Power electronics applications are widely used in different fields of engineering like computer, Telecommunication, electrical power and Mechanical), one of the most useful power electronics converters is DC-DC buck converter. Owing to its numerous applications, its performance needs to be improved through a suitable controller. In this Paper, A digital current mode controller is proposed and implemented for Buck converter. Proposed current mode control technique is simulated in MATLAB/SIMULINK and results are validated through hardware implementation. Both simulation and experimental analysis show effectiveness of the proposed controller.

Conventional energy resources are being replaced by Renewable energy sources mainly due to increasing environmental concerns. Photovoltaic (PV) and Fuel cell (FC) are suitable to be used in modern DC microgrids due to their DC output. In this research work, a DC microgrid structure is proposed for small residential areas using hybrid PV and FC generation. Power Electronic converters are used to regulate generated voltage of the two sources for integration to a common DC bus. Proposed system is simulated using MATLAB SIMULINK to observe its performance. Simulation results show that output voltage is properly maintained at different DC buses of the microgrid. FC is suitable to cope up the variation in PV output and maintain load requirements.

In the work is discussed in results of air pollution monitoring on four stations and passive sampling in 2017. In Tbilisi in some cases high concentrations of some pollutants have been identified. An air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem. The substance can be solid particles, liquid droplets, or gases. A pollutant can be of natural origin or man-made. Pollutants are classified as primary or secondary. Primary pollutants are usually produced from a process, such as ash from a volcanic eruption. Other examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant. Some pollutants may be both primary and secondary: they are both emitted directly and formed from other primary pollutants [1]. The average concentration of each contaminant is given in Table 1.

The approaching energy emergency, increased by the proceeding with the exhaustion of fossil fuels, complements the requirement for sending of Conventional & Non- Conventional energy resources in Bangladesh, now like never before some time recently. Despite the fact that hydrocarbon resources in the nation are restricted, the significant accessibility of Conventional & Non- Conventional energy sources as fossil fuels, natural gas, nuclear energy and hydroelectric energy offers chances of reasonable energy-based advancements like wave energy, energy from the Bay-of-Bengal and potential sources of geothermal energy. Insufficiency in the energy area is a noteworthy issue in Bangladesh, which obstructs the smooth financial improvement work processes. Along the lines, Bangladesh is confronting trouble to accomplish a generally maintained advance in the economy because of the absence of a sound energy security. With the goal of exploring this advance, this paper displays an exhaustive investigation of the contemporary Conventional & Non- Conventional energy situation and future prospect in Bangladesh as far as appropriation, research and infrastructural improvement in the nation. It has found the components that are valuable to diminish the current energy supply emergency and abridged the present energy situation, absence of foundation and customary energy sources to advance the Conventional & Non-Conventional energy sources to satisfy the energy request in future in Bangladesh.

The main purpose of social supermarkets is to serve to customers, which are in material deprivation. As nonprofit organizations, they perform several business activities on everyday basis. Those activities include: (1) collecting donations in money, (2) organization of acceptance of donations in form of food and toiletries from traditional supply chains, (3) acquiring food and other stuff from other sources and (4) distribution of food, toiletries and other stuff for free and/or (5) selling goods at extremely discounted prices to socially endangered people. There are numerous possibilities of social networks implementation in such type of organizations. The aim of this paper is to analyze how social supermarkets implement social networks in communication with donors, volunteers, end users and general public. In the paper, three cases of active social supermarkets in Croatia are analyzed in order to explain the usage of social networks in their everyday operations

Conventional energy resources are being replaced by Renewable energy sources mainly due to increasing environmental concerns. Photovoltaic (PV) and Fuel cell (FC) are suitable to be used in modern DC microgrids due to their DC output. In this research work, a DC microgrid structure is proposed for small residential areas using hybrid PV and FC generation. Power Electronic converters are used to regulate generated voltage of the two sources for integration to a common DC bus. Proposed system is simulated using MATLAB SIMULINK to observe its performance. Simulation results show that output voltage is properly maintained at different DC buses of the microgrid. FC is suitable to cope up the variation in PV output and maintain load requirements.

