dysphagia Diet (NDD) scale—were examined in the in vitro pharynx. The bolus velocities recorded in the simulator pharynx were in the range of 0.046–0.48\ua0m/s, which is within the range reported in clinical studies. The corresponding wall shear rates associated with these velocities ranged from 13\ua0s −1 (pudding consistency) to 209\ua0s −1 (honey-thick consistency). The results of the in vitro manometry tests using different consistencies and bolus volumes were rather similar to those obtained in clinical studies. The in vitro device used in this study appears to be a valuable tool for pre-clinical analyses of thickened fluids. Furthermore, the results show that it is desirable to consider a broad range of shear rates when assessing the suitability of a certain consistency for swallowing

Simultaneous X-ray Video-Fluoroscopy and Pulsed Ultrasound Velocimetry Analyses of the Pharyngeal Phase of Swallowing of Boluses with Different Rheological Properties

The Ultrasound Velocity Profiling (UVP) technique allows real-time, non-invasive flow mapping of a fluid along a 1D-measuring line. This study explores the possibility of using the UVP technique and X-ray video-fluoroscopy (XVF) to elucidate the deglutition process with the focus on bolus rheology. By positioning the UVP probe so that the pulsed ultrasonic beam passes behind the air-filled trachea, the bolus flow in the pharynx can be measured. Healthy subjects in a clinical study swallowed fluids with different rheological properties: Newtonian (constant shear viscosity and non-elastic); Boger (constant shear viscosity and elastic); and shear thinning (shear rate-dependent shear viscosity and elastic). The results from both the UVP and XVF reveal higher velocities for the shear thinning fluid, followed by the Boger and the Newtonian fluids, demonstrating that the UVP method has equivalent sensitivities for detecting the velocities of fluids with different rheological properties. The velocity of the contraction wave that clears the pharynx was measured in the UVP and found to be independent of bolus rheology. The results show that UVP not only assesses accurately the fluid velocity in a bolus flow, but it can also monitor the structural changes that take place in response to a bolus flow, with the added advantage of being a completely non-invasive technique that does not require the introduction of contrast media

Colour stability and water-holding capacity of M. longissimus and carcass characteristics in fallow deer (Dama dama) grazed on natural pasture or fed barley

The effects of feeding regimen on carcass characteristics, meat colour and water-holding capacity of M. longissimus were studied in 24 female fallow deer (Dama dama). All animals were farm raised; twelve were grazed on pasture and twelve were fed barley and a small amount of hay prior to slaughter. The animals were slaughtered at two occasions (during the Southern Hemisphere spring); after 19 weeks of feeding (n=12; 6 grazing and 6 barley fed animals; group 1) and after 24 weeks of feeding (n=12; 6 grazing and 6 barley fed animals; group 2). The barley/hay-fed deer had significantly higher body condition scores and carcass weights than the pasture raised group. No difference in meat ultimate pH values between the treatment groups was recorded. The meat from the pasture raised deer had significantly longer colour display life after 2 and 3 weeks of refrigerated storage (+ 2.0 ºC) in vacuum bags. There was no difference in drip loss between the two treatment groups. However, significantly lower drip losses were found in meat from the animals in group 2 compared with the ones in group 1 (P ≤ 0.001). It was concluded that the feeding regimen of the animals is an important factor that contributes to the variation in quality of fresh chilled deer meat (venison), mainly the colour stability and display life of vacuum packaged meat.Abstract in Swedish / Sammanfattning: I denna undersökning ingick 24 dovhjortshindar (Dama dama) för att studera effekterna av olika typer av foder (bete och korn) på slaktkroppskvalitet samt färg och vattenhållande förmåga i köttet (M. longissimus). Alla djur var uppfödda på en hjortfarm, 12 betade gräs och 12 utfodrades med korn och en liten mängd hö före slakt. Djuren slaktades vid två olika tillfällen (under våren på det södra halvklotet); efter 19 veckors utfodring (n=12; 6 betesdjur och 6 kornfodrade djur; grupp 1) och efter 24 veckors utfodring (n=12; 6 betesdjur och 6 kornfodrade djur; grupp 2). De dovhjortar som utfodrats med korn och hö var i bättre kondition och hade högre slaktvikter jämfört med de djur som betat gräs. Ingen skillnad i köttets pH-värde mellan de två utfodringsgrupperna kunde dock påvisas. Köttet från de betande dovhjortarna hade bättre färgstabilitet efter lagring i 2 och 3 veckor (+ 2.0 ºC) i vakuumförpackning. Det fanns ingen skillnad mellan kött från betande och korn/hö-utfodrade djur i vattenhållande förmåga. Däremot hade kött från djur i grupp 2 (slaktade efter 24 veckors utfodring) bättre vattenhållande förmåga jämfört med grupp 1 (P ≤ 0.001). Vi kunde konstatera att de olika fodertyperna påverkade kvaliteten hos färskt kyllagrat kött, framförallt färgstabiliteten hos vakuumförpackat kött

