Rehabilitation of Hybrid RC-I Beams with Openings Using CFRP Sheets

This research presents an experimental investigation of the rehabilitation efficiency of the damaged hybrid reinforced concrete beams with openings in the shear region. The study investigates the difference in retrofitting ability of hybrid beams compared to traditional beams and the effect of two openings compared with one opening equalized to two holes in the area. Five RC beams classified into two groups, A and B, were primarily tested to full-failure under two-point loads. The first group (A) contained beams with normal weight concrete. The second group (hybrid) included beams with lightweight concrete for web and bottom flange, whereas the top flange was made from normal concrete. Two types of openings were considered in this study, rectangular, with dimensions of 100×200 mm, and two square openings with a side dimension of 100 mm. A full wrapping configuration system for the shear region (failure zone) was adopted in this research. Based on the test results, the repaired beams managed to recover their load carrying capacity, stiffness, and structural performance in different degrees. The normal concrete beam regains its total capacity for all types of openings, while the hybrid beams gain 84% of their strength. The strength of hybrid concrete members compared with normal concrete is 81 and 88% for beams of one opening and two openings, respectively. Doi: 10.28991/CEJ-2022-08-01-012 Full Text: PDF

The Modeling of the Capacity of the Moroccan Healthcare System in the Context of COVID-19

The outbreak of SARS-Cov2 in China and its subsequent spread has caused a global pandemic. The authors conducted a simple susceptible-infected (SI) model of the spread of COVID-19 in Moroccan population. The model is based on combining the average contact rate (µmax) extracted from the early exponential phase of the outbreak with a logistic simulation over time. Interestingly, this modeling approach showed a perfect fit with a strong correlation between real confirmed and estimated cases when calibrated on the Chinese declining outbreak. Subsequently, the model was applied for studying the ongoing COVID-19 outbreak in Morocco to determine the needed time for reaching 10,000 confirmed cases whose 15% (1,500) are at risk of developing health complications requiring patient care in hospitals. The latter total capacity does not exceed 1,640 beds according to the authorities. Incorporating these parameters in the logistic model, they predicted that the Moroccan healthcare system will be at 27%, 50%, 76%, and 90% of saturation on April 11, 16, 23, and May 4, 2020, respectively.

FEATURES OF CALCULATION OF THE REQUIRED QUANTITY OF GRAIN TERMINAL TRACKS IN SEA PORTS IN MODERN CONDITIONS

Purpose. Ukraine is one of the world's five largest producers of grain crops. Much of the grain is exported. Traditionally, grain cargoes are exported through the western land crossings and seaports of the Black and Azov Seas, with the bulk of grain exports going through the port of Nikolaev and the ports of Greater Odessa. Rail transport provides delivery to exporting ports up to 2/3 of the total volume of grain transshipment in ports. Given the significant number of operations in the general technological process of processing grain wagons in ports, the required capacity of technical equipment of railway transport (number of tracks, locomotives, weighing devices, etc.) plays a significant role in the duration of the transshipment process and total operating costs. In this regard, determining the required number of ways to service the flow of grain for export is an urgent task. Methods. Comprehensive analysis of technical equipment and technology of railway transport of grain terminals in seaports, statistical analysis, graph-analytical modeling. Results. Based on the processing of statistics on the delay of wagons due to commercial marriages with grain cargo in the seaport, the conditional division of detained wagons due to and, consequently, the duration of delay of wagons into long and short. The characteristics of random values of the delay of the car are established and the dependence of the number of detained cars on the value of the total car traffic with grain cargo entering the transshipment is obtained. For short-term delays it is a polynomial dependence of the second degree, for long-term delays it is characterized by exponential dependence. Based on research, an additional track capacity has been established for the sedimentation of detained cars and recommendations have been developed for the number of such tracks and their length. Based on the rationing of the duration of shunting operations with delayed wagons, an additional working fleet of shunting locomotives for servicing delayed wagons was determined and recommendations for the location of wagon scales for commercial weighing of wagons in the process of processing grain wagons in the port. Practical significance. The obtained results can be used to determine the number of tracks and the total capacity of grain terminals in seaports. The duration of additional shunting operations to service the detained cars allows to clarify the calculation of the required locomotive fleet of grain terminals.

Aging-related Resiliency Theory Development

As a dynamic developmental process, the older population further displays the capacity to resist change over time, improve resilience, and keep a basis for the continuity working and progress over positive management of detrimental consequences of life risks and difficulties. This study aims at developing a theory that endeavors to explore the process of developing aging-related resiliency in people’s later in life that can lead to a successful aging experience. In the development of a theory, this study utilized a deductive reasoning approach specifically, using the axiomatic approach. Aging-related Resiliency Theory was efficaciously developed by three propositions generated from four axioms that were derived after reviewing several sets of literature and studies. This developed theory implies that various deleterious events in life activate older persons to respond, adapt, and recover effectively. Acceptance emerges as they acknowledge the natural effects of aging while taking adaptive strategies and supportive resources to be resilient to one’s environment. In this sense, it impacts their optimistic outlook towards successful aging. Based on the extraction of axioms, such propositions denoted those older adults call to respond with their total capacity to accept, adapt, recover, and continuously resist deleterious life experiences while using enriched coping strategies and resources towards an optimistic outlook in achieving successful aging. Therefore, emphasizing to improve their capacity to respond to natural decline to essential processes could benefit them at promoting a healthier life span.