Bangladesh is a developing country and crisis of power is one of the acute quandaries in any developing country like Bangladesh. Power is the most paramount factor and the demand of power is incrementing rapidly in the country. There are several reasons behind the power failure like lack of commitment of ascendancy, system loss, circumscription of resources, high demand, corruption in potency, low generation capacity etc. To overcome the problem of power crisis, renewable energy can be a great source. Bangladesh has huge untapped renewable energy resources which can be utilized to solve and aid the power crisis. In this paper we described about different forms of renewable energy that can be acclimated to meet the power demand by proper utilization at low cost and less risk. We also discussed about several sectors of renewable energy sources such as solar energy, wind energy, tidal energy, bio energy, hydro power, geothermal, ocean wave energy and energy from Bay-of-Bengal. Skilled manpower and new technology are required for taking initiative steps for power sectors utilizing renewable energy

In the work is discussed in results of air pollution monitoring on four stations and passive sampling in 2017. In Tbilisi in some cases high concentrations of some pollutants have been identified. An air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem. The substance can be solid particles, liquid droplets, or gases. A pollutant can be of natural origin or man-made. Pollutants are classified as primary or secondary. Primary pollutants are usually produced from a process, such as ash from a volcanic eruption. Other examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant. Some pollutants may be both primary and secondary: they are both emitted directly and formed from other primary pollutants [1]. The average concentration of each contaminant is given in Table 1.

We perhaps have been following the wrong path in looking at the Riemann conjecture by forgetting the article title. Riemann wanted us, as he makes clear in his title, to talk about and discuss “On the Number of Primes Less Than A Given Magnitude.” We can be happy that our look at his title “On the Number of Primes Less Than A Given Magnitude” helped us understand prime numbers a bit better than talking about the real part of ½ in relation to the zeta function. If we consider prime numbers of less than a given magnitude as on a graph or listed, we see many points that lie outside the critical strip as a type of disproof

The Godel incompleteness Theorem argues “your set of axioms will always be incomplete-they won’t be sufficient to prove all the facts. In mathematics as in life, parts of the truth are destined to remain forever elusive.” [1] Kurt Godel was a famous Austrian Mathematician and some appreciation for his incompleteness theorem should be given. Hodge Conjecture could be disproved in a few words, as axioms often are incomplete. If we take a set of irrational algebraic cycles, the result will be an irrational combination of classes. We cannot add irrational algebraic cycles and make up a rational linear combination. Yes, Hodge as we show can make up fantasies, inventions, or ideas like the Hodge Class, but that is only a definitional proof. When tested on real irrational algebraic cycles, the definition is just that a definition and not really a description of all algebraic geometric cycles like irrational shapes. The irrational algebraic cycle easily disproves the conjecture, as combinations will not be rational!

This paper discusses the paper waste can be the alternative materials for furniture to replace the wood and metal materials. Furniture is an important product that occupies indoor and outdoor spaces that used for sitting, lying, storing, eating, sleeping and working. Paper waste in landfills has the higher amount of waste compared to other waste such as plastics, glass, metals and food waste. Besides, the recycling process is the best way to overcome the major environmental issues such as the pollution, deforestation, pervasive logging, landfill waste, dangerous greenhouse gases and global warming. So, the human must play their roles in recycling activities, process, and campaign. The advantages of the paper materials for furniture such as easy to handle, cost saving, lightweight, strong, and stiff. The waste materials had been applied in construction activities already been proven so that it can be the alternative materials to reduce the cost and usage of raw materials. The futuristic design of paper materials furniture is the best approach to satisfy the customer’s requirements and the new successor in furniture industries by using Product Development Process (PDP). The paper waste materials into furniture products is a part of the innovation and Green Technology approach.

The behavior of a building during earthquakes depends critically on its planner aspect ratio. This paper deals with an evaluation of the seismic performance of vernacular masonry buildings with different planner aspect ratio. performed. Subsequently, the available capacity spectrums are obtained to the corresponding demand spectrum to demonstrate the pushover responses of the buildings.