Use Of Coarse Research Articles

Product development and characterization of a lipid-based Ayurvedic polyherbal formulation: Kalyanaka Ghrita

BackgroundKalyanaka Ghrita (KG) is polyherbal oleaginous medicament consisting of extracts from twenty-eight different plants, indicated for management of psychosomatic disorders like Unmada (Schizophrenia), Apasmara (Epilepsy) and numerous other ailments. ObjectiveTo develop and validate standard manufacturing procedure of KG by following Ayurvedic principles in three batches to ensure process uniformity and standards. Materials and methodsThree batches of KG were prepared by adopting principles of Ashtanga Hrudya and Ayurvedic Formulary of India to ensure consistency in manufacturing process. Observations during process such as temperature, duration were recorded. KG was subjected to chief desired characteristics, organoleptic (color, odour, taste, texture, touch), physicochemical (acid value, peroxide value, iodine value, saponification value, loss on drying, refractive index, specific gravity, mineral oil, rancidity test, viscosity) as per pharmacopeial standard. Chromatographic screening and fingerprinting of KG were conducted through GCMS whereas quantification of curcumin and chebulagic acid biomarkers were assessed through HPLC. ResultsAverage yield of KG was 83.41%, with average intermittent heating duration of 20.35 h subsequently divided into three days. Temperature throughout preparation ranged from 66 °C to 101 °C. KG was pale olive in colour, exhibiting pleasant taste, characteristic smell, and soft texture. Organoleptic and physicochemical characters were comparable for three batches of KG while safety parameters were found within permissible limits. ConclusionPharmaceutical standardization of Kalyanaka Ghrita is necessary for establishing biological and chemical profile of formulations. Present study recommends use of coarse powdered ingredients for optimal yield during pharmaceutical process, and heating up to Madhyama Paka stage calibrated over three days with average temperature of 85 °C. The data obtained from this study may contribute to future research and development activities, serving as a basis for manufacturing standards of KG.

Individual differences in spatial working memory strategies differentially reflected in the engagement of control and default brain networks.

Spatial locations can be encoded and maintained in working memory using different representations and strategies. Fine-grained representations provide detailed stimulus information, but are cognitively demanding and prone to inexactness. The uncertainty in fine-grained representations can be compensated by the use of coarse, but robust categorical representations. In this study, we employed an individual differences approach to identify brain activity correlates of the use of fine-grained and categorical representations in spatial working memory. We combined data from six functional magnetic resonance imaging studies, resulting in a sample of $155$ ($77$ women, $25 \pm 5$ years) healthy participants performing a spatial working memory task. Our results showed that individual differences in the use of spatial representations in working memory were associated with distinct patterns of brain activity. Higher precision of fine-grained representations was related to greater engagement of attentional and control brain systems throughout the task trial, and the stronger deactivation of the default network at the time of stimulus encoding. In contrast, the use of categorical representations was associated with lower default network activity during encoding and higher frontoparietal network activation during maintenance. These results may indicate a greater need for attentional resources and protection against interference for fine-grained compared with categorical representations.

Material behaviour and flexural performance of low carbon concrete beams containing very high quantities of recycled and secondary materials

As the global urban population continues to grow, reducing the carbon footprint of our built environment is on the critical path towards achieving net-zero CO2 targets by 2050. Representing the largest contributor to infrastructure-related emissions, the cement and concrete sectors are accelerating their efforts to develop low carbon concrete structures. In line with this critical path, this paper presents a first of its kind study on the performance of reinforced concrete beams produced using concrete containing very high quantities (greater than 80%) of recycled and secondary materials. A total of 24 low carbon concrete mixtures were developed and evaluated. Mixtures included the use of coarse and fine recycled concrete aggregates (100% replacement of natural aggregates) and the use of ground granulated blast furnace slag (50% replacement of portland cement). Using a combination of novel mixture proportioning and two-stage mixing methods, mixtures were adjusted to improve compressive strength, workability, and batch-to-batch consistency. Several low carbon concrete mixtures containing greater than 70% recycled and/or secondary materials achieved compressive strengths of approximately 30 MPa. Twelve reinforced concrete beams (2.25 m) were tested in four-point bending. Reinforced concrete beams produced with low carbon concrete with up to 89% recycled and/or secondary materials had ultimate moment capacities which were, on average, only 5% lower compared to the conventional concrete beams. Current CSA A23.3 design equations were conservative in their estimates of ultimate moment capacity for both the conventional and low carbon concrete beams.

