Fully integrated high quality factor GmC bandpass filter stage with highly linear operational transconductance amplifier

This paper presents an electrical, fully integrated, high quality (Q) factor GmC bandpass filter (BPF) stage for a wireless 27 MHz direct conversion receiver for a bendable sensor system-in-foil (Briem, 2016). The core of 10 the BPF with a Q factor of more than 200 is an operational transconductance amplifier (OTA) with a high linearity at an input range of up to 300 mVpp,diff. The OTA’s signal-to-noise-and-distortion-ratio (SNDR) of more than 80 dB in the mentioned range is achieved by stabilizing its transconductance Gm with a respective feedback loop and a source degeneration resistance RDG. The filter stage can be tuned and is tolerant to global and local process variations due to offset and common-mode 15 feedback (CMFB) control circuits. The results are determined by periodic steady state (PSS) simulations at more than 200 global and local process variation parameter and temperature points and corner simulations. It is expected, that the parasitic elements of the layout have no significant influence on the filter behaviour. The current consumption of the whole filter stage is less than 600 μA

Modelling the economic efficiency of using different strategies to control Porcine Reproductive & Respiratory Syndrome at herd level

PRRS is among the diseases with the highest economic impact in pig production worldwide. Different strategies have been developed and applied to combat PRRS at farm level. The broad variety of available intervention strategies makes it difficult to decide on the most cost-efficient strategy for a given farm situation, as it depends on many farm-individual factors like disease severity, prices or farm structure. Aim of this study was to create a simulation tool to estimate the cost-efficiency of different control strategies at individual farm level. Baseline is a model that estimates the costs of PRRS, based on changes in health and productivity, in a specific farm setting (e.g. farm type, herd size, type of batch farrowing). The model evaluates different intervention scenarios: depopulation/repopulation (D/R), close & roll-over (C&R), mass vaccination of sows (MS), mass vaccination of sows and vaccination of piglets (MS + piglets), improvements in internal biosecurity (BSM), and combinations of vaccinations with BSM. Data on improvement in health and productivity parameters for each intervention were obtained through literature review and from expert opinions. The economic efficiency of the different strategies was assessed over 5 years through investment appraisals: the resulting expected value (EV) indicated the most cost-effective strategy. Calculations were performed for 5 example scenarios with varying farm type (farrow-to-finish – breeding herd), disease severity (slightly – moderately – severely affected) and PRRSV detection (yes – no). The assumed herd size was 1000 sows with farm and price structure as commonly found in Germany. In a moderately affected (moderate deviations in health and productivity parameters from what could be expected in an average negative herd), unstable farrow-to-finish herd, the most cost-efficient strategies according to their median EV were C&R (€1′126′807) and MS + piglets (€ 1′114′649). In a slightly affected farrow-to-finish herd, no virus detected, the highest median EV was for MS + piglets (€ 721′745) and MS (€ 664′111). Results indicate that the expected benefits of interventions and the most efficient strategy depend on the individual farm situation, e.g. disease severity. The model provides new insights regarding the cost-efficiency of various PRRSV intervention strategies at farm level. It is a valuable tool for farmers and veterinarians to estimate expected economic consequences of an intervention for a specific farm setting and thus enables a better informed decision

Bending analysis of thin functionally graded plate under in-plane stiffness variations

The paper developed a new analytical solution for elastic deformation of thin rectangular functionally graded (FG) plates with in-plane stiffness (Young's modulus) variation, which has important applications in various thin-walled structures. Also the problem was solved numerically using the graded finite element method (FEM). The relevant governing equations of elasticity were solved assuming static analysis and power law distribution of the material stiffness. The plate deflections and stresses from the well-known through-the-thickness stiffness variation solution were used to verify the graded finite element method. The analytical solutions for the displacements and stresses were derived for in-plane stiffness variations. The finite element (FE) solutions were obtained both using linear hexahedral solid elements and shell elements with spatially graded stiffness distribution, implemented in the ABAQUS FE software. These solutions were verified against the finite element (FE) solutions, and are in very good agreement for various stiffness gradients. The analytical solution based on CPT was compared with that provided by higher shear deformation theory (HSDT) and graded solid element FE solution. The results obtained demonstrate that the direction of material stiffness gradient and the nature of its variation have significant effects on the mechanical behavior of FG plate. Moreover, the good agreement found between the exact solution and the numerical simulation demonstrates the effectiveness of graded solid elements in the modeling of FG plate deflection under bending. The types of analytical solutions obtained can be used to obtain deflections and stresses in thin structures with specified stiffness gradients induced by manufacturing processes, such as multi-material 3D printing

