The Activity of Purple Sweet Potato Leaves (Ipomea batatas Ver.) Extract to Calcium Oxalate Concentration of Male Rat (Rattus novergicus)

Purple sweet potato leaves (Ipomea batatas Ver.) has been proven to have anti-lithiasis effects in vitro in treating kidney stone disease. This is due to the high content of potassium in the leaves. The study aimed to analyze the effect of purple sweet potato leaf extract on kidney stone decay in male white rats induced by ethylene glycol 0.75% and ammonium chloride 2% for 10 days. In this study, 24 mice were divided into 6 groups: normal or without induction group, positive control, negative control, dose group 300 mg/200-gram body weight, 400 mg/200-gram body weight, and 500 mg/200-gram body weight. The parameters observed were calcium levels in the urine tested using Atomic Absorption Spectrophotometry, oxalate levels in urine tested using UV VIS Spectrophotometer. The results of this study indicate that purple sweet potato leaf extract at a dose of 500 mg/200-gram body weight can increase the levels of calcium and oxalate in the urine of rats compared with negative controls.

Spatiotemporal investigation of material property changes in building stone following initial emplacement

<p>Visual inspection of deterioration phenomena across the façades of a historical monument demonstrates the spatial variability of weathering processes. Multiple previous weathering simulation and exposure trials have been developed to investigate the connection between weathering processes and spatial variability of response. However, in landscape systems theory, stability is a function of both spatial and temporal components. Temporal sensitivity is a function of both the magnitude and frequency of formative events and the spatial sensitivity of the material.</p><p>One area of urban stone decay literature that requires further attention is the initial response of quarry ‘fresh’ material to emplacement within a building. Previous small-scale investigations have demonstrated that alteration commences within a few months to a year of emplacement. These early changes to the material will have a lasting influence upon the development of future weathering processes and their spatial distribution. The necessity to investigate both the spatial and temporal components of this transition, well suits the capabilities of spatiotemporal kriging tools.</p><p>The influence of aspect upon the initial alterations of the material’s properties are of significance to interpreting the weathering response to transition. Therefore, five sandstone blocks were placed within an exposure frame, located in South Belfast, for a duration of one year. One block was exposed to each of the four cardinal points whilst the fifth was positioned to represent a horizontal surface on a structure, such as a window sill or balustrade. Permeability measurements were recorded in a regular grid across the exposed surface of the block once a month, creating a data set that is both spatially and temporally dense. No previous studies have collected a similar quantity of points, across both space and time, to investigate weathering processes. The application of only spatial techniques proved to be inappropriate to fully interpret the complexity of the changing material properties. Use of spatiotemporal kriging allowed the modelling of the sample blocks to illustrate the changing material properties over time. The outcome of this work is the development of a better-informed understanding of the initial alteration of building stones placed within the urban environment. Additionally, the observed variance of the temporal component has improved our understanding of the nature of early episodic change within the stone decay system.</p>

Rock Features and Alteration of Stone Materials Used for the Built Environment: A Review of Recent Publications on Ageing Tests

This work presents a review of recent publications, with publication date between 2017 and 2019, with information on the relation between rock characteristics and the effects of diverse agents associated with alteration of stone materials in the built environment. It considers information obtained from ageing tests performed under laboratory conditions and by exposure to outdoor agents. Several lithological groups were considered, with sedimentary carbonate rocks being the most frequently studied lithotypes and silicate metamorphic rocks being the group with scarcer information. In terms of ageing tests, salt weathering was the most frequent one while there was a noticeable lesser amount of information from tests with biological colonization. The collected data showed the influence of diverse features, from specific minerals to whole-rock properties and the presence of heterogeneities. These information are discussed in the context of formulating a general framework for stone decay.

Synthetic calcium carbonate improves the effectiveness of treatments with nanolime to contrast decay in highly porous limestone

Three synthetized polymorphs of calcium carbonate have been tested in combination with the suspension of nanolime particles as potential consolidating agents for contrasting stone decay and overcome some of the limitations of nanolime agents when applied to substrates with large porosity. The modifications induced in the pore network of the Maastricht limestone were analyzed with microscopy and in a non-invasive fashion with small angle neutron scattering and synchrotron radiation micro-computed tomography. A reduction in porosity and pore accessibility at the micrometric scale was detected with the latter technique, and ascribed to the improved pore-filling capacity of the consolidation agent containing CaCO3 particles. These were found to be effectively bound to the carbonated nanolime, strengthening the pore-matrix microstructure. Penetration depth and positive effect on porosity were found to depend on the particle size and shape. Absence of significant changes in the fractal nature of the pore surface at the nanoscale, was interpreted as indication of the negligible contribution of nanolime-based materials in the consolidation of stones with large porosity. However, the results indicate that in such cases, their effectiveness may be enhanced when used in combination with CaCO3 particles, owing to the synergic effect of chemical/structural compatibility and particle size distribution.

Thermal, physical and mechanical characterization of volcanic tuff masonries for the restoration of historic buildings

An in-depth knowledge of building materials is essential in order to preserve them. Tuffs are one of the main types volcanic rocks in the Canary Islands. They are mainly used in masonry or as a filler of the ornamental parts of the façades. In both cases, they have been protected to guarantee their durability. However, in recent years, the renderings have been eliminated and the stone has been exposed to the elements. In this paper, two types of Canary-Island volcanic tuffs were characterized from a physical and mechanical point of view as well as their energy conservation, in order to better understand their behaviour and analyze the criteria for preserving them. Thermal conductivity and fluxes increase 2-3 times in wet conditions, as compared to dry ones. This, together with their high porosity demands the use of renderings to avoid stone decay, and at the same time improving living conditions.

Principal Components Analysis (PCA) of Monument Stone Decay by Rainwater: A Case Study of “Basílica da Estrela” Church, Portugal

An extended version of Principal Components Analysis (PCA) of monument stone decay phenomena occurring at “Basilica da Estrela” church, Lisbon, Portugal, is now presented. The PCA rationale and general methodological procedure is presented, as a first step of a stepwise approach to the eigenvector methods of data analysis. PCA, as others “Eigenvector Methods”, seeks to reveal the underlying structure that might exist within a set of multivariate observations. Temperature, pH, electrical conductivity and main ionic species were measured on several seepage samples over three years inside the monument. PCA results are discussed in the perspective of a nondestructive tool.