16 research outputs found
“KNOWLEDGE AND PRACTICE REGARDING SAFETY STANDARDS OF ORALRADIOLOGY AMONG DENTAL PRACTITIONERS IN DENTAL COLLEGE, BIHAR”CORRESPONDING AUTHOR - DR BINU SINGH
No full textIn Dentistry, radiographic evaluation is required but professional negligence or ignorancecanleadtoradiation hazards so the knowledge regarding safety standards among Dentists is necessary. Theaimofthe study was to investigate the knowledge and behavior of Dental practitioner regardingsafetyduringoral radiographic procedures. It was a survey based study enrolled 100 dentists. A13semi -structured,validated questionnaire was used to assess knowledge and practice related to safety standardsinOralRadiology. The study revealed that amongst 100 Practitioners; 48 had > 5 years experiences, 86hadone machine, 61 had less than 5 years old machine. 97 used RVG, 73 took less than 10radiographsperday, 65 didn’t hold the X-Ray film with their fingers, 59 didn’t use lead apron and49stoodnearpatient without wearing lead apron, 54 did periodic check-up only when needed, 50 hadtorepeat,54didn’t know safe distance, 75 didn’t know the exposure time and 52 took radiographsofpregnantwomen. The study conclude that the periodic training and regular monitoring should bemandatorytoimprove knowledge about radiation and dose reduction technique
RADIOGRAPHIC ASSESSMENT OF THIRD MOLAR AGENESIS PATTERNS IN YOUNG ADULTS- A DIGITAL PANORAMIC STUDY
No full textThird molars are the teeth that are frequently congenitally absent, which may be related to evolutionary changes altering the size of the jaw and teeth. Orthopantomogram (OPG) is a radiographic modality that is routinely employed in dental practice to detect pathologies of both the dentition and jawbones. The aim of the study was radiographic assessment of 400 third molars for agenesis in young adults of age 12-20 years with orthopantomogram. This retrospective study was performed on 400 archived digital panoramic radiographs retrieved from the department of Oral medicine and radiology for the comparative evaluation of third molars agenesis between the genders, maxillary and mandibular arches and between the right and left sides. A total of 400 panoramic radiographs were included in the study, in which 79 exhibited agenesis of third molars in males while 65 showed agenesis in females. Maxillary third molar (128) showed a higher prevalence of agenesis than mandibular third molars (77), while right quadrant showed 128 and left quadrant show 126 third molar agenesis. It was concluded that isolated third molar agenesis is part of a developmental mechanism resulting also in craniofacial size reduction. This might be the effect of an evolutionary process observed in humans
PREVALENCE OF ORAL MUCOSAL LESION AMONG PATNA POPULATION – A SURVEY
No full textOral mucosa is an effective protective barrier and is commonly affected by lesions that may be innocuous to those that are malignant. Aim of this study was to study the prevalence of oral mucosal lesions in Patna population. Out of 2500 subjects, 1585 were males and 915 were females. The maximum number of participants were in the age group of 25-34 years. Habit of Cigarette smoking was found in 160 subjects. In smokeless form, Khaini in 435 and Gutkha habit in 320 subjects were seen. Oral mucosal lesions were present in 950 of which 335 lesions were non-tobacco users and 615 subjects were tobacco users. Tobacco pouch keratosis was seen in 240 subjects (29.81%) followed by OSMF in 145 (18.01%) among tobacco users. Lichen planus was the most common oral mucosal lesion in 85 subjects (5.01%) among non-tobacco users. The study population is predominantly male. Smokeless tobacco, particularly Khaini and Gutkha, is a significant concern in this population, while smoking tobacco and alcohol consumption are less prevalent. The presence of lesions in over one-third of the participants highlights a potential health issue within this population. There is a strong relationship between tobacco use and the occurrence of oral mucosal lesions.
