Optimal suspension settings for ride comfort of road vehicles

In this paper a numerical study is presented for the effect of the settings of the suspension parameters of a road vehicle for the ride comfort. The chassis of the IK GMC midibus model is investigated as an example. The suspension parameters are represented by hard springs and dampers. By the appropriate choice of the suspension parameters it can be achieved that the influence of the dynamical forces is minimal for the oscillation of the carbody and for the dynamically computed internal forces, respectively. The nonlinear constrained optimization models provide appropriate tools to investigate the effect of the suspension parameters for the average acceleration and displacement of the chassis, respectively

Developing Hungarian cadastral database of green roofs and the trends in green roof construction industry

Our research goal was – taking into account the needs mentioned above – developing a cadastral database of green roofs, as well as the presentation of the first results. Main data used in the database: year of construction, type of green roof (extensive, intensive), dimensions (m2), customer's name, contractor company's name, maintenance services (presence, absence), irrigation system (presence, absence). The big advantage of the database is that it can be expanded to meet additional demande, the downside is its voluntary basis. Based on the results of three years of research we can say that spreading of green roofs in the 90s in Hungary was slow. Real breakthrough was observed from 2000, mainly due to large investments in the city. Based on the analysis of the customers, it became clear that the growth was not due to a general increase in environmental awareness of the people, but to the stricter rules for creating green spaces in the National Requirements Regarding Town Planning and Construction (OTÉK, annex No. 5.) The amount of green roofs constructed (m2) has a hectic fluctuation in the studied period (1991-2012), which comes from the fact that both office and residential buildings are mostly developed in a project-like way. The analysis of the database showed that a total of 287,843 m2 green roofs were built in Hungary by 31/12/2012 – of which 64,799 m2 (22.75%) was extensive green roof, and 219,943 m2 (77.25%) was intensive green roof. We evaluated the analysis of the model with SPSS 20.0 for Windows software package, based on the research of HARNOS and LADÁNYI (2005). The coefficient of determination R2= 0.996, so the model offers a good explanation for the data dispersion. Processing the related ANOVA we obtained F = 1678.52, which is very high so we can claim that the choosen bi-logistic model fits well. Based on the t-tests related to the parameters (calculated values are: tχ1 = 16.43; tχ2 = 7.99; tm1 = 61.80, Tm2 = 58.75; Δt1 = 6.4, Δt2 = 4.34), we accept the parameter estimates as good ones. In the last two years decline in the construction industry has a significant influence on the development volume of green roofs which is mainly due to global trends

Method for the rapid determination of soil physical parameters of extensive green roofs

Optimization of soil mixes used for extensive green roofs is essential in a long-term, well-functioning system design and implementation. One of the key elements of this is determining the soil physical characteristics of the used components with the following critical elements: rock mass, rock volume, space between particles, water absorption and water retention capacity, surface water retention. In our research we developed a new method for rapid identification of soil physical performance characteristics of extensive green roofs. The performance indicators were divided into three groups: 1. density-related indicators: loose density, wet loose density, rock material density, wet density of the rock, crystal structure density, rock mass per unit rock volume; rock volume per unit rock volume, rock mass per unit wet rock volume, rock mass per unit wet rock mass. 2. Water content related indicators: water content (porosity) per unit mass of wet rock, water content (porosity) per unit wet rock volume, water content per unit volume of wet granules, surface water per unit volume of granules, surface water per unit mass of granules. 3. Indicators related to space between particles: space between grains per unit volume of granules, space between grains per unit mass of granules. During the development of the procedure and method it was important for us that the parameters should have been determined simply and easily. Further advantages of the developed method are that they are fast, cheap and reasonably accurate and help rock/soil mixture characterization and quantitative comparability. We illustrate the method and the system of performance indicators on examples of growing media mixes for extensive use

Method for the rapid determination of soil physical parameters of extensive green roofs

Optimization of soil mixes used for extensive green roofs is essential in a long-term, well-functioning system design and implementation. One of the key elements of this is determining the soil physical characteristics of the used components with the following critical elements: rock mass, rock volume, space between particles, water absorption and water retention capacity, surface water retention. In our research we developed a new method for rapid identification of soil physical performance characteristics of extensive green roofs. The performance indicators were divided into three groups: 1. density-related indicators: loose density, wet loose density, rock material density, wet density of the rock, crystal structure density, rock mass per unit rock volume; rock volume per unit rock volume, rock mass per unit wet rock volume, rock mass per unit wet rock mass. 2. Water content related indicators: water content (porosity) per unit mass of wet rock, water content (porosity) per unit wet rock volume, water content per unit volume of wet granules, surface water per unit volume of granules, surface water per unit mass of granules. 3. Indicators related to space between particles: space between grains per unit volume of granules, space between grains per unit mass of granules. During the development of the procedure and method it was important for us that the parameters should have been determined simply and easily. Further advantages of the developed method are that they are fast, cheap and reasonably accurate and help rock/soil mixture characterization and quantitative comparability. We illustrate the method and the system of performance indicators on examples of growing media mixes for extensive use

