Mechanical characterization & regression analysis of Calamus rotang based hybrid natural fibre composite with findings reported on retrieval bending strength

Research on Bio-based natural fiber material promoted the development of reinforcement and expand their possible structural applications. In this study, fibers are extracted from the stem of Calamus rotang (common rattan-Indian Species). Further, the fiber is processed to get novel hybrid combinations with glass fibers by manual hand lay-up technique. Three sets of samples were prepared for the different volume fractions of 60:40, 30:30:30, and 60:32:8 of glass fiber/epoxy as neat composite sample (NCS), a hybrid combination of C. rotang /glass fiber with epoxy as modified reinforced composite sample (MRCS) and glass fiber/epoxy with calamus stem powder as modified matrix composite sample (MMCS) respectively. Mechanical tests including tensile, flexural, impact, and ILSS tests are conducted as per ASTM Standards. Comparative studies have been done to evaluate the effect of novel species of C. rotang on mechanical properties with neat GFRP composites. Addition to this regression analysis has been carried out to achieve the experimental correlation for tensile and bending tests. Microstructural analysis for all the tested samples has been done to assess the fracture mode. Novel findings on retrieval bending strength for MMCS has been reported for the first time for composite materials. Study proves that novel species have a significant impact on the basic properties of materials.

The Assessment of Serum Fibronectin Levels as a Potential Biomarker for the Severity of Drug-Sensitive Pulmonary Tuberculosis: A Pilot Study

BACKGROUND

Tuberculosis (TB) is a global health burden caused by Mycobacterium tuberculosis (Mtb) infection. Fibronectin (Fn) facilitates Mtb attachment to host cells. We studied the Fn levels in smear-positive TB patients to assess its correlation with disease severity based on sputum smears and chest X-rays.

METHODS

Newly detected consecutive sputum AFB-positive pulmonary TB patients (n = 78) and healthy control subjects (n = 11) were included. The mycobacterial load in the sputum smear was assessed by IUATLD classification, ranging from 0 to 3. The severity of pulmonary involvement was assessed radiologically in terms of both the number of zones involved (0-6) and as localized (up to 2 zones), moderate (3-4 zones), or extensive (5-6 zones). The serum human fibronectin levels were measured by using a commercially available enzyme-linked immunosorbent assay (ELISA) kit (Catalogue No: CK-bio-11486, Shanghai Coon Koon Biotech Co., Ltd., Shanghai, China).

RESULTS

The PTB patients showed lower Fn levels (102.4 ± 26.7) compared with the controls (108.8 ± 6.8), but they were not statistically significant. Higher AFB smear grades had lower Fn levels. The chest X-ray zones involved were inversely correlated with Fn levels. The Fn levels, adjusted for age and gender, decreased with increased mycobacterial load and the number of chest radiograph zones affected. A Fn level <109.39 g/mL predicted greater TB severity (sensitivity of 67.57% and specificity of 90.38%), while a level <99.32 pg/mL predicted severity based on the chest radiology (sensitivity of 84.21% and specificity of 100%).

CONCLUSIONS

The Fn levels are lower in tuberculosis patients and are negatively correlated with severity based on sputum mycobacterial load and chest radiographs. The Fn levels may serve as a potential biomarker for assessing TB severity, which could have implications for early diagnosis and treatment monitoring.

Unmasking the Silent Threat: Periodontal Health's Impact on COPD Severity and Hospitalization

OBJECTIVE

This study investigated the relationship between chronic obstructive pulmonary disease (COPD) and periodontitis, focusing on how periodontal health impacts COPD airflow limitation, exacerbations, and hospitalization.

BACKGROUND

Periodontitis, a multifactorial inflammatory disease, is characterized by destruction of tooth-supporting structures, while COPD is a global pulmonary disorder with high mortality.

METHODS

A total of 199 COPD patients aged over 40 years underwent lung function tests (spirometry), 6 min walk test, and St George's Respiratory Questionnaire-COPD (SGRQ-C) to assess lung health. Periodontal indices such as probing depth (PD), clinical attachment loss (CAL), and plaque index (PI) were assessed.

