Environmental friendly approach for selective extraction and recovery of molybdenum (Mo) from a sulphate mediated spent Ni-Mo/Al2O3 catalyst baked leach liquor.

Solvent extraction separation of molybdenum (Mo) from the sulphate mediated leach solution bearing Aluminium (Al) and Nickel (Ni) was carried out using N-Methyl-N, N, N-tri-octyl-ammonium chloride. Extensive investigation for extraction study molybdenum in the function of time, Eq.pH, extractant concentration, diluents, temperature, strip solution concentration and phase ratio(A:O) for both extraction and stripping was examined to attain a suitable condition on its selective and enriched extraction. As per the equilibrium study and increasing trend of Eq. pH (pHe) at the correspondence initial pH, it was apparent about association of 1 mol of H+ ion during extraction which with was further supported on extraction of Mo as HMO4- at the pHe of 3.48. The association of 1 mol of exrractant during the extraction of Mo was also well evident from the slope analysis study. This indicates about anion exchange phenomenon due to Cl- ion of the N-Methyl-N, N, N-tri-octyl-ammonium chloride (extractant) with HMo4- from aqueous phase during complex formation reaction. The FTIR of the organic sample before and after extraction further confirms in support of the complex formation of the molybdenum with the extractant during extraction. The extraction isotherm was constructed at optmum extraction condition: pHe of 3.48 with 0.08M N-Methyl-N, N, N-tri-octyl-ammonium chloride predicts on need of 2-counter current stages for quantitative extraction of Mo at A:O = 3:1. To investigate the regeneration behaviour of adopted extractant along with enriched stripping of molybdenum, ammoniacal reagents were used in stripping study. The stripping of Mo showed promising and efficient using the mixture of the ammoniacal reagents (NH4OH + NH4Cl) over the either of the solo reagents. The stripping Mc-Cabe Thiele diagram was plotted using 2M NH4OH + NH4Cl ensures on quantitative stripping of Mo at SO: SS = 2:1 at 2 no. of stages. Both extraction and stripping isotherm results are validated at predicted isotherm conditions by 6-cycles counter current simulation (CCS) study leading to obtain 6-fold enrichment of Mo in stripped solution phase. The subsequent enriched content of Mo (∼60 g/L) in stripped solution phase was precipitated out followed by calcinations 400 °C to obtain a high pure MoO3. The recovered calcined product as MoO3 resulted through the proposed processing approach was as ascertained from XRD analysis.

Air quality modeling for policy development.

Atmospheric models constitute the best tools available for the setting of policy, and may, in some cases, be the only tools that are available. The best examples of their kind bring together all current knowledge of pollutant behavior in the atmosphere, making it possible to unravel the often complex interactions between pollutants and atmospheric dynamics. They also allow the possibility of evaluating hypothetical changes in emissions and other conditions to evaluate potential abatement strategies, or to assess the impact of proposed new emission sources. This paper provides an overview of mathematical atmospheric models and their application to the development of air quality policy. The paper discusses the types of atmospheric models currently in use, categorized by spatial scale, and the requirements for credible modeling. Issues associated with model validity and accuracy are described and case studies are reviewed to illustrate atmospheric model use in policy development and the need for careful analysis in interpreting model predictions.

Systematic and ecological studies on Chlorophyceae of North India and their relationship with water quality.

In the course of systematic and ecological studies on algal flora of fresh water environment of three different agroclimatic zone of Uttar Pradesh revealed one hundred eighty two species represented by fifty-two genera inhabiting fresh water bodies having different physico-chemical properties. In both the regions members of order Conjugales were dominant and represented by ninety nine species belonging to fourteen genera. This is followed by Chlorococcales having fifty two species represented by nineteen genera and Chaetophorales with nine species of four genera only. In the central Uttar Pradesh a positive correlation was found between hydrogen ions concentration with temperature and species diversity, while in western Uttar Pradesh a highly positive correlation was found in electrical conductivity and total dissolved solids.

Fresh water blue green algae from three agro-climatic zones of Uttar Pradesh, India: distribution pattern with seasonal variation.

