Power tiller vibration acceleration envelope curves on transportation mode

Application of power tillers are being increased as a main source of power supply for agricultural equipment due to their economic benefits. Beside on field applications, they are also engaged on transportation of agricultural products and human beings on rural roads. In spite of these advantages, power tillers are a big source of vibration generation too. Therefore, their operators have to work in a harsh environment. Single cylinder diesel engine used in power tillers and lack of suspension system are the main cause for generating high levels of vibration. The present research work was conducted on a 13-hp power tiller to determine the maximum and minimum vibration acceleration envelope curves on transportation mode. The power tiller vibration acceleration signals were measured for four transmission ratios and five engine speeds at positions of the power tiller handle and trailer seat to be pulled by the power tiller as well as wrist, arm, chest and head of the power tiller operator’s. The recorded time domain signals were converted to frequency domain signals using Fast Fourier Transform (FFT) algorithm. The 1/3rd octave frequency band was determined from the frequency domain signals. The maximum and minimum envelope curves were determined from the 1/3rd octave bands. The envelope curves at the handle position showed that the root mean square (RMS) values of vibration acceleration for frequencies of 8 to 80 Hz were exceeded 2 m/s2 (hand-arm exposure limit for 8 hours working per day) and at 31.5 Hz it reached to 11 m/s2. At the trailer seat position, the RMS values of vibration acceleration were exceeded the standard limits for comfortable operation in the frequency ranges of 3.15 to 6.3 and 25 to 40 Hz. Furthermore, the derived envelope curves seem to be suitable guidelines for designing and developing vibration control systems in the power tiller

Investigating a Power tiller Handle and Seat Vibration on Transportation mode

In this paper, vibration a power tiller vibration was investigated at handle position as well as seat position of a trailer pulled by the power tiller. The experiments were conducted at five levels of engine speed, four levels of transmission gear ratio during transportation, and in three directions. Then the weighted 1/3rd octave spectrum was calculated from the narrow band vibration acceleration signals. The amount of vibration damage on operator's body and allowable exposure limits were calculated based on ISO standards. The results showed that the vibration increased with increasing the engine speed for all the gear ratios and directions. The magnitude of vibration was the greatest at vertical direction in all the experiments. The vibration allowable exposure time was in the range of 2.32-5.7 years at the power tiller handle for the different engine speeds and gear ratios. The total equivalent vibration, A (8), at the trailer seat was in the range of 0.5 to 0.87 m/s2 and it exceeded the allowable limits for the reduced comfort boundary, fatigue-decreased boundary and exposure limit for 8 hours/day. So, it is necessary to reduce the vibration transmitted to the operator’s hand and body by designing and developing adequate insulating systems

Protective Effects of Hydroxytyrosol on Renal Ischemia-reperfusion Injury in Mice

Background: Renal ischemia reperfusion (IR), one of the most important causative mechanisms of acute kidney injury, is a major clinical problem that occurs in some hospitalized patients. The aim of this study was to investigate the effects of hydroxytyrosol (HT) on renal ischemia-reperfusion injury in mice.Methods: Male mice were randomly assigned to three groups (N = 9): (1) sham operated, (2) renal IR (45 min ischemia followed by 24 h reperfusion), or (3) renal IR+HT (5 mg/kg orally for 7 days before renal IR and one hour before IR). Animals were sacrificed and the blood and kidney tissue samples were collected for glutathione (GSH) and malondialdehyde (MDA) evaluation.Results: Renal IR injury led to decreases in renal tissue GSH and increases in MDA levels compared to sham operated. Hydroxytyrosol partially inhibited the IR-induced decrease in GSH activity. In addition, in the renal IR+HT group, MDA was increased compared to the renal IR group.Conclusions: These findings suggest that HT diminished oxidative stress in renal tissue after renal IR

Protective Effects of Hydroxytyrosol on Renal Ischemia-reperfusion Injury in Mice

