Transformation properties and microstructure of sputter-deposited Ni-Ti shape memory alloy thin films

The influence of annealing parameters on the martensitic phase transformation in sputter-deposited Ti rich Ni-Ti films is systematically studied by differential scanning calorimetry and by transmission electron microscopy. The annealing temperature range extends from the crystallization temperature of the films up to 900°C. For increasing temperature, multiple phase transformations, transformations via an R-phase or direct martensite/austenite transformations are observed. A similar behavior is found for increasing annealing time. Related changes of the film microstructure, such as the strongly varying distribution of round Ti2Ni precipitates in the grains, are analyzed. Transformation temperatures could be shifted over a wide range by adjusting the film composition from 48 to 54 at.% Ti. The corresponding transformation curves, grain structure as well as nature and amount of precipitates were investigated. No subsequent annealing process is required for films deposited on substrates heated above about 500°C. In this case, the as-deposited films have a very fine-grained and homogeneous microstructur

Evaluation of fluralaner and afoxolaner treatments to control flea populations, reduce pruritus and minimize dermatologic lesions in naturally infested dogs in private residences in west central Florida USA

Citation: Dryden, M. W., Canfield, M. S., Kalosy, K., Smith, A., Crevoiserat, L., McGrady, J. C., . . . Sun, F. (2016). Evaluation of fluralaner and afoxolaner treatments to control flea populations, reduce pruritus and minimize dermatologic lesions in naturally infested dogs in private residences in west central Florida USA. Parasites & Vectors, 9, 11. doi:10.1186/s13071-016-1654-7Background: A study was conducted to evaluate and compare the effectiveness of two different oral flea and tick products to control flea infestations, reduce pruritus and minimize dermatologic lesions over a 12 week period on naturally infested dogs in west central FL USA. Methods: Thirty-four dogs with natural flea infestations living in 17 homes were treated once with a fluralaner chew on study day 0. Another 27 dogs living in 17 different homes were treated orally with an afoxolaner chewable on day 0, once between days 28-30 and once again between days 54-60. All products were administered according to label directions by study investigators. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, and once between days 28-30, 40-45, 54-60 and 82-86. Dermatologic assessments were conducted on day 0 and once monthly. Pruritus assessments were conducted by owners throughout the study. No concurrent treatments for existing skin disease (antibiotics, anti-inflammatories, anti-fungals) were allowed. Results: Following the first administration of fluralaner or afoxolaner, flea populations on pets were reduced by 99.0 % and 99.3 %, respectively within 7 days. Flea populations on the fluralaner treated dogs were 0 (100 % efficacy) on days 54-60 and 82-86 after the administration of a single dose on day 0. Administration of 3 monthly doses of afoxolaner reduced flea populations by 100 % on days 82-86. Flea numbers in indoor-premises were markedly reduced in both treatment groups by days 82-86, with 100 % and 98.9 % reductions in flea trap counts in the fluralaner and afoxolaner treatment groups, respectively. Marked improvement was observed in FAD lesion scoring, Atopic Dermatitis lesions scoring (CADESI-4) and pruritus scores with both formulations. Conclusions: In a clinical field investigation conducted during the summer of 2015 in subtropical Florida, a single administration of an oral fluralaner chew completely eliminated dog and premises flea infestations and markedly reduced dermatology lesions and pruritus. Three monthly doses of the afoxolaner chewable also eliminated flea infestations in dogs, markedly reduced premises' flea populations and similarly improved dermatology lesions and pruritus

TEM studies of in situ martensitic transformation in NiTi thin films

Amorphous sputter-deposited Ti-rich NiTi thin films were annealed at different temperatures between 600°C and 900°C for 10 min to 3 hours inducing Ti2Ni precipitation. Differential scanning calorimetry (DSC) was performed on these specimens and their microstructure was investigated by transmission electron microscopy (TEM). In samples annealed at 600°C and 700°C for a short time, the DSC curves show, in addition to the R transformation, a multiple phase transformation with broad peaks. TEM observations reveal the presence of a great number of spherical Ti2Ni precipitates inside the grains and some larger precipitates at the grain boundaries. Annealing at higher temperature results in clear defined DSC peaks. The density of the precipitates inside the grains decreases while the number and the size of the precipitates at the grain boundaries increase. TEM studies of in-situ martensitic transformation showed that the distribution of the Ti2Ni precipitates strongly influences the martensitic transformation behaviour while the austenite/R-phase transformation is not affected. In samples with a large amount of precipitates inside the grains, a two-step transformation was observed : the martensite appears first along all the grain boundaries and then in the centre of the grains. This unusual feature of the martensitic transformation is considered to be responsible for the multiple transformation observed in the DSC curves