The paper deals with 45 species of 21 genera of fresh water blue green algae (BGA) from three different agro-climatic zones of Uttar Pradesh. Samples were collected from different habitats varying in physico-chemical properties. Out of 45 species, 13 species belonged to order Chroococcales, 31 to order Nostocales, while only 1 species belonged to order Stigonimatales i.e. Fischerella mucicola. The physico-chemical parameters like pH, temperature, dissolved oxygen, electrical conductivity, nitrate, nitrite and rainfall play an important role in the periodicity of BGA. A positive correlation was found between dissolved oxygen (DO) of different ponds and species diversity, except in the case of western region of Uttar Pradesh (Farukhabad and Mahoba districts) where a positive correlation was found in electrical conductivity and total dissolved solids.

Assessing the effects of transboundary ozone pollution between Ontario, Canada and New York, USA.

We investigated the effects of transboundary pollution between Ontario and New York using both observations and modeling results. Analysis of the spatial scales associated with ozone pollution revealed the regional and international character of this pollutant. A back-trajectory-clustering methodology was used to evaluate the potential for transboundary pollution trading and to identify potential pollution source regions for two sites: CN tower in Toronto and the World Trade Center in New York City. Transboundary pollution transport was evident at both locations. The major pollution source areas for the period examined were the Ohio River Valley and Midwest. Finally, we examined the transboundary impact of emission reductions through photochemical models. We found that emissions from both New York and Ontario were transported across the border and that reductions in predicted O3 levels can be substantial when emissions on both sides of the border are reduced.

An interesting case of primary cutaneous actinomycosis.

Actinomycosis is an infection commonly seen in tropical countries. It is characterized by chronic and progressive suppurative inflammation, typically presenting on the neck, thorax, and abdomen. Primary cutaneous actinomycosis is a rare entity, and the diagnosis requires a high index of clinical suspicion. Anaerobic cultures may be negative despite repeated attempts. Microscopic examination reveals the diagnosis in the majority of cases, and treatment requires administration of parenteral or oral penicillin for at least 6 weeks. We report a case of cutaneous actinomycosis affecting the arm. This patient was treated with phenoxymethylpenicillin.

Do we understand trends in atmospheric sulfur species?

Anomalies appear to exist in our understanding of atmospheric sulfur compounds, specifically as evidenced in the time trends of the different chemical forms of these compounds. Trends determined at a number of locations by several different groups seem to indicate that, responding to emission reductions across North America, the concentration of SO2 in the atmosphere is declining more rapidly than that of aerosol SO4(2-). A number of possible reasons for this discrepancy are examined, but it is not possible to provide a definitive answer at this stage. The intent is to stimulate debate, because shortcomings in our understanding of the processes involved could have profound implications for the credibility of abatement strategies and policies for both acid deposition and fine particulate matter (PM).

Antisense peptide interactions studied by electrospray ionization mass spectrometry.

Non-covalent interactions between met- and leu-enkephalins and their antisense peptides were studied by electrospray ionization mass spectrometry. Mixtures of sense and antisense peptides gave both the corresponding homodimers and heterodimers. The relative abundance ratios of the heterodimer to that of the homodimer of the sense peptide and the relative stability constants of the heterodimers were compared with the corresponding values from mixtures of the sense peptides and a control peptide. The results show that there is a preferential interaction between the sense and antisense peptides compared with that between the sense and control peptides.

Trends in poisoning in children: experience at a large referral teaching hospital.

