13 research outputs found

    Feasibility study of the electric power generation unit start-up using the three-phase synchronous generator with the AC exciter

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    The article presents the feasibility study of using the three-phase synchronous generator with the AC exciter as a starter for the Fiat 0.9 TwinAir CNG 80 HP internal combustion engine. The investigated power generation unit consists of the above mentioned internal combustion engine which can be powered by a biogas and the three-phase electric power generator MeccAlte 16 kW with the AC exciter. The use of an electric generator for starting a combustion engine is an innovative approach, which eliminates the need for additional components like starter reducing the mass and the failure frequency of the device. Similar approaches have been already investigated by the aircraft manufacturers for starting the jet engines of the airliners and are widely used in the hybrid engines for vehicles. The field winding of the three-phase synchronous generator described in the paper is connected to the AC exciter via a rotating rectifier bridge. This solution eliminates the necessity of using slip rings and facilitates a voltage regulation of the generator. The authors of the paper analyse the technical and practical possibilities of using such a synchronous generator with the exciter as a starting motor by measuring its output power and starting torque. The economic aspects of such a solution for unit and mass production have been also considered

    Control of fiat multiair valve-lift system using atmega microcontroller

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    The article presents a device based on the ATmega microcontroller for precise Fiat MultiAir valve-lift system control. The Fiat MultiAir system is the patented electromechanical actuation system of the inlet valves. It allows a control of the inlet valves open time for each combustion chamber independently. The described device has been installed in the Fiat 0.9 TwinAir CNG 80 HP internal combustion engine controlled by the ECU Master open motor controller. As the ECU Master Controller software and hardware does not support Fiat’s MultiAir system control, the above-mentioned device had to be designed. The device consists of the ATmega88 microcontroller, which analyses the signals from the shaft and the cam sensors. Then, the DC converter is powering the solenoid valves of the MultiAir system via two transistors. When the solenoid valve is closed, the incompressible hydraulic fluid transmits the inletcam lobe’s motion to the valve as in a traditional engine. When the solenoid valve is open, the oil bypasses the passage, decoupling the valve, which then closes conventionally via spring pressure. In order to find the specific moments of turning the solenoids on and off the measurements on the original Fiat motor controller have been performed. The acquired oscillograms have been analysed and presented in the article. Studied Fiat 0.9 TwinAir engine is a part of the power generation unit and has been coupled with the three-phase electric power generator MeccAlte 16 kW with an AC exciter

    Efficacy and safety of risedronate 150-mg once a month in the treatment of postmenopausal osteoporosis: 2-year data

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    Summary: This study showed that risedronate 150-mg once a month provides similar efficacy and safety at 2 years compared with risedronate 5-mg daily for the treatment of postmenopausal osteoporosis. This adds to the range of risedronate dosing options and provides an alternative for patients who prefer once-a-month dosing. Introduction: Risedronate is effective in the treatment of postmenopausal osteoporosis in oral daily, weekly, or on two consecutive days per month doses. This 2-year randomized, double-blind, multicenter study assesses the efficacy and safety of a single risedronate 150-mg once-a-month oral dose compared with the 5-mg daily regimen. Methods: Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5-mg daily (n = 642) or 150-mg once a month (n = 650) for 2 years. Bone mineral density (BMD), bone turnover markers, new vertebral fractures, and adverse events were evaluated. The primary efficacy endpoint was the mean percent change from baseline in lumbar spine BMD after 1 year. Results: Four hundred ninety-eight subjects in the daily group (77.6 %) and 513 subjects in the once-a-month group (78.9 %) completed the study. After 24 months, the mean percent change in lumbar spine BMD was 3.9 % (95 % confidence interval [CI], 3.43 to 4.42 %) and 4.2 % (95 % CI, 3.68 to 4.65 %) in the daily and once-a-month groups, respectively. The once-a-month regimen was determined to be non-inferior to the daily regimen. The mean percent changes in BMD at the hip were similar in both dose groups, as were changes in biochemical markers of bone turnover. The incidence of adverse events, adverse events leading to withdrawal, and upper gastrointestinal tract adverse events were similar in the two treatment groups. Conclusions: After 2 years, treatment with risedronate 150-mg once a month provided similar efficacy and tolerability to daily dosing and provides an alternative for patients who prefer once-a-month oral dosing

    Effect of weight and storage time of broiler breeders’ eggs on morphology and biochemical features of eggs, embryogenesis, hatchability, and chick quality

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    The transfer of hatchability results obtained under experimental conditions to the commercial ground with a positive financial effect proves the value and usefulness of these data. On the other hand, finding results on commercial processes of broiler breeders’ egg incubation in the literature is challenging. The presented study aimed to determine the effects of egg weight and storage time on the physical, biochemical characteristics of hatching eggs, embryogenesis and hatchability in Ross 308 broiler breeders. On the laying day, the eggs were divided into four weight groups: S – small eggs (57–61 g), M – medium eggs (62–66 g), L – large eggs (67–71 g), and XL – extra-large eggs (72–76 g). The eggs were then stored for 3, 7, 14, and 21 days under controlled conditions. As the egg storage time increased, a decrease in the yolk quality (lower index) was observed. The highest Haugh units were found in eggs from the S and M groups. The cholesterol content of the M, L, and XL groups was lower on days 7, 14, and 21 as compared to that of eggs only stored for 3 days. Egg weight loss during incubation decreased with an increase in the egg weight. An extension of the egg storage time caused an increase in the loss of egg weight. On the 14th and 18th days of hatching, an increase in the eggshell temperature was noted with an increase in the weight of the egg. The eggs stored for 7 days were characterised by the highest shell temperature on each day. The highest hatchability percentage was recorded for the M group. The hatchability rate decreased with the prolongation of the storage time, while the number of crippled chicks after hatching increased. The results confirmed that the increased weight of the eggs and prolonged storage time (14 and 21 days) increased the weight and decreased the length of the newly hatched chicks, respectively. Chicks from the heaviest eggs and those stored for 14 and 21 days showed poor results on the Pasgar score® test. The observations indicate the need to adopt various (of those available) methods to assess the quality of newly hatched chicks in hatcheries in order to produce high-quality broiler chickens. The results also indicate that prolonged egg storing beyond 14 days may affect the thyroid hormone economy during the hatching of chicks, especially in the XL group

    House dust and forage mite allergens and their role in human and canine atopic dermatitis

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    This article reviews the literature regarding the role of house dust and forage mite allergens in canine atopic dermatitis. The presence of immunoglobulin E (IgE) to these mites, especially to Dermatophagoides farinae, is common in both normal and atopic dogs. Exposure of dogs to the different mites is described both in the direct environment and in the coat of animals for house dust mites and in the food for forage mites. Allergens causing allergic disease in dogs seem to be different from those in humans. Dogs seem to react to high molecular weight allergens, compared to the low molecular weight group 1 and group 2 proteases that are commonly implicated in humans with atopic diseases. Despite numerous published studies dealing with this subject, a number of questions still need to be addressed to better understand the exact role of these mites in the pathogenesis of canine atopic dermatitis and to improve the quality of the allergens used in practice.T. J. Nuttall, Peter B. Hill, E. Bensignor, T. Willemse and the members of the International Task Force on Canine Atopic Dermatiti
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