Effect of Addition of Treated Coir Fibres on the Compression Behaviour of Clay

This paper presents the effect of treated coir fibres (15 mm in length) on the unconfined compressive strength of clay. Dry, sodium hydroxide and carbon tetrachloride–treated coir fibres were used in the study. The coir fibre content was varied from 0.4% to 1.6%. The results indicated that the unconfined compressive strength of clay and clay with dry coir fibres can be increased by treatment with carbon tetrachloride and sodium hydroxide. The increase in unconfined compressive strength was highest with carbon tetrachloride treatment. The clay reinforced with treated fibres was able to bear higher strains at failure as compared to clay and clay with dry fibres. With the increase in coir fibre content (0.4%-1.6%) in clay, there was an increase in the unconfined compressive strength. The clay with treated coir fibres can be used for making bricks for mud houses in rural India

Shear Strength Behaviour of Clay Reinforced with Treated Coir Fibres

The effect of treated coir fibres on the shear strength behaviour of clay is presented in this study. A series of consolidated undrained test were performed on soil reinforced with untreated, sodium hydroxide treated and carbon tetrachloride treated fibres. The coir fibre content was varied from 0.4% to 1.6%. The results indicated that the deviator stress at failure of the clay and clay with untreated coir fibres can be increased by treatment with carbon tetrachloride and sodium hydroxide. A significant increase was also observed in shear strength parameters of clay reinforced with coir fibres at different percentages. The two parameter dependent hyperbolic models were used for predicting the experimental results. The back predicted stressstrain curve at dierent fibre percentage was found to compare well with the experimental results. The clay reinforced with untreated/treated coir fibres has shown improved strength behaviour, it can be used for short term stability problems

Soft Computing Based Prediction of Unconfined Compressive Strength of Fly Ash Stabilised Organic Clay

The current study uses machine learning techniques such as Random Forest Regression (RFR), Artificial Neural Networks (ANN), Support Vector Machines Ploy kernel (SVMP), Support Vector Machines Radial Basis Function Kernel (SVMRBK), and M5P model tree (M5P) to estimate unconfined compressive strength of organic clay stabilized with fly ash. The unconfined compressive strength of stabilized clay was computed by considering the different input variables namely i) the ratio of Cao to Sio2, ii) organic content (OC), iii) fly ash (FAper) content, iv) the unconfined compressive strength of organic clay without fly ash (UCS0) and v) the pH of soil-fly ash (pHmix). By comparing the performance measure parameters, each model performance is evaluated. The result of present study can conclude the random forest regression (RFR) model predicts the unconfined compressive strength of the organic clay stabilized with fly ash with least error followed by Support Vector Machines Radial Basis Function Kernel (SVMRBK), Support Vector Machines Ploy kernel (SVMP), Artificial Neural Networks (ANN) and M5P model tree (M5P). When compared to the semi-empirical model available in the literature, all of the model predictions given in this study perform well. Finally, the RFR and SVMRBK sensitivity analyses revealed that the CaO/SiO2 ratio was the most relevant parameter in the prediction of unconfined compressive strength

Performance of T-shaped skirted footings resting on sand

A series of plate load tests were performed on a model T-shaped skirted footing by varying the normalized skirt depth and relative density of sand from 0.25 to 1.5 and 30 % to 60 %, respectively. The findings revealed that, regardless of the roughness condition, the observed peak in the pressure settlement ratio corresponding to relative densities of 30%, 40%, 50%, and 60% gradually vanished as the normalized skirt depth was increased from 0.25 to 1.5. The results further revealed that at a given pressure, a lesser settlement ratio was observed for a skirted footing than the footing without a skirt. The most significant benefit of providing a skirt to the footing was obtained when the base and skirt were partially rough and the relative density of sand was kept at 30%. In all the cases, the observed bearing capacity ratio for the present skirted footing was higher than the H-shaped skirted footing reported in the literature. Finally, an empirical equation was proposed to predict the bearing capacity ratio and settlement reduction factor for a given skirt depth and sand relative density

