14 research outputs found

    Joining ceramics to metals using metallic foam

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    A general method for brazing ceramics to metals using a compliant metallic foam as a buffer layer has been developed. Using stainless steel foams, bonds between alumina and 316 stainless steel with shear strengths up to 33 MPa have been achieved. The resultant ductility enhances the resistance of the joint to thermal cycling; AlN-Inconel 600 bonds exhibited good thermal shock resistance. Alumina - stainless steel bonds withstood more that 60 thermal cycles between 200 and 800°C in air

    Field evaluation of phostoxin and zinc phosphide for the control of zoonotic cutaneous leishmaniasis in a hyperendemic area, central Iran

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    Background & objectives: ZCL is a growing threat in many rural areas of Iran which involves 17 out of 31 provinces. This study was conducted from April to November 2011 for evaluation of the efficacy of phostoxin and zinc phosphide against rodents. Methods: Rodent control operations were carried out using phostoxin and zinc phosphide. To evaluate the effect of rodent control operation on the main vector density, an entomological survey was carried out. The effects of the operation on the disease incidence were also evaluated. Results: After intervention, the reduction rate of rodent burrows was 32.68% in the village treated with phostoxin and 58.14% in the village treated with zinc phosphide. The number of rodent holes in the control area showed 6.66-fold increase at the end of the study. The incidence of the disease decreased to 19.23 and 11.40 in areas treated with phostoxin and zinc phosphide, respectively. A total of 4243 adult sandflies were collected and identified. The most common and dominant species was Phlebotomus papatasi. In the village treated with phostoxin, the density of P. papatasi in outdoors was lower than indoors. Nevertheless, the density of P. papatasi in the village treated with zinc phosphide was higher in outdoors. Interpretation & conclusion: It is concluded that phostoxin is less effective and has low safety in comparison with zinc phosphide, so that this rodenticide can be used only in special situations such as lack or ineffective rodenticides and only in the colonies far from human and animal dwelling places in small scales

    Microstructure and interfacial reactions during active metal brazing of stainless steel to titanium

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    Microstructural evolution and interfacial reactions during active metal vacuum brazing of Ti (grade-2) and stainless steel (SS 304L) using a Ag-based alloy containing Cu, Ti, and Al was investigated. A Ni-depleted solid solution layer and a discontinuous layer of (Ni,Fe)2TiAl intermetallic compound formed on the SS surface and adjacent to the SS-braze alloy interface, respectively. Three parallel contiguous layers of intermetallic compounds, CuTi, AgTi, and (Ag,Cu)Ti2, formed at the Ti-braze alloy interface. The diffusion path for the reaction at this interface was established. Transmission electron microscopy revealed formation of nanocrystals of Ag-Cu alloy of size ranging between 20 and 30 nm in the unreacted braze alloy layer. The interdiffusion zone of β-Ti(Ag,Cu) solid solution, formed on the Ti side of the joint, showed eutectoid decomposition to lamellar colonies of α-Ti and internally twinned (Cu,Ag)Ti2 inter- metallic phase, with an orientation relationship between the two. Bend tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the Ti- braze alloy interface, through the (Ag,Cu)Ti2 phase layer

    Crystallographic reconstruction study of the effects of finish rolling temperature on the variant selection during bainite transformation in C-Mn high-strength steels

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    The effect of finish rolling temperature (FRT) on the austenite- () to-bainite () phase transformation is quantitatively investigated in high-strength C-Mn steels. In particular, the present study aims to clarify the respective contributions of the conditioning during the hot rolling and the variant selection (VS) during the phase transformation to the inherited texture. To this end, an alternative crystallographic reconstruction procedure, which can be directly applied to experimental electron backscatter diffraction (EBSD) mappings, is developed by combining the best features of the existing models: the orientation relationship (OR) refinement, the local pixel-by-pixel analysis and the nuclei identification and spreading strategy. The applicability of this method is demonstrated on both quenching and partitioning (Q&P) and as-quenched lath-martensite steels. The results obtained on the C-Mn steels confirm that the sample finish rolled at the lowest temperature (829{\deg}C) exhibits the sharpest transformation texture. It is shown that this sharp texture is exclusively due to a strong VS from parent brass {110}, S {213} and Goss {110} grains, whereas the VS from the copper {112} grains is insensitive to the FRT. In addition, a statistical VS analysis proves that the habit planes of the selected variants do not systematically correspond to the predicted active slip planes using the Taylor model. In contrast, a correlation between the Bain group to which the selected variants belong and the FRT is clearly revealed, regardless of the parent orientation. These results are discussed in terms of polygranular accommodation mechanisms, especially in view of the observed development in the hot-rolled samples of high-angle grain boundaries with misorientation axes between and

