Women and Education through the Ages

The author discusses the history of women\u27s education, focusing on the Roman era, the Medieval Period, and the 19th century

Energy Performance Investigation of a Direct Expansion Ventilation Cooling System with a Heat Wheel

Climate change is continuously bringing hotter summers and because of this fact, the use of air-conditioning systems is also extending in European countries. To reduce the energy demand and consumption of these systems, it is particularly significant to identify further technical solutions for direct cooling. In this research work, a field study is carried out on the cooling energy performance of an existing, operating ventilation system placed on the flat roof of a shopping center, located in the city of Eger in Hungary. The running system supplies cooled air to the back office and storage area of a shop and includes an air-to-air rotary heat wheel, a mixing box element, and a direct expansion cooling coil connected to a variable refrigerant volume outdoor unit. The objective of the study was to investigate the thermal behavior of each component separately, in order to make clear scientific conclusions from the point of view of energy consumption. Moreover, the carbon dioxide cross-contamination in the heat wheel was also analyzed, which is the major drawback of this type heat recovery unit. To achieve this, an electricity energy meter was installed in the outdoor unit and temperature, humidity, air velocity, and carbon dioxide sensors were placed in the inlet and outlet section of each element that has an effect on the cooling process. To provide continuous data recording and remote monitoring of air handling parameters and energy consumption of the system, a network monitor interface was developed by building management system-based software. The energy impact of the heat wheel resulted in a 624 kWh energy saving and 25.1% energy saving rate for the electric energy consumption of the outdoor unit during the whole cooling period, compared to the system without heat wheel operation. The scale of CO2 cross-contamination in the heat wheel was evaluated as an average value of 16.4%, considering the whole cooling season

Nitrogen Removal Controlled by Ammonium-Analyser in the North Pest Wastewater Treatment Plant

At the North Pest Wastewater Treatment Plant, a nutrient removal process has been in operation since 2011. New tanks have been built, which can receive approximately half of the pre-settled wastewater. A pre- denitrification system has been planned and built both to the old and new lines. Due to the relatively small anoxic zones, periodic aeration was initiated first in the new line to achieve the lowest possible effluent total nitrogen concentration. Because of its positive impact, the operation of periodic aeration was initiated in the old line as well. Ammonium-analysers are used to control the aeration periods. Due to this process, the plant can provide a very low total nitrogen effluent value (below 10 mg dm-3 on average) as well as save energy and operational costs

Zr(IV)-Assisted Peptide Hydrolysis

The development of new reagents to efficiently cleave peptides and proteins has become increasingly important for protein structural studies and other applications. However, this has proved to be a very challenging task due to the extreme stability of the peptide amide bond. Transition metal complexes cleave proteins and peptides through either oxidative or hydrolytic pathways. However, hydrolytic cleavage is preferred over oxidative cleavage, because the latter process produces irreversibly modified peptide fragments. Metal-assisted peptide hydrolysis is introduced in Chapter I. The metals Ce(IV), Co(II), Co(III), Cu(II), Fe(III), Mo(IV), Ni(II), Pd(II), Pt(II), Zn(II), and Zr(IV) are described as promising non-enzymatic hydrolysis reagents. In Chapter II, Zr(IV)-assisted hydrolysis of the dipeptide Gly-Gly and of its N- and C- blocked analogs is described. The highest levels of cleavage were observed at pH values ranging from 4.4 to 4.7. When the pH was raised to ~ 7.0, hydrolysis yields were decreased and amounts of zirconium precipitation were increased proportionately. Zirconium(IV)-assisted peptide hydrolysis in the presence of 4,13-diaza-18-crown-6 is reported in Chapter III. The goal of this work was to use an azacrown ether to reduce Zr(IV) precipitation and enhance levels of hydrolysis at neutral pH. An experiment in which 16 glycine containing dipeptides were hydrolyzed by Zr(IV) and by Zr(IV)/4,13-diaza-18-crown-6 indicated that 4,13-diaza-18-crown-6 markedly enhanced the reactivity of Zr(IV) under near physiological conditions. Because Zr(IV) precipitation was not reduced in these reactions, we proposed that hydrolysis of peptides by Zr(IV)/4,13-diaza-18-crown-6 might be heterogeneous in nature. In Chapter IV, seventeen macrocyclic and open-chain Zr(IV) ligands were compared in order to gain mechanistic insights that would enable hydrolysis yields at neutral pH to be further improved. While the macrocyclic ligands 4,13-diaza-18-crown-6 and 4,10-trioxa-7,13-diazacyclopentadecane tended to produce higher levels of Zr(IV)-assisted dipeptide cleavage, it was not necessary to have a ring structure to enhance Zr(IV) reactivity. With respect to the open-chain ligands, the potential ability to form multiple chelate rings appeared to coincide with reduced levels of Zr(IV) precipitation as well as with reduced levels of dipeptide hydrolysis. In Chapter V, a summary of our results and conclusions is presented