RESULTS

We found a significant negative correlation between periodontal disease severity and lung function (lower FEV1, FVC, and FEV1/FVC ratio) after adjusting for smoking. Likewise, periodontal parameters (PPD, PI, and CAL) exhibited negative correlations with lung function. These periodontal indices were independently associated with airflow limitation severity, exacerbations frequency, and prior-year hospitalization. Linear regression indicated that each unit increase in PPD, PI, and CAL corresponded to estimated increases in GOLD airflow limitation grading (0.288, 0.718, and 0.193, respectively) and number of exacerbations (0.115, 0.041, and 0.109, respectively). In logistic regression, PPD, PI, and CAL adjusted odds ratios (ORs) were estimated to increase by 1.29 (95%CI: 1.03-1.62), 3.04 (95%CI: 1.28-7.2), and 1.26 (95%CI: 1.06-1.49), respectively, for hospitalization in previous year.

CONCLUSION

Periodontitis is associated with COPD airflow limitation, exacerbation, and hospitalization, with PI being the most clinically relevant periodontal factor. Dentists and physicians should monitor and increase awareness among COPD patients to maintain oral hygiene for prevention of periodontal diseases and mitigate its effect on COPD progression.

Pollution characteristics and ecological risks of trace elements in PM2.5 over three COALESCE network sites - Bhopal, Mesra, and Mysuru, India

Time-synchronized, 24 h integrated PM_2.5 trace element (TE) measurements made as a part of the COALESCE project (Venkataraman et al., 2020) at Bhopal, Mesra, and Mysore during all of 2019 were analyzed in this study. The concentrations of 15 key elements ranged between 0.05 ng m^-3 and 50 μg m^-3 across the study sites. Pronounced seasonal variation of elements from multiple source classes showed that the crustal origin elements (Al, Si, Fe, Ti, and Ca) peaked during the pre-monsoon season, while the anthropogenic activities driven element (P, S, K, V, Mn, Cu, Zn, and Pb) concentrations increased during the winter and post-monsoon seasons. Spearman correlation coupled with hierarchical clustering separated the matrix of elements into three common clusters at all sites, corresponding to crustal sources, combustion and biomass burning emissions, and industrial/non-exhaust vehicular emissions, respectively. Furthermore, episodes of metal pollution throughout the year were examined using characteristic radar charts of TEs to identify the association between TE sources and poor air quality. For example, maximum metal pollution in Bhopal occurred during the post-monsoon season, attributable to biomass burning, dust storms, industrial and non-exhaust vehicular emissions. Finally, an ecological risk assessment revealed that the risk index was higher than the threshold value of 600 for all heavy metals at all sites. Pb, Cu, and Zn were the top contributors to 'extremely high risk' amongst all heavy metals. Overall, the results show that although TE concentrations at all three locations were much lower than in other urban locations in India, the risk from heavy metals to the ecosystem (and likely to human health) cannot be ignored. The findings warrant a full source apportionment of fine PM to better identify TE-rich source contributions and future studies to examine the atmospheric processing and eco-system uptake of TEs.

Tracing the predominant sources of carbon in PM2.5 using δ13C values together with OC/EC and select inorganic ions over two COALESCE locations

As part of the COALESCE (Carbonaceous Aerosol Emissions, Source apportionment and Climate Impacts) campaign, ambient PM_2.5 was collected at two regional sites (Bhopal and Mysuru) in India during 2019. We utilized organic carbon (OC), elemental carbon (EC) and water-soluble inorganic ions together with δ¹³C values, to better understand total carbon (TC) sources at these locations. The annual average δ¹³C values (-26.2 ± 0.6‰) at Mysuru and Bhopal (-26.6 ± 0.6‰) were comparable. However, at Mysuru, except during winter, day-to-day variability was much lower (narrow range of -26.8 to -26.0‰) than that at Bhopal (range: -28.1 to -24.7‰), suggesting that TC was contributed by few sources, likely dominated by vehicular emissions. Seasonal average δ¹³C values at Bhopal increased slightly (-25.8 ± 0.5‰) during the winter (Jan-Feb) and decreased (-27.0 ± 0.3‰) during the monsoon (Jun-Sep) season compared to the annual average. The decrease in δ¹³C values during the monsoon season was likely driven by enhanced secondary organic aerosol formation. Further, based on MODIS derived fire spots and back trajectories, we infered that the δ¹³C values (-27.5 to -26.0‰) in Bhopal during the post-monsoon season (Oct-Dec) were indicative of dominant biomass burning contributions. The inorganic ions/TC ratio during this season suggested that biomass burning aerosol was aged and may have been transported from crop residue burning in the Indo-Gangetic plains. At Mysuru, like the trend at Bhopal, the δ¹³C values during the monsoon season were lower than those during the winter season. Finally, δ¹³C values were input to a Bayesian model-MixSIAR to demonstrate the usefulness of such models in apportioning TC. In its simplest implementation, the model separated TC sources into fossil fuel emissions and non-fossil fuel sources . Fossil fuel combustion emissions accounted for 47 ± 19% and 62 ± 22% of the TC at Bhopal and Mysuru, respectively.