KeywordsOral mucosal lesions, leukoplakia, oral submucous fibrosis, Malignant lesions
Biodiesel production from jatropha seeds: Solvent extraction and in situ transesterification in a single step
No full textThe objective of this study was to investigate solvent extraction and in situ transesterification in a single step to allow direct production of biodiesel from jatropha seeds. Experiments were conducted using milled jatropha seeds, and n-hexane as extracting solvent. The influence of methanol to seed ratio (2:1–6:1), amount of alkali (KOH) catalyst (0.05–0.1 mol/L in methanol), stirring speed (700–900 rpm), temperature (40–60 °C) and reaction time (3–5 h) was examined to define optimum biodiesel yield and biodiesel quality after water washing and drying. When stirring speed, temperature and reaction time were fixed at 700 rpm, 60 °C and 4 h respectively, highest biodiesel yield (80% with a fatty acid methyl ester purity of 99.9%) and optimum biodiesel quality were obtained with a methanol to seed ratio of 6:1 and 0.075 mol/L KOH in methanol. Subsequently, the influence of stirring speed, temperature and reaction time on biodiesel yield and biodiesel quality was studied, by applying the randomized factorial experimental design with ANOVA (F-test at p = 0.05), and using the optimum values previously found for methanol to seed ratio and KOH catalyst level. Most experimental runs conducted at 50 °C resulted to high biodiesel yields, while stirring speed and reaction time did not give significantly effect. The highest biodiesel yield (87% with a fatty acid methyl ester purity of 99.7%) was obtained with a methanol to seed ratio of 6:1, KOH catalyst of 0.075 mol/L in methanol, a stirring speed of 800 rpm, a temperature of 50 °C, and a reaction time of 5 h. The effects of stirring speed, temperature and reaction time on biodiesel quality were not significant. Most of the biodiesel quality obtained in this study conformed to the Indonesian Biodiesel Standard
The discovery of a conjugate system of faults in the Wharton Basin intraplate deformation zone
No full textThe deformation at well-defined, narrow plate boundaries depends on the relative plate motion, but how the deformation takes place within a distributed plate boundary zone remains a conundrum. This was confirmed by the seismological analyses of the 2012 great Wharton Basin earthquakes [moment magnitude (Mw) 8.6], which suggested the rupture of several faults at high angles to one another. Using high-resolution bathymetry and seismic reflection data, we report the discovery of new N294°E-striking shear zones, oblique to the plate fabric. These shear zones are expressed by sets of normal faults striking at N335°E, defining the direction of the principal compressional stress in the region. Also, we have imaged left-lateral strike-slip faults along reactivated N7°E-oriented oceanic fracture zones. The shear zones and the reactivated fracture zones form a conjugate system of faults, which accommodate present-day intraplate deformation in the Wharton Basin
Stratigraphic Control of Frontal Décollement Level and Structural Vergence and Implications for Tsunamigenic Earthquake Hazard in Sumatra, Indonesia
No full textInternational audiencePropagation of fault rupture to the seafloor is a likely cause of enhanced tsunami generation during megathrust earthquakes. New, high‐resolution seismic reflection profiles and swath bathymetry collected across the northern limit of the Mw 7.8, 25 October 2010 Mentawai tsunami earthquake rupture reveal significant and systematic lateral variations in both the stratigraphic level of the frontal Sunda megathrust and the vergence of its frontal ramp faults. Where ramp faults are uniformly seaward vergent, the décollement resides on top of a strong reflector marking the inferred top of pelagic sediments. Where ramp faults are bivergent (both landward and seaward), the décollement is localized within the subducting clastic sequence, above a xseismically transparent unit inferred to be distal fan muds. Where ramp faults are uniformly landward vergent, the décollement is directly on top of the oceanic crust of the subducting Investigator Fracture Zone. Enhanced surface uplift and tsunamigenesis during the 2010 tsunamigenic earthquake appear to have coincided with propagation of rupture into frontal areas with well‐developed structural bivergence. Frontal bivergence is a geological signal of low basal traction during accrual of slip, and offshore of Sumatra this structural style may mark areas of enhanced tsunami hazard posed by small‐magnitude, shallow megathrust ruptures that propagate into the incoming terrigenous sequence at near‐trench levels
Is there a Nascent Plate Boundary in the Northern Indian Ocean?