Background: Renal ischemia reperfusion (IR), one of the most important causative mechanisms of acute kidney injury, is a major clinical problem that occurs in some hospitalized patients. The aim of this study was to investigate the effects of hydroxytyrosol (HT) on renal ischemia-reperfusion injury in mice.Methods: Male mice were randomly assigned to three groups (N = 9): (1) sham operated, (2) renal IR (45 min ischemia followed by 24 h reperfusion), or (3) renal IR+HT (5 mg/kg orally for 7 days before renal IR and one hour before IR). Animals were sacrificed and the blood and kidney tissue samples were collected for glutathione (GSH) and malondialdehyde (MDA) evaluation.Results: Renal IR injury led to decreases in renal tissue GSH and increases in MDA levels compared to sham operated. Hydroxytyrosol partially inhibited the IR-induced decrease in GSH activity. In addition, in the renal IR+HT group, MDA was increased compared to the renal IR group.Conclusions: These findings suggest that HT diminished oxidative stress in renal tissue after renal IR

Medindo a satisfação dos moradores do município de Mehregan, em Mashhad, na perspectiva da habitação sustentável

Demographic developments in Mashhad and surrounding rural areas which are now considered urban break points It is well established that these areas have become centers of attraction for low-income immigrants who intend to migrate to Mashhad, as well as low-income urban strata that have previously lived in Mashhad. Since all four types of worn-out urban textures, including urban heritage, non-urban, marginal and rural urban textures, are the middle and lower decay habitats, "The 5000 unit project of Mehregan Town of Mashhad" has played an important role in the physical and functional organization of these tissues and responding to the needs of the poor. In view of the above, and several years after the project was inaugurated, the superstructure and infrastructure problems of the project are the subject of research in this research. The research method in this study was descriptive-analytical and applied. According to the number of households in the city that formed the statistical population of the study, and based on Cochran's formula, the sample population was 366 persons. Also, Delphi method has distributed 32 questionnaires to expert experts. Descriptive and inferential statistical analysis of completed questionnaires and experts has been done with the help of nonparametric and parametric statistical methods. The results of field surveys showed that the observed frequency of low-satisfaction residents was 222 and above all, so it is safe to say that 95% of respondents are not satisfied with their residence in Mehregan town. It is believed that the residential units constructed in Mehregan town of Mashhad have poor compliance with the standards and standards of sustainable housing.Desenvolvimentos demográficos em Mashhad e áreas rurais circunvizinhas que agora são consideradas pontos de ruptura urbana Está bem estabelecido que essas áreas se tornaram centros de atração para imigrantes de baixa renda que pretendem migrar para Mashhad, bem como estratos urbanos de baixa renda que anteriormente morava em Mashhad. Como todos os quatro tipos de texturas urbanas desgastadas, incluindo herança urbana, texturas urbanas não urbanas, marginais e rurais, são habitats de decadência média e baixa, "O projeto da unidade de 5000 unidades da cidade de Mehregan, Mashhad" desempenhou um papel importante. a organização física e funcional desses tecidos e a resposta às necessidades dos pobres. Tendo em vista o exposto, e vários anos após a inauguração do projeto, os problemas de superestrutura e infraestrutura do projeto são objeto de pesquisa nesta pesquisa. O método de pesquisa neste estudo foi descritivo-analítico e aplicado. De acordo com o número de domicílios da cidade que formaram a população estatística do estudo, e com base na fórmula de Cochran, a população da amostra era de 366 pessoas. Além disso, o método Delphi distribuiu 32 questionários para especialistas. A análise estatística descritiva e inferencial dos questionários e especialistas preenchidos foi realizada com a ajuda de métodos estatísticos não paramétricos e paramétricos. Os resultados de pesquisas de campo mostraram que a frequência observada de residentes de baixa satisfação era 222 e, acima de tudo, portanto, é seguro dizer que 95% dos entrevistados não estão satisfeitos com sua residência na cidade de Mehregan. Acredita-se que as unidades residenciais construídas na cidade de Mashhad, em Mehregan, não cumpram com os padrões e padrões de habitação sustentável