Associations of Vitamin D, chronic obstructive pulmonary disease and acute exacerbations of COPD with anxiety and depression: a nested case control study

Background: Lower vitamin D levels have not only been associated with chronic obstructive pulmonary disease (COPD), exacerbations and lower lung functions, but also with anxiety and depression. We examined the associations of severity of anxiety and depression using HAM-A (Hamilton Anxiety Rating Scale) and HAM-D (Hamilton Depression Rating Scale) scores with COPD and vitamin D levels. Methods: Observational nested case control study was conducted in MUDHRA cohort. One hundred COPD subjects and 100 age- gender- matched non-COPD subjects (controls) underwent evaluation of socioeconomic status, respiratory symptoms, spirometry, severity of anxiety and depression, six minute walk test and estimation of serum vitamin D levels. Independent association of low vitamin D levels with severity of anxiety and depression was assessed by logistic regression. Results: COPD group had higher mean±SD anxiety and depression scores (HAM-A 8.0±3.5, HAM-D 8.72±4) compared to control group (HAM-A 4.51±2.2, HAM-D 4.3±2). The COPD group had 53 subjects with mild/moderate anxiety/depression whereas control group had 16 subjects with mild/moderate anxiety/depression. In COPD group, subjects with mild/moderate anxiety/depression had lower vitamin D levels compared to subjects with no/minimal anxiety/depression, while the difference in control group was not significant. In logistic regression, anxiety and depression levels had independent association with vitamin D levels, lung function variables, six-minute walk distance and presence of COPD. In COPD subgroup, anxiety and depression levels had independent association with breathlessness, GOLD FEV1 staging, CAT score, SGRQ-C Symptom score and exacerbation of COPD. Conclusions: Greater proportion of COPD subjects suffer from anxiety and depression as compared to subjects without COPD. Severity of anxiety and depression was greater in COPD subjects. Poorer lung functions, higher respiratory symptoms and lower vitamin D levels are associated with higher levels of anxiety and depression in COPD subjects.  There is an urgent need to recognise anxiety and depression in COPD patients.

Circulating Secretoglobin Family 1A Member 1 (SCGB1A1) Levels as a Marker of Biomass Smoke Induced Chronic Obstructive Pulmonary Disease

Secretoglobin family 1A member 1 (SCGB1A1) alternatively known as club cell protein 16 is a protective pneumo-protein. Decreased serum levels of SCGB1A1 have been associated with tobacco smoke induced chronic obstructive pulmonary disease (TS-COPD). Exposure to biomass smoke (BMS) is an important COPD risk factor among women in low and lower-middle income countries. Therefore, in a cross-sectional study (n = 50/group; total 200 subjects) we assessed serum SCGB1A1 levels in BMS-COPD subjects (11 male, 39 female) compared to TS-COPD (all male) along with TS-CONTROL (asymptomatic smokers, all male) and healthy controls (29 male, 21 female) in an Indian population. Normal and chronic bronchitis like bronchial mucosa models developed at the air–liquid interface using human primary bronchial epithelial cells (3 donors, and three replicates per donor) were exposed to cigarette smoke condensate (CSC; 0.25, 0.5, and 1%) to assess SCGB1A1 transcript expression and protein secretion. Significantly (p < 0.0001) decreased serum SCGB1A1 concentrations (median, interquartile range, ng/mL) were detected in both BMS-COPD (1.6; 1.3–2.4) and TS-COPD (1.8; 1.4–2.5) subjects compared to TS-CONTROL (3.3; 2.9–3.5) and healthy controls (5.1; 4.5–7.2). The levels of SCGB1A1 were positively correlated (r = 0.7–0.8; p < 0.0001) with forced expiratory volume in 1 s, forced vital capacity, their ratios, and exercise capacity. The findings are also consistent within the BMS-COPD sub-group as well. Significantly (p < 0.03) decreased SCGB1A1 concentrations were detected with severity of COPD, dyspnea, quality of life, and mortality indicators. In vitro studies demonstrated significantly (p < 0.05) decreased SCGB1A1 transcript and/or protein levels following CSC exposure. Circulating SCGB1A1 levels may therefore also be considered as a potent marker of BMS-COPD and warrant studies in larger independent cohorts.

