Lime Refractories with Limestone and Synthetic Calcium Hydroxide Additions

The effects of fine, natural limestone and synthetic calcium hydroxide additions on the sintering and microstructure of two natural, dead-burned limes were investigated. Density increases were achieved and microstructural changes were observed. The high reactivities of the decomposition products of the carbonates and hydroxides enhanced the sintering processes to yield refractory bodies with densities in excess of 90% of theoretical. Microstructurally, the additions promoted grain growth and simultaneously modified the porosity of these high-density refractory bodies.     

Sphingoid bases in infant formulas

Sphingolipids are a group of lipids present in all eukaryotic cells. They consist of a long-chain sphingoid base that is amide-bound to a fatty acid and a polar group on C-1 sphingosine. Sphingosine is the most widespread base in mammals. The goal of this study is to determine the concentrations of free and total sphingosine and sphinganine in infant formulas and human milk. Following the extraction of sphingolipids, base and acidic hydrolysis was preformed. Sphinganine and sphingosine were determined by means of high-performance liquid chromatography. The results of this research illustrate the differences between the concentrations of sphingoid bases in infant formulas and human milk. On the basis of the obtained results, it can be concluded that despite all efforts made to produce infant formulas as similar to human milk as possible, in terms of their structure and the amount of their constituents, there are differences that could be biologically significant and thus need to be further researched.     

Injectable Platelet-Rich Fibrin as a Drug Carrier Increases the Antibacterial Susceptibility of Antibiotic—Clindamycin Phosphate

The aim of this study was to investigate the change in clindamycin phosphate antibacterial properties against Gram-positive bacteria using the platelet-rich fibrin as a carrier matrix, and evaluate the changes in the antibiotic within the matrix. The antibacterial properties of CLP and its combination with PRF were tested in a microdilution test against reference cultures and clinical isolates of Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis). Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis was done to evaluate the changes in the PRF_CLP matrix. Release kinetics of CLP was defined with ultra-performance liquid chromatography (UPLC). According to FTIR data, the use of PRF as a carrier for CLP ensured the structural changes in the CLP toward a more active form of clindamycin. A significant decrease in minimal bactericidal concentration values (from 1000 µg/mL to 62 µg/mL) against reference cultures and clinical isolates of S. aureus and S. epidermidis was observed for the CLP and PRF samples if compared to pure CLP solution. In vitro cell viability tests showed that PRF and PRF with CLP have higher cell viability than 70% after 24 h and 48 h time points. This article indicates that CLP in combination with PRF showed higher antibacterial activity against S. aureus and S. epidermidis compared to pure CLP solution. This modified PRF could be used as a novel method to increase drug delivery and efficacy, and to reduce the risk of postoperative infection.     

Numerical modeling of failure mechanisms in phyllite mine slopes in Brazil

This paper presents three case studies comprising failure mechanisms in phyllite mine slopes at Quadrilá-tero Ferrífero, State of Minas Gerais, Brazil. Numerical modeling techniques were used in this s...     

Structural changes in catalytic hydroprocessing of syncrude coker gas oil

A method of Structural Group Analysis (SGA) was used to characterize feed and liquid products from catalytic hydroprocessing using a commercial Ni-Mo catalyst. Comparison of the structural profiles revealed significant changes in the concentration of various structural groups. SGA is a promising tool for investigating chemical changes in complex reacting systems.     

Three theoretical interpretations of order effects in persuasive communications.

The "set," "reinforcement," and "sensory variation" hypotheses are reviewed in terms of their ability to predict the results of order effects in the persuasive situation where opposed arguments on the same topic are utilized. The set hypothesis is most successful when the communicative materials presented are unfamiliar to the S. The sensory variation hypothesis is most successful when the topics of the cummunications are concerned with familiar social issues. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of milk replacer feeding strategies on performance,ruminal development,and metabolism of dairy calves

Performance, rumen development, and metabolism of male Holstein calves (n = 54) were evaluated according to 1 of 3 liquid feeding strategies: 4 L of milk replacer (MR)/d until 60 d old (4L-60d), 6 L of MR/d until 29 d old and 4 L/d from 30 to 60 d (6L-29d/4L-60d), or 6 L of MR/day until 60 d old (60d-6L). Water and starter were provided ad libitum. Intakes of MR and starter were monitored daily and body weight (BW) weekly. Blood samples for glucose and insulin concentrations and ruminal content samples for volatile fatty acids and ruminal ammonia concentrations were collected at 15, 30, 45, 60, 75, and 90 d of age. Six calves on each treatment were euthanized at 30, 60, and 90 d of age. Empty weights of forestomach and abomasum, papillae length, and mitotic index were measured. Average MR intake/d (expressed as a percent of BW) was greater for calves receiving 6 L/d than for those receiving 4 L/d until 30 d of age. Calves on the 6L-29d/4L-60d had the smallest MR intake from 30 to 60 d old, followed by the 4L-60d and 6L-60d treatments. Starter intake (kg of dry matter/day) did not differ between groups. It increased from 0.065 kg/d in the first month to 0.386 kg/d in the second month, and to 2.065 kg/d after weaning. Weight gain was greater for calves fed more MR in the first month, but no difference was observed during the second month. After weaning, 6L-60d calves had greater rate of weight gain than others and were heavier at 30, 60, and 90 d of age. Weight of empty forestomachs, ruminal pH, and ammoniac nitrogen concentration were not different among groups. Propionate concentration was lower for 6L-60d calves, but acetate and butyrate concentrations were not influenced by MR feeding strategy. Calves fed more MR until d 30 had greater ruminal epithelium mitotic index. The different MR feeding strategies did not influence papillae length or ruminal epithelium thickness. Lesions such as ruminal parakeratosis or hyperkeratosis were not observed. The MR feeding strategy did not affect glucose concentration, but insulin was higher in 6L-60d calves than in the other groups. Glucose concentration increased with age, whereas insulin decreased until 45 d old, and then started to increase until 90 d. In conclusion, MR feeding strategy did not influence ruminal development. Feeding calves 6 L of MR/d over 60 d resulted in greater rate of weight gain without negative effects on starter intake or forestomach development. The weight advantage that 6L-60d calves obtained preweaning was maintained until 90 d of age.     

Environmental effects on a grid connected 900 W photovoltaic thin-film amorphous silicon system

This study analyses the performance of a small scale, grid connected, thin-film, amorphous silicon photovoltaic system located in Abu Dhabi (United Arab Emirates). It was observed that due to the sandy environment dust accumulated relatively quickly over a short period of time, significantly degrading the performance of the system. Relating to this local natural phenomenon, the amount of solar irradiance the system was exposed to shows the greatest effect on performance. The effect of ambient temperature and humidity were considered and displayed slight effects on the output of the system, and it was observed that a significant loss in power occurred through the inverter. Also observed in reducing the performance of the system was the Staebler-Wronski effect, a phenomenon inherent to amorphous silicon, which reduces the overall output of the system after exposure to light over an extended period of time.