Environmentally Friendly Masonry Mortar Blended with Fly Ash, Corn Cob Ash or Ceramic Waste Powder

Implementing a circular approach through waste valorization in mortar production with environmentally efficient mix design is a viable pathway for relieving the ecological burden of greenhouse gas emissions, resource depletion and waste management. The main objective of this paper is to evaluate the feasibility of using fly ash (FA), corn cob ash (CCA), and ceramic waste powder (CWP) as supplementary cementitious materials (SCM) in cement-lime masonry mortars. As part of an extensive experimental study, twelve mortar mixtures were made: three reference and nine blended, with mixing ratios of 1:1:5, 1:0.7:4.2, and 1:1:4 ((cement + SCM)/lime/sand), by volume. The examined properties include workability, compressive and flexural strengths, dry bulk density, capillary water absorption, adhesive bond strength, and water vapor permeability. The compressive and flexural strengths of tested mortars were notably impaired, with reductions of up to 60%, while the capillary water absorption coefficient rose by 100% compared to the reference values. The adhesive bond strength of some blended mortars exceeded the strength of the reference mortars. Nevertheless, all blended mortars fulfilled the requirements for general-purpose mortars, while the majority met the criteria for structural masonry applications. In addition, a performance-based index and weighting triangle were used for the comparison and ranking of all analyzed mortar mixtures. The findings of this study may herald a novel use of FA, CCA, and CWP as more eco-friendly binding materials in contemporary construction leading to the reduction in the process's carbon footprint, the improvement in cost efficiency, and the mitigation of the detrimental environmental impact of waste disposal.

Effects of Grinding Methods and Water-to-Binder Ratio on the Properties of Cement Mortars Blended with Biomass Ash and Ceramic Powder

To combat environmental challenges-such as the depletion of natural resources and a high carbon footprint-and contribute to the effort of achieving zero-waste technology and sustainable development, the use of agricultural and industrial wastes in the cement industry has created a research interest. This study explores the potential of two types of harvest residue ash (HRA) and three types of ceramic waste (CP) as supplementary cementitious materials (SCMs) through: (1) the characterization of raw materials and (2) examining the physical properties and mechanical performance of cement-based mortar samples prepared with 10%, 30% and 50%wt of the selected SCMs ground into powder form as cement replacement. Two main variables were the water-to-binder ratio (w/b) and the effect of different grinding procedures. Experimental results demonstrated that flexural and compressive strengths were not significantly impaired by SCM additions of up to 50%, but higher replacement levels led to an increased permeability and higher capillary water absorption due to the dilution effect. Also, a lower w/b was shown to effectively reduce the porosity of mortar and increase its mechanical properties, allowing for higher shares of SCMs to be utilized. This study verifies the technical feasibility of cob corn ash and ceramic powder application as SCMs in mortar formulations, further promoting the practice of incorporating industrial and agricultural by-products in greener cementitious composites.

Basal and stress induced concentrations of adrenal gland catecholamines and plasma ACTH during aging

Basal and stress levels of catecholamines (CA) in the adrenal glands, and circulatory levels of adrenocorticotropic hormone (ACTH) were examined in female Wistar rats aged 1, 3, 10 and 24 months. Our data showed reduction in basal dopamine (DA) concentration in adrenal glands and an increase in this catecholamine in response to stress at all ages (1, 3, 10, 24 months). The greatest levels of basal norepinephrine (NE) and epinephrine (E) concentrations in the adrenal glands were noted in intact rats at the age of 24 months. On the other hand, the stress response of NE and DA had a tendency to fall, reaching basal values at the age of 10 and 24 months of age. Basal circulatory levels of ACTH showed a reduction with age. The stress response of ACTH was reduced in animals aged 10 and 24 months. Reduced basal values of adrenal DA and increased NE and E values, suggest that there is increased adrenomedullar activity at the age of 24 months. On the other hand, the reduced or even absent stress response of NE and E observed in the adrenals, in 10 and 24 months old rats, may be of interest in considering the ability of these animals for adaptation. Basal and stress values of plasma ACTH are significantly reduced with the onset of senescence in female rats.

[The effect of knowledge regarding the importance of oral health in pregnancy]

INTRODUCTION

Although in modern dental medicine a pregnant woman and her foetus are completely safe during all dental procedures, the prevention is still the most effective measure for the preservation of oral health in pregnancy. However, pregnant women often visit a stomatologist only when there are already serious disturbances, regardless of the fact that they are referred to a stomatologist even at their first visit to a gynaecologist. The aim of the study was to investigate (possible) changes in pregnant women's attitudes toward oral health during pregnancy according to our educational programme.