Determinants of Tobacco Use and Nicotine Dependence Among Healthcare Students and Their Undergraduate Peers

Background:

Global estimates suggest that tobacco will account for 8 million deaths per year by 2030. The Global Adult Tobacco Survey (2016-17) reported that more than half of men and one in ten women aged 15 years and above smoke in India.

Introduction:

Health science courses students (HCS), being the future of our health care system, are expected to be more knowledgeable regarding the hazards of tobacco and are considered less likely to use it compared to their peers (non-HCS) from other fields. The aim of the study is to determine the prevalence and determinants of tobacco use and levels of nicotine dependence amongst HCS and non-HCS students.

Methods:

Web-based survey (response rate of 72%) employing Global Youth Tobacco Survey (GYTS) and Fagerström standardized questionnaires (n = 4770 [21.5 (SD: ± 1.61) years: 62% male] was filled by HCS (43.5%) and non-HCS (56.3%) students from three universities. A descriptive, comparative and multivariate analysis was performed.

Results:

Half of non-HCS and a third of HCS used tobacco, with a higher proportion of male users in both groups. 70% of overall participants showed ‘low nicotine dependence’ with a higher proportion of ‘high dependence’ within the non-HCS group (13.89% vs. 9.2%). There were crucial differences in specific determinants and ages of initiation of tobacco use between the two groups.

Conclusion:

Tobacco use in HCS, apart from personal health risks, may potentially affect their future commitment to support patients in tobacco cessation programs. There is a need for further research into tobacco prevention and cessation programs tailored to the needs of student groups based on the determinants affecting them.

Vitamin D deficiency is associated with chronic obstructive pulmonary disease and exacerbation of COPD

INTRODUCTION

Low Vitamin D levels have been associated with Chronic Obstructive Pulmonary Disease (COPD) and acute exacerbations.

OBJECTIVES

There is a paucity of data on Vitamin D and COPD, its severity and exacerbations in populations that are exposed to sunlight regularly with high levels of physical activity most of their lives.

METHODS

Serum levels of 25-OH-Vitamin-D were assessed in 100 COPD subjects and 100 age- and gender-matched controls from the rural community-based MUDHRA cohort in South India. Levels of <20 ng/mL were defined as Vitamin D deficiency. Smoking habits, occupation, Charlson co-morbidity index, Standard of living index(SLI), body mass index(BMI), 6-minute walking distance were examined for associations with logistic regression between controls and COPD subjects. Unconditional logistic regression was used to examine the association with exacerbation of COPD.

RESULTS

Vitamin D deficiency was observed in 64.5% (95%CI 57.7-70.8) of the subjects in spite of regular exposure to sunlight. Subjects with COPD had higher risk of Vitamin D deficiency (Adjusted OR: 5.05; 95%CI 1.4-17.8) as compared to controls. Amongst subjects with COPD, Vitamin D deficient subjects were three times more likely to have exacerbations in the previous year (Adjusted OR:3.51; 95%CI 1.27-9.67) as compared to COPD subjects without Vitamin D deficiency. Levels of Vitamin D <20.81 ng/mL and <18.45 ng/mL had the highest levels of combined sensitivity and specificity for COPD and acute exacerbation of COPD (AECOPD) respectively.

CONCLUSION

In a rural population exposed to sunlight many hours a day throughout their lives, low Vitamin D levels were associated with COPD and exacerbations of COPD.