BACKGROUND: Poisoning is a major problem in the paediatric population. The offending substances used vary from place to place. Information on poisoning trends in India is meagre and there is an impression among clinicians that there has been a change in the commonly used poisons over the years. This retrospective study aimed to determine the pattern of poisoning in children and to study the nationwide trend over the past five decades. METHODS: Case records of children (age group: 1 month and above) admitted to the Department of Paediatrics, King George's Medical College, Lucknow, Uttar Pradesh in three alternate calendar years, i.e. 1989, 1991 and 1993 were screened. All children were grouped into three categories based on the poison: (i) bites and stings, (ii) medicinal compounds, and (iii) non-medicinal compounds. The Indian literature on poisoning in children was reviewed and decade-wise data from a total of 22 studies (including the present study) were used to determine the changing trend. RESULTS: Childhood poisoning constituted 2.1% of the total paediatric admissions and 1.2% of total deaths. Non-medicinal compounds were the largest contributors (69.2%), of which kerosene alone was responsible for 47% of cases. Medicinal compounds, and bites and stings accounted for 21.6% and 9.2% of these cases, respectively. The case-fatality rate was 9.2%. Comparison of our data, after excluding bites and stings, with a previous study (1977-79) from our institution showed that kerosene poisoning continues to be responsible for a substantial part of the morbidity (51.8% v. 31.5%). Also, poisoning due to insecticides and pesticides has increased (13.7% v. 2.1%) while that due to plant poisons (primarily dhatura) has reduced markedly (4.8% v. 19.2%). CONCLUSION: Mortality due to poisoning in children has remained high over the last five decades (2.9%-4.7%). Kerosene has remained the single largest contributor to childhood poisoning (51.5% in the 1960s v. 52.8% in the 1990s).

Microfilaria in a fine needle aspirate of primary solid malignant tumor of the maxillary antrum. A case report.

BACKGROUND: Lymphatic filarial disease is very common in tropical countries like India. The incidental finding of microfilariae in various benign cytologic smears is very common. Microfilariae in malignant effusions have also been reported, but their coexistence with solid malignant tumor at the primary site has not been reported so far. CASE: A 45-year-old male presented with a painful, rapidly growing swelling over the right maxilla that had been present for three months. On routine fine needle aspiration cytology, a microfilaria along with squamous carcinoma cells in a primary solid malignant tumor of the maxillary antrum was found. CONCLUSION: This is the first case reported in English of the incidental finding of a microfilaria in a primary tumor of the maxillary antrum.

Pseudohypoparathyroidism-Albright hereditary osteodystrophy.

A 13 year old girl with short stature, and retarded mental growth with coarse facies and deranged thyroid function test was initially suspected as a case of hypothyroidism and was started on thyroxine. Lack of response to treatment and on further investigations it was diagnosed as a case of pseudohypoparathyroidism. High index of suspicion and careful evaluation is important to diagnose such an entity.

Brainstem auditory evoked response in newborns with hyperbilirubinemia.

OBJECTIVE: To determine the initial Brainstem Auditory Evoked Response (BAER) abnormalities in neonates with hyperbilirubinemia and the possible reversibility of abnormal BAER after therapy. DESIGN: Prospective cohort study. SETTING: Tertiary care hospital. SUBJECTS: 30 term neonates with hyperbilirubinemia (S. bilirubin < 15 mg/dl) as cases and 25 normal term neonates as controls. METHODS: Duration of study was from August 1995 to August 1996. BAER were recorded before therapy at peak hyperbilirubinemia, after therapy, and the age of 2-4 months using electric response audiometer (Nihon Neuropack Four Machine). Denver Development Screening Test (Denver II) was performed at 1 year of age. RESULTS: Seventeen out of thirty (56.7%) neonates with hyperbilirubinemia showed abnormalities on initial BAER. Commonest abnormality seen was raised threshold of wave V in 12 neonates (40%). Other abnormalities observed were absence of all waves at 90 dB (23.3%), prolongation of latencies of various waves (26.7%) and prolongation of various intervals (26.7%). Abnormalities in BAER correlated significantly with bilirubin level. After therapy abnormalities reverted back to normal in 10 cases but persisted in 7 out of 17 (41.17%) cases with initial abnormal BAER. Development screening at 1 yr was abnormal in 3 infants all of whom had persistent abnormalities in BAER. CONCLUSION: Serial BAER is a useful, non invasive tool to detect neurodevelopment delay secondary to neonatal hyperbilirubinemia.

Cardiovascular responses to treadmill exercise testing in anemia.

