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The current review presents an insight into the recent developments of biodegradable materials used for orthopedic surgery and bone regeneration purposes. Conventional biodegradable devices for osteosynthesis are effective only in low or mild load-bearing applications. To mitigate this limitation, development of biodegradable materials with improved mechanical strength has attracted researcher's attention. These biodegradable materials play a crucial role in severe bone defect repair. When scaffolds are made up of the biodegradable materials then they serve as a crawling bridge for formation of new bone tissues by providing a platform to cells and growth factors. In view of this context, this review focuses on detailed discussion of different polymers and ceramic materials for bone regeneration purposes along with their respective advantages and disadvantages. Results of the review reveals that new bone formation takes place more easily and faster around ceramic materials in comparison to polymeric materials due to their osteoconductive as well as osteoinductive properties. Viewing their biocompatible, osteoconductive, and bioactive properties, the studied biomaterials cover the largest share in orthopedic surgery. Finally, some surface modification procedures for improving functionality of biomaterials are pointed out. It is hoped that this review will guide further research on biomaterials applications and modifications underlying bone renewal by providing reference and some inspiration for the upcoming investigators of this field. [ABSTRACT FROM AUTHOR]

Measurement errors are an important consideration in sample surveys. Neglecting their influence can give misleading and inaccurate results. In this paper, we propose three variance estimators using Optional Randomized Response Technique (ORRT) in the presence of measurement error. Performance of the proposed estimators are evaluated through a simulation study and a numerical example. [ABSTRACT FROM AUTHOR]

The strife for more incredible and sustainable human development is often associated with compromised environmental standards. Early growth may increase pollutant emissions that can be regulated later. Human development, the main ingredient of sustainable development, may increase emissions or reduce them through technological improvements. The emerging seven (E7) economies provide an intriguing case to test the direct and indirect impact of human development on CO2 emissions to confirm the nexus in the early stage of industrialization. The study applies the structural equation approach to investigate the relationship between the human development index (HDI), green technological innovations, and CO2 emissions in E7 economies over the period 1990–2021. Our findings indicate that HDI increases consumption-based CO2 emissions both directly and indirectly, where even the mediating impact of innovations is also positive, thereby confirming the fact that HDI and innovations both may have deteriorated implications for environmental performance at the earlier stages of development. The study findings imply that the policymakers of the transition economies need to rethink their policy choices regarding controlling pollution and safeguarding the environment. The study's conclusion has essential ramifications for reducing pollution through enacting HDI and supporting innovations. [ABSTRACT FROM AUTHOR]

This study used multi-platform remote sensing datasets to assess the impacts of land use and land cover (LULC) change on forest biomass density across the Three Gorges Reservoir (TGR) region along the Yangtze River. This study maps land use and land cover (LULC) change and forest aboveground biomass estimation (AGB) using Sentinel-2A and GEDI-L4B data based on observations between 2019 and 2022. The data analysis results of monitoring revealed a strong association frequency between land-use change and forest land cover since the significant relationship with forest aboveground biomass density has also been explored. The total deforestation decreased significantly in 2022. The accuracy assessment results show a classification accuracy of between 90.4% and 94.1%, with a kappa coefficient of 82.4%–92.1%. For the TGR region forest, the minimum to maximum mean above-ground biomass values are from 15.81 to 373.66 Mgha-1, respectively. Moreover, the fitting performance of the statistical analysis of aboveground biomass density of forest mean for the forest was quite decent with training (R2: 0.92, RMSE: 12.30 Mg/ha) and testing (R2: 0.79, RMSE: 18.07 Mg/ha) datasets. The results highlight LULC change impacts, particularly forest land class over forest AGB stands, and the effectiveness of the GEDI-L4B product in regional biomass estimation in the TGR region. [ABSTRACT FROM AUTHOR]

AbstractIn this present article, we have suggested memory-type ratio, exponential ratio, product and exponential product estimators based on exponentially weighted moving average statistic for the estimation of heterogeneous population variance using stratified sampling design in presence of measurement error for time-scaled surveys. Mathematical expressions of approximate mean square error are derived using Taylor and exponential expansions for the proposed memory-type estimators. We have also discussed the situations in which the memory-type estimators would perform efficiently than the conventional estimators. The results of extensive simulation study revealed that the proposed memory-type estimators based exponentially weighted moving average statistic would perform better than the conventional estimators in the presence measurement error for time-scaled surveys under certain condition. [ABSTRACT FROM AUTHOR]