Pilot study investigating diagnostic utility of serum MMP-1 and TGF-β1 in asthma in 'real world' clinical practice in India

AIMS

At a tissue level, matrix metalloproteinase-1 (MMP-1) and transforming growth factor-beta 1 (TGF-β1) contribute to allergic airway inflammation, tissue remodelling and disease severity in asthma via different pathways. Their peripheral blood levels and role in diagnosis and therapeutic monitoring has not been adequately explored. We investigated the association between MMP-1 and TGF-β in moderate and severe persistent asthma and evaluated their performance characteristics by constructing receiver operating characteristic curves.

METHODS

Serum MMP-1 and TGF-β1 were measured using ELISA in 75 adults; moderate persistent asthma (n=25), severe persistent asthma (n=25) and healthy community controls (n=25). Severity of asthma was determined as per Global Initiative for Asthma guidelines. Subjects were followed up for 3 months and treatment responsiveness was assessed by spirometry and symptom response.

RESULTS

Serum MMP-1 and TGF-β1 were significantly elevated in asthmatics compared with controls (p<0.0001 and p<0.01). While serum MMP-1 was elevated in severe asthma compared with moderate asthma (p<0.05), TGF-β1 was lower in severe asthma compared with moderate asthma (p<0.05). The performance characteristics of serum MMP-1 and TGF-β1 were promising in this cohort with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 82%, 100%, 100% and 99% and 62%, 100%, 100% and 97.8%, respectively; sensitivity of MMP-1 being superior.

CONCLUSION

This pilot study showed that serum MMP-1 and TGF-β1 levels are elevated in chronic asthma and may serve as a useful adjunct in differentiating moderate from severe asthma. A large multicentre study in well characterised cohort of asthmatics is warranted to investigate their role in diagnosis and therapeutic monitoring.

Risk Factors Associated with Development of Pulmonary Arterial Hypertension and Corpulmonale in Patients with Chronic Obstructive Pulmonary Disease

Background:

Chronic Obstructive Pulmonary Disease is an important cause of morbidity and mortality globally. The onset of pulmonary hypertension and corpulmonale is associated with decreased survival in patients with COPD.

Objective:

To assess risk factors associated with the development of pulmonary hypertension and corpulmonale and to identify high-risk phenotypes who may need early evaluation and intervention.

Methods:

Consecutive adult patients with COPD were evaluated for factors influencing the development of pulmonary hypertension and corpulmonale which included symptomatology, hospitalization in the previous year, MMRC dyspnea grade, SGRQ score, 6 minute walk test, ABG, CRP, spirometry and echocardiography.

Results:

We found Pulmonary Hypertension in 36(30%) patients and 27(22.5%) had corpulmonale. On multivariate analysis, we found PaO2 ≤75 mm Hg and six minute walk test <80% predicted to be significantly associated with the development of Pulmonary hypertension and we found hospitalization in the previous year to be significantly and independently associated with the development of corpulmonale.

Conclusion:

We observed hospitalization in the previous year was an independent risk factor for the development of corpulmonale and six-minute walk test <80% predicted, PaO2 <75 mm Hg were independent risk factors for the development of pulmonary hypertension.

Putative Systemic Biomarkers of Biomass Smoke-Induced Chronic Obstructive Pulmonary Disease among Women in a Rural South Indian Population

RATIONALE

Exposure to biomass smoke (BMS) has been implicated in chronic obstructive pulmonary disease (COPD). About 3 billion people worldwide use biomass fuel for cooking and heating. Women in rural communities of low- and lower-middle-income countries are disproportionately exposed to massive amounts of BMS during active cooking hours (4-6 h/day). Therefore, BMS exposure is considered as a risk factor for COPD in the same order of magnitude as tobacco smoke. In rural India, due to cultural reasons, women are the primary cook of the family and are mostly nonsmokers. Thus, BMS-induced COPD is predominant among rural Indian women. However, BMS-COPD remains a relatively unexplored health problem globally. Therefore, we investigated the serum chemokine and cytokine signatures of BMS-COPD and tobacco smoke-induced COPD (TS-COPD) patients compared to their control in a rural South Indian population for this field study.

