Preparation and Characterization of Copper Borates as Lubricant Additives

The present study attempts the preparation of copper borate as a lubricating oil additive by the reaction of copper nitrate and borax solutions. Effects of borax/copper ratio, surface active agent （Span 60）, pH, temperature and mixing time on properties of the products were investigated. The obtained products were not pure form; therefore they were analyzed in detail. They were characterized by color measurement, X-ray diffraction, SEM, zeta sizer, ICP, EDX, TG, DSC, CHNS analysis and FTIR spectroscopy. Mainly Cu2（OH）3NO3 with nitrate ions partially substituted with borate ions was obtained at pH 3.7. There were borate ions equivalent to 0.32 tools of Cu（BO）2 per tool of CUE（OH）3NO3. The borate ions should have replaced partially the nitrate ions in Cu2（OH）3NO3 without changing its crystal structure. On the other hand, Cu （BO2）l 5（OH）074＇（H20）015 was produced at pH 10.2. It also contained 0.11 mol NO3- per tool. By mixing of dilute solutions at pH 8.2 and drying at room temperature nanopartieles of Cu（BO2）I 5（H20）6 having 0.05 NO3 per tool was obtained. The precipitates obtained at pH 10.1 and 8.2 were tested as lubricant additives. When they were added to lubricating oil with Span 60, the friction coefficient was reduced 28 % and 65 % for the precipitates prepared at pH 10.1 and 8.2, respectively.     

Assessment of Open Pit Dewatering Requirements and Pit Lake Formation for the Kışladağ Gold Mine,Uşak,Turkey

The K??lada? gold mine (U?ak, Turkey) has operated since 2006 and is projected to close by 2030, leaving a large open pit. We quantified dewatering requirements during the operational period, predicted pit lake formation during the post-closure period, and assessed the likely impacts on groundwater resources. Groundwater inflow into the pit during 17 years of mining was calculated using analytical and numerical models. The analytical model yielded lower inflow rates because it does not account for groundwater that will be released from storage. Post-closure, pit lake water balance calculations show that the system will reach equilibrium 585 years after dewatering ceases and that lake levels will stabilize at 816 m above sea level (masl). Further analysis indicated that 830 masl is a critical level, below which the pit will behave as a sink; above that, it will be a flowthrough system that could possibly affect downgradient groundwater quality.     

Experimental study on the effect of frost parameters on domestic refrigerator finned tube evaporator coils

In this study, parameters affecting the frost formation on the evaporator of a refrigerator and the structure of frost were examined. Air velocity measurements both at the air inlet and outlet channels of the evaporator were performed, and the effect of air velocity on frost formation was examined. The rate of evaporation of water inside the refrigerator cabin was also recorded.     

Latex sensitization in general pediatric surgical patients: a call for increased screening of patients

BACKGROUND/PURPOSE: Latex sensitization is a well-documented occurrence in children with myelodysplastic and urologic anomalies. The incidence of latex allergy in general pediatric surgical patients, however, has not been previously addressed. The purpose of this study was to examine the risk of perioperative latex reactions in a general pediatric surgical practice over a 1-year period. METHODS: This study examined the occurrence of latex sensitization using two methods. First, the preoperative anesthesia records of patients that have undergone surgery from October 1995 through September 1996 at Mott Children's Hospital were reviewed retrospectively. Second, all patients who had intraoperative anaphylaxis attributable to latex sensitization, including those from three additional hospitals, were evaluated. RESULTS: During a 12-month period, 1,523 pediatric general surgical operations were performed at the C.S. Mott Children's Hospital. Of these, only 11 operations on five patients were performed under latex precautions. All of these patients had a preoperative diagnosis of latex sensitivity. During the same period, intraoperative anaphylactic reactions caused by latex allergy occurred in two of the general surgical patients (0.13%) at the C.S. Mott Hospital. Four additional cases are also reported from other study hospitals. None of these patients were suspected, based on current screening methods, of having a latex allergy before their surgery. CONCLUSIONS: Latex allergy is a potentially life-threatening condition in the pediatric general surgical population. Further study is needed to develop criteria to preoperatively identify patients at risk for latex sensitization.     