Vitamin A Transport Mechanism of the Multitransmembrane Cell-Surface Receptor STRA6.

Vitamin A has biological functions as diverse as sensing light for vision, regulating stem cell differentiation, maintaining epithelial integrity, promoting immune competency, regulating learning and memory, and acting as a key developmental morphogen. Vitamin A derivatives have also been used in treating human diseases. If vitamin A is considered a drug that everyone needs to take to survive, evolution has come up with a natural drug delivery system that combines sustained release with precise and controlled delivery to the cells or tissues that depend on it. This "drug delivery system" is mediated by plasma retinol binding protein (RBP), the principle and specific vitamin A carrier protein in the blood, and STRA6, the cell-surface receptor for RBP that mediates cellular vitamin A uptake. The mechanism by which the RBP receptor absorbs vitamin A from the blood is distinct from other known cellular uptake mechanisms. This review summarizes recent progress in elucidating the fundamental molecular mechanism mediated by the RBP receptor and multiple newly discovered catalytic activities of this receptor, and compares this transport system with retinoid transport independent of RBP/STRA6. How to target this new type of transmembrane receptor using small molecules in treating diseases is also discussed

The role of geology in the spatial prediction of soil properties in the watershed of Lake Balaton, Hungary

There is no standard methodology which allows the incorporation of geological information into digital soil mapping (DSM) despite the great potential of geology as environmental covariate in DSM. To fill this gap, in this study, a geochemical parent material classification scheme was tested on the watershed area of Lake Balaton, for which soil maps at a finer scale have not yet been created. A parent material map was prepared on the basis of a 1:100 000 surface geology map in order to make the incorporation of soil modelling and mapping possible. Legacy data of 12400 soil sample points was used in order to examine the role of geology in the quantitative distribution of some soil properties and element content (liquid limit, soil organic carbon, pH(KCL), CaCO3, Mg, Cu, Zn, Mn). Results confirm that the SiO2 content of the parent material influences the properties of the derived soils. In the second part of the study Random Forest models were developed for three major soil properties (liquid limit, soil organic carbon, pH) with the use of additional environmental covariates: elevation, slope, aspect, curvature, topographic position index (TPI), annual average temperature, annual average precipitation, remote sensing based normalized difference vegetation index (NDVI) and land cover information. The performance and accuracy of the models were evaluated on the basis of the coefficient of determination (R2) and root mean square error (RMSE), calculated on a randomly selected validation dataset (20% of the database). The models performed with R2 values of 0.72, 0.6 and 0.68 for liquid limit, soil organic carbon and pH respectively. The importance of variables was also examined in the RF models, and this demonstrated that while geology is among the best-performing predictors, in neither case is it the most important variable. Ninety metre resolution maps of the three major soil properties were compiled by making spatial predictions with the RF models developed here. For validation of the maps, an independent soil database was used, which showed that the prediction performed well on the cultivated area where the concordance correlation coefficients (CCC) were 0.73, 0.73 and 0.69 for liquid limit, pH and soil organic carbon respectively.</p