METHODS

Concentrations of 40 serum chemokines and cytokines were measured using a multiplexed immunoassay. The study cohort consisted of BMS-COPD (female; n = 29) and BMS-exposed subjects without COPD (BMS-CONTROL; female; n = 24). For comparison, data from TS-COPD patients (male, n = 23) and tobacco smokers without COPD (TS-CONTROL; male, n = 22) were investigated. Subjects were matched for age, sex, and biomass exposure. Tobacco consumption was slightly higher in TS-COPD subjects compared to TS-CONTROL. BMS-exposed and TS-exposed subjects (currently exposed) were from the same locality with similar dwelling habits and socioeconomic status. A validated structured questionnaire-based survey and spirometry was performed. An additional control group with no tobacco and BMS exposure (TS-BMS-CONTROL; n = 15) was included. Statistical significance was set at p ≤ 0.01.

RESULTS

Serum median concentrations (pg/ml) of CCL15 [8799.35; 5977.22], CCL27 [1409.14; 1024.99], and CXCL13 [37.14; 26.03] were significantly higher in BMS-CONTROL compared to BMS-COPD subjects. Nine analytes exhibited higher concentrations in TS-CONTROL compared to TS-COPD subjects. Comparison of chemokine and cytokine concentrations among BMS-COPD versus TS-COPD and BMS-CONTROL versus TS-CONTROL subjects also revealed distinct molecular signatures.

CONCLUSION

Our data identifies CCL27 and CXCL13 as putative, plausibly homeostatic/protective biomarkers for BMS-COPD within the investigated population that warrants validation in larger and multiple cohorts. The findings further indicate exposure-specific systemic response of chemokines and cytokines.

The Mysuru stUdies of Determinants of Health in Rural Adults (MUDHRA), India

Between 2006 and 2010, in 16 randomly selected villages in rural areas of Mysore district, in south India, 8,457 subjects aged 30 and above were screened for symptoms of chronic respiratory disease. Of the 8,457 subjects, 1,692 were randomly invited for further evaluation of lung function and chronic obstructive pulmonary disease (COPD) by spirometry, and 1,085 of these subjects underwent lung function assessments for prevalent COPD and its risk factors. These 1,085 subjects, who were then aged between 35 and 80 years, constituted the Mysuru stUdies of Determinants of Health in Rural Adults (MUDHRA) cohort. Among other findings, threshold of biomass fuel smoke exposure suitable for use as a dichotomous risk factor for the diagnosis of chronic bronchitis was established, with a minimum biomass smoke exposure index of 60 found to be significantly associated with an elevated risk of developing chronic bronchitis. Five years later (between 2014 and 2016), 869 of the 1,085 participants were followed up with repeat lung function assessments for incident COPD and all-cause mortality. A subset of these participants (n=200) underwent blood tests for vitamin D levels, antioxidant activity, an assessment for anxiety and depression, and another subset (n=98) underwent a bioplex assay for 40 serum cytokines.

Antibiotic Prescription, Organisms and its Resistance Pattern in Patients Admitted to Respiratory ICU with Respiratory Infection in Mysuru

Aim of Study:

Respiratory infections account for significant morbidity, mortality and expenses to patients getting admitted to ICU. Antibiotic resistance is a major worldwide concern in ICU, including India. It is important to know the antibiotic prescribing pattern in ICU, organisms and its resistance pattern as there is sparse data on Indian ICUs.

Materials and Methods:

We conducted a prospective study from August 2015 to February 2016. All patients getting admitted to RICU with respiratory infection who were treated with antibiotics were included into study. Demographic details, comorbidities, Clinco-pathological score (CPI) on day1 and 2 of admission, duration of ICU admission, number of antibiotics used, antibiotic prescription, antimicrobial resistance pattern of patients were collected using APRISE questionnaire.

Results:

During study period 352 patients were screened and 303 patients were included into study. Mean age was 56.05±16.37 and 190 (62.70%) were men. Most common diagnosis was Pneumonia (66%). Piperacillin-tazobactam was most common empirical antibiotic used. We found 60% resistance to piperacillin-tazobactam. Acinetobacter baumanii was the most common organism isolated (29.2%) and was highly resistant to Carbapenem (60%). Klebsiella pneumoniae was resistant to Amikacin (45%), piperacillin (55%) and Ceftazidime (50%).