Emergence of Synthetic Cannabinoids: Pharmacological insights and adverse effects

Despite the risks involved in the use of synthetic cannabinoids, their applications in researches gained huge popularity. Researches into synthetic cannabinoids have increased recently as a result of relaxed global legal developments. Synthetic cannabinoids such as Dronabinol and Nabilone may help with symptoms of chronic pain, muscle stiffness, nausea and vomiting brought on by chemotherapy and unmanageable adolescent epilepsy. The coarse use of cannabinoids is typically associated with psychotropic effects like relaxation, euphoria and a vague gratifying feeling, but their aberrant uses are also associated with serious adverse-effects. Despite this cognizance, affinity between the molecular structure of synthetic cannabinoids and their receptors mediated pharmacological activities is yet not well understood. Around the world, numerous experiments are being conducted in order to explore their therapeutic values as well as toxicities. The experimental models beneficial for the evaluation of emerging cannabinoids of synthetic origin include the cannabis tetrad test, drug discrimination, dependence, withdrawal and assays of tolerance. Real risks and perceived hazards can have significant disparity. Certain empirical approaches and scientific methods could be used to compare and appraise the therapeutic indications and adverse effects of the synthetic cannabinoids. The present review provides a scientific discussion of these substances and their pharmacological insights as well as adverse effects referring latest references.

Quantification and characterization of the microstructural damage of recycled aggregate self-compacting concrete under cyclic temperature changes

Recycled Aggregate (RA) usually increases porosity and weakens Interfacial Transition Zones (ITZs) of concrete, which favors the appearance of internal thermal damage. Four Self-Compacting Concrete (SCC) mixes with coarse and fine RA were subjected to positive and negative cyclic temperature variations to characterize their thermal damage and quantify its effects. Two damage mechanisms were found. On the one hand, micro-cracks appeared in the ITZs. On the other hand, micro-cracks arose from the micro-pores and propagated through the cementitious matrix. Both damage mechanisms were promoted by the use of coarse and fine RA, respectively. The damage was most notable at sub-zero temperatures and when adding coarse RA. Furthermore, it primarily affected compressive strength, although ultrasonic pulse velocity and hardened density also decreased, which served as non-destructive indicators to indirectly quantify the level of thermal internal damage of SCC.

Synthesis of MAX phase-based ceramics from early transition metal hydride powders

MAX phase ceramics are typically prepared by the reactive sintering of elemental powders that are often coarse, expensive, and prone to oxidation. The temperature-driven dehydrogenation of metal hydride powders offers an alternative synthesis approach, as the hydrides decompose into phase-pure, dimensionally fine elemental powder particles. The increased reactivity of these in situ formed, fine powder particles drastically reduces the formation temperature of the antecedent intermetallic phases, without forming excess binary carbides or facilitating powder oxidation in the Ti-Al-C and Zr-Al-C systems. This work elucidates the effect of metal hydrides on the sequence of formation reactions in MAX phase ceramics. In the Zr-Al-C system, the use of coarse, oxidation-prone elemental Zr powders prevented MAX phase formation, whereas spark plasma sintering of ZrH2 powders at 1500 °C produced ceramics containing 60 wt% Zr3AlC2. Similarly, in the Ti-Al-C system, spark plasma sintering of TiH2 powders at 1200 °C produced phase-pure Ti3AlC2 ceramics.

