Condition Monitoring System (CMS) substantiates potential economic benefits and enables prognostic maintenance in wind turbine-generator failure prevention. Vibration Monitoring and Analysis is a ...powerful tool in drive train CMS, which enables the early detection of impending failure/damage. In variable speed drives such as wind turbine-generator drive trains, the vibration signal acquired is of non-stationary and non-linear. The traditional stationary signal processing techniques are inefficient to diagnose the machine faults in time varying conditions. The current research trend in CMS for drive-train focuses on developing/improving non-linear, non-stationary feature extraction and fault classification algorithms to improve fault detection/prediction sensitivity and selectivity and thereby reducing the misdetection and false alarm rates. In literature, review of stationary signal processing algorithms employed in vibration analysis is done at great extent. In this paper, an attempt is made to review the recent research advances in non-linear non-stationary signal processing algorithms particularly suited for variable speed wind turbines.
•Captures Recent Adavancements in Wind turbine Condition Monitoring.•Surveys the Morden Non Stationary Signal Processing Techniques.•Describes the data driven and model based signal processing trends.•Gives overall picture about the nonstationary signal processing algorithms used in Wind Turbines.
The consumption of fossil fuels in excess leads to chronic effect of greenhouse gas (GHG) emissions on the environment. These adverse environmental impacts of GHG have invoked reasonable awareness on ...renewable energy resources. Bioethanol from lignocellulosic agricultural residue (profusely available renewable raw materials in the tropical areas) exhibits promising alternative to the petroleum based fossil fuel which reduces the net emission of GHGs. But due to certain technological barriers the large scale production of lignocellulosic bioethanol has not been successfully commercialized. To achieve the goal, economically viable bioethanol production technology, which includes pretreatment, enzymatic hydrolysis, fermentation, and dehydration, needs to be developed. Ionic liquid aided pretreatment can recover more than 80% cellulose and 42% lignin from lignocelluloses, which generally contains 30–46% cellulose and 18–25% lignin. Processing of the recovered cellulose towards bioethanol production requires enzymatic hydrolysis, which gives almost 76% reducing sugar yield. Use of ultrafiltration and nanofiltration in hydrolysis concentrates 27% reducing sugar as well as recovers more than 73% enzyme with 50% catalytic activity. Ultrafiltration rejects 100% yeast as well as reveals 15g/l/h ethanol productivity, which can be subjected to membrane based dehydration by way of pervaporation to produce 99.8wt% ethanol. The scope of this review focuses on eco-friendly and sustainable method for bioethanol production. A holistic and dedicated approach of this review helps to solve the various technological concerns and realize large scale commercialization of lignocellulosic ethanol.
•Preparation of sodium iron titante (NaFeTiO) inorganic ion exchanger.•Characterization of NaFeTiO by ICP-MS, XRD, TGA and Raman spectroscopy.•Evaluation of NaFeTiO for the ion exchange of Cs+ and ...Sr2+ from aqueous medium.•High strontium exchange capacity (233 mg.g-1) compared to other adsorbents.•Suitable for strontium separation from alkaline waste.
Sodium iron titanate (NaFeTiO) inorganic ion exchanger was synthesized and the ion exchange behaviour of cesium, strontium and europium ion on NaFeTiO was studied. The sodium iron titanate was prepared by the hydrolysis of tetraethyl ortho titanate with sodium hydroxide in the presence of ferric chloride at the Ti/Fe mole ratio of 25.7. The ion exchange material was characterized by elemental analysis, sodium exchange capacity, X-Ray diffraction, thermogravimetry, and Raman spectroscopy. The distribution coefficient (Kd, mL/g) of cesium, strontium and europium on NaFeTiO was measured as a function of pH of the aqueous phase, duration of equilibration, concentration of sodium, cesium, strontium and europium ion in aqueous phase. The Kd of cesium gradually increased with increase of pH, and that of strontium also increased up to pH 6 followed by saturation in Kd values. However, the distribution coefficient of europium increased up to pH 4 followed by the precipitation of europium at higher pH values. The rate of ion exchange of cesium and strontium on NaFeTiO was rapid in the initial stages of equilibration followed by the establishment of equilibrium occurring after 200 min. The kinetics of extraction was fitted in to pseudo-first order and -pseudo-second order rate equations. The NaFeTiO was found to follow the ion exchange mechanism, in which the sodium ion from NaFeTiO was exchanged with cesium or strontium ion from aqueous phase. The strontium exchange capacity on NaFeTiO was determined to be 233 mg g−1. The loaded metal ions was recovered using 0.5 M nitric acid.
The Household Air Pollution Intervention Network (HAPIN) trial aims to assess health benefits of a liquefied petroleum gas (LPG) cookfuel and stove intervention among women and children across four ...low- and middle-income countries (LMICs). We measured exposure contrasts for women, achievable under alternative conditions of biomass or LPG cookfuel use, at potential HAPIN field sites in India, to aid in site selection for the main trial.
