Entrepreneurship – Some General Knowledge

The aim of this article is to provide some general information about entrepreneurship and some insights on the early theories about it. A brief overview of the main entrepreneurship measurement programme will provide some facts about the evolution of the entrepreneurial activity in Romania in the last few years

Modelling and robust control of a flexible beam Quanser experiment

In this paper, the robust optimal model matching control design method is applied to a flexible beam Quanser experiment. The neglected nonlinearities of the real experiment in the controller design step lead to important differences between the simulation and experimental results, including vibrations of the real beam and/or stationary errors due to insensibility zone. In order to eliminate these tracking errors and reduce the vibrations of the beam we proposed an improved control law by using some blocks with variable structure. Because some of the model’s parameters are imprecisely known, an identification procedure is needed. The paper presents a subspace identification method, which is a relatively new approach used for the state space model identification. Finally, the performance of the proposed controller is illustrated by some experimental results

Case Studies in Biogas Production from Different Substrates

The present paper involves applicative research in the field of biogas production with the accent on small laboratory scale installations built for biogas production, preliminary testing of substrate for biogas production and combustion applications for biogas-like mixtures. The interconnected aspect of the presented material involves cumulative expertise in multidisciplinary fields of interest and continuous development of possibilities to determine the energetic potential of substrates subjected to biodegradable fermentation conversion for further applications. The research analyzed the combustion behavior of biogas with different methane/carbon dioxide ratio without and in the presence of specific catalysts. Also, laboratory analysis on biomass substrates for determining their physical and chemical potential for different applications was performed. The main conclusions are drawn revolve around the untapped potential of the different types of biomasses that are not commonly used in the production of renewable energy carriers, like biogas, and also the potential use of residual biomass in combustion processes for an enclosed life cycle from cradle to the grave. The study involving the use of catalysts in biogas combustion processes present possible solutions which can be developed and implemented for increasing the combustion quality by using relatively cost-effective materials for the production of catalytic materials

Platyscelio hits again: the first record of this genus in the Dominican Republic

After the presence of the genus Platyscelio was noticed and confirmed in the Neotropical realm, in this paper the genus is recorded from the Panamanian realm, in Dominican Republic. In the Neotropical realm Platyscelio is represented through P. africanus Risbec, previously considered as being present only in the Afrotropical realm, but in the Panamanian realm we found a different species – P. pulchricornis Kieffer

Reducing the Effects of Drought and Degradation of Agricultural Soils, in the Context of Climate Change, through the Application of Regenerative Ecological Technologies

The agricultural sector has a limited capacity for expansion, consequently, deficient technologies based on the widespread use of synthetic chemicals have been implemented in the last decades, having a major negative impact on natural ecosystems, biodiversity, and environmental services. Desertification, land degradation, and drought, combined with human activity and environmental changes, cause important soil losses and a reduction in natural defenses against droughts and floods. The combined impact of climate change, land mismanagement and unsustainable freshwater use has long been affecting agricultural productivity, the most common cause being unsustainable land management practices. This chapter aims to briefly assess the most effective strategies for reducing the impact of climate change on agricultural crops, as well as to prevent or reverse the process of desertification and systematic loss in food quality and quantity. Regenerative management practices such as minimum tillage technologies, cover crops and mulching, inoculation with microorganisms, nutrients cycling, the balance of the organic fertilizers or foliar application help farmers in managing healthy soils, capable of growing rich and ecological crops without the use of chemical hazardous substances

Study for a photovoltaic system to supply electricity to an isolated apiary

The paper presents, based on the study and the experience of the authors in the field, some considerations, especially from an application aspect, useful in building a photovoltaic system for supplying electricity to an isolated apiary, as well as simulations for such a system, made with the PVGIS program . The main high-performing electric machines of today with relatively high energy consumption from an isolated beehive are identified, as well as their specific mode of use, during a calendar year, an essential factor for establishing the installed power of such a photovoltaic system and a its effective technical-economic design

Pervin Abla

Mahmut Yesari'nin Yeni Ses'te tefrika edilen Pervin Abla adlı romanıArşivdeki eksikler nedeniyle romanın tam metni verilememiştir