NUMERICAL ANALYSIS OF TWO DIMENSIONAL HEAT CONDUCTIVITY IN STEADY STATE REGIME

Solving the differential equation of the heat conduction the temperature in each point of the body can be determined. However, in the case of bodies with boundary surface of sophisticated geometry no analytic method can be used. In this case the use of numerical methods becomes necessary. The finite element method is based on the integral equation of the heat conduction. This is obtained from the differential equation using variation calculus. The temperature values will be calculated on the finite elements. Then, based on these partial solutions, the solution for the entire volume will be determined. Using this method we can divide into elements also fields with any border. In this paper the temperature distribution in an orthotropic body and in a pipe insulation is analysed using a software developed by the author

A study on the frost self-protection of cooling towers

The paper presents the results of an experimental research conducted using a climaxed stand on the griddle self-protection to frost of cooling towers. The parameters have been followed to influence the forming of ice curtains on the air access section into the tower and it is proposed an analytic relation for calculating the aerodynamic resistance of the self-protection system

OPTIMIZATION OF LOOPED WATER SUPPLY NETWORKS

The paper approaches the optimization of looped networks supplied by direct pumping from one or more node sources, according to demand variation. Traditionally, in pipe optimization, the objective function is always focused on the cost criteria of network components. In this study an improved nonlinear model is developed, which has the advantage of using not only cost criteria, but also energy consumption, consumption of scarce resources, operating expenses etc. Discharge continuity at nodes, energy conservation in loops and energy conservation along some paths between the pump stations and the adequate `critical nodes´ are considered as constraints. This problem of nonlinear programming with equality constraints finally turns into a system of nonlinear equations to be solved by the `gradient method´. The nonlinear optimization model considers head losses or discharges through pipes as variables to be optimized in order to establish the optimal diameters of pipes and is coupled with a hydraulic analysis. The paper compares a nonlinear optimization model to some others, such as the classic model of average economical velocities and Moshnin optimization model. This shows the good performance of the new model. For different analyzed networks, the saving of electrical energy, due to diminishing pressure losses and operation costs when applying the new model, represents about 10...30\%

Energetical optimization of water distribution systems in large urban centers

In the present conditions of water distribution towards the users by pumping, in large urban centers, the reconsideration of the structure and functioning principles of the distribution systems, from the point of view of the energetical optimization, becomes a necessary and major problem, which can be solved by a new structural design. This paper presents and analyses in a detailed manner, giving numerical examples, certain optimization methods and solutions for the distribution systems, with a view to diminishing the pumping energetic consumption, using interior potential elements, ascertaining the energetical and economical efficiency

The influence of postemergence herbicide on the main yield components in white lupin (Lupinus albus L.) – cv. "Ruxandra"

White lupin (Lupinus albus L.) is an underutilized crop that started to become extremely interesting for bio and conventional farmers due the high protein content of the seeds and, mainly, due the nitrogen fixation capacity. Nowadays, challenging economic environment and changing climate conditions had led to a bust in fertilizers prices worldwide. Identification and utilization in crop rotation systems of crop with nitrogen fixation capacity is an optimal alternative. One of the biggest problem in the white lupin cultivation technology is caused by the special sensitivity of this species at postemergence herbicide. This sensibility makes weed control a very difficult task for farmers. In this paper we present results obtained in 2022 season at the Ezăreni Farm, Iasi, Romania. Principal yield components were studied and compared among postemergence herbicide variants. Comparative studies were done using the cultivar RUXANDRA, obtained and registered by us

The effect of abiotic stress on white lupin (Lupinus albus l.) cv. "Mihai" plants in different density conditions

Lupinus albus (white lupin) is a crop well adapted to marginal lands and has a large potential for enhanced bio economy use. In general, lupins have the ability to fix atmospheric nitrogen, mobilise soil phosphate and are suitable for low nutritional cultivation. Modern varieties should be selected for high yield of green silage or high yield of seeds which contain more than 20% oil, more than 40% protein and the remaining materials are carbohydrates, mainly oligosaccharides characterized as “prebiotics”. In this experiment, three new white lupin sorts were tested in experimental fields. Breeding activities we compensated by optimized cultivation technology for these cultivars. One of the biggest problem in the white lupin cultivation this year was caused by the extreme draught and high temperatures registered during the vegetation period. Results present the observations obtained in 2022 season at the Ezăreni Farm. Comparison of the selected cultivars was performed using two different density condition. Results indicated that white lupins could be an interesting alternative for farmers and can contribute to new optimised crop rotation system

Identification of novel candidate targets for suppressing ovarian cancer progression through IL-33/ST2 axis components using the system biology approach

Background: Cancer-associated fibroblasts (CAFs) of ovarian cancer (OvC) are the most prevalent element of the tumor microenvironment (TM). By promoting angiogenesis, immunological suppression, and invasion, CAFs speed up the growth of tumors by changing the extracellular matrix’s structure and composition and/or initiating the epithelial cells (EPT). IL-33/ST2 signaling has drawn a lot of attention since it acts as a pro-tumor alarmin and encourages spread by altering TM.Methods: Differentially expressed genes (DEGs) of the OvC tumor microenvironment were found in the GEO database, qRT-PCR, western blotting, and immunohistochemistry, and their presence and changes in healthy and tumor tissue content were examined. Primary cultures of healthy fibroblasts and CAFs obtained from healthy and tumor tissues retrieved from OvC samples were used for in vitro and in vivo investigations. Cultured primary human CAFs were utilized to investigate the regulation and the IL-33/ST2 axis role in the inflammation reactions.Results: Although ST2 and IL-33 expression was detected in both epithelial (EPT) and fibroblast cells of ovarian cancer, they are more abundant in CAFs. Lipopolysaccharides, serum amyloid A1, and IL-1β, the inflammatory mediators, could all induce IL-33 expression through NF-κB activation in human CAFs. In turn, via the ST2 receptor, IL-33 affected the production of IL-6, IL-1β, and PTGS2 in human CAFs via the MAPKs-NF-κB pathway.Conclusion: Our findings suggest that IL-33/ST2 is affected by the interaction of CAFs and epithelial cells inside the tumor microenvironment. Activation of this axis leads to increased expression of inflammatory factors in tumor CAFs and EPT cells. Therefore, targeting the IL-33/ST2 axis could have potential value in the prevention of OvC progression