We recruited participants from potential field sites within Villupuram and Nagapattinam districts in Tamil Nadu, India, that were identified during a feasibility assessment. We performed. (i) cross-sectional measurements on women (N = 79) using either biomass or LPG as their primary cookfuel and (ii) before-and-after measurements on pregnant women (N = 41), once at baseline while using biomass fuel and twice - at 1 and 2 months - after installation of an LPG stove and free fuel intervention. We involved participants to co-design clothing and instrument stands for personal and area sampling. We measured 24 or 48-h personal exposures and kitchen and ambient concentrations of fine particulate matter (PM2.5) using gravimetric samplers.
In the cross-sectional analysis, median (interquartile range, IQR) kitchen PM2.5 concentrations in biomass and LPG using homes were 134 μg/m3 IQR:71-258 and 27 μg/m3 IQR:20-47, while corresponding personal exposures were 75 μg/m3 IQR:55-104 and 36 μg/m3 IQR:26-46, respectively. In before-and-after analysis, median 48-h personal exposures for pregnant women were 72 μg/m3 IQR:49-127 at baseline and 25 μg/m3 IQR:18-35 after the LPG intervention, with a sustained reduction of 93% in mean kitchen PM2.5 concentrations and 78% in mean personal PM2.5 exposures over the 2 month intervention period. Median ambient concentrations were 23 μg/m3 IQR:19-27). Participant feedback was critical in designing clothing and instrument stands that ensured high compliance.
An LPG stove and fuel intervention in the candidate HAPIN trial field sites in India was deemed suitable for achieving health-relevant exposure reductions. Ambient concentrations indicated limited contributions from other sources. Study results provide critical inputs for the HAPIN trial site selection in India, while also contributing new information on HAP exposures in relation to LPG interventions and among pregnant women in LMICs.
ClinicalTrials.Gov. NCT02944682 ; Prospectively registered on October 17, 2016.
Lignin forms a recalcitrant structure in lignocellulosic biomass and hence huge amount of enzymes are required for disintegrating it into their subsequent components, like glucose and other ...by-products. Thus, the pretreatment is an ineluctable step in the bioethanol scheme for the delignification of biomass and also the recovery of lignin, an emerging value added polymer in many industrial applications. A green facile method was developed wherein humic acid (HA) acts as a catalyst and surfactant in the alkali pretreatment of sugarcane bagasse for the step reduction in lignin recovery scheme with phenomenal properties and enhanced enzymatic-hydrolysis. HA assisted experiments were performed with and without calcium chloride (CaCl2). Effective disintegration of lignocellulose by the cleavage of β-O-4 moieties resulted in forming lignin and hydrolyzable biomaterial via two pathways. Possible covalent linkages between the HA and lignin resulted in the release of esters as a byproduct. Thus, the delignified biomass, the isolated lignin and a variety of esters, could be valorised in various industrial applications. The biomass was characterized by XRD and SEM analysis. The isolated lignin was characterized using FTIR, NMR, GPC, SEM, and TGA – DTA studies. The yield of recovered pure lignin for the two process was 90–100%, as measured through gravimetric analysis. The produced esters were confirmed using FTIR studies. Batch enzymatic hydrolysis was performed for the HA assisted de-lignified bagasse (without CaCl2), which demonstrated a 19% increase in glucose yield compared to the alkali treated bagasse. The produced hydrolysates were subjected to fermentation for the production of ethanol.
•A humic acid‒alkali based protocol was developed for fractionation of lignocellulose.•Humic acid helps bypass multiple filtrations, centrifugation and precipitation steps.•Isolated lignin showed unusual properties such as varied weight distributions.•Humic acid‒assisted protocol also achieved an increase in the glucose yield.•A novel pretreatment scheme is proposed for the better circular economy.
Background:
Calcium intake of 1gram/day in pregnancy reduces the risk of pre-ecclampsia and preterm birth. Universal free calcium supplementation program was started throughout India at considerable ...cost to the government. Although coverage is high, this program is only effective if there is good adherence among mothers, and this is unknown.
Objectives:
1. To estimate the prevalence of adherence to calcium tablets among mothers attending antenatal clinic at Kundrathur PHC. 2. To identify the determinants and barriers to Calcium tablet adherence.
Methodology:
A cross sectional mixed methods study was conducted among mothers attending antenatal clinic at Kundrathur PHC during November 2023. Mothers with >20 weeks gestation were recruited consecutively. They were interviewed using the Morisky Medication Adherence Scale (MMAS-8). Barriers to adherence was elicited by freelisting and analysed with Visual Anthropac.
Results:
89 mothers completed the study. The participants had a mean age of 25.29+4.275 years. Majority of mothers were literate, and primi gravida (57.3%). Mean MMAS score was 4.98+1.79(95% CI 4.61, 5.36) out of maximum possible 8. Adherence was low among 69.7%, medium in 23.6% and high in only 6.7%. Only 3.4% mothers were aware of the role of calcium in hypertension. There was a significant association between adherence and level of education (X2 37.422, df 8, p<0.001) and having a support person (OR 11.5 95%CI 2.568, 51.502). Major barriers identified were forgetfulness (S 0.462), big tablets (S 0.205), difficulty in swallowing (S 0.130), timing (S.077), and vomiting (S 0.077).