Feeding soy or fish meal to Alaskan reindeer (Rangifer tarandus tarandus) – effects on animal performance and meat quality

Fourteen reindeer (8 steers and 6 females) were used to compare the effects of two different reindeer diets (a feed mix based on barley, brome hay and soybean meal (SBM) or fishmeal (WFM) as protein source) on animal growth performance, feed conversion efficiency and ultimate meat quality. Samples from free-ranging reindeer (n=4; 2 steers and 2 females) on the Seward Peninsula were included to provide comparisons with the traditional reindeer meat produced in Alaska. No significant difference was observed in overall weight gain between the WFM and SBM animals or between females and steers; however, the feed conversion efficiency was significantly higher for the reindeer fed the WFM mix. Carcass dressing percentage from the SBM group was higher compared with the WFM animals. No differences were found in live weight, carcass characteristics, meat pH, temperature decline, shear force, meat color or cooking loss when comparing the treatment groups. The meat samples (M. longissimus) from the free-range group had the highest amount of omega-3 fatty acids and also the highest amount of polyunsaturated fatty acids (PUFA). Meat from the animals fed SBM was significantly higher in triglyceride content and lower in phospholipid content compared with the two other groups. No significant differences were found when the trained panel compared the sensory attributes of the meat. Off-flavor attributes related to “wild’ or “gamey” flavor was reported by consumers for samples from the WFM and free-range reindeer (15 and 24 per cent of the consumers, respectively). No “fish-related” flavor was reported. In conclusion, no negative effects in either animal performance or meat quality characteristics by using fish meal as opposed to soybean meal as a protein supplement in a milled reindeer diet were found.Abstract in Swedish / Sammandrag:Utfordring av ren med soja- eller fiskmjøl – effekter på tillväxt, foderutnyttjande och köttkvalitet I vår undersökning ingick 14 renar (8 kastrerade sarvar (härkar)och 6 vajor) för att jämföra effekter av två olika renfoder (baserade på korn, hö och soja- (SBM) eller fiskmjöl (WFM) som proteintillskott) med avseende på tillväxt, foderutnyttjande och köttkvalitet. Köttprover från naturbetande renar (n=4; 2 härkar och 2 vajor) från Seward Peninsula inkluderades i studien för att representera kvaliteten på traditionellt producerat renkött från Alaska. Inga signifikanta skillnader i tillväxt observerades, varken mellan SBM- och WFM-grupperna eller mellan härkar och vajor. Foderutnyttjandet var dock signifikant bättre hos WFM-renarna. Slaktutbytet var högst för renarna i SBM-gruppen, däremot rapporterades inga skillnader i levandevikt, slaktkroppsegenskaper, pH-värde och temperatur i ytterfilén, skärmotstånd, färg eller vattenhållande förmåga i köttet när de tre grupperna av renar jämfördes (SBM, WFM och naturbetande djur). Köttet från de naturbetande renarna hade det signifikant högsta innehållet av både omega-3-fettsyror och av fleromättade fettsyror. Kött från SBM-renarna hade det högsta innehållet av triglycerider och det lägsta innehållet av fosfolipider jämfört med de andra två grupperna. Den tränade smakpanelen kunde inte hitta några skillnader i sensoriska egenskaper hos köttet från renarna i de tre olika grupperna. I en konsumentundersökning rapporterades kommentarer om olika ”vilt-relaterade” bismaker i kött från naturbetande renar (24% av konsumenterna) och från WFM-gruppen (15% av konsumenterna), men inga ”fisk-liknande” bismaker i köttet kunde påvisas. Att byta ut sojamjöl mot fiskmjöl som proteintillskott i renfoder hade inga negativa effekter på renarnas tillväxt, foderutnyttjande eller på renköttets kvalitet