OBJECTIVE: To study exercise performance on a treadmill in anemic children. DESIGN: Prospective case control study. SETTING: Department of Pediatrics and Intensive Care Unit, Department of Medicine, King George's Medical College, Lucknow. SUBJECTS: The study population consisted of 41 cases of anemia (10 mild, 21 moderate and 10 severe) and 11 normal age and height matched children aged between 7-12 years. METHODS: These subjects were exercise tested on Quinton Model Q5000 treadmill using Modified Naughton Q5000 protocol. Heart rate, systolic blood pressure, double product, ECG changes, exercise duration and metabolic equivalents achieved during peak exercise were studied. Statistical analysis was performed using analysis of variance (ANOVA) test. RESULTS: No significant difference was observed in values of resting heart rate, heart rate at peak exercise, recovery heart rate, blood pressure response, resting double product, double product at peak exercise, recovery double product and ECG changes in any of the study groups (p > 0.05). However, the gain in heart rate at peak exercise compared to basal value, and double product, total exercise duration and metabolic equivalent (MET) values at peak exercise were significantly low in anemic children on comparison to normal controls (p < 0.001). CONCLUSIONS: Cardiovascular responses are blunted in anemia, mainly because of depleted cardiac reserve.

Brainstem auditory evoked response in tuberculous meningitis.

Brainstem auditory evoked response (BAER) abnormalities in tuberculous meningitis (TBM) were determined in 50 cases of tuberculous meningitis (36 male and 14 female) and 50 normal healthy children. Fifty six per cent cases had abnormal BAER findings. The commonest BAER abnormality observed in 32% was a combination of prolonged latency and prolonged interval while unilateral and bilateral absent response was observed in 4% cases. Prolonged latency was observed in 16% patients. Seizure activities, modified glasgow coma scale (GCS), raised intracranial pressure (ICP) and TBM stage III were significantly correlated with abnormal BAER, while age, sex, duration of illness, depressed sensorium, neurological deficit and CSF findings did not have a significant correlation with abnormal BAER. Follow up could be done in ten patients only. All the three patients with only prolonged latency had a normal BAER on follow up, two out of four patients with prolonged latency and prolonged interval had normalization of BAER while in three patients, initial as well as follow up BAER was normal. The present study shows that BAER abnormalities are observed in more than fifty per cent of the patients of tuberculous meningitis.

Brainstem auditory evoked response in neonates with birth asphyxia.

OBJECTIVE: To determine the brainstem auditory evoked response (BAER) abnormalities and their reversibility in neonates with birth asphyxia. DESIGN: Prospective case control study. SETTING: Tertiary care teaching hospital. METHODS: 30 term Neonates with 5-min Apgar < 6 and hypoxic ischemic encephalopathy (HIE) underwent BAER testing with follow up at 3 months. An equal number of normal term neonates served as controls. RESULTS: 13 out of 30 (43.3%) neonates with birth asphyxia showed some abnormality in BAER wave form. The commonest type of BAER abnormalities seen were transient prolongation of latencies of various waves (69.2%) and prolonged interside latency difference (69.2%). Other abnormalities observed were prolonged interwave interval (23.1%) and prolonged interside interval difference (7.7%). Abnormalities in BAER were significantly associated with stages of HIE and duration of neurological abnormalities more than 5 days. On follow up of 16 cases at 3 months of age, BAER abnormalities reverted back to normal in all the neonates. The Denver Developmental Screening Test (DENVER II) was suspect in 4 cases but the BAER was normal. CONCLUSION: BAER abnormalities in asphyxic neonates are transient and revert back to normal at 3 months of age. BAER does not appear to be a useful tool for early detection of neurological handicaps.

Brainstem auditory evoked response (BAER) in childhood bacterial meningitis.

Brainstem auditory responses were recorded in 50 children of bacterial meningitis and age matched 50 normal children. Abnormal BAER was found in 32 (64%) patients of bacterial meningitis. These abnormalities included prolonged latency (56.2%); unilateral absent response (25%); bilateral absent response (25%) and prolonged interwave interval (25%). Follow-up could be done in 23 patients of 46 survivors. All the patients with prolonged latency either became normal or improved. In majority of the patients having absent response, the abnormality persisted. Abnormal BAER was significantly associated with age < 2 years (p < 0.02), Modified GCS Score < or = 8 (p < 0.001), Seizures (p < 0.02), raised Intracranial Pressure (ICP) (p < 0.02) and CSF sugar < 20 mg% (p < 0.05).