Pengaruh Penggunaan Agregat Kasar dan Halus dari Quarry Siulak Deras dan Quarry Sungai Rumpun di Kabupaten Kerinci terhadap Kuat Tekan Beton Normal

In Kerinci Regency, especially around areas of Gunung Tujuh and Siulak areas, people generally use materials from Sungai Rumpun quarry and Siulak Deras quarry for the concrete mixture. A preliminary test by organic impurity test showed that the organic substances in the aggregate from the Sungai Rumpun quarry had a high organic content, while the aggregate from the Siulak Deras quarry had a low organic content. Therefore, this study aims to investigate the characteristics of the aggregate from Sungai Rumpun quarry and the Siulak Deras quarry and to determine the effect of the use of coarse and fine aggregate from both quarries on the compressive strength of concrete. This study is an experimental research that is conducted at the Civil Engineering Laboratory of the Padang Institute of Technology (ITP). In this study, the tests for physical properties of coarse and fine aggregates are conducted, then samples for the concrete compressive test are prepared, and the compressive strength test is carried out. Based on the results of this study, it can be concluded that aggregates from the Sungai Rumpun quarry are not recommended to be used for the concrete mixture of normal strength concrete (fc'=20 MPa), because the results of the compressive strength test showed that the average compressive strength does not reach the designed compressive strength (fc'). On the other hand, the aggregates from the Siulak Deras are recommended to be used for the concrete mixture of normal strength concrete because the compressive strength reaches the designed compressive strength.

Analysis of surface urban heat islands based on local climate zones via spatiotemporally enhanced land surface temperature

Surface Urban heat island (SUHI) is a major adverse environmental consequence of urbanization. Many algorithms measuring SUHI across varying spatial or temporal scales are developed rapidly with the availability of thermal infrared (TIR) remote sensing data from satellites. However, the trade-off between the spatial and temporal resolution of TIR sensors limits the study of SUHI on both spatial and temporal domains. Therefore, this study aims to improve the characterization of SUHI using spatiotemporally enhanced land surface temperature (LST) derived from the synergistic use of coarse- and fine-spatial-resolution TIR data. Combining the spatial downscaling and temporal interpolation techniques, we generated daily 100 m-resolution LST in both daytime and nighttime to analyze the SUHI in different local climate zones (LCZs) in Beijing. LCZ is a manifestation of the urban form on the thermal environment, covering hundreds of meters to several kilometers in horizontal scale. The results indicate the spatiotemporally enhanced LST is reliable in capturing the LCZ-based SUHI magnitude compared with original observations, and providing a more accurate time range when the SUHI reaches to its maximum compared with those time-discontinuous original observations. Compared with temporally interpolated coarse-resolution LST, the spatiotemporally enhanced LST shows a larger annual variation of SUHI (especially in LCZ 2 with a mean absolute SUHI difference of 0.8 K and 1.3 K for daytime and nighttime, respectively) and provides larger SUHI difference between compact building and open building (especially when there is a significant SUHI effect). The superiority of the spatiotemporally enhanced LSTs in analyzing LCZ-based SUHI is more evident in daily and monthly SUHI analysis than in single-day analysis or annual analysis, especially in compact building types (LCZ 1 and 2). These findings are valuable information for better and healthier urban planning for SUHI mitigation and public health care.

A Modified Discrete Scheme in the Ausas Cavitation Algorithm

Abstract In order to reduce the dependence of accuracy on the number of grids in the Ausas cavitation algorithm, a modified Ausas algorithm was presented. By modifying the mass-conservative Reynolds equation with the concept of linear complementarity problems (LCPs), the coupling of film thickness h and density ratio θ disappeared. The modified equation achieved a new discrete scheme that ensured a complete second-order-accurate central difference scheme for the full film region, avoiding a hybrid-order-accurate discrete scheme. A journal-bearing case was studied to show the degree of accuracy improvement and the calculation time compared to a standard LCP solver. The results showed that the modified Ausas algorithm made the asymptotic and convergent behavior with the increase of nodes disappear and allowed for the use of coarse meshes to obtain sufficient accuracy. The calculation time of the modified Ausas algorithm is shorter than that of the LCP solver (Lemke’s pivoting algorithm) for middle- and large-scale problems.

