Stability and noise spectra of relative Loran-C frequency comparisons

Relative comparisons of Loran-C frequency transmissions between the master station of Catanzaro (Simeri Crichi) and the X, Z slave stations of Estartit (Spain) and Lampedusa (Italy) are carrying out by the GG LORSTA monitor station of the Mediterranean Sea Loran-C chain. These comparisons are able to emphasize the relative and, under certain conditions, the absolute rate of the emitting standard frequencies of the slave stations and some relevant statistical properties of the Loran-C Method for frequency transmission and time synchronization. The stability of each Loran-C frequency standard transmission is subject to perturbations, more or less known, due to the propagation medium and other causes. Following the Allan (1966) method for data processing, the performance of the relative rate of frequency of the transmissions of the X, Z slave stations are described calculating the standard deviation of a set of N frequency measurements from its mean averaged during sampling times. This standard deviation is designated as the measure of the stability of the Loran-C frequency transmission

Effect of corrosion degradation on failure mechanisms of aluminium/steel clinched joints

The effect of corrosion phenomena in critical environmental conditions on the mechanical performance of steel/aluminium hybrid joints, obtained by clinching technique, was studied by ageing in salt spray environment. The investigation was carried out on asymmetrical joints with total thickness of 2.5 mm. The joint strength at varying ageing time was determined by means of single lap shear tests.The experimental results have shown that corrosion degradation phenomena significantly affect the performance and failure mechanisms of the joints, causing premature failure of the joint at very low stress level.Moreover, it was observed that the joint geometry characterized by thicker aluminium foil, had good durability properties showing acceptable mechanical properties even at long ageing times. The fracture modes have been analysed in all the above-mentioned conditions and a failure map, at increasing ageing time, for the two joint geometries has been proposed. Keywords: Clinched joints, Durability, Corrosion, Single lap shear test, Failure ma

Diagnostic evaluation of a point-of-care test for culture and microbial susceptibility testing in canine dermatological infections in clinical practice

Background and Aim: Empirical antimicrobial therapy is frequently given in superficial bacterial folliculitis (SBF) and otitis externa (OE) in dogs, especially for the initial clinical presentation. Culture and subsequent antimicrobial susceptibility testing (AST) are generally limited to chronic cases with poor response to initial therapy. Several factors contribute to the failure to implement the use of AST in veterinary practice, i.e., long laboratory turnaround time or special requirements for sample shipping. Point-of-care (PoC) testing might reduce laboratory turnaround time and costs and the risk of emergence of multidrug-resistant pathogens. This study evaluated the Speed Biogram\u2122 PoC test in canine SBF and OE compared with conventional methods for culture and AST. Materials and Methods: Thirty-four canine samples were analyzed: eleven from SBF, seven from bacterial OE, four from mixed OE, six from Malassezia spp. OE, and six negative controls. Sensitivity (Se) and specificity (Sp) of the PoC test and the agreement between the PoC test and conventional methods were evaluated. Results: Se and Sp of PoC test in discriminating between healthy and unhealthy subjects were 100% (95% confidence interval [CI] 87.66-100.00) and 100% (95% CI 54.1-100.0), respectively. For bacterial identification, the k value was 0.532. Se and Sp of PoC tests for AST were 81.73% (95% CI 72.95-88.63) and 93.10% (95% CI 88.86-96.98), respectively with a total good agreement between tests (mean k=0.714), but major (8/27) and very major (19/27) errors were observed in 55% of bacterial conventional culture-positive samples. Conclusion: PoC test can identify dogs with SBF and OE, but AST is not sufficiently accurate. The lack of susceptibility testing for methicillin makes this test inappropriate for use in small animal practice

A topological weakening and softening map as simplified tool to assess the performances recovery of hybridized natural fiber reinforced composites subjected to alternate salt-fog/dry cycle

While receiving a growing attention in recent years, natural fibers cannot completely replace synthetic fibers as composite reinforcement for structural applications due to both their low durability in wet or humid environments and their limited and not homogenous overall performance. In this context, the purpose of this paper is to assess the impact of a humid/dry cycle on the mechanical stability of epoxy-based laminates reinforced with flax and glass fibers by using a topological weakening and softening map as simplified tool. The objective is, preliminarily, to evaluate the influence of glass fiber hybridization on the properties recovery of flax fiber reinforced composites subjected to alternate salt-fog/dry cycle. All laminates studied were subjected to salt spray for 15 or 30 days, and then stored in a dry controlled environment (50% relative humidity and 22 °C) for up to 21 days. The results evidenced that, compared to flax fiber reinforced composites, the glass hybridization of flax composite significantly reduce the mechanical performances degradation over time during the humid stage (about 28.0% better than flax one in stiffness). Furthermore, the mechanical performance recovery is promoted during the dry stage. A simplified topological map was lastly developed to graphically assess the decline and recovery of composites’ performances during the humid/dry cycle, amplifying the application and design effects of this approach

