Influence of soil fabric on dynamic properties of sand: An experimental study

Natural field sites originate under the action of external sources such as rivers, wind, or marine environments. These sources are responsible for constituting a variety of soil fabrics, which ultimately modify the deformation characteristics. Additionally, the dynamic properties of a site present the characterization of a region and have been profusely utilized by field engineers and researchers. In the present study, the dynamic properties of soil specimens have been evaluated for specimen preparation techniques, namely, air pluviation (AP) and water sedimentation (WS). The cyclic triaxial tests were conducted on the strain-controlled consolidated undrained specimens at a frequency of 0.1 Hz. This frequency has been used in several studies to replicate earthquake or liquefaction scenarios. The calculation of shear modulus (G) and damping ratio (D) was performed using symmetric hysteresis loops generated through cyclic loadings. The outcomes suggest that the specimen prepared using the WS technique possesses a larger shear modulus value than AP ones. The reason behind this observation was the lower degradation characteristics of the WS-prepared specimens. Additionally, the liquefaction susceptibility of the specimens has been noticed for different specimens. © 2023 ISEC Press

Experimental study on repeatedly loaded foundation soil strengthened by wraparound geosynthetic reinforcement technique

In the recent past, the potential benefits of wraparound geosynthetic reinforcement technique for constructing the reinforced soil foundations have been reported. This paper presents the experimental study on the behaviour of model strip footing resting on sandy soil bed reinforced with geosynthetic in wraparound and planar forms under monotonic and repeated loadings. The geosynthetic layers were laid according to the reinforcement ratio to minimise the scale effect. It is found that for the same amount of reinforcement material, the wraparound reinforced model resulted in less settlement in comparison to planar reinforced models. The efficiency of wraparound reinforced model increased with the increase in load amplitude and the rate of total cumulative settlement substantially decreased with the increase in number of load cycles. The wraparound reinforced model has shown about 45% lower average total settlement in comparison to unreinforced model, while the double-layer reinforced model has about 41% lower average total settlement at the cost of approximately twice the material and 1.5 times the occupied land width ratio. Moreover, wraparound models have shown much greater stability in comparison to their counterpart models when subjected to incremental repeated loading. © 2021 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Numerical modeling of virus transport through unsaturated porous media

This paper describes the movement of virus in one-dimensional unsaturated porous media. The governing virus transport equations consider the inactivation in liquid phase, liquid–solid interface, air–liquid interface, and sorption in both liquid–solid and air–liquid interfaces. Finite-volume method has been used for solving the advection and dispersion processes of the virus transport equation. The effects of transport parameters on virus concentration profiles have been investigated for virus present in liquid phase, adsorbed liquid–solid and liquid–air phases. The results show that the movement of viruses in three phases is affected by soil moisture, inactivation rate, pore velocity, and mass transfer coefficients. It is found that the magnitude of virus sorption is higher at the air–liquid interface as compared to the liquid–solid interface. A higher value of mass transfer coefficient leads to an increase in the virus concentration in both liquid–solid and air–liquid interfaces

Estimation of field compaction parameters

This paper describes the current Indian and Australian practices of the estimation of field compaction parameters (maximum dry unit weight and optimum moisture content) based on the laboratory compaction tests, which do not consider large-size particles of the field soil samples. The study indicates that in the absence of realistic estimation procedure, some pavements have failed due to the excessive settlement. A detailed derivation of improved expressions for determining the field compaction parameters is presented. The improved expressions would be useful for the pavements and earthworks and for developing the standards on the compaction tests for the field applications

Scholarly Communications of Mizoram University on Web of Science in Global Perspective: A Scientometric Assessment

Objectives: Scientometric assessment of the performance of scholarly communications of Mizoram University in world scenario. Methods: The ten years of scholarly communications have been retrieved from Web of Science for Mizoram University. The study analyses the scholarly communications, citations data, h-index, prolific contributors, forms of scholarly communications, funding agencies, highly cited scholarly communications, top areas of scholarly communications, authorship patterns and degree of collaboration. Results: Physics and Chemistry subjects found the highest productive area of scholarly communications, multiple authorship is prevalent with high degree of collaboration among authors, Department of Science and Technology (DST) as the topmost funding agency, South Korea found the strong collaborative country with Mizoram University in academic research, “Tiwari D” as the highest cited author, “Thapa RK” as the highest productive author, and increased growth in number of scholarly communications as well as citations. Contributions: The study analyzed the scholarly communications in terms of scientometric assessment and presented the current scenario of Mizoram University’s scholarly communications at the world level based on WoS database. It gives the insight to understand the situation of scholarly communications and make the future course of action accordingly. Mizoram University’s academic departments may also take the future course of action for more research to boost-up the university’s contribution at the global level

Load-bearing capacity of a footing resting on the fly ash slope with multi-layer reinforcements