Developing Hungarian cadastral database of green roofs and the trends in green roof construction industry

Our research goal was – taking into account the needs mentioned above – developing a cadastral database of green roofs, as well as the presentation of the first results. Main data used in the database: year of construction, type of green roof (extensive, intensive), dimensions (m2 ), customer's name, contractor company's name, maintenance services (presence, absence), irrigation system (presence, absence). The big advantage of the database is that it can be expanded to meet additional demande, the downside is its voluntary basis. Based on the results of three years of research we can say that spreading of green roofs in the 90s in Hungary was slow. Real breakthrough was observed from 2000, mainly due to large investments in the city. Based on the analysis of the customers, it became clear that the growth was not due to a general increase in environmental awareness of the people, but to the stricter rules for creating green spaces in the National Requirements Regarding Town Planning and Construction (OTÉK, annex No. 5.) The amount of green roofs constructed (m2 ) has a hectic fluctuation in the studied period (1991-2012), which comes from the fact that both office and residential buildings are mostly developed in a project-like way. The analysis of the database showed that a total of 287,843 m2 green roofs were built in Hungary by 31/12/2012 – of which 64,799 m2 (22.75%) was extensive green roof, and 219,943 m2 (77.25%) was intensive green roof. We evaluated the analysis of the model with SPSS 20.0 for Windows software package, based on the research of HARNOS and LADÁNYI (2005). The coefficient of determination R2 = 0.996, so the model offers a good explanation for the data dispersion. Processing the related ANOVA we obtained F = 1678.52, which is very high so we can claim that the choosen bi-logistic model fits well. Based on the t-tests related to the parameters (calculated values are: tχ1 = 16.43; tχ2 = 7.99; tm1 = 61.80, Tm2 = 58.75; Δt1 = 6.4, Δt2 = 4.34), we accept the parameter estimates as good ones. In the last two years decline in the construction industry has a significant influence on the development volume of green roofs which is mainly due to global trends

Expression of the translation termination factor eRF1 is autoregulated by translational readthrough and 3'UTR intron-mediated NMD in Neurospora crassa

Eukaryotic release factor 1 (eRF1) is a translation termination factor that binds to the ribosome at stop codons. The expression of eRF1 is strictly controlled, since its concentration defines termination efficiency and frequency of translational readthrough. Here, we show that eRF1 expression in Neurospora crassa is controlled by an autoregulatory circuit that depends on the specific 3'UTR structure of erf1 mRNA. The stop codon context of erf1 promotes readthrough that protects the mRNA from its 3'UTR-induced nonsense-mediated mRNA decay (NMD). High eRF1 concentration leads to inefficient readthrough, thereby allowing NMD-mediated erf1 degradation. We propose that eRF1 expression is controlled by similar autoregulatory circuits in many fungi and seed plants and discuss the evolution of autoregulatory systems of different translation termination factors

Vékonylemez folyásgörbéjének felvétele zömítővizsgálat segítségével

Ez a tanulmány egytengelyű nyomóvizsgálat eredményeit mutatja be a DC04 autóipari vékonylemez folyásgörbéjének meghatározására. A folyásgörbe meghatározásának általános módszere a szakítóvizsgálat, amely a kontrakció jelensége miatt nem megbízható nagy alakváltozások esetén. Ezért nyomóvizsgálatot alkalmaztunk, amely két-három nagyságrenddel nagyobb alakváltozásokat eredményezett, mint húzás esetén. A súrlódás csökkentése érdekében kétféle kenőanyagot használtunk. A súrlódási együtthatót a próbatestek hordósodásának mérésével kaptuk meg úgy, hogy a próbatesteket a hengerlési irányban és arra merőlegesen is elvágtuk. A geometriai méréseket mikroszkóp segítségével hajtottuk végre. Az alakítási szilárdság meghatározásához a Siebel-egyenletet és a Christiansen et al. módszert használtuk. Végül, a folyásgörbegörbe kiszerkesztéséhez a Swift- és a Hockett-Sherby-egyenletet alkalmaztuk. Eredményeink azt mutatják, hogy bár a folyásgörbe jó közelítéssel ábrázolható, a kis lemezvastagságok nagy szórást eredményeznek. | This study presents the experimental results of uniaxial compression test for determining the flow curve of DC04 automotive thin sheet. The common method for flow curve definition is the tensile test, which is not reliable for high strains due to the necking phenomenon. For this reason, we used compression test that resulted two-or- three magnitude higher strains than in case of tension. To lower the friction, two types of lubricants were used. The friction coefficient was obtained by measuring the buckling of the test pieces following the cutting of all the specimens in the rolling direction and perpendicular to it. For measuring the geometry, microscopic investigations were used. To obtain the flow stress, the Siebel equation and the Christiansen et al. method were used. Lastly, the Swift and Hockett-Sherby equations were applied for the calculation of the flow curve. Our results show that although the flow curve can be plotted with good approximation, the small sheet thicknesses result in large scatter

