Synthesis, Characterization and Catalytic Properties of Microporous Cobalt Aluminosilicate (CoLTL) Molecular Sieves

Thermally stable divalent cobalt substituted microporous aluminosilicate (CoLTL) molecular sieves were synthesized and characterized. These studies revealed isomorphous substitution of divalent cobalt in tetrahedral framework of LTL structure. In addition, the typical blue color of CoLTL confirms the tetrahedral environment of divalent cobalt in the framework, and as a result the catalyst showed excellent activity for the oxidation of cyclohexane under mild reaction conditions. Furthermore, unlike the many other cobaltbased microporous (heterogeneous) catalysts reported so far, CoLTL does not show any dislodgement or segregation of cobalt upon calcination or any other post-synthesis treatments. In this study, the performance of CoLTL was also compared with cobalt-containing aluminophosphate and silicate molecular sieves having AFI and MFI structures, respectively

Comparative analysis of modulation techniques in frequency converter

Abstract: A generalized frequency converter has been realized which makes use of a cyclo-converter in newer form AC-AC converter. An attempt has been made to operate this converter both in a conventional low frequency AC-AC converter and a new high frequency AC-AC converter. The ability to directly affect the frequency conversion of power without any intermediate stage involving DC power is a huge advantage of the system. The output of this converter has a frequency either fo = fi × Nr or fo = fi / Nr. where Nr is an integer and fi is the source frequency. A methodology is developed to generate the required trigger signal for any integer multiple/sub multiple of the output frequency. The undesirable harmonic components in the output of the frequency converter have been minimized using four modulation techniques namely; sinusoidal pulse width modulation (SPWM), delta modulation (DM), trapezoidal modulation (TM) and space vector modulation (SVM) technique. The converter is simulated using well known software package MATLAB. Comparative simulation analysis is presented for a single phase frequency converter (SPFC) topology with all these modulation techniques when the converter is operating both step up as well as for step down mode

Harmonic minimization in modulated frequency single-phase matrix converter

Abstract: This Field Programmable Gate Array (FPGA) based digital controller has been developed to improve the output of the frequency converter using Hardware Description Language. An attempt has been made to analyze converters using three modulation techniques namely sinusoidal pulse width modulation (SPWM), delta modulation (DM) and trapezoidal modulation (TM) to reduce the harmonics. It has been found that for the Sine PWM, the total harmonic distortion factor (THD) is high when the output frequency is greater than input frequency. The output is improved with delta modulation scheme where the total harmonic distortion is found minimum as compare to the SPWM and TM techniques. The circuit has been tested qualitatively by observing various waveforms on digital storage oscilloscope (DSO). The overall system is compact and no external memory system is required. Tests have been carried out to show the effectiveness and flexibility of the proposed method

A comparative biochemical study on the non diabetic obese and non obese subjects with cardiovascular disease

Cardiovascular disease is now a major public health problem in India and is emerging as a major killer. The non diabetic obese and non obese subjects with cardio vascular disease” were carried out with the objective of studying or investing the (effect) cause of cardiovascular diseases in obese and Non-obese subjects. The level of lipoprotein a of non obese subject showed a significant (P < 0.001) increase than in the obese subject. The level of lipid ratio (total cholesterol / HDL cholesterol) found to be significantly (P < 0.001) high in obese subjects than in non-obese subjects. The present study has been designed to evaluate or investigate the risk of cardiovascular disease due to obesity in both male and female middle age group

Pulmonary tuberculosis in HIV individuals: Preliminary report on clinical features and response to treatment