Evaluation of Feline Packed Red Blood Cell Units Obtained by Blood Sedimentation and Stored for 42 Days for Transfusion Purposes

Component therapy involves separation of whole blood (WB) into its components (packed red blood cells\u2014PRBCs\u2014and plasma), for specific replacement therapy and to reduce transfusion reactions. In cats, blood for transfusion is commonly collected using an open system and administered as WB, in part because of the challenge of preparing components from a small blood volume. Feline blood has a high erythrocyte sedimentation rate; therefore, if the syringe containing collected blood is placed upright, plasma can be removed from the red cells shortly after collection for separate storage of plasma and PRBCs. The aim of this study was to assess the characteristics of feline PRBC units obtained by blood sedimentation both at collection and after storage for 42 days. Blood was collected from fourteen feline blood donors into three 20-ml syringes pre-charged with CPDA-1:blood ratio of 1:7 using an open system. A pre-donation CBC was performed in each donor. The three syringes were allowed to sediment for approx. 1 hour at room temperature. Then plasma was aseptically expressed into plain transfer bags and RBC expressed into another transfer bag pre-charged with 10 ml of SAG-M. PRBCs units were stored in a blood-dedicated refrigerator and sampled using blood bag segments at preparation time (D0) and after 42 days storage (D42). On pre-donation blood and on PRBC units at D0 and D42 the following parameters were evaluated: I) hematological parameters (RBC, Hb, Hct, WBC, PLT); II) percentage hemolysis; III) morphological index (only for PRBC units), scored of 0 to 3 based on echinocyte transformation of the normal discocyte; IV) aerobic and anaerobic blood culture (only for PRBC units). From donor to PRBC units there was a significant increase in RBC count (mean increase +1886\ub1SD1399 \u3bcL/103), Hb concentration (+2.8\ub12.2 g/dl), Hct percentage (+8.3\ub15.5%). Significant reduction was found in PLT count (-249\ub1189 \u3bcL/103). Comparing PRBC at D0 and D42 a significant increase was found in percentage hemolysis (+1.2%), morphological index (+0.9) and a significant reduction in RBC count (-460\ub1679 \u3bcL/103), Hct percentage (-3.2\ub13.5%), WBC count (median -2589 \u3bcL/103), and PLT count (median -43 \u3bcL/10). All blood cultures were negative for bacterial growth. PRBC units obtained by sedimentation of donated blood appear to be a suitable blood component for treatment of normovolemic anemia. However, storage for 42 days, as suggested for canine and feline PRBC units, resulted in significant hematological changes that could reduce oxygen delivery after transfusion

Evaluation of feline red blood cells collected with an open system and stored for 35 days as whole blood units

Introduction: The increasing access to veterinary hospital blood banks and commercial sources of feline blood products means that transfusion therapy is more widely available to veterinarians and feline stored blood products are used more often. Despite the increasing availability of feline blood collected and stored for transfusion purposes, few studies have investigated storage lesions in feline whole blood (FWB) units and no study has evaluated hematological changes in FWB units. The objective of this study was to assess changes in feline RBCs collected and stored for transfusion purposes as FWB units. Methods:A prospective, laboratory invitrostudy wasconducted. Twelve nonleukoreduced FWB units were collected with an open system using three 20-mL syringes prefilled with citrate, phos- phate, dextrose, and adenine (CPDA-1) preservative-anticoagulant solution with ratio with blood of 1:7 from anesthetized feline blood donors. Units were stored in a blood bank dedicated refrigerator and sampled every 7 days (D7, D14, D21, D28) from collection (D0) to the end of storage (35 days, D35). At each time point, the following were evaluated: (1) hematological parameters (RBC, HGB, HCT, MCV, MCH, MCHC, RDW); (2) percentage of hemolysis; (3) morphological index, scored of 0 to 4 based on echinocyte transformation of the normal discocyte; and (4) aerobic and anaerobic blood culture. Results were statistically compared to D0, with t-test or Wilcoxon test, as appropriate with statistical significance set at P < 0.01. Results: There was no significant difference in hematological parameters at any time point with respect to D0. Significant increases were found in percentage of hemolysis and morphological index starting from 21 days of storage (P = 0.0002 and P = 0.0039, respectively). Mean hemolysis percentage value was less than 1% up to 21 days of storage. All blood cultures were negative for bacterial growth. Conclusion: RBCs in FWB units collected with an open system can undergo some significant hematological changes, but these results suggest that storage for up to 21 days is safe. In vivo studies are required to establish if these changes affect the ability of stored RBCs to circulate and provide adequate oxygen delivery after transfusion