Conclusion:
Adherence to Calcium supplementation is low among mothers. Educating mothers regarding importance and role of calcium may ensure better results of the program. Forgetfulness is the major barrier, and having a designated support partner in pregnancy, who helps in reminding and giving supplements, can help improve the adherence.
Background:
In India the elderly population (>60years) is on a raising trend has more than tripled in last 50 years and the projections for 2031 is 178.59 million of total population. As the health ...of the elderly will be an important issue defining the health of the whole population, hence elderly malnutrition is on focus.
Objectives:
To estimate the prevalence of malnutrition and factors associated with malnutrition among elderly population in rural field practice area of Madras Medical College.
Methodology:
This cross-sectional study was conducted from October to November-2023 among 480 elderly participants selected by simple random sampling in Medavakkam area. This study was done by using an interviewer administered semi-structured questionnaire that includes socio-demographic details and Mini Nutritional Assessment Questionnaire. Body Mass Index used to identify Obesity based on Asia Pacific BMI guidelines. Data was entered in MS-Excel and analysed using SPSS v16.
Results:
Among 480 participants,79.8% were in the age group of 60-70years,18.1% and 2.1% were in the age group of 71-80years and >80years respectively. Among them 53.1%were male. The prevalence of malnutrition and at risk of malnutrition were 7.7%(95%CI:5.5-10.5) and 39%(95%CI:34.6- 43.5) respectively which was assessed using MNA-questionnaire. Prevalence of obesity was 45.8%(95%CI:41.3-50.4) based on Asia-Pacific BMI guidelines. A significant association was found between malnutrition and older age groups, female gender, no formal education, kutcha house, widowed, unemployed and dependent financial status.
Conclusion:
According to this study, prevalence of malnutrition and at risk of malnutrition were lesser than previous studies done in rural South India, but the prevalence of Obesity found to be high (45.8%). Both undernutrition and over-nutrition are important health issues to be considered in elderly population. These problems can be solved through community level nutrition status screening of elderly and health education to the elderly and their families regarding balanced dietary practices and lifestyle modification, thereby enhancing their nutritional status and their quality of life.
Shear wave velocity (
V
s
) is one of the most important input parameter to represent the stiffness of the soil layers. It is preferable to measure
V
s
by in situ wave propagation tests, however it ...is often not economically feasible to perform the tests at all locations. Hence, a reliable correlation between
V
s
and standard penetration test blow counts (SPT-N) would be a considerable advantage. This paper presents the development of empirical correlations between
V
s
and SPT-N value for different categories of soil in Chennai city characterized by complex variation of soil conditions. The extensive shear wave velocity measurement was carried out using Multichannel Analysis of Surface Waves (MASW) technique at the sites where the SPT-N values are available. The bender element test is performed to compare the field MASW test results for clayey soils. The correlations between shear wave velocity and SPT-N with and without energy corrections were developed for three categories of soil: all soils, sand and clay. The proposed correlations between uncorrected and energy corrected SPT-N were compared with regression equations proposed by various other investigators and found that the developed correlations exhibit good prediction performance. The proposed uncorrected and energy corrected SPT-N relationships show a slight variation in the statistical analysis indicating that both the uncorrected and energy corrected correlations can predict shear wave velocity with equal accuracy. It is also found that the soil type has a little effect on these correlations below SPT-N value of about 10.
Background
Many clinical studies have evaluated the role of biochemical mediators like insulin-like growth factor 1 (IGF-1) in assessment of skeletal maturity. But still the reliability of IGF‑1 as ...an indicator of skeletal maturity remains controversial.
Objective
To assess the correlation between IGF‑1 and different radiographic skeletal maturity indicators.
Search methods
Seven electronic databases (PubMed, Scopus, EMBASE, Medline, Cochrane CENTRAL, Web of Science and SciELO) were searched until January 2020 without any restriction based on language or date of publication.
Selection criteria
The study design included cross-sectional and longitudinal studies comparing IGF‑1 and other skeletal maturity indicators (SMIs).
Data collection and analysis
Data extraction was done by two reviewers independently; 15 studies were eligible to be included in the quantitative synthesis.
Results
There was significant positive correlation between IGF‑1 and different SMIs until puberty which was 0.95 (confidence interval CI = 0.89, 1.02) for males and 0.87 (CI = 0.77, 0.97) for females. A negative correlation between IGF‑1 and different SMIs was found after puberty which was −0.86 (CI = −0.97, −0.75) for males and −0.89 (CI = −0.98, −0.81) for females. The type of SMI compared and type of IGF‑1 sample used accounted for the high heterogeneity found across the studies. Chronological age and number of months passed after puberty showed moderate negative correlation with mean IGF‑1 levels which were −0.57 (CI = −0.67, −0.47) and −0.54 (CI = −0.66, −0.42). Annual increments in mandibular length showed significant positive correlation of 0.69 (CI = 0.48, 0.90).
Conclusions
IGF‑1 would serve as a promising alternative to conventional radiographic skeletal maturity indicators and in predicting the amount of residual mandibular growth.
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