Conclusion:

Piperacillin-tazobactam was the most common antibiotic prescribed to patients with respiratory infection admitted to ICU. More than half of patients (60%) had resistance to the empirical antibiotic used in our ICU, highlighting the need for antibiogram for each ICU. Thirty six percent of patient had prior antibiotic use and had mainly gram negative organisms with high resistance to commonly used antibiotics.

Residence time of pollutants discharged in the Gulf of Kachchh, northwestern Arabian Sea

A 2D Hydrodynamic-Particle Analysis model was applied to the Gulf of Kachchh (GoK) to estimate the residence time of pollutants. The tidal currents in the Gulf have a strong E-W component, which prevents the material in the north being transported towards south. In the regions situated very close to the open boundary, where the GoK waters exchange freely with the northern Arabian Sea, dilution takes place rapidly with the incoming waters and hence, the residence time is on the order of 1 day. Influence of eddies and a dynamic barrier across the Sikka-Mundra section on the residence time is apparent. Eastern GoK shows a relatively large residence time, on the order of 2-4 days, warranting caution while releasing industrial wastes in the northeastern Gulf. The region around location-5 behaves like a bay; the dissolved matter gets trapped in this bay and the residence time increases by 3-4 days.

Investigation of the electrochemical treatment for distillery wastewater

The treatability study of distillery wastewater by electrochemical (EC) oxidation technique as pretreatment has been carried out. Batch experiments were conducted using stainless steel plates as electrodes to assess the effects of operating parameters such as pH, electrolysis duration (ED) and current density (CD). The EC treatment removed 58% COD at current density 0.12 A cm(-2) and at wastewater pH 3 with 120 min of ED. The BOD to COD ratio increased from 0.25 to 0.76 indicating considerable improvement in wastewater biodegradability. The maximum anodic efficiency and minimum energy consumption observed were 7.44 kg COD h(-1) A(-1) m(-2) and 0.19 kWh kg(-1) COD respectively.

Synthesis of phthalocyanine stabilized rhodium nanoparticles and their application in biosensing of cytochrome c

A single step synthesis route is described for the preparation of rhodium nanoparticles using a cobalt aminophthalocyanine macrocyclic complex as a stabilizer. The results of nanoparticles characterization using electronic absorption, Raman and X-ray spectroscopes as well as transmission electron microscopy are reported. Rhodium nanoparticle modified electrode behavior as examined by cyclic and differential pulse voltammetry is also provided. The nanoparticles were found to be well dispersed and stabilized throughout the macromolecular matrix. TEM studies showed that they have an average diameter of 3 to 5 nm with spherical shape. The colloidal rhodium was then used for electrochemical sensing of cytochrome c using glassy carbon electrode. The results showed that the colloidal rhodium nanoparticles enhanced the electron transfer process between cytochrome c and the electrode. Differential pulse voltammetric measurements of cytochrome c at the colloidal rhodium nanoparticles modified glassy carbon electrode showed a linear relationship with the oxidation peak currents in the concentration range of 100 nM to 3 microM of cytochrome c.

Electrochemical oxidation of pharmaceutical effluent using cast iron electrode

Electrochemical oxidation of low (BOD/COD) ratio pharmaceutical wastewater was investigated in this study, using cast iron electrode. The batch experimental results were assessed in terms of COD and BOD concentration while the recalcitrance was monitored in terms of change in the (BOD/COD) ratio during the process. The effects of operating parameters like pH, electrolysis duration and current density were studied on the treatment efficiency and their operating ranges were experimentally determined. The efficiency and energy consumption of anode were estimated. Cast iron electrode has been found to be effective in removing 72% COD after 2hours of electrolysis. In particular, it was found that the (BOD/COD) ratio had improved from 0.18 to 0.3 after 120 min. of electrolysis indicating improvement of biodegradability of wastewater. It has been found, the pharmaceutical wastewater could be effectively pretreated by anodic oxidation.

Colour and organic removal of biologically treated coffee curing wastewater by electrochemical oxidation method

The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD x h(-1) x A(-1) x m(-2) and energy consumption 20.61 kWh x kg(-1) of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD x h(-1) x A(-1) x m(-2) to 0.144 kWh x kg(-1) of COD while decrease the energy consumption from 20.61 kWh x kg(-1) of COD to 12.86 kWh x kg(-1) of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.