Hematological, biochemical and microbiological evaluation of feline whole blood units collected using an open system and stored for 35 days

Despite the increasing availability of feline blood, which is collected and stored for transfusion purposes, few studies have assessed the effect of storage on feline whole blood (WB) units. The purpose of this study was to investigate selected hematologic and biochemical changes during storage of feline WB units and to determine when they occurred. Data from a quality control program for WB units was used in this study. Twelve feline WB units, collected using an open system, were sampled every 7 days from the point of collection to the end of storage at 35 days (D0, D7, D14, D21, D28, and D35). Measurements at each time point were: (1) hematologic parameters; (2) percentage hemolysis; (3) morphologic index scored at 0\u20133, based on echinocyte transformation of the erythrocytes; and (4) selected biochemical parameters. Aerobic and anaerobic culture was performed at D0 and D35. Results were compared statistically to D0 (statistical significance set at <0.01). Storage did not result in statistically significant changes in measured hematological parameters. There were statistically significant increases in percentage hemolysis and morphologic index, starting from D21 (P = 0.000 and P = 0.004, respectively). Glucose decreased significantly from D21 (P = 0.003); potassium increased significantly from D7 (P=0.001); and sodium increased significantly, starting from D28 (P = 0.009). Bacteria were not isolated. Blood in feline WB units collected using an open system underwent some significant storage changes that were time-dependent. As these changes could affect the quality and the utility of stored WB used in feline transfusion medicine, further study is required to determine their clinical importance

Assessment of ageing effect on the mechanical behaviour of steel/aluminium self-piercing riveted joint

Self-piercing riveting (SPR) is a new performing technology able to joint several kinds of metal and non-metal supports together. The combined effect of joint configuration and environmental conditions could have detrimental effect on the ageing effect on mechanical behaviour of dissimilar metal SPR joints. The joining of dissimilar materials, such as steel and aluminium, realized by self-piercing riveting (SPR) technique was studied to evaluate the ageing effects on its mechanical behaviour in critical environmental conditions. The investigation was carried out on symmetrical or unsymmetrical joints at varying total thicknesses (i.e. 2.0, 2.5 and 3.0 mm). The joint resistance was determined by single-lap shear tests. A design of experiment (DoE) has been performed by using Minitab® followed by the statistical analysis (ANOVA) of the experimental data. Long-term ageing tests in salt spray environment were performed to evaluate the durability of the mechanical joint. The experimental results evidenced that the corrosion degradation phenomena influenced significantly both the performance and failure mechanisms of the joints; also, the joint configuration is a significant factor for the corrosion effect. In the salt spray, the aluminium sheet undergoes a noticeable degradation due to galvanic Al/Fe corrosion. The set characterized by thinner aluminium sheet evidenced a gradual reduction of the mechanical strength with increasing ageing time due to the prevalence of thinning induced by aluminium corrosion. Instead, for S10-A15 samples (characterized by a thicker thickness of aluminium sheet) during the first 7 weeks, stable mechanical performances were observed. The experimental results evidenced that the corrosion degradation phenomena influence significantly both performances and failure mechanisms of SPR joints. Furthermore, the durability of the SPR joint is strongly affected by the joint configuration, and the best results were observed in the unsymmetrical joint with thicker aluminium sheet

Prevalence of Ca Blood Type and Alloantibodies in a Population of Horses from Italy

A knowledge of the blood groups and alloantibodies present is essential for the safe transfusion of blood products in horses. Pre-transfusion screening and blood typing minimizes the risk of incompatible RBC transfusions and prevents immunization of the recipient against incompatible RBC antigens. The frequencies of blood groups can vary among different breeds. Knowledge of a breed's blood group prevalence can be very useful for identifying the best blood donors during transfusion in clinical practice. The aims of this study were to estimate the prevalence of the Ca blood type in horses from Italy using a monoclonal immunocromatographic method and to estimate the prevalence of anti-Ca alloantibodies in Ca- horses using agglutination on gel technique. Ca blood type was determined on 110 whole blood samples. The prevalence of the Ca+ blood type was 79.1%. This study also provides data about the prevalence of Ca+ blood group in Italian Saddle Horses (77,3%) and Dutch Warmblood (58,3%). No significant association was found between Ca blood type and sex with 79.5% and 78.8% of females and males testing Ca+, respectively. The total number of Ca- samples with detectable anti-Ca alloantibodies was 7/23 (30.4%)