A Comprehensive Concurrency Control Technique for Real-Time Database System

Real-time database must maintain the Temporal Consistency of the data which cannot be achieved with the conventional concurrency control techniques as they focus only on the consistency of the data. Different protocols exhibit good performance on different situations. But a single technique is inadequate to meet the demand of real-time database. To improve the concurrency control technique for real-time transactions, this paper will present a comprehensive technique that coordinates multi-version, OCC Sacrifice, Speculative Concurrency Control and 2PL-HP protocols. The presented technique uses best suited protocol based on the contention of transactions. Thus it can significantly improve the concurrency of transactions as well as increase the number of transactions

Boosting landfill gas production from lignin-containing wastes via termite hindgut microorganism.

Lignocellulose comprises a significant portion of municipal solid waste (MSW) - 40-70% in developed countries, including paper, wood, and yard waste. Cellulose and hemicellulose are often shielded by lignin, posing a barrier to waste decomposition and landfill gas generation. Unfortunately, lignin is resistant to microbial degradation under low-oxygen conditions that normally occur in MSW landfills. The bacterium strain TAV5, microaerophilic and member of phylum Verrucomicrobia, isolated from the hindgut of the Reticulitermes flavipes termite, the most widely distributed subterranean termite in North America. Its genome contains genes associated with methylotrophic competency which code for enzymes that structurally modify lignin. The overall goal of this research was to use TAV5 to modify lignin and boost methane production from MSW. Batch-scale reactors (125 mL) were filled with paper, yard, or wood waste, and four ratios of mixed of waste. Reactors were seeded with different ratios of TAV5 to anaerobic digester (AD) microorganisms (representing landfill anaerobic microorganisms). Based on batch tests, optimal ratios of TAV5 to AD microorganisms were used to seed wastes (mixed, yard, and wood) in 6-gallon reactors. Addition of TAV5 increased methane production from mixed waste, yard waste, and wood, by 49%, 34%, and 297%, respectively. TAV5 decreased acid soluble lignin by 7-39%, depending on waste type. TAV5 grown under aerobic conditions and room temperature (not requiring a heated anaerobic chamber) was found to remain viable and increase methane production under low-level oxygen conditions (1-2%). This finding will potentially lessen costs for growing large volumes of it for seeding landfills

Augmented reality marker-based technology for augmenting newspaper advertisement

In this research, we describe an augmented reality android-based idea in which we utilize augmented reality marker-based technology for augmenting newspaper advertisement with electronic information that does not modify the format of the newspaper document and remains exactly the same, substantially improves the utility of paper by reducing the portion of the printed Ad on the newspaper. An implementation on a camera phone is discussed that lets users retrieve data and access links from newspaper advertisements to electronic data. We carefully examined over twenty people of different ages and occupations who participated in the newspaper-based AR and we got a significant overall response. Further analysis implies that this may assist students in understanding the complex 3D objects, which they can manipulate, learn tasks and improve skills

Design and Development of a Single-Axis Solar Tracking System

With solar tracking, it will become possible to generate more energy since the solar panel can maintain a perpendicular profile to the rays of the sun. Even though the initial cost of setting up the tracking system is considerably high, there are cheaper options that have been proposed over time. This research discuss the design and construction of a prototype for a solar tracking system that has a single axis of freedom. Light Dependent Resistors (LDRs) are used for sunlight detection. The control circuit is based on an ATMega328P microcontroller. It was programmed to detect sunlight via the LDRs before actuating the servo to position the solar panel. The solar panel is positioned where it is able to receive maximum light. As compared to other motors, the servo motors are able to maintain their torque at high speed. They are also more efficient with efficiencies in the range of 80-90%. Servos can supply roughly twice their rated torque for short periods. Through tracking, there will be increased exposure of the panel to the sun, making it have increased power output. The trackers can either be dual or single axis trackers. As a single tracking system is cheaper, less complex, and still achieves the required efficiency, so it was used

Utilization of fermented wheat bran extract medium as a potential low-cost culture medium for Chlorella ellipsoidea