In this study, we have proposed memory-type ratio and product estimators for the estimation of population variance based on exponentially weighted moving averages (EWMA) statistic. The EWMA statistic simultaneously utilizes the current and previous information in time-scaled surveys. The equations of approximate mean square errors are established for proposed memory-type ratio and product estimators. The performance of the proposed estimators is evaluated mathematically by deriving the conditions in which memory-type ratio and product estimators are better than the conventional ratio and product estimators. The results of simulation study and real data application revealed that the use of previous sampled information excels the efficiency of the proposed estimators for time-scaled surveys. [ABSTRACT FROM AUTHOR]

Aim of this research paper was to investigate the potential of fish scales as an adsorbent for crystal violet dye exclusion from wastewater and to optimize various adsorption parameters for maximum adsorption of dye. Parameters studied were solution pH, adsorbent dose, contact time, dye concentration, and temperature. Results showed maximum percentage degradation, i.e., 90% under optimized conditions such as pH 12 solution, 0.4 g adsorbent dose, with 40 min of exposure time and 40 ppm of dye concentration at 10 °C solution temperature. Adsorbent was characterized using FTIR, and SEM techniques to explore the functionality and to study morphology of adsorbent, respectively. Results confirmed that carboxyl, amino, phosphate, and sulfonate groups and heterogeneous adsorbent surface was accountable for crystal violet dye adsorption on fish scales. pH pzc of the fish scale was 8. Adsorption isotherms such as Langmuir, Freundlich, and D-R isotherm models were also investigated. Contact time data was applied to various kinetic models, i.e., pseudo-first order, and pseudo-second order kinetic models. Thermodynamic study was also investigated. Results confirmed that experimental data fitted well to Freundlich isotherm model ( R 2 = 0.9983) and pseudo second order kinetic model ( R 2 = 0.9970) as ARE error analysis values of these models were 1.191692 E + 06 and −160.66, respectively (lower than that of other models. Computed ΔG and ΔH values confirmed adsorption process to be spontaneous and of endothermic kind. Applicability of established procedure with tap water was 78% and regeneration percentage was 72% which showed the effectiveness of fish scales powder for removal of crystal violet dye from wastewater. [ABSTRACT FROM AUTHOR]

In the recent times, the use of geosynthetic-reinforced soil (GRS) technology has become popular for constructing safe and sustainable pavement structures. The strength of the subgrade soil is routinely assessed in terms of its California bearing ratio (CBR). However, in the past, no effort was made to develop a method for evaluating the CBR of the reinforced subgrade soil. The main aim of this paper is to explore and appraise the competency of the several intelligent models such as artificial neural network (ANN), least median of squares regression, Gaussian processes regression, elastic net regularisation regression, lazy K-star, M-5 model trees, alternating model trees and random forest in estimating the CBR of reinforced soil. For this, all the models were calibrated and validated using the reliable pertinent historical data. The prognostic veracity of all the tools mentioned supra were assessed using the well-established traditional statistical indices, external model evaluation technique, multi-criteria assessment approach and independent experimental dataset. Due to the overall excellent performance of ANN, the model was converted into a trackable functional relationship to estimate the CBR of reinforced soil. Finally, the sensitivity analysis was performed to find the strength and relationship of the used parameters on the CBR value. [ABSTRACT FROM AUTHOR]

With the increasing prevalence of solar photovoltaics in the renewable energy mix, the need for device-level assessment has greatly increased. This is challenging in rural, off-grid areas with limited access to advanced testing facilities for performance evaluation and enhancement. This paper presents a cost-effective design of a solar simulator based on a 1000 W metal halide lamp coupled with a truncated ellipsoidal reflector optimized through parametric iterations. The complex geometry is reduced to a three-parameter model. An optimal design is attained using this model. The reflector is fabricated and tested using spectrometry and pyranometry. Stabilization time for the device after the start-up was measured at intervals of 10 seconds to be ~ 4 minutes. The average intensity in the focal plane is 2220–3117 W/m2 for a photovoltaic cell having a square size of 2 × 2 cm2. Hence, the ray-tracing model used for this study is conservative in predicting light intensity for an elliptical concentrator. Similarly, spectral analysis shows a strong similarity of 88.7% between natural sunlight and artificial light of the solar simulator thereby advocating the capability of the simulator to demonstrate the effect of temperature on the power output of photovoltaic cells. Overall, the total hardware and fabrication cost amounts to less than $500 for a single lamp. [ABSTRACT FROM AUTHOR]