Objectives: To study the clinical, radiological and immunological profile of pulmonary tuberculosis in HIV infected patients and assess the response to short-course chemotherapy regimens. Methods: Seventy eight patients (68 males and 10 females) with HIV infection and having symptoms suggestive of tuberculosis attending the Government Hospital for Thoracic Medicine, Tambaram or the Tuberculosis Research Centre, Chennai were studied. The diagnosis of tuberculosis was based on clinical evaluation, bacteriological examination including sputum smear and culture and chest skiagram. HIV diagnosis was based on two tests (rapid/ELISA), detecting different antigens. CD4+ T cell counts were done on all patients initially and at the end of treatment. Blood tests and skiagrams were repeated at 2 months and at the end of treatment. All the patients were treated with standard (RNTCP) short course regimens. Patients were given all the doses under supervision during the initial intensive phase and through community DOTS providers in the continuation phase. Results: Sixty five patients had culture confirmed pulmonary tuberculosis, of whom 54 had smear positive disease, initially. The radiological manifestations were varied, with 11 subjects having miliary tuberculosis, 54 with non-homogeneous opacities and 10 with cavitation. The mean CD4 cell count at intake was 192 ± 172 cells/cumm. Patients showed good initial response to treatment with significant weight gain. At the end of 2 months of treatment, 91% of patients had sputum cultures negative for Mycobacterium tuberculosis. However, the CD4 % fell significantly by the sixth month. The study is being continued to assess the long-term response to SCC of patients with HIV and tuberculosis. Conclusions: Tuberculosis has a varied clinical presentation in patients with HIV infection. The spectrum of radiographic features ranges from normal to a miliary pattern. Inspite of clinical and bacteriological improvement during treatment, immunologic deterioration may continue

Analytic Behaviour of Competition among Three Species

We analyse the classical model of competition between three species studied by May and Leonard ({\it SIAM J Appl Math} \textbf{29} (1975) 243-256) with the approaches of singularity analysis and symmetry analysis to identify values of the parameters for which the system is integrable. We observe some striking relations between critical values arising from the approach of dynamical systems and the singularity and symmetry analyses.Comment: 14 pages, to appear in Journal of Nonlinear Mathematical Physic

Comparison of Interactive Teaching in Online and Offline Platforms among Dental Undergraduates

In recent years, the educational system has focused more on the holistic development of an individual. Modern technology has changed the educational environment to provide students with better academic opportunities. Along with the education system, teaching techniques and learning tools have also changed with digital evolution. This research was undertaken to assess the academic performance of interactive teaching methods in offline and online platforms in Periodontics among BDS undergraduates at a dental college in India. This prospective study was conducted among 49 students: Group I (n = 24, online class through Zoom) and Group II (n = 25, offline classes). The subject was divided into three modules and was covered in one week. The topics covered, teaching methods, lectures, and activities were similar for both groups. A formative assessment mark was obtained from written tests during the module, whereas the summative assessment mark was recorded from exams conducted towards the end of the module. In the results, a statistically significant difference was not observed in terms of formative assessment between Group I (77.88 ± 12.89) and Group II (77.80 ± 16.09) (p = 0.98). In addition, a statistically significant difference was not observed in terms of summative assessment between Group I (80.54 ± 8.39) and Group II (80.28 ± 11.57) (p = 0.93). Overall, this study suggests that interactive teaching methods in both offline and online platforms in Periodontics showed equivalent performance by the undergraduate dental students

Sustainable electrospun materials with enhanced blood compatibility for wound healing applications—A mini review

Wound healing is a complex process that requires an appropriate environment to support healing. Wound dressings play a crucial role in wound management by protecting the wound and promoting healing. Recent advancements in wound dressing technology include the development of bio-absorbable electrospun dressings incorporating essential oils, which have shown promise in enhancing wound healing potential. However, there is still a need for sustainable wound dressing technology that is effective, safe, and environmentally friendly. This review addresses this need by emphasizing the potential of bio-absorbable electrospun wound dressings incorporating essential oils and advocating for a paradigm shift toward sustainable crop-origin materials and the elimination of toxic solvents in wound dressing fabrication

Synergetic effect of probiotic, molasses and immunostimulant supplementation on the production of white leg shrimp Litopenaeus vannamei Boone, 1931

820-828The aim of the study is to find out a suitable combination of supplements for the successful production of shrimp Litopenaeus vannamei. The experiment was performed in two different shrimp farms located in the same area at Athirampattinam (Farm-A) and (Farm-B), Tamil Nadu, East coast of India. Each group consisted of three ponds, farm-A supplemented with probiotic, immunostimulant and molasses. Subsequently, farm-B was supplemented with chemicals and probiotics. The shrimp average body weight (23.2 ± 0.41 g) survival (84 ± 0.05 %) and production (6.98 tons/ha) was significantly higher (P ) in farm-A than the farm-B. The water parameters such as temperature, pH, salinity, transparency, dissolved oxygen, total ammonia, nitrite, total plate count and Vibrio population were significantly varied between these two farms. The safe water quality parameter values were obtained in farm-A. Henceforth, the present study was concluded that the supplementation of probiotic, immunostimulant and molasses combination enhanced the shrimp production