Image-Based deterioration assessment of fiber reinforced No Aggregate concrete

Aggregates are the major ingredients of concrete and based on the data acquired from various sources demand will keep spiking up day by day. To overcome this problem utilization of a variety of waste materials, such as recycled coarse aggregates, fly ash, silica fume, GGBS, Gypsum, etc. is used to produce concrete mixes. NO AGGREGATE CONCRETE (NAC) was developed to protect natural resources from exploitation through experimental research and trials. This eliminates the use of coarse and fine particles in concrete manufacturing. Using a digital image processing technique based on a simple visible spectrum, the current study evaluates the NO AGGREGATE CONCRETE (NAC) deterioration due to a chemical attack. For durability testing, M30 concrete cubes were cast. For 7, 14, and 28 days, concrete specimens were subjected to sodium hydroxide (NaOH) and magnesium sulphate (MgSO4) degradation at a 5 percent concentration. After the required exposure time, each face of the individual cube is taken, and the related statistics of greyscale intensity were obtained. Using image analysis software to analyze digital images, it is possible to build a correlation with greyscale intensities of numerous established deterioration measures. With digital image-based analysis, it is possible to create a link between the greyscale intensities of many established deterioration indicators such as mass loss, dimension loss, and strength loss. In NaOH and MgSO4-exposed concrete, both the intensity of the greyscale and the mean greyscale as strong predictors of the extent of deterioration. The mean greyscale intensities enable identification of exposure and deterioration due to different chemicals. Digital image analysis enables the development of correlation with greyscale intensities of various established deterioration measures such as mass loss, dimension loss, and strength loss. Both the intensity of greyscale as well as mean greyscale are found to be good predictors of the extent of deterioration in concrete exposed to NaOH and MgSO4.

Recycled Refractory Brick as Aggregate for Eco-friendly Concrete Production

The amount of construction and demolition waste continues to increase year by year.These wastes have a significant harmful influence on the environment; refractory brick is among of these wastes. this paper concerns the reuse of refractory brick wastes to produce an eco-friendly concrete. To achieve this objective,coarse and fine Natural Aggregates (NA) were partially replaced with recycled Refractory Brick Aggregates (RBA). According to the design of experiment, two families of mixes were prepared and tested: the first mixes was made with coarse and fine NA (as reference concrete) and the second mixes made by replacing 20% of coarse and fine NA by coarse and fine RBA. For each of the mentioned families, three cement dosages of 350 kg/m3 , 400 kg/m3 , 450 kg/m3 were investigated. A series of experiments including water porosity, density, Ultrasonic Pulse Velocity (UPV) and compressive strength were assessed. Observed results indicate that the use of coarse and fine RBA had a relatively influence on the water porosity and UPV of concrete. However, the use of coarse and fine RBA produces a slightly decreased the density of concrete (below 2%). Moreover, the use of coarse and fine RBA in concrete improved the compressive strength. Hence, coarse and fine RBA can be successfully used to produce concrete with acceptable properties.

Investigation of the feed resource for buffalo

Buffaloes make better use of coarse and inferior feed by converting them to biologically valuable animal production. They make very good use of the additional production of crop production, such as straw, sunflower cakes, sprouts and other. The aim is to study the physicochemical and fatty acid composition of the rations of buffalo of the Bulgarian mura breed in a church farm in Gigentsi village, Pernik District. The application of standard methods for the nutrition of buffaloes in separate periods - pastured with succulent fodder, winter (indoor) with coarse fodder, through which the ruminants are provided with the necessary nutritional components, allows to obtain high quality milk as a basic raw material for the production of dairy products. The use of succulent fodder and the incorporation of root crops into the feed instead of the buffalo concentrate provides them with respect to linoleic and alphalinolenic fatty acids, which are substrates for the synthesis of CLA (anticancer action) in rumen of ruminants.

Progress in developing self-consolidating concrete (SCC) constituting recycled concrete aggregates: A review

Recycled concrete aggregate (RCA) derived from demolition waste has been widely explored for use in civil engineering applications. One of the promising strategies globally is to incorporate RCA into concrete products. However, the use of RCA in high-performance concrete, such as self-consolidating concrete (SCC), has only been studied in the past decade. This paper summarizes recent publications on the use of coarse and/or fine RCA in SCC. As expected, the high-water absorption and porous structure of RCA have posed challenges in producing a high-fluidity mixture. According to an analysis of published data, a lower strength reduction (within 23% regardless of coarse RCA content) is observed in SCC compared with vibrated concrete, possibly due to the higher paste content in the SCC matrix, which enhances the weak surface layer of RCA and interfacial transition zone. Similarly, SCC tends to become less durable with RCA substitution although the deterioration can be minimized by using treated RCA through removing or strengthening the adhered mortar. To date, the information reported on the role of RCA in the long-term performance of SCC is still limited; thus, a wide range of research is needed to demonstrate the feasibility of RCA—SCC in field applications.