In many real-world survey situations, the use of auxiliary information together with the survey variable is very common phenomenon. The ratio and regression estimators are most commonly used estimation methods that incorporate the auxiliary information in various forms to improve the efficiency of the estimators. Adaptive cluster sampling is specifically developed for the estimation of rare and clustered population parameters and applied to a wide range of situations like, plants and animals of rare and endangered species, uneven minerals and drug users. In this paper, we proposed a generalized estimator with a single auxiliary variable for the estimation of highly clumped population mean under adaptive cluster sampling design. The proposed estimator utilizes the different combination of known parameters of the auxiliary variable. The expressions of approximate bias and mean square error are derived up to the first-order approximation. The Proposed estimator is found to be more efficient than the estimators proposed under certain conditions. A numerical study is carried out on real and artificial bivariate populations to support the performance of the proposed estimator over the above-mentioned estimators. [ABSTRACT FROM AUTHOR]

The steady and controlled desalination is achievable with Hybrid-CV-CC capacitive deionization (CDI). In this paper, we assess the performance of Hybrid-CV-CC CDI by evaluating the standard performance indicators within reasonable ranges of operating and design parameters, i.e., flow rate, voltage, capacitance, cell volume, and current. However, the conflicts among performance indicators for similar operating conditions instigate the need for optimum tradeoffs. Therefore, multi-criteria optimization techniques were used for the estimation of optimum tradeoffs in the system performance. The optimized system annunciated net improvement in performance in terms of desalination (salt absorbed), energy consumption, and average salt adsorption rate up to 16%, 70%, and 117%, respectively. [ABSTRACT FROM AUTHOR]

Many researchers used auxiliary information together with survey variable to improve the efficiency of population parameters like mean, variance, total and proportion. Ratio and regression estimation are the most commonly used methods that utilized auxiliary information in different ways to get the maximum benefits in the form of high precision of the estimators. Thompson first introduced the concept of Adaptive cluster sampling, which is an appropriate technique for collecting the samples from rare and clustered populations. In this article, a generalized exponential type estimator is proposed and its properties have been studied for the estimation of rare and highly clustered population variance using single auxiliary information. A numerical study is carried out on a real and artificial population to judge the performance of the proposed estimator over the competing estimators. It is shown that the proposed generalized exponential type estimator is more efficient than the adaptive and non adaptive estimators under conventional sampling design. [ABSTRACT FROM AUTHOR]

Adaptive cluster sampling (ACS) is considered to be the most suitable sampling design for the estimation of rare, hidden, clustered and hard-to-reach population units. The main characteristic of this design is that it may select more meaningful samples and provide more efficient estimates for the field investigator as compare to the other conventional sampling designs. In this paper, we proposed a generalized estimator with a single auxiliary variable for the estimation of rare, hidden and highly clustered population variance under ACS design. The expressions of approximate bias and mean square error are derived and the efficiency comparisons have been made with other existing estimators. A numerical study is carried out on a real population of aquatic birds together with an artificial population generated by Poisson cluster process. Related results of numerical study show that the proposed generalized variance estimator is able to provide considerably better results over the competing estimators. [ABSTRACT FROM AUTHOR]

The use of robust measures helps to increase the precision of the estimators, especially for the estimation of extremely skewed distributions. In this article, a generalized ratio estimator is proposed by using some robust measures with single auxiliary variable under the adaptive cluster sampling (ACS) design. We have incorporated tri-mean (TM), mid-range (MR) and Hodges-Lehman (HL) of the auxiliary variable as robust measures together with some conventional measures. The expressions of bias and mean square error (MSE) of the proposed generalized ratio estimator are derived. Two types of numerical study have been conducted using artificial clustered population and real data application to examine the performance of the proposed estimator over the usual mean per unit estimator under simple random sampling (SRS). Related results of the simulation study show that the proposed estimators provide better estimation results on both real and artificial population over the competing estimators. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the possible impacts of curing and storage conditions on dissolution of controlled release diphenhydramine HCl pellets coated with EUDRAGIT® NE30D. The accumulative percentage of dissolved active drug was used as the response in three statistical experimental design studies: 32 full factorial, Box–Behnken and 23 designs. By only considering curing temperature and curing time, both factors were found to significantly affect the dissolution rate, but curing temperature had greater impact than curing time. When considering polymer coating level, curing temperature and curing time together, polymer coating level and curing temperature had important effects on dissolution rate, but curing time became insignificant among these three factors. The addition of the water-soluble additives hydroxypropyl methyl cellulose and mannitol made coating films less sensitive to curing, and there was little or no difference in their effect in the model studied. Lower levels of a water-insoluble additive (kaolin) had little impact on dissolution; however, when the level of water-insoluble additive increased, the coating film became more sensitive to curing, especially at the lower curing temperature of 30°C. [ABSTRACT FROM AUTHOR]

