Dynamic Design of Systems with Semi-rigid Connections Based on Experimental Investigation of the Full Scale Structure

Semi-rigid connections in the construction permit mutual rotation of the nodes. Since such connections are quite common in constructions, especially in the precast ones, it is of interest to determine their dynamic characteristics that is the subject of this proposed paper. During our investigation full scale experiments have been carried out and experimentally determined dynamic characteristics have been compared with those obtained by use of the computational model. The real dynamic characteristics are determined and resonant frequencies of the basic modes in the horizontal and vertical directions, the forms of vibrations at these frequencies, as well as the corresponding coefficient of viscous damping. Testing has been done on the frame structure without facade walls. For the typical precast system "Minoma 1" with span of 12m, "Minoma 2" with span of 20m, and "Minoma 3" with span of 27m, dynamic characteristics: have been determined experimentally by use of forced harmonic excitation, free oscillations and ambient vibration. Experimentally and theoretically obtained values are in a relatively good agreement that is a good starting point for mathematical modeling

Quality of Honey Bee Bread Collected in Spring

Pollen is the only source of protein that honey bees collect from nature. It is very important for the development of brood, and consequently, for the development of the colony. Honey bee bread is the pollen which the bees collect from flowers and store in honeycomb cells. Honey bee bread has a modified structure due to the fermentation process under the influence of enzymes it passes through. For this study, ten honey bee colonies were selected. Honey bee bread was sampled from the combs. The quality of pollen and honey bee bread was determined by the chemical composition, using standard methods used in food analysis. Total nitrogen was determined by Kjeldahl method. Micro- and macroelements were determined by spectrophotometric method. The pollen collected from two sites had rich protein content (29.93 % and 27.63 % on average)

Isolation of chromium resistant bacteria from a former bauxite mine area and their capacity for Cr (VI) reduction

The Cr (VI) reducing capacity of bacteria has been investigated in many different soils and waters but little or no information is available from soils originating from bauxite mine areas. From soil, mud and rhizospheres of the floating aquatic plant Potamogeton natans L. and the terrestrial plant Carduus acanthoides L., the Cr content was determined and the microbial populations were sampled. The highest total chromium concentration (204.6 mgkg-1) was found in the rhizosphere of C. acanthoides. To determine the numbers and percentages of chromate-resistant bacteria, the autochthonous microbial populations were subjected to different Cr (VI) concentrations (40, 100, 300 and 1000 mM as K2Cr2O7). At 1000 mM Cr (VI) in the medium, about 25% of bacteria from soil and 45% of bacteria from the rhizospheres were resistant. Of 34 bacterial isolates, within 24 h, only Bacillus stearothermophilus 12 ms, Pseudomonas sp. 12 bk3 and Serratia fonticola 7 be were able to reduce 50 μM Cr (VI). Using prolonged 72 h incubation, they were able to reduce 500 μM Cr (VI) concentrations added to the medium. These chromate-resistant bacteria isolated from rhizosphere of plants growing in bauxite mine soil have great potential for bioremediation of Cr (VI)-polluted wastes.Key words: Chromate-resistant bacteria, chromate reduction, bauxite mine, rhizosphere, plant

COMPARISON OF MOTIVATION FOR PARENTING IN HEALTHY AND DEPRESSED PATIENTS

Objective: The aim of present study was to examine whether there is a difference in parenting motives between patients diagnosed with depression and control groups (non-depressed). Material and Method: The survey included 66 patients who were treated at the Psychiatric Hospital in Novi Pazar (average age= 44.64, SD=10.00) and 65 subjects who were not diagnosed with depression (average age=42, SD=13.05). Participants volunteered to participate in the research and received no compensation for their participation. Respondents were given a Parent Motivation Scale. Results: Results showed that participants in our study are motivated for parenthood mostly by instrumental motivation, altruistic and fatalistic motivations are equally present, and narcissistic motivation is the lowest. Instrumental, fatalistic and altruistic motives for parenting are significantly lower in group consisted of depressed patients. There was no difference in narcissistic motivation between two groups. Conclusion: This finding can be seen in the light of the general condition and the characteristic of people suffering from depression. In them, namely, all aspects of motivation are reduced and it is not surprising that this is so with the motives for parenting

The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME)

<p>Abstract</p> <p>Background</p> <p>This study aimed to investigate the influence of age on sperm quality, as analysed by motile sperm organelle morphology examination (MSOME).</p> <p>Methods</p> <p>Semen samples were collected from 975 men undergoing evaluation or treatment for infertility. Sperm cells were evaluated at 8400× magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. Two forms of spermatozoa were considered: normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV, defined as vacuoles occupying > 50% of the sperm nuclear area). At least 200 spermatozoa per sample were evaluated, and the percentages of normal and LNV spermatozoa were determined. The subjects were divided into three groups according to age: Group I, less than or equal to 35 years; Group II, 36-40 years; and Group III, greater than or equal to 41 years.</p> <p>Results</p> <p>There was no difference in the percentages of normal sperm between the two younger (I and II) groups (<it>P ></it>0.05). The percentage of normal sperm in the older group (III) was significantly lower than that in the younger (I and II) groups (<it>P </it>< 0.05). There was no difference in the percentage of LNV spermatozoa between the younger (I and II) groups (<it>P ></it>0.05). The percentage of LNV spermatozoa was significantly higher in the older group (III) than in the younger (I and II) groups (<it>P </it>< 0.05). Regression analysis demonstrated a significant decrease in the incidence of normal sperm with increasing age (<it>P </it>< 0.05; r = -0.10). However, there was a significant positive correlation between the percentage of spermatozoa with LNV and male age (<it>P </it>< 0.05, r = 0.10).</p> <p>Conclusion</p> <p>The results demonstrated a consistent decline in semen quality, as reflected by morphological evaluation by MSOME, with increased age. Considering the relationship between nuclear vacuoles and DNA damage, these age-related changes predict that increased paternal age should be associated with unsuccessful or abnormal pregnancy as a consequence of fertilisation with damaged spermatozoa. Given that sperm nuclear vacuoles can be evaluated more precisely at high magnification, these results support the routine use of MSOME for ICSI as a criterion for semen analysis.</p

Hybrid Meta-heuristics with VNS and Exact Methods: Application to Large Unconditional and Conditional Vertex p-Centre Problems

Large-scale unconditional and conditional vertex p-centre problems are solved using two meta-heuristics. One is based on a three-stage approach whereas the other relies on a guided multi-start principle. Both methods incorporate Variable Neighbourhood Search, exact method, and aggregation techniques. The methods are assessed on the TSP dataset which consist of up to 71,009 demand points with p varying from 5 to 100. To the best of our knowledge, these are the largest instances solved for unconditional and conditional vertex p-centre problems. The two proposed meta-heuristics yield competitive results for both classes of problems