In several parts of the world, the disposal of waste materials like fly ash is a challenging task. The applications of fly ash as structural fills in foundations is one of the best solutions to disposal problems, because they can be used in large volumes in such application. There may be difficulty due to poor load-bearing capacity of fly ash, especially when footings rest on the top of the fly ash fill slope; but inclusion of polymeric reinforcements as horizontal sheets within the fill may be advantageous in improving the load-bearing capacity of reinforced fly ash slope. The aim of present investigation is to find out the efficacy of multi layer reinforcements in improving the load-bearing capacity when incorporated within the body of fly ash embankment. An increase in load bearing capacity due to the incorporation of reinforcement layers in the model slope was observed in the laboratory tests. The experimental results were compared with the numerical findings obtained from the finite element analysis using commercial software PLAXIS 2D version 9.0

Scholarly Communications of Mizoram University on Web of Science in Global Perspective: A Scientometric Assessment

Objectives: Scientometric assessment of the performance of scholarly communications of Mizoram University in world scenario. Methods: The ten years of scholarly communications have been retrieved from Web of Science for Mizoram University. The study analyses the scholarly communications, citations data, h-index, prolific contributors, forms of scholarly communications, funding agencies, highly cited scholarly communications, top areas of scholarly communications, authorship patterns and degree of collaboration. Results: Physics and Chemistry subjects found the highest productive area of scholarly communications, multiple authorship is prevalent with high degree of collaboration among authors, Department of Science and Technology (DST) as the topmost funding agency, South Korea found the strong collaborative country with Mizoram University in academic research, “Tiwari D” as the highest cited author, “Thapa RK” as the highest productive author, and increased growth in number of scholarly communications as well as citations. Contributions: The study analyzed the scholarly communications in terms of scientometric assessment and presented the current scenario of Mizoram University’s scholarly communications at the world level based on WoS database. It gives the insight to understand the situation of scholarly communications and make the future course of action accordingly. Mizoram University’s academic departments may also take the future course of action for more research to boost-up the university’s contribution at the global level

Improvement in CBR of the expansive soil subgrades with a single reinforcement layer

The performance of a pavement is very sensitive to the characteristics of the soil subgrade, which provides a base for the whole pavement structure. It is therefore of utmost importance that the performance of such pavements is improved by adopting proper design and construction methodology. This paper presents the results of a series of California bearing ratio (CBR) and swell tests to evaluate the beneficial effects of placing a single layer of reinforcement horizontally at vmying depths fl·om the top smface of the subgrade soil. The position of the reinforcing layer is optimized for two different types of reinforcement namely, geogrid and jute geotextile. Results revealed that insertion of a single layer of horizontal reinforcement placed within the specimen at cCitain specified depth fi:om the top of the compacted specimen not only controls the swell potential significantly but also improves the CBR value considerably

An Emerging Trend in Tablet Technology:- Floating Tablets of Ranitidine HCl

The rationale of this research was to prepare a gastroretentive drug delivery system of Ranitidine HCL. Floating Drug delivery system used to target drug release in the stomach or to the upper part of the intestine. The oral delivery of Ranitidine is tested by preparing a non-disintegrating floating dosage form, which increase its absorption in the stomach by increasing the drug’s gastric residence time. The polymer PVC and Sodium bicarbonate was used as the gas–generating agents. Sodium bicarbonate causes the tablets to floats for more then 24hr. The prepared tablets were evaluated on their physicochemical properties and drug release characters. In-vitro release studies indicate that the Ranitidine release form the floating dosage form was uniform followed zero order release. A combination of sodium bicarbonate (70mg) and citric acid (15mg) was found to achieve Optimum in vitro buoyancy. The tablets with methocel K100 were found to float for longer duration of time as compared to formulations containing methocel K15M. The drug release from the tablets was sufficiently sustained.Keywords: Ranitidine; Floating tablets; Methoce

A simplified simulation model to estimate the storage length of the right-turn lane in left-hand traffic at signalised intersections for different signal phases and cycle timings

Introduction: A large number of the current guidelines and models are used to estimate the right-turn lane (RTL) length in left-hand traffic at signalised intersections under split phase, in which the movement of traffic in the right-turn lane and through lane happen concurrently. There is a need to examine other phase types and timings as a part of the RTL design. This is particularly significant in the case of established intersections that cannot be modified due to physical constraints. Methods: A MATLAB based simulation programme was developed to provide an estimate of the right-turn lane storage length for different traffic volumes in order to avoid the problems associated with blockage and overflow of the right turn vehicles in 95% of the traffic signal cycles. The model enhances flexibility when dealing with the complexity of the design of the storage length taking into account different signal phases and timings to overcome the aforementioned problems. The simulation model also takes into consideration the left-over queue from the previous cycle which was ignored by most of the previous studies. Results and Conclusion: The model input includes as a configuration matrix containing the sequence of operational states of the intersection. This ensures the flexibility and the simplicity of manipulating the data to reflect all phase types and timings. The model results have been compared against a recently developed analytical model in which similar signal phases and timings were investigated. The outcomes agree to the results that are obtained from the analytical model in most of the signal phases. The developed simulation model is flexible enough to be used further to simulate the situation when there is a large difference between the approaching and opposing traffic volumes and optimise the green time in case of split phase. In this study, the simplified simulation model for estimating the RTL storage length has been developed for the left-hand traffic countries; however, the study is equally applicable to the left-turn lane (LTL) in right-hand traffic countries