Kétfázisú acéllemezek ráncosodásának vizsgálata deformációs térkép segítségével

A leggyakoribb tönkremeneteli módok a lemezalakításban az elvékonyodás, a szakadás és a ráncosodás. A tervezési fázisban éppen ezért igyekszünk ezen tönkremeneteleket megakadályozni. Az elvékonyodás és a szakadás jelenségére számos elmélet született, amely törekszik arra, hogy minél pontosabb alakváltozási határértékeket fogalmazzon meg, ellenben a ráncosodás, egy kevésbé kutatott terület. Ebben a cikkben, mélyhúzott csészék peremének alakváltozásain keresztül vizsgáljuk annak a lehetőségét, hogy egy ráncosodási kritériumot állítsunk fel, amely segítheti a tervezési fázist, mint bemeneti paraméter. A teszteket azonos paraméterek mellett szimulációs és valós környezetben is elvégeztük. | In sheet metal forming, the most common forms of failure are necking, tearing and wrinkling. The challenge in technology design is to predict and prevent these failures. Although several studies has been carried out in the field of necking and rupture failure, the area of wrinkling is less researched. In this paper, we investigate how to establish a wrinkling criterion by examining the deformation field, i.e. the deformation map on drawn cups’ flange. In this study we investigated the wrinkling behaviour on deep-drawn cups, by varying the normal forces. The physical tests were also implemented into a finite element software, for subsequent validation. Our results show that the deformation measuring could be a useful tool for the wrinkling definition, with the proper selection of the border values of the phenomenon

Effect of the Flow Curve Determination on the Thinning of Drawn Parts

This study presents the results of finite element simulations based on different variations of the flow curve of DC04 automotive thin sheet. The aim of our research is to investigate how different flow curve equations affect the variation of sheet thickness in cup drawing tests. In order to exclude other influencing factors in the experiment, both the sheet material and the geometric properties of the specimen, as well as the external state factors were considered to be the same in all cases. The finite element simulations were performed using Simufact 2021.1 software. Our results shows that there are no significant differences in wall thicknesses until we reach the zone of double necking, where essential differences are observed

Xenoestrogens Ethinyl Estradiol and Zearalenone Cause Precocious Puberty in Female Rats via Central Kisspeptin Signaling

Xenoestrogens from synthetic or natural origin represent an increasing risk of disrupted endocrine functions including the physiological activity of the hypothalamo-pituitary-gonad axis. Ethinyl estradiol (EE2) is a synthetic estrogen used in contraceptive pills, whereas zearalenone (ZEA) is a natural mycoestrogen found with increasing prevalence in various cereal crops. Both EE2 and ZEA are agonists of estrogen receptor alpha (ERalpha) and accelerate puberty. However, the neuroendocrine mechanisms that are responsible for this effect remain unknown. Immature female Wistar rats were treated with EE2 (10 mu g/kg), ZEA (10 mg/kg) or vehicle for 10 days starting from postnatal day 18. As a marker of puberty, vaginal opening was recorded and neuropeptide- and related transcription factor mRNA levels were measured by quantitative real time PCR and in situ hybridization histochemistry. Both ZEA and EE2 accelerated vaginal opening, increased uterine weight and the number of antral follicles in the ovary and resulted in increased central expression of gnrh. These changes occurred in parallel with an earlier increase of kiss1 mRNA in the anteroventral and rostral periventricular (AVPV/PeV) hypothalamus, and increased kisspeptin (KP) fiber density and KP-GnRH appositions in the preoptic area. These changes are compatible with a mechanism in which xenoestrogens overstimulate the developmentally unprepared reproductive system, which results in advanced vaginal opening and enlargement of the uterus at the periphery. Within the hypothalamus, ZEA and EE2 directly activate AVPV KP neurons to stimulate GnRH mRNA. However, GnRH and gonadotropin release and ovulation are disrupted due to xenoestrogen-mediated inhibitory KP signaling in the arcuate nucleus