Microalgae, Chlorella ellipsoidea is an excellent energy source for food and biofuel production. Nevertheless, the production cost of C. ellipsoidea using Bold's Basal Medium (BBM) is expensive, which led to exploring the alternation of a low-cost medium for large-scale production. Low-cost fermented wheat bran extract medium (FWBEM), which has good nutritional properties, might be an alternative approach to mass production of C. ellipsoidea. The present study was conducted to evaluate the growth and production of C. ellipsoidea using different concentrations of FWBEM. Wheat bran was fermented at the concentration of 8.33, 6.66, and 5.00 g/L water and used as treatments for T2, T3, and T4, respectively. The BBM was used as the control medium (T1). The growth and production of C. ellipsoidea were monitored at three days intervals through cell dry weight, specific growth rate, optical cell density, chlorophyll a content, and cell numbers. Those growth data revealed that C. ellipsoidea cultured at 6.66 g/L (T3) concentration did not vary significantly with the standard inorganic BBM. However, T2 and T4 showed substantially lower cell growth and chlorophyll a content than control and T3. Compared to the BBM, a significant reduction in production cost was obtained in the FWBEM. Based on the cell biomass growth, pigmentation, and production cost, FWBEM at a 6.66 g/L could be used as an alternative medium to BBM. Therefore, FWBEM has excellent potential to be used for the low-cost production of C. ellipsoidea

Knowledge, attitudes and practices associated with the COVID-19 among slum dwellers resided in Dhaka City: A Bangladeshi interview-based survey

Background: The emergent COVID-19 has impacted unprecedentedly to all classes of people. Slum-dwellers’ knowledge, attitudes and practices (KAP) toward COVID-19 are currently poorly understood. The present study aimed to investigate the KAP toward COVID-19 among slum dwellers resided in Dhaka City, Bangladesh. Methods: A cross-sectional offline survey was carried out enrolling 406 slum dwellers (53.2% male; mean age = 44.9 years [SD = 12.1]; age range = 18–85 years) between August and September, 2020. The face to face interview was conducted to collect data from six selected slum areas in Dhaka City using convenience sampling. The questionnaire consisted of informed consent along with questions concerning observational checklists, socio-demographics and KAP. Results: A sizeable minority were observed without wearing face masks during the survey periods (18.2%) and a vast portion (97.5%) without any hand protection. The mean scores of KAP were 6.1 ± 2.6 (out of 17), 12.3 ± 1.7 (out of 14) and 9.8 ± 1.6 (out of 12), respectively. Moreover, the KAP were strongly and positively correlated with each other. Conclusions: The findings revealed that the majority of slum dwellers in Bangladesh have limited knowledge of COVID-19. Poor practices (i.e. face mask and hand protection) were directly observed during the survey. The findings suggest the immediate implementation of health education programs and adequate interventions

Puff or pass: do social media and social interactions influence smoking behaviour of university students? A cross-sectional mixed methods study from Dhaka, Bangladesh.

OBJECTIVE: To determine whether the odds of being a smoker differ based on social media use and social interactions among urban university students in Bangladesh. HYPOTHESIS: Social media use and social interactions influence the smoking behaviour of Bangladeshi university students, particularly in starting and maintaining cigarette smoking. DESIGN AND SETTING: A cross-sectional study using mixed methods on 600 student smokers and non-smokers recruited from two public and two private universities in Dhaka, Bangladesh, a lower middle-income country with limited resources. Exclusion criteria were those who did not use any form of social media and PhD students. RESULTS: Odds of smoking were significantly higher for those who socialised more than 4 hours/day (p<0.05; OR 1.75; 95% CI 1.12 to 2.75) and typically at night (p<0.05; OR 2.80; 95% CI 1.95 to 4.00). Odds of smoking were also higher for those who liked (p<0.05; OR 4.85; 95% CI 3.32 to 7.11), shared (p<0.05; OR 20.50; 95% CI 13.02 to 32.26) and followed (p<0.05; OR 2.88; 95% CI 1.36 to 6.11) tobacco-related content on social media. Qualitative analysis resulted in emergent themes of smokers imitating tobacco-related photos or videos seen on social media and peers as an influence for smoking initiation. CONCLUSION: This study suggests social media and social interactions may influence smoking behaviour in university students in Dhaka, Bangladesh. Future research should continue to investigate the roles social media and social interaction have on smoking in order to explore social media-based smoking cessation interventions or dissemination of smoking health hazards through social media