Elevated levels of radon and thoron in the indoor atmosphere may cause the deleterious effects on the mankind. Mining sites and their environs attract a special interest in radon studies as higher ...levels are frequently reported in the habitats. In the present study, radon and thoron levels were measured in the dwellings of Buddonithanda, a village in the environs of proposed uranium mining site, with pin-hole (SSNTDs) dosimeters for the period of a year. The measured radon and thoron levels were found to vary widely from 14 to 675 Bq m
(geometric mean = 94 Bq m
) and from 21 to 704 Bq m
(geometric mean = 121 Bq m
), respectively. An attempt was made to understand the large spatial variation of these levels. The seasonal and diurnal variation studies were used in unraveling the behavior of the radioactive isotopes in indoor environment and the same was explained with the help of a simplified mathematical model. Quantification of inhalation dose due to radon and thoron was done with suitable occupancy factors.
► We have introduced a low-cost, abundantly locally available non-conventional adsorbent in place of activated carbons. ► The kinetic data were well described by second order kinetic model and ...intra-particle diffusion model. ► The Langmuir and generalized isotherm models were the best fitting for the isotherm results. ► Removal capacity of Jujuba seeds is more than so many agricultural wastes. ► Relative cost of Jujuba seeds for the removal of Congo red can be compared with activated carbons
The feasibility of using Indian Jujuba Seeds (IJS) (
Zizyphus maruritiana), abundantly available in and around the Nallamalla forest in Andhra Pradesh, for the anionic dye (Congo red, CR) adsorption from aqueous solution, has been investigated as low cost and eco-friendly adsorbent. Adsorption studies were conducted on a batch process, to study the effects of contact time, initial concentration of CR, pH and temperature. Maximum colour removal was observed at pH 2. The equilibrium data was analyzed by the Langmuir, the Freundlich and the General isotherms. The data fitted well with the Langmuir model, with a maximum adsorption capacity of 55.56
mg
g
−1. The pseudo-second-order kinetics was the best for the adsorption of CR, by IJS (
Z. maruritiana) with good correlation. Thermodynamic parameters, such as standard free energy change (Δ
G°), standard enthalpy change (Δ
H°) and standard entropy change (Δ
S°), were analyzed. The results suggest that IJS (
Z. maruritiana) is a potential low-cost adsorbent for the CR dye removal from synthetic dye wastewater.
Due to digitization, a huge volume of data is being generated across several sectors such as healthcare, production, sales, IoT devices, Web, organizations. Machine learning algorithms are used to ...uncover patterns among the attributes of this data. Hence, they can be used to make predictions that can be used by medical practitioners and people at managerial level to make executive decisions. Not all the attributes in the datasets generated are important for training the machine learning algorithms. Some attributes might be irrelevant and some might not affect the outcome of the prediction. Ignoring or removing these irrelevant or less important attributes reduces the burden on machine learning algorithms. In this work two of the prominent dimensionality reduction techniques, Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) are investigated on four popular Machine Learning (ML) algorithms, Decision Tree Induction, Support Vector Machine (SVM), Naive Bayes Classifier and Random Forest Classifier using publicly available Cardiotocography (CTG) dataset from University of California and Irvine Machine Learning Repository. The experimentation results prove that PCA outperforms LDA in all the measures. Also, the performance of the classifiers, Decision Tree, Random Forest examined is not affected much by using PCA and LDA.To further analyze the performance of PCA and LDA the eperimentation is carried out on Diabetic Retinopathy (DR) and Intrusion Detection System (IDS) datasets. Experimentation results prove that ML algorithms with PCA produce better results when dimensionality of the datasets is high. When dimensionality of datasets is low it is observed that the ML algorithms without dimensionality reduction yields better results.
Indoor radon activity concentrations were carried out using twin cup dosimeters with SSNTDs in four districts viz., Karimnagar, Peddapalli, Jagtial and Rajanna Sircilla of Telangana state, India. The ...part of study area falls under Karimnagar Granulite Terrain, the geological region recognized for the occurrence of high uranium content metasedimentary enclaves within granite. The radon concentrations, in the study area, were found to vary from 7 to 457 Bq m
−3
with a geometric mean of 62 Bq m
−3
(GSD 2.24). The estimated radon activity is observed to obey log-normal distribution. The analysis of seasonal variation confirmed that the indoor radon concentration levels are relatively higher in the winter. Variation of radon activity levels in dwellings with different types of building materials was also studied and presented in this paper.
Heterostructures developed using CeO2 show promising peculiarities in the field of metal oxide gas sensors due to the great variations in the resistance during the adsorption and desorption ...processes. NiO decorated CeO2 nanostructures (NiO/CeO2) were synthesized via a facile two-step process. High resolution transmission electron microscopy (HRTEM) results revealed the perfect decoration of NiO on the CeO2 surface. The porous nature of the NiO/CeO2 sensor surface was confirmed from scanning electron microscopy (SEM) analysis. Gas sensing studies of pristine CeO2 and NiO/CeO2 sensors were performed under room conditions and enhanced gas sensing properties for the NiO/CeO2 sensor towards isopropanol were observed. Decoration of NiO on the CeO2 surface develops a built-in potential at the interface of NiO and CeO2 which played a vital role in the superior sensing performance of the NiO/CeO2 sensor. Sharp response and recovery times (15 s/19 s) were observed for the NiO/CeO2 sensor towards 100 ppm isopropanol at room temperature. Long-term stability of the NiO/CeO2 sensor was also studied and discussed. From all the results it is concluded that the decoration of NiO on the CeO2 surface could significantly enhance the sensing performance and it has great advantages in designing best performing isopropanol gas sensors.
•Dual biodiesel was prepared by mixing Rapeseed and Mahua biodiesel by equal volume.•Engine performance and Emission characteristics of diesel engine using dual biodiesel (RM) were measured.•Dual ...biodiesel blend BL20 gives closer performance to diesel.•CO, HC emission and Smoke opacity of BL20 were reduced by 20.66%, 8.56% and 6.9% than diesel respectively.•NOx emission for dual biodiesel blend BL20 was 3.77% higher than diesel.
This paper demonstrates the performance and emission characteristics of a variable compression ratio diesel engine (VCRDE) with the dual biodiesel. The dual biodiesel used is a blend of Rapeseed (RA) and Mahua biodiesel (MU) in equal proportion by volume. The experiment is conducted under different load conditions with constant engine speed of 1500 rpm. The biodiesels used here are prepared by transesterification process and formed one new biodiesel (RM) with mixing of Rapeseed biodiesel and Mahua biodiesel by equal volume (1:1). The performance test is done for 100% RA, 100% MU and different RM blends such as BL20, BL40, BL60 and BL80, along with diesel. The obtained results have shown that, the blend BL20 gave the best performance and is closest to diesel fuel. Further, based on the experimental results the brake thermal efficiency of the blend BL20 was found to be 2.79% lesser than diesel fuel. Also, the emission characteristics of BL20 such as CO, HC and smoke at full load conditions were 20.66%, 8.56% and 6.9% lesser than diesel respectively. On the other hand, the NOx emission was obtained slightly higher than the diesel fuel by 3.77%.The outcomes of this paper corroborate that, without any modification in engine, the blend BL20 can be used as an alternate fuel for the diesel.
Tissue engineering (TE) and regenerative medicine integrate information and technology from various fields to restore/replace tissues and damaged organs for medical treatments. To achieve this, ...scaffolds act as delivery vectors or as cellular systems for drugs and cells; thereby, cellular material is able to colonize host cells sufficiently to meet up the requirements of regeneration and repair. This process is multi-stage and requires the development of various components to create the desired neo-tissue or organ. In several current TE strategies, biomaterials are essential components. While several polymers are established for their use as biomaterials, careful consideration of the cellular environment and interactions needed is required in selecting a polymer for a given application. Depending on this, scaffold materials can be of natural or synthetic origin, degradable or nondegradable. In this review, an overview of various natural and synthetic polymers and their possible composite scaffolds with their physicochemical properties including biocompatibility, biodegradability, morphology, mechanical strength, pore size, and porosity are discussed. The scaffolds fabrication techniques and a few commercially available biopolymers are also tabulated.
Al-ZnO/CuO nanocomposite based gas sensor exhibits high sensitivity, good selectivity, fast response and recovery time to ammonia at R.T.
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•Low cost sol–gel synthesis of pure ZnO, ...ZnO/CuO and Al-ZnO/CuO nanocomposites.•Oxygen active sites are increased by forming porous structured films.•High selectivity towards ammonia even at low concentration.•The sensor has good repeatability, fast response and recovery time towards ammonia.
Pure ZnO nanoparticles (NPs), ZnO/CuO and Al-ZnO/CuO nanocomposites (NCs) were prepared using co-precipitation followed by sol–gel method. The structural and morphological properties of resulting materials were characterized by X-ray diffraction (XRD), micro Raman, high-resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) respectively. The XRD results confirmed that the ZnO-CuO composite is formed without the presence of any ZnO-CuO alloy. The gas sensing performance of pure ZnO, ZnO/CuO and Al-ZnO/CuO nanocomposites towards ammonia gas at room temperature was investigated. The gas sensing results revealed that the Al-ZnO/CuO nanocomposite based gas sensor has superior gas sensing properties like, high response, good stability, and fast response (14s) and recovery (9 s) time towards 500ppm (parts per million) ammonia gas at room temperature compared to pure ZnO and ZnO/CuO based sensors. Further the gas sensing performance of Al-ZnO/CuO sensor towards different volatile organic compound (VOC) gases was tested.
Batteries based on a fluoride shuttle (fluoride ion battery, FIB) can theoretically provide high energy densities and can thus be considered as an interesting alternative to Li-ion batteries. Large ...improvements are still needed regarding their actual performance, in particular for the ionic conductivity of the solid electrolyte. At the current state of the art, two types of fluoride families can be considered for electrolyte applications: alkaline-earth fluorides having a fluorite-type structure and rare-earth fluorides having a tysonite-type structure. As regard to the latter, high ionic conductivities have been reported for doped LaF3 single crystals. However, polycrystalline materials would be easier to implement in a FIB due to practical reasons in the cell manufacturing. Hence, we have analyzed in detail the ionic conductivity of La1–y Ba y F3–y (0 ≤ y ≤ 0.15) solid solutions prepared by ball milling. The combination of DC and AC conductivity analyses provides a better understanding of the conduction mechanism in tysonite-type fluorides with a blocking effect of the grain boundaries. Heat treatment of the electrolyte material was performed and leads to an improvement of the ionic conductivity. This confirms the detrimental effect of grain boundaries and opens new route for the development of solid electrolytes for FIB with high ionic conductivities.
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