Analytical solutions for elastic deformation of functionally graded thick plates with in-plane stiffness variation using higher order shear deformation theory

This paper presents the deformation solution of functionally graded (FG) plates with variation of material stiffness through their length using higher order shear deformation theory (HSDT) including stretching effects. The present theory accounts for both the shear deformation and thickness stretching effect by a sinusoidal variation of the displacement field across the thickness. Equations of motion are derived from Hamilton's principle, and the relevant governing equations of elasticity are solved with a power law distribution of material property (material stiffness) to derive the analytical solution of the deflection of the FG plate. The problem is then modelled using the finite element method (FEM). The resultant analytical solutions are verified against the finite element (FE) solutions. The FE solutions are obtained using linear hexahedral solid elements with spatially graded property distribution (at different Gauss points), which is implemented by a user material subroutine (UMAT) in the ABAQUS FE software. It can be concluded that the present exact formulation is not only accurate, but also simple in predicting the bending of FG plates. Also, this study can be applied to find the optimum material distribution to produce controlled-stiffness distribution in FG plates corresponding to prescribed characteristics. Moreover, the good agreement found between the exact solution and the numerical simulation demonstrates the effectiveness of graded solid elements in the modelling of FG plate deflection under bending

Stress analysis of functionally graded plate under different gradient direction

Functionally Graded Materials (FGMs) are advanced engineered materials whereby material composition and properties vary spatially in macroscopic length scales, caused by manufacture process. One approach to produce FGMs is use of additive manufacturing (3D printing), which can control local composition and microstructure. During 3D printing of FGMs, the reliability requirements for the product should be considered to meet desired or application-specific performance criteria. Furthermore, the gradient distribution and its relationship with the loading direction will affect the macro stiffness and mechanical behavior. The purpose of this paper is to investigate the general stress field of an FGM rectangular plate for different gradient directions, perpendicular, parallel and inclined to the loading direction, both analytically and numerically. Also, the influence of different elastic modulus function variation, such as power law and exponential functions, on the stress and displacement fields is studied through a numerical example. The relevant governing equations of elasticity are solved with elastio-static analysis with power law volume fraction, and verified against finite element (FE) solutions. The FE solution is obtained using plane stress elements with spatially graded property distribution (at different gauss points), which is implemented by a user material subroutine (UMAT) in Abaqus FE software. The comparison between the exact solution and numerical simulation shows the efficiency of graded elements in modelling of FGM. Also, the results demonstrate that the direction of material property gradient and the nature of its variation have significant effects on the mechanical behavior of the FGM plate. This paper presents an approach for design of new materials with controlled macro properties

Numerical and experimental study on free vibration of 3D-printed polymeric functionally graded plates

The paper presents the free vibration analysis of simply supported 3D printed polymeric functionally graded (FG) plates with variation of material stiffness and density along their length. The analytical formulation based on Higher- Order Shear Deformation Theory (HSDT) accounts for both the shear deformation and thickness stretching effect by a sinusoidal variation of the displacement field across the thickness. The problem is then modelled using the finite element (FE) method. The FE solutions are obtained using linear hexahedral solid elements with spatially graded property distribution at different Gauss points, which is implemented by a subroutine (USDFLD) in the ABAQUS FE software. In order to validate the proposed graded FE solutions, experimental tests using Portable Digital Vibrometer (PDV) performed to capture the first natural frequency of designed and manufactured 3D printed polymeric FG plates. It can be concluded that the presented analytical formulation is not only accurate, but also provides for simple prediction of the free vibration of FG plates. Also, the good agreement found between the numerical models and experimental results demonstrates the effectiveness of graded solid elements in the modelling of FG plate vibration

