Modeling of reaction kinetics in generation of hydrogen from wastewater by microbial electrolysis

High carbon footprints and limited availability of fossil fuels have motivated researchers to find alternatives to fossil fuels and the ways of producing them. Hydrogen is an alternative fuel and can be generated by electrohydrogenesis in a Microbial Electrolysis Cell (MEC) using wastewater. At times, the microorganisms known as exoelectrogens are added externally to the wastewater in the form of biomass. Biomass serves as a parameter to optimize the yield of hydrogen. In this research work an attempt is made to understand the effect of the biomass concentration on the substrate utilization by the exoelectrogens and product formation. This research work also aims at studying the biochemical reaction kinetics and to identify a model that best describes the kinetics of the reactions involved, at the electrodes. It was observed that on increasing the biomass concentration from 0.7g/L to 1.4 g/L, the gas liberation rate increased from 9.42 ml/day to 15.33 ml/day and substrate utilization increased from 86.8% to 94.3%. This was in close agreement with the solution of the identified model. It was found out that the energy efficiency of MEC improved substantially by 30% and the energy demand was decreased by 38.5% when the initial biomass concentration was doubled

Tuberculous gingival enlargement: A rare clinical manifestation

Tuberculosis (TB) is an inflammatory granulomatous disease that rarely presents as primary lesion in gingiva. Gingival involvement has been reported in only a very limited number of cases. A 13-year-old boy presented with gingival enlargement in the maxillary and mandibular anterior region associated with enlargement of lower lip with no systemic manifestations. He had a history of tuberculous lymphadenitis before 5 years which was inadequately treated. The patient's erythrocyte sedimentation rate was 70 mm/h. Histopathological report of the gingival lesion revealed noncaseating granulomas with nests of epithelioid cells and multinucleated Langhans giant cells. The patient was then referred to a physician for management, who initiated active antitubercular treatment following which the condition resolved. The aim of this article is to emphasize the importance of early diagnosis of primary TB of the gingiva which may be misdiagnosed when oral lesions are not associated with any apparent systemic infection

Assessment of knowledge, practices, and work place condition related to ergonomics among dental students of Bhopal city - A questionnaire study

Background: Dental profession is susceptible to various postural and nonpostural occupational risks. Aim : To determine knowledge, practice, and condition of work place regarding ergonomic posture among dental students from Bhopal city, Central India. Also to observe any correlation among knowledge, practice, and condition of work place scores. Materials and Methods : A self-administered questionnaire study was conducted among 231 dental students. The questionnaire consisted of three parts: Knowledge, practice, and condition of work place. Analysis of variance was used to compare mean of knowledge, practice of clinical posture, and condition of work place. Pearson′s correlation coefficient has been applied to compute correlation among knowledge, practice, and condition of work place scores. A P value < 0.05 was considered significant for all statistical analyses. Results : We found that 70% of dental students perform torsion of the body and cervical flexion to improve vision and prefer direct vision when working. Only 59% reported that they are working with ergonomically designed dental unit and instruments. Most of them reported that the work stool is not comfortable. Mean knowledge, practice, and condition of work place scores were 3.93 (1.26), 5.01 (1.58), and 2.60 (1.14), respectively. Significant differences between the groups were noted for means of practice scores (P ≤ 0.01). Significant linear correlation was seen between knowledge-practice scores (r = 0.20) (P ≤ 0.01), practice-condition of work place scores (r = 0.14) (P ≤ 0.05), and knowledge-condition of work place scores (r = 0.14) (P ≤ 0.05). Conclusion : The knowledge of ergonomic postural requirements and their clinical application among the dental students surveyed were not satisfactory. A multifactorial approach that includes preventive education, postural and positioning strategies, proper selection, and use of ergonomic equipment should be employed