Volumetric Characteristics of HRS-WC Mixed Using Petroleum Bitumen Grade 60/70 as Binder

This study aims to determine the volumetric values consisting of VIM, VMA and VFB on the binder layer mixture using HRS-WC gradation using petroleum bitumen as a binder. The method used in this research is experimental method in laboratory. In this study, variations of asphalt content used were 5.5%, 6.0%, 6.5%, 7.0% dan 7.5%. These variations were obtained from the calculation of effective asphalt level of 5.9%. The results show that the VIM values decreases along with the increase of bitumen content used. VIM values obtained were 6.69%, 5.82%, 5.18%, 4.42% and 3.34%, respectively. The VMA values obtained were 18.12%, 18.38%, 18.84%, 19.21% and 19.30% for each bitumen content. Besides that, the value of VFB is also taken into account and the values obtained for each quality of bitumen content are 63.10%, 68.41%, 72.57%, 76.99% and 82.71%.

Performance of Asphalt Mixture with Asbuton Based on Marshall Characteristics Compacted at Hot and Cold Temperatures

The use of natural asphalt is an alternative to meet the high demand for oil asphalt. Asbuton is natural asphalt from Buton Island, Indonesia. However, the use of Asbuton is not as easy as oil asphalt because the asphalt it contains is hard. The asphalt-concrete mixture must go through a rejuvenation process for several days before being compacted. This study aims to determine the performance of asphalt-concrete mixture using Asbuton if it is compacted immediately after mixing, without giving time for the rejuvenation process. Compaction is done when the mixture is hot and after the mixture is cold. Compaction of the asphalt-concrete mixture in hot temperature (150ºC), based on mechanical characteristics (stability, flow, and Marshall Quotient), has better performance than that compacted in cold temperature (30ºC). However, compaction in both hot and cold temperatures, based on their volumetric characteristics, does not meet the requirements for use as road pavements. The performance of the asphalt mixture can be improved by giving time in the process of softening the asphalt content in Asbuton

Quantitative Analysis of Synthetic Magnetic Resonance Imaging in Alzheimer’s Disease

Objectives: The purpose of this study was to evaluate the feasibility and whether synthetic MRI can benefit diagnosis of Alzheimer’s disease (AD).Materials and Methods: Eighteen patients and eighteen age-matched normal controls (NCs) underwent MR examination. The mini-mental state examination (MMSE) scores were obtained from all patients. The whole brain volumetric characteristics, T1, T2, and proton density (PD) values of different cortical and subcortical regions were obtained. The volumetric characteristics and brain regional relaxation values between AD patients and NCs were compared using independent-samples t-test. The correlations between these quantitative parameters and MMSE score were assessed by the Pearson correlation in AD patients.Results: Although the larger volume of cerebrospinal fluid (CSF), lower brain parenchymal volume (BPV), and the ratio of brain parenchymal volume to intracranial volume (BPV/ICV) were found in AD patients compared with NCs, there were no significant differences (p > 0.05). T1 values of right insula cortex and T2 values of left hippocampus and right insula cortex were significantly higher in AD patients than in NCs, but T1 values of left caudate showed a reverse trend (p < 0.05). As the MMSE score decreased in AD patients, the BPV and BPV/ICV decreased, while the volume of CSF and T1 values of bilateral insula cortex and bilateral hippocampus as well as T2 values of bilateral hippocampus increased (p < 0.05).Conclusion: Synthetic MRI not only provides more information to differentiate AD patients from normal controls, but also reflects the disease severity of AD.

The role of private farming in providing the population with food

Since its appearance, private farming has performed several functions, the most important of which is to provide the rural and urban population with food. The article explores the change in the mechanism for performing this function. The volumetric characteristics of its implementation in dynamics are given, the calculation of the number of rural and urban population of the USSR and Russia, who used private farming to provide with food, is made. Based on the analysis of the currently changed conditions for the functioning of this sector of the economy. a predictive assessment of its existence in the future is made

Determination of Volumetric Characteristics of FAM Mixtures using X-Ray Micro-Computed Tomography and Their Effects on the Rheological Behavior of the Material

Fine aggregate matrix (FAM) has been regarded as a key constituent of asphalt mixtures. Although several design methods have been recently proposed to prepare FAM specimens that represent the materials contained within the asphalt concretes, the volumetric characteristics of FAM may not be uniformly distributed within samples compacted using devices such as the Superpave gyratory compactor (SGC). This can mislead the mechanical analyses conducted with testing specimens that are typically extracted from different locations of the compacted samples, as they can present varying volumetric characteristics. This study employs the advanced micro-computed tomography (CT) scan technique to evaluate the air void distribution within FAM specimens extracted from different locations of SGC samples compacted with distinct air void contents. Rheological tests are performed in a dynamic shear rheometer to determine the dynamic shear modulus of the testing specimens. A statistical analysis is conducted to evaluate potential correlations between the volumetric and the rheological characteristics of the FAMs and to identify locations within the SGC samples from which small cylindrical specimens with similar characteristics can be extracted and used for testing. The adoption of advanced techniques such as the CT scan is essential for the advancement of the knowledge on the complex characteristics of asphalt mixtures, and may facilitate the fabrication of FAMs that are more representative of those that comprise asphalt concretes, as well as allow the use of similar replicates in mechanical tests.