The Effect of Colchicine in Improving the Symptoms of Patients with Knee Osteoarthritis

BACKGROUND AND OBJECTIVE: Due to low effectiveness of drugs in osteoarthritis treatment, finding new drugs always consider. Although colchicine has been described as a disease moderator medicine for osteoarthritis disease or symptoms, few studies have been carried out about the effect of it in soothing symptoms of patients with knee osteoarthritis. METHODS: This RCT was conducted on 62 patients with idiopathic knee osteoarthritis. Pain intensity, the degree of functional disability, and the patients’ clinical health were assessed by VAS, modified WOMAC index and modified HAQ questionnaire, respectively. The patients were then randomly assigned to two groups of oral colchicine group (0.5mg/bid) and placebo group and undergone treatment for 4 months. Assessment repeated in 3rd and 4th months. IRCT code: IRCT2015071623240N1. FINDINGS: Compared to the beginning of the study, the intensity of pain in both groups was reduced and the degree of functional disability and the patients’ clinical health were improved in the 3rd and 4th months of study, too. Nevertheless, the percentages of pain severity improvement in colchicine group in comparison to placebo were significantly higher (3rd mo: 29% vs. 16%, respectively, p=0.030; 4th mo: 37% vs. 20%, respectively, p=0.014). In addition, the percentages of physical function improvement in colchicine group in comparison to placebo were significantly higher (3rd mo: 26% vs. 16%, respectively, p=0.048; 4th mo: 28% vs. 20%, respectively, p=0.036). CONCLUSION: Use of colchicine for four months in patients with knee osteoarthritis can reduce pain and improve physical function

Simple hierarchical and general nonlinear growth modeling in sheep

Differential equations and advanced statistical models have been used to predict growth phenomena. In the present study, general nonlinear growth functions such as von Bertalanffy, Gompertz, logistic, and Brody, along with hierarchical modeling were applied to investigate the phenotypic growth pattern of Iranian Lori-Bakhtiari sheep. Growth data from 1410 Lori- Bakhtiari lambs were used in the present study. The results showed that the Brody function outperformed the other three nonlinear growth functions. In addition, including hierarchical growth modeling results allowed the adoption of many random effect structures, suggesting that hierarchical growth modeling has a useful role in growth data modeling. This method provides an estimation of growth parameters based on individual animals, improving individual growth selection. The results suggest this approach for growth modeling. Combining the strength of individual growth modeling with general growth modeling, e.g., von Bertalanffy, Gompertz, logistic, and Brody would be deeply appealing in the future. In this regard, dealing with sheep growth phenomenon using pure mathematical models, i.e. grey system theory models that could be new powerful prediction tools for breeders and experts, has not been done yet. However, running the analysis on large datasets will require significantly higher computational power than is ordinarily available

Colour M-mode superiority in evaluation of improvement in myocardial performance indices following successful percutaneous coronary intervention (PCI)

Aim: This study aimed at evaluating the early effects of successful elective percutaneous coronary intervention (PCI) on systolic and diastolic function. Methods: We consecutively studied the systolic and diastolic function in 21 patients with stable coronary artery disease (CAD) and left ventricular ejection fraction (LVEF) > 40 before and 48 hours after successful elective PCI. Results: Tei index and systolic indices (LVEF, regional wall motion abnormality score, tricuspid annular plane systolic excursion and peak systolic velocity of mitral and tricuspid annulus) did not change significantly. Among the diastolic indices, only velocity propagation (Vp) improved significantly (from 42.9 ± 10.8 to 51.8 ± 10.7, p-value = 0.008) following PCI. Diastolic velocities, E/A ratio, deceleration time (DT), early and late diastolic velocities of mitral annulus in TDI, pulmonary vein systolic (PVs) and diastolic flow velocity (PVd) did not show significant improvement. Conclusion: Propagation velocity of mitral inflow was the earliest index to recover following successful PCI in patients with stable CAD