No full textInternational audienceThe northern Indian Ocean has been widely recognized as an area of broadly distributed deformation within the composite India-Australia-Capricorn plate, hosting several diffuse boundary zones and a diffuse triple junction. The occurrence, along reactivated fracture zones, of the exceptionally large (Mw=8.6 and Mw=8.2) 2012 Wharton Basin strike-slip earthquakes, however, questions whether this composite plate is breaking apart along a discrete boundary. Using recent bathymetric and seismic data, we analyze the most prominent fracture zone (F6a), whose structural trace is particularly well-expressed. We identify sixty kilometric-scale pull-apart basins with geometric properties (length/width ratios) similar to those observed along continental strike-slip plate boundaries. Four of the pull-aparts formed above narrow, sub-vertical faults extending into the oceanic crust. Within the broad Wharton deformation zone, the significant slip rates (0.8 to 2.5 mm/yr) and unusually large co-seismic displacements recorded along F6a suggest that it may be a nascent plate boundar
Caracterização, extração e purificação por cromatografia de compostos de urucum (Bixa orellana L.)
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Química
Evidence of pervasive trans-tensional deformation in the northwestern Wharton Basin in the 2012 earthquakes rupture area
No full textInternational audienceThe Wharton Basin in the Indian Ocean is one of the most extensively deforming ocean basins, as confirmed by the occurrence of several very large earthquakes starting from January 12, 2012 with Mw 7.2 followed by the great earthquakes of April 11, 2012 with Mw 8.6 and Mw 8.2. Although the Mw 7.2 and Mw 8.2 earthquakes seem to have ruptured the re-activated N–S striking fracture zones, the largest event (Mw 8.6) required the rupturing of several faults, oblique to each other, in a very complex manner. In order to understand the nature of deformation in these earthquakes rupture zones, we recently acquired 90 000 km2 of bathymetry, 11 400 km of sub-bottom profiling, gravity and magnetic data covering the rupture areas of the 2012 earthquakes east of the Ninety-East Ridge, in the northwestern Wharton Basin. These new data reveal six N8°E striking re-activated fracture zones (F5b, F6a, f6b, F7a, F7b and F8), where the fracture zone F6a can be followed for over 400 km and seems to be most active. The epicenters of the Mw 8.6 and Mw 8.2 earthquakes lie on the fracture zones F6a and F7b, respectively. The newly observed fracture F5b in the east is short, and has an extensional basin at its southern tip. The fracture zone F8 defines the eastern boundary of the Ninety-East Ridge. The presence of en echelon faults and pull-apart basins indicate left-lateral motion along these fracture zones. In between these fracture zones, we observe pervasive 290° striking right-lateral shear zones at 4–8 km intervals; one of which has cut through a seamount that might have ruptured during the Mw 8.6 earthquake. We also observe another N20°E striking left-lateral shear zones in the vicinity of F7b and F8, which is coincident with the strike of one of the nodal planes of the Mw 8.6 focal mechanism. These N20°E striking shear zones are interpreted as R Riedel shears and the N290°E striking shear zones as R′ Riedel shears. These shear zones are formed by a series of N335°E striking en echelon normal faults. Our data also show the presence of N65°E striking thrust faults east of the Ninety-East Ridge, orthogonal to the regional principal direction of compression. Furthermore, extensive bending-related faulting is also observed close to the Sumatra trench with normal faults also striking at N335°E, similar to the normal faults that form the shear zones. Normal faults with a similar orientation are also present at the southern tip of F5b. We explain all these observations with a single coherent model of deformation in the Wharton Basin, where a dominant part of the regional NW–SE compressional stress is accommodated along the N8°E re-activated fracture zones, and the rest is distributed along shear zones, thrust and normal faults between these fracture zones. The thrust and normal faults are orthogonal to each other and define the direction of principal compressive and extensive stresses in the region whereas the two shear zone systems form a conjugate pair
Sino-Indonesian relations : a study of Indonesian perceptions of China
No full textAvailable from British Library Document Supply Centre- DSC:DXN056009 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