Formalization and Automation of Time-Space Conflict Analysis

With increasing pressure for shorter delivery schedules, space is a critical resource at construction sites. Current industry practice lacks a formalized approach or tool to help project managers analyze spatial conflicts between activities prior to construction. Consequently, time-space conflicts occur frequently and significantly impact construction processes. Time-space conflicts have three characteristics that impede the detection and analysis of time-space conflicts prior to construction: (1) They have a temporal aspect; (2) they have different forms creating different problems; and (3) multiple types of spatial conflicts can exist between a pair of conflicting activities. This research formalizes time-space conflict analysis as a classification task and addresses these challenges by automatically (1) detecting conflicts in four dimensions; (2) categorizing the conflicts according to a taxonomy of time-space conflicts that is developed; and (3) prioritizing the multiple types of conflicts between the same pair of conflicting activities. This research extends previous research on construction space management by developing a taxonomy of time-space conflicts and by defining an approach for the analysis of time-space conflicts prior to construction.     

Electrochemical determination of HIV drug Abacavir based on its reduction

Abacavir (I), a drug used in the treatment of HIV, is electrochemically reduced at the dropping mercury electrode in a four-electron process, similar to structurally related adenine (III) and adenosine triphosphate (IV). To undergo the reduction, the species is protonated in the vicinity of the electrode. The protonations take place on the 6-amino group and on one of the pyrimidine ring nitrogens. The role of covalent hydration of the pyrymidine ring has been interpreted. Best suited as supporting electrolytes for analytical purposes are solutions of 0.1-1.0 M sulfuric, perchloric, or hydrochloric acids. Procedures of analyses of tablets containing I were established and validated, based on peak currents obtained by linear sweep, differential pulse, or square-wave voltammetry with a hanging mercury drop electrode as indicator electrode. The procedure proved to be more sensitive and more reliable than that based on oxidation on a glassy carbon electrode, proposed previously.     

Cyclic fatigue resistance and energy dispersive X‐ray spectroscopy analysis of novel heat‐treated nickel–titanium instruments at body temperature

The aim of this study was to evaluate the cyclic fatigue resistance of Dia‐X, WaveOne Gold and One Curve files in a water bath at intracanal temperature (35°C). Thirty‐nine instruments Dia‐X, WaveOne Gold, and One Curve systems (n = 13) were tested in an artificial canal with a curvature angle of 60° and a radius of 3 mm. A water bath setup at a temperature of 35°C was used to simulate the intracanal temperature and time to fracture (TTF) as seconds was recorded. The mean data were analyzed statistically using one‐way ANOVA, and post hoc Tukey test (p = .05). The fractured surface of the instruments was examined with scanning electron microscopy (SEM) and chemical composition of the instruments were investigated with energy dispersive X‐ray spectroscopy (EDS). Statistically significant differences were detected in TTF values of all the systems as follows: One Curve > WaveOne Gold > Dia‐X (p < .05). One Curve instruments demonstrated the highest TTF values in all the tested instruments. The EDS microanalysis revealed similar NiTi composition of on the surface of One Curve, WaveOne Gold, and Dia‐X instruments. The novel manufacturing process, including C‐wire heat treatment and the variable cross‐section of the One Curve files, could be the main factors affecting the fatigue life of the instruments.     

Book review

The change which is occurring within both our urban and rural areas as a result of increasing tourism is but one expression of the continuing saga of human change and conflict.

There seems to be two quite distinct causes for the conflict that arises with tourist developments.

1. Differing views on the technical implications of the changes that will occur as a result of a proposed development, e.g. will increasing tourist visitation of the Barrier Reef lead ultimately to its destruction or simply bring about modifications which will change some of its form but not threaten its long term existence as one of the wonders of the world;

2. A belief by a small or large section of the community that the particular development threatens to change their lifestyle, either:

(a) by direct intrusion into the local environment which they have become adapted to or

(b) preventing their enjoying some distant location which they have visited in the past.     

Macroanatomic,light and scanning electron microscopic studies of the pecten oculi in the stork (Ciconia ciconia)

This study was undertaken to investigate the pecten oculi of stork by using macroscopic, light and electron microscopic techniques. A total of 20 eyes that were obtained from 10 storks were used. The eyes were cleaned and isolated by dissection. After various procedures, four of the pecten oculi were examined by light microscope while the other four with an electron microscope. The remaining 12 eyes were assigned for macroscopic investigation. Pecten oculi of the stork were determined as accordion‐like structures that originated from n. opticus, consisting of 15–17 plica and projecting up to 2/5 of the diameter of the bulbus oculi. Light microscopic examination revealed two types of blood vessels. Afferent–efferent vessels were larger in diamater (40–45 µm), fewer in