In vitro induction of tuber formation for the synthesis of secondary metabolites in Chlorophytum borivilianum Sant. et Fernand

Chlorophytum borivilianum Sant. et Fernand an endangered herb is valued for several medicinal properties in its tuberous roots. An efficient and reproducible method for inducing in vitro tubers from stem disc explant has been developed. Stem disc possessing shoot buds were induced to develop multiple shoots in Murashige and Skoog (MS) medium supplemented with vitamins, 3% sucrose, 0.8% agar and 5 mg/L benzylaminopurine (BAP). Healthy regenerated shoots were rooted in MS basal medium containing 3% sucrose (w/v), 0.8% agar supplemented with indole-3-acetic acid (2 mg/L). On further sub culturing, the maximum percentage of tuber formation was obtained in growth hormone free half (½) MS liquid media supplemented with vitamins and 1.5% sucrose after 8 to 9 weeks. The saponin contents of the in vitro and in vivo raised tubers were qualitatively and quantitatively analyzed by highperformance liquid chromatography (HPLC) and liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). There was a significant similarity in the saponins in both tubers. The in vitro raised tubers showed similar high metabolite content than in vivo grown tubers which is required for medicinal applications. The rooted plantlets were transferred to peat and sand (2:1) with more than 80% success. This is the 1st report of in vitro tuber formation and secondary metabolites screening of C. borivilianum. This work will give a strong impetus to the pharmaceutical and neutraceutical sectors.Keywords: Chlorophytum borivilianum, tuber formation, saponin, liquid medium, high-performance liquid chromatography (HPLC)African Journal of Biotechnology Vol. 12(20), pp. 2900-2907

Fear, risk perception, and engagement in preventive behaviors for COVID-19 during nationwide lockdown in Nepal

The world has faced huge negative effects from the COVID-19 pandemic between early 2020 and late 2021. Each country has implemented a range of preventive measures to minimize the risk during the COVID-19 pandemic. This study assessed the COVID-19-related fear, risk perception, and preventative behavior during the nationwide lockdown due to COVID-19 in Nepal. In a cross-sectional study, conducted in mid-2021 during the nationwide lockdown in Nepal, a total of 1484 individuals completed measures on fear of COVID-19, COVID-19 risk perception, and preventive behavior. A multiple linear regression analysis was used to identify factors associated with COVID-19 fear. The results revealed significant differences in the fear of COVID-19 in association with the perceived risk of COVID-19 and preventive behaviors. Age, risk perception, preventive behavior, and poor health status were significantly positively related to fear of COVID-19. Perceived risk and preventive behaviors uniquely predicted fear of COVID-19 over and above the effects of socio-demographic variables. Being female and unmarried were the significant factors associated with fear of COVID-19 among study respondents. Higher risk perception, poor health status, and being female were strong factors of increased fear of COVID-19. Targeted interventions are essential to integrate community-level mental health care for COVID-19 resilience

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p\u3c0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p\u3c0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile. INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction

Security Issues with In-Vehicle Networks, and Enhanced Countermeasures Based on Blockchain

Modern vehicles are no longer simply mechanical devices. Connectivity between the vehicular network and the outside world has widened the security holes that hackers can use to exploit a vehicular network. Controller Area Network (CAN), FlexRay, and automotive Ethernet are popular protocols for in-vehicle networks (IVNs) and will stay in the industry for many more years. However, these protocols were not designed with security in mind. They have several vulnerabilities, such as lack of message authentication, lack of message encryption, and an ID-based arbitration mechanism for contention resolution. Adversaries can use these vulnerabilities to launch sophisticated attacks that may lead to loss of life and damage to property. Thus, the security of the vehicles should be handled carefully. In this paper, we investigate the security vulnerabilities with in-vehicle network protocols such as CAN, automotive Ethernet, and FlexRay. A comprehensive survey on security attacks launched against in-vehicle networks is presented along with countermeasures adopted by various researchers. Various algorithms have been proposed in the past for intrusion detection in IVNs. However, those approaches have several limitations that need special attention from the research community. Blockchain is a good approach to solving the existing security issues in IVNs, and we suggest a way to improve IVN security based on a hybrid blockchain