Properties of recycled aggregates from different composition and its influence on concrete strength

abstract: As a solution to the high depletion of natural resources and huge waste generated by the construction industry, the use of coarse recycled aggregate has become a trend in many countries. The construction and demolition waste is heterogeneous and mostly composed of concrete and masonry debris. The recycling process usually involves not only crushing and screening but also advanced techniques to separate these two fractions. These processes are costly and most frequently ineffective. Although most studies and international standards focused only on recycled concrete aggregate for structural use, it is possible to achieve similar characteristics with mixed recycled aggregates that have a ceramic fraction of up to 20%. This initiative can decrease recycling costs and make it more feasible. Therefore, this work presents an experimental investigation of a Brazilian recycled aggregate, which was separated into three fractions: mixed, concrete, and masonry aggregates. The analyses showed that the mixed recycled aggregate displayed geometric, physical, and mechanical properties similar to the recycled concrete aggregate. In addition, concrete made with 20% of mixed recycled aggregate presented a reduction of only 0.6% in maximum compressive strength and 36.8% in the modulus of elasticity compared with concrete made with the same amount of recycled concrete aggregate.

Optimization of the Interacting Stiffened Skins and Ribs Made of Composite Materials

A decomposition strategy for the structural optimization of a fiber-reinforced aircraft wing box is proposed. The proposed method decomposes the wing-box optimization into two levels: a system-level and a subsystem-level optimization. The ribs are the subsystems of the problem. Each rib has a local set of design variables and constraints. The loads on the ribs are the crushing loads caused by the bending of the wing. At the system level, the wing-box skins are optimized while accounting for the effect of the skin design on the loads applied to the ribs. The sensitivity of the rib mass to the applied loads is evaluated using the Lagrange multipliers of the optimized rib design. To enhance the numerical efficiency of the two-level optimization, the changes of the loads on the ribs are subjected to a reduction by principal component analysis (PCA). In both the wing-level and rib-level optimization problems, the level-set strategy for the optimization of composite structures, previously introduced by the authors, is employed. This method permits an advantageous use of coarse and fine finite element models employing a standard commercial finite element code. The proposed method is applied to the design of a composite horizontal tail plane. The accuracy of and the computational time savings by the proposed PCA-based reduction scheme are quantified.

FRP-confined recycled glass aggregate concrete: Concept and axial compressive behavior

In this study, the axial compressive behavior of fiber-reinforced polymer (FRP)-confined recycled glass aggregate concrete (RGAC) was experimentally investigated. In the FRP-confined RGAC, the FRP, a high performance material with high strength and excellent corrosion resistance, is utilized both as confinement and cover to the core concrete in order to increase mechanical performance (strength and deformability) and durability resistance to harsh environmental attack, respectively. Axial compression tests were carried out on a series of RGAC cylindrical columns, including 21 unconfined RGAC specimens and 42 CFRP-confined RGAC specimens. The key test variables examined in this study include the FRP jacket thickness and replacement ratio of aggregates. The test results showed that the compressive behavior (e.g. strength and elastic modulus) of FRP-confined RGAC is comparable to that of FRP-confined normal concrete when the replacement ratio of RGAs is not large than 50%, although the compressive behavior of RGAC has a notable decrease with increasing replacement ratio of recycled glass aggregates (RGAs). The test results also demonstrated that a combined use of coarse and fine RGAs slightly improved the compressive behavior of both confined and unconfined RGAC. Based on this study, an effective way of re-using glass waste can be developed.

Averaged strain energy density estimated rapidly from nodal displacements by coarse FE analyses: Cracks under mixed mode loadings

AbstractThe strain energy density (SED) averaged over a structural volume allows to assess the fracture and fatigue behaviour of cracked components under mixed‐mode loadings. To rapidly estimate the averaged SED, two approaches have been previously proposed: (a) the direct approach; (b) the peak stress method (PSM) and nodal stress (NS) approach. In this paper, the nodal displacement (ND) approach is presented to rapidly estimate the averaged SED from the nodal displacements by FE analyses. This method combines the advantages of all previous approaches, ie, the use of coarse meshes able to capture the contributions of both stress intensity factors (SIFs) and higher order terms, without requiring geometrical modelling of the control volume. To validate the method, cracked plates and cracked bars under mixed‐mode loadings have been analysed. The averaged SED values estimated by the ND approach agree with those calculated by the direct approach, within a range of applicability.