Economic aspects of the development of the world markets of petroleum products since the middle of the XX century

The study of the development of the world markets of petroleum products in the period from 1950 to 2021 allows us to conclude that up to 2014 there was a steady increase in the total capacity of the world oil industry . The increase in capacity occurred against the background of a quantitative decrease in oil refineries and an increase in their production capacity. The decrease in the number of small oil refining units was accompanied by an increase in the average capacity in the oil industry.

Solar Irrigation System in Indonesia: Practical Assessment and Evaluation for Converting Fossil Fuels with Solar Energy

This study proposes a sustainable solar-powered irrigation system (SPIS) for a 75-hectares rice farm in Krandegan Village, Purworejo Regency, Indonesia. The existing water pumping system uses diesel engines which cost around Rp. 200 million per year that cannot be provided by the farmers. The SPIS was designed based on water requirements calculated according to the Food and Agriculture Organization (FAO). The technical design of SPIS used Lorentz Compass considering local solar energy sources and the availability of SPIS components in the local markets. The entire farm in Krandegan requires 11 SPISs with a total capacity of the solar panel of 20.8 kWp. Also, the SPISs use 11 centrifugal DC pumps; 10 surface and 1 submersible type. The SPIS in Krandegan would require a total cost of Rp. 1.29 billion. Without the financial support of the capital costs from other parties, the simple payback time (SPT) would be around 6.5 years, which is good for a solar photovoltaic (PV) project. SPIS is not only a viable solution to replace diesel engines in supplying water to the rice farm in Krandegan, but is also in line with the seventh target of Indonesia’s Village sustainable development goals (SDGs).

Regional Exploration and Characterisation of CO2 Storage Prospects in the Utsira-Skade Aquifer, North Viking Graben, North Sea

Subsurface CO2 storage is considered a key element of reducing anthropogenic emissions in virtually all scenarios compatible with limiting global warming to 1.5°C. The Utsira-Skade Aquifer (Utsira, Eir and Skade Formations), northern North Sea, has been identified as a suitable reservoir. Although the overall storage capacity of the full aquifer has been estimated based on regional data, it is lacking an integrated assessment of containment and internal heterogeneity, to identify optimal areas for injection and for calculation of site-specific storage capacities. A high-resolution, broadband 3D seismic reflection dataset, full waveform inverted velocity data and 102 exploration wells are utilised to provide a catalogue of CO2 storage prospects in the northern Utsira-Skade Aquifer. This is achieved through: 1) definition of the aquifer’s spatial limits; 2) calculation of porosity distribution; 3) assessment of the extent, geomorphology, thickness variability, and containment confidence (CC) of mudstones; and 4) mapping of closures through fill-to-spill simulations. CO2 storage capacity was calculated for the prospects using two approaches; using the full reservoir thickness (FRT) beneath the closures and using only the thickness from the closure top to the spill point (TSP), i.e., within structural traps. Porosity ranges from 29 to 39% across the aquifer and is higher in the Utsira and Eir Fms. relative to the underlying Skade Fm. The mudstone separating the Skade and Eir/Utsira Fm. has a thickness > 50 m, and is a potential barrier for CO2. Other intra-aquifer mudstones were mainly interpreted to act as baffles to flow. Structural traps at the top Utsira and Skade Fms. yield fifteen prospects, with criteria of > 700 m depth and FRT storage capacity of > 5 Mt CO2. They have a combined storage capacity of 330 Mt CO2 (FRT) or 196 Mt CO2 (TSP). Five prospects have a positive CC score (total capacity: 54 Mt CO2 FRT or 39 Mt CO2 TSP). Additional storage capacity could be achieved through more detailed analysis of the seal to upgrade the CC scores, or through use of a network of the mapped closures with a fill-to-spill approach, utilising more of the aquifer.

Hydropower in Russia: Case Study on Hydrological Management of the Volga-Kama Cascade

The capacity of hydroelectric power plants (HPPs) in the Russian Federation (RF) exceeds 50 GW. It is about 20% of the total capacity of all power plants in the country. The Volga River basin is the biggest in Europe with the catchment area of 1 360 000 km2. It covers the most populated and most industrialized part of the European Russia. The largest cascade of reservoirs in Russia and Europe is the Volga-Kama cascade (VKC) constructed in 1930–1980. It consists of 12 great water reservoirs and HPPs with total capacity about 12 GW. The main peculiarity for the VKC management is the combination of different requirements by various economy sectors: safety, energy, navigation, water needs for domestic and industrial services, agriculture and fishery, recreation and ecological rules. These sectors often make conflicting demands for the VKC operation. The VKC management principle is to balance and satisfy all of them taking into account the changing climate and economical effectiveness. Modern decisions for the VKC management are based on two principles. First is the constant optimization of the whole VKC management rules, taking into account both climate change and the Strategy of the country development. The second is the constant technical modernization of the VKC equipment to achieve the best economical effectiveness and safety for ecosystems and population.

Recent hydrological droughts in Brazil and their impacts on energy security

Brazil is heavily reliant on water resources. Hydroelectric plants generate about 64% of all electricity consumed. To increase yield capacity, a 2050 expansion is also planned. 78% of water used is for agriculture (irrigation and livestock), 9% for industry, and 9.1% for urban supply. However, the country has endured the worst droughts in recorded history over the last two decades, resulting in severe socioeconomic and environmental impacts. The purpose of this study was to determine the current state of knowledge regarding hydrological drought patterns, hydrometeorological factors, and their effects on the country’s hydroelectric power plants. Droughts have occurred in most of Brazil’s regions since 2014/15, causing severe impacts in many of the basins studied. Now that most hydroelectric power plants are operating at a fraction of their total capacity, the country’s hydroelectric generation is been impacted.