Bearing capacity and settlement prediction of multi-edge skirted footings resting on sand

Este documento presenta la aplicación de redes neuronales artificiales (ANN) y el análisis de regresión multivariable (MRA) para predecir la capacidad de carga y el asentamiento de las zapatas bordeadas de bordes múltiples en arena. Estos parámetros se definen, respectivamente, en términos de la relación de capacidad de carga (BCR) de carga de la zapata con zócalo y sin zócalo y el factor de reducción de asentamiento (SRF), la razón de la diferencia en la solución de zócalo sin zócalo y zapatas bordeadas para el asentamiento de zapatas sin falda a una presión determinada. Las ecuaciones modelo para predecir la BCR y el SRF de la zapata de forma regular se desarrollaron primero utilizando los datos disponibles recopilados de la literatura. Estas ecuaciones se modificaron posteriormente para predecir la BCR y el SRF de la zapata bordeada de bordes multiples, para la cual se generaron los datos mediante la realización de una prueba de laboratorio a pequeña escala. Los parámetros de entrada elegidos para desarrollar modelos ANN fueron el ángulo de fricción interna (ϕ), la profundidad del faldón (Ds) al ancho de la relación de zapata (B) para la predicción del BCR; en cuanto al SRF, se consideró un parámetro de entrada adicional: la tensión normal (?). La arquitectura para los modelos ANN desarrollados fue 2-2-1 y 3-2-1 para la BCR y el SRF, respectivamente. El R2 para las zapatas bordeadas de bordes múltiples estuvo en el rango de 0,940-0,977 para el modelo ANN y 0,827-0,934 para el análisis de regresión. De manera similar, el R2 para la predicción del SRF pudo haber sido de 0,913-0,985 para el modelo ANN y 0,739-0,932 para el análisis de regresión. Se reveló que la BCR predicha y el SRF para las zapatas con borde de múltiples bordes con el uso de ANN es superior al MRA. Además, los resultados del análisis de sensibilidad indican que tanto el BCR como el SRF de las zapatas bordeadas de bordes múltiples se ven más afectados por la profundidad de la falda, seguida del ángulo de fricción de la arena.This paper presents the application of artificial neural networks (ANN) and multivariable regression analysis (MRA) to predict the bearing capacity and the settlement of multi-edge skirted footings on sand. Respectively, these parameters are defined in terms of the bearing capacity ratio (BCR) of skirted to unskirted footing and the settlement reduction factor (SRF), the ratio of the difference in settlement of unskirted and skirted footing to the settlement of unskirted footing at a given pressure. The model equations for the prediction of the BCR and the SRF of the regular shaped footing were first developed using the available data collected from the literature. These equations were later modified to predict the BCR and the SRF of the multi-edge skirted footing, for which the data were generated by conducting a small scale laboratory test. The input parameters chosen to develop ANN models were the angle of internal friction (ϕ) and skirt depth (Ds) to the width of the footing (B) ratio for the prediction of the BCR; as for the SRF one additional input parameter was considered: normal stress (?). The architecture for the developed ANN models was 2-2-1 and 3-2-1 for the BCR and the SRF, respectively. The R2 for the multi-edge skirted footings was in the range of 0,940-0,977 for the ANN model and 0,827-0,934 for the regression analysis. Similarly, the R2 for the SRF prediction might have been 0,913-0,985 for the ANN model and 0,739-0,932 for the regression analysis. It was revealed that the predicted BCR and SRF for the multi-edge skirted footings with the use of ANN is superior to MRA. Furthermore, the results of the sensitivity analysis indicate that both the BCR and the SRF of the multi-edge skirted footings are mostly affected by skirt depth, followed by the friction angle of the sand