    Factors affecting the quality of hospital hotel services from the patients and their companions� point of view: A national study in Iran

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    Background: The hospitality design of a hospital is a complex process that depends on careful planning, systematic thinking, and consideration of various factors. This study aimed to determine the viewpoints of patients and their relatives on factors affecting hospital hotel services in Iran in 2015. The results of this study can be used to design a suitable model for the assessment and improvement of hospitality service quality. Materials and Methods: In this cross-sectional descriptive study, 10 hospitals of Iran were included. The subjects of the study included 480 patients and their companions from different internal and surgical wards. Simple random sampling method was performed at the hospitals, where patients were selected through stratified sampling based on hospital wards, and in each ward, through systematic sampling based on the bed numbers. A researcher-made questionnaire was used as the study tool which was developed through reviewing the literature and opinions of experts. Its internal reliability was determined based on Cronbach�s alpha coefficient (α =0.85). Results: In reviewing the eleven aspects of hospital hotel services regarding the patients� and their companions� viewpoint, services related to all aspects, whether human, economic, operational, personnel identification, safety, health care services, physical, clinical welfare, cultural, patient guidance, or public welfare services, received mean scores of higher than three (out of five). Conclusion: The present study showed that in the patients� and their companions� viewpoint, factors affecting hospital hotel services in the country are very important. The tool used in this study can be a criterion for assessing the status of the hotel services of the country�s major hospitals, so accordingly, the assessment and improvement of the existing conditions can be possible. © 2016 Journal of Research in Medical Sciences

    The Influence of Adding Porous Interlayer in the Brazing of Ceramic to Metal

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    Associated-risk determinants for anthroponotic cutaneous leishmaniasis treated with meglumine antimoniate: A cohort study in Iran

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    BackgroundThe control of cutaneous leishmaniasis (CL) is facilitated by knowledge of factors associated with the treatment failures in endemic countries. The aim of this evaluation was to identify the potential risk determinants which might affect the significance of demographic and clinical characteristics for the patients with anthroponotic CL (ACL) and the outcome of meglumine antimoniate (MA) (Glucantime) treatment.Methodology/principal findingsThis current was executed as a cohort spanning over a period of 5 years which centered in southeastern part of Iran. Altogether, 2,422 participants were evaluated and 1,391 eligible volunteer patients with ACL caused by Leishmania tropica were included. Overall, 1,116 (80.2%) patients received MA intraleisionally (IL), once a week for 12 weeks along with biweekly cryotherapy, while 275 (19.8%) patients received MA alone (20 mg/kg/day for 3 weeks) (intramuscular, IM). The treatment failure rate in ACL patients was 11% using IL combined with cryotherapy plus IM alone, whilst 9% and 18.5% by IL along with cryotherapy or IM alone, respectively. Multivariate logistic regression model predicted 5 major associated-risk determinants including male (odds ratio (OR) = 1.54, confidence interval (CI) = 1.079-2.22, p = 0.018), lesion on face (OR = 1.574, CI = 1.075-2.303, p = 0.02), multiple lesions (OR = 1.446, CI = 1.008-2.075, p = 0.045), poor treatment adherence (OR = 2.041, CI = 1.204-3.46, p = 0.008) and disease duration > 4 months (OR = 2.739, CI = 1.906-3.936, p≤0.001).Conclusions/significanceThe present study is the original and largest cohort of ACL patients who treated with MA. A comprehensive intervention and coordinated action by the health authorities and policy-makers are crucial to make sure that patients strictly follow medical instructions. Early detection and effective therapy < 4 months following the onset of the lesion is critical for successful treatment of the patients. Since a significant number of patients are still refractory to MA, reducing man-vector exposure and development of new effective alternative drugs are essential measures against ACL due to L. tropica
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