METHODS

One hundred and sixty pregnant patients were randomly selected for the educational programme and were enrolled in the study. In direct contact (groups of 4 to 14 pregnant patients) they received basic information about the condition for attaining and maintaining their and foetal good health [1]. In order to establish the results, three anonymous questionnaires were conducted. Two of them made the questionnaire A because of identical results obtained before and after the education, and the third questionnaire B was different, and was conducted at the end. The questionnaire B concerned the personal point of view of pregnant women about the obtained information [2].

RESULTS

The results of the first two questionnaires (questionnaire A) are shown in Graph with a quantity of correct answers expressed in percents. The results of the questionnaire B are formulated according to answers to a question with "YES" and "NO", and they are expressed in percentage. The following results were obtained for questionnaire B: A hundred percent of pregnant women stated that they had learned something new about oral health, 67 percent had immediately changed their nutrition for healthy food, 100 percent of them understood well the significant role of fluor prophylaxis, 16 percent did not accept it for unknown reasons, but 100 percent thought that it was very useful to hear lectures about oral health [3].

DISCUSSION

A great interest existed for all preventive stomatologic measures and dental procedures during pregnancy, which formerly, as a rule, were avoided because of ignorance [4]. It is necessary to carry out a proper prevention, and adequately inform and motivate pregnant women, so that we could have a satisfied mother and carefree child in the future.

The effect of constant light on the concentration of catecholamines of the hypothalamus and adrenal glands, circulatory hadrenocorticotropin hormone and progesterone

The participation of adrenocorticotropic hormone (ACTH) in the control of adrenal glands and the regulation of ACTH secretion in female rats exposed to constant light for six weeks were studied. A significant increase of plasma ACTH (p < 0.05) in rats exposed to constant light is in correlation with an increase of epinephrine (E) synthesis in adrenal gland (p < 0.05) when compared to intact controls. On the other hand, ACTH secretion is in inverse relation with a significantly reduced concentration of dopamine (DA) and norepinephrine (NE) in hypothalamus (p < 0.05). In addition, higher concentration of plasma ACTH in rats exposed to constant light through its effect on the adrenal cortex is responsible for the appearance of polycystic ovaries. As a contribution to this assumption is the result showing an increased concentration of serum progesterone in rats exposed to constant light when compared to corresponding controls which is probably of adrenal origin. These results indicate an inverse relationship between plasma ACTH concentrations and DA and NE concentrations in hypothalamus and that the hypothalamo-pituitary-adrenal axis has a significant role in the regulation of ovarian function.

Influence of maternal adrenalectomy on the ultrastructure of the adrenal gland in neonatal rats

Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.

Adrenocorticotropic (ACTH) cells of rats after head irradiation

The heads of intact rats and of rats 15 days after adrenalectomy were irradiated with 1200 R. Some of the adrenalectomized animals with irradiated heads were treated with 5 mg of deoxycorticosterone acetate. In adrenocorticotropic cells of adrenalectomized rats 15 and 30 days after irradiation, the decreased amount of the granular endoplasmic reticulum and the Golgi regression imply a considerably decreased protein synthesis. The finding of an increased number of granules and of granules larger than normal suggests that they are the result of slowed down transport and secretion of the products of these cells' activities. After head irradiation an increased number of degenerative cells was evident in the pituitary of both intact and adrenalectomized rats. The degree of the degenerative changes and the number of degenerative cells was higher 30 than 15 days after irradiation and both were decreased if the adrenalectomized rats were treated with deoxycorticosterone acetate.

[Study of endemic nephropathies]

Clinical and microscopic investigations in the kidneys of patients with endemic nephropathy have revealed alterations in the epithelial cells of glomeruli and in the epthelium of nephron segments, and thickening of the basal membranes. These changes have been studied from the viewpoint of distrubances in filtration and reabsorption, and indicate that the primary alterations occur in the glomeruli, i.e. the nephrons, of the patients observed.

Pituitary cell activities in gonadectomized rats treated with estrogen

The incorporation of 14C-leucine into LTH and STH, the uptake of 3H-estradiol into the pituitary and the appearance of the LTH and LH cells were studied in male and female rats gonadectomized at the age of 30 days and chronically treated with estradiol (E). The biosynthesis of LTH in the pituitary of ovariectomized rats was decreased 15 and 60 days after the operation to the level of intact males. This decrease is followed by the reduction of the number of immunochemically stained LTH producing cells. Chronical administration of estradiol stimulated the LTH synthesis and maximal incorporation of 14C-leucine was obtained in ovariectomized rats. Maximal relative increase of labeled LTH was noticed in the pituitaries of intact male rats treated with E. STH synthesis is inhibited by treatment with E and maximal decrease was obtained in intact males. The luteinizing LH cells were still hypertrophic in the pituitaries of gonadectomized E treated rats, but the number of castration cells was reduced. On the basis of these results we can conclude that the castration of 30-day-old rats of both sexes does not alter the sex difference in the reaction of LTH and STH cells to estradiol.