Monitoring ecosystem service change in the City of Shenzhen by the use of high‐resolution remotely sensed imagery and deep learning

AbstractInformation concerning land‐use change is imperative for improving conservation policies that promote sustainable land development. However, to date, most of the previous studies have largely focused on the use of coarse‐ or moderate‐resolution data, with which it may not be possible to identify the land‐use classes in urban environments. Due to the improved spatial details, high‐resolution (HR) remote sensing imagery provides us with an opportunity for the semantic interpretation of urban landscapes. Therefore, in this study, we took the City of Shenzhen (1997 km2) in China as an example to assess the detailed land‐use change and its effect on ecosystem services (ESs), based on HR satellite data from 2005 to 2017. In particular, deep learning was used to obtain accurate land‐use maps, because this technique is able to model the hierarchical representations of features and can thus effectively characterize urban scenes. The results revealed the following findings: (a) The overall accuracy of the proposed approach was 96.9% and 97.1% for 2005 and 2017, respectively, outperforming state‐of‐the‐art semantic classification models; (b) residential and commercial areas in Shenzhen increased dramatically over the study period by 10,416 and 9,168 ha, at the expense of ecological land; (c) supply capacity of the ecosystem decreased by 13.7%, but demand for ESs showed an increase of 23.5%. By courtesy of HR images, detailed land‐use changes and the associated ESs can be monitored, which facilitates the in‐depth understanding of urban environmental systems.

Deformable soil with adaptive level of detail for tracked and wheeled vehicles

This paper describes a model for deformable soil based on triangular meshes with vertical deformation. Such soil model can be used in a multi-body simulation environment to study the performance of wheeled or tracked vehicles. The formulation is inspired by the soil contact model (SCM), but unlike the original idea, our implementation uses triangular meshes with arbitrary topology. We leverage on this representation of the soil in order to provide a system that automatically refines the level of detail (LOD) of the mesh when tyres or track shoes sink into the soil; this allows the use of coarse meshes as initial approximations of large areas, for the sake of faster performance and lowoverhead on computer memory. A general-purpose collision detection algorithm is used to detect the shape of contacting objects, hence allowing the use of generic geometries to represent lugs, tyre threads, or even track shoes or robotic legs. The method has also been tested with deformable tyres.

The spatial level of analysis affects the patterns of forest ecosystem services supply and their relationships

The implementation of the Ecosystem Services (ES) framework (including supply and demand) should be based on accurate spatial assessments to make it useful for land planning or environmental management. Despite the inherent dependence of ES assessments on the spatial resolution at which they are conducted, the studies analyzing these effects on ES supply and their relationships are still scarce. To study the influence of the spatial level of analysis on ES patterns and on the relationships among different ES, we selected seven indicators representing ES supply and three variables that describe forest cover and biodiversity for Catalonia (NE Iberian Peninsula). These indicators were estimated at three different scales: local, municipality and county. Our results showed differences in the ES patterns among the levels of analysis. The higher levels (municipality/county) removed part of the local heterogeneity of the patterns observed at the local scale, particularly for ES indicators characterized by a finely grained, scattered distribution. The relationships between ES indicators were generally similar at the three levels. However, some negative relationships (potential trade-offs) that were detected at the local level changed to positive (and significant) relationships at municipality and county. Spatial autocorrelation showed similarities between patterns at local and municipality levels, but differences with county level. We conclude that the use of high-resolution spatial data is preferable whenever available, in particular when identifying hotspots or trade-offs/synergies is of primary interest. When the main objective is describing broad patterns of ES, intermediate levels (e.g., municipality) are also adequate, as they conserve many of the properties of assessments conducted at finer scales, allowing the integration of data sources and, usually, being more directly relevant for policy-making. In conclusion, our results warn against the uncritical use of coarse (aggregated) spatial ES data and indicators in strategies for land use planning and forest conservation.