The purpose of this work is to develop a bio-relevant dissolution method for formulation screening in order to select an enhanced bioavailable formulation for a poorly water-soluble drug. The methods used included a modified rotating disk apparatus for measuring intrinsic dissolution rate of the new chemical entity (NCE) and the USP dissolution method II for evaluating dissolution profiles of the drug in three different dosage forms. The in vitro dissolution results were compared with the in vivo bioavailability for selecting a bio-relevant medium. The results showed that the solubility of the NCE was proportional to the concentration of sodium lauryl sulfate (SLS) in the media. The apparent intrinsic dissolution rate of the NCE was linear to the rotational speed of the disk, which indicated that the dissolution of the drug is a diffusion-controlled mechanism. The apparent intrinsic dissolution rate was also linear to the surfactant concentration in the media, which was interpreted using the Noyes and Whitney Empirical Theory. Three formulations were studied in three different SLS media using the bulk drug as a reference. The dissolution results were compared with the corresponding bioavailability results in dogs. In the 1% SLS—sink conditions—the drug release from all the formulations was complete and the dissolution results were discriminative for the difference in particle size of the drug in the formulations. However, the data showed poor IVIV correlation. In the 0.5% SLS medium—non-sink conditions—the dissolution results showed the same rank order among the tested formulations as the bioavailability. The best IVIV correlation was obtained from the dissolution in 0.25% SLS medium, an over-saturated condition. The conclusions are: a surfactant medium increases the apparent intrinsic dissolution rate of the NCE linearly due to an increase in solubility. A low concentration of surfactant in the medium (0.25%) is more bio-relevant... [ABSTRACT FROM AUTHOR]

A new commercially available sustained-release matrix material, Kollidon® SR, composed of polyvinylacetate and povidone, was evaluated with respect to its ability to modulate the in vitro release of a highly water-soluble model compound, diphenhydramine HCl. Kollidon SR was found to provide a sustained-release effect for the model compound, with certain formulation and processing variables playing an important role in controlling its release kinetics. Formulation variables affecting the release include the level of the polymeric material in the matrix, excipient level, as well as the nature of the excipients (water soluble vs. water insoluble). Increasing the ratio of a water-insoluble excipient, Emcompress®, to Kollidon SR enhanced drug release. The incorporation of a water-soluble excipient, lactose, accelerated its release rate in a more pronounced manner. Stability studies conducted at 40°C/75%RH revealed a slow-down in dissolution rate for the drug-Kollidon SR formulation, as a result of polyvinylacetate relaxation. Further studies demonstrated that a post-compression curing step effectively stabilized the release pattern of formulations containing ≥47% Kollidon SR. The release mechanism of Kollidon-drug and drug-Kollidon-Emcompress formulations appears to be diffusion controlled, while that of the drug-Kollidon-lactose formulation appears to be controlled predominantly by diffusion along with erosion. [ABSTRACT FROM AUTHOR]

AbstractCoconut coir was explored as economical sorbent for the adsorptive removal of lanthanum ion (La3+) from aqueous media. Both column and batch studies were conducted to assess the effective removal of La3+ on coconut coir by optimizing different adsorption variables such as bed height, flow rate, pH, adsorbent dosage, shaking time, initial metal concentration, and temperature. Characterization of coconut coir was carried out by scanning electron microscopy (SEM), FT-IR, and BET studies prior and subsequent to adsorption. The effective removal of La3+ was defined in certain media by the pHzpc, which was found to be 5.7 ± 0.1. The optimum 94.04 ± 0.2% adsorption of La3+ on coconut coir was observed by shaking 4 cm3 of 90 mol/L solution of La3+ with 0.3 g adsorbent dose for 10 min at neutral pH. The Langmuir adsorption capacity was found to be qe=2.88±0.02 mg g−1 and Freundlich adsorption capacity was KF =0.1294±0.03 mg g−1. The pseudo-second-order kinetic and Langmuir isotherm models provided an ideal fit for the adsorption process. The column analysis also showed direct correlation of bed height and initial metal concentration with % adsorption, while % removal decreased as flow rate increased. The high regression coefficient values confirm that the BDST model is in line with the test data. Van’t Hoff equation proved the spontaneous endothermic process. Effect of external ions and desorption are also studied. The results suggest that coconut coir is a cost effective and efficient bio-sorbent for La3+ ion adsorption from aqueous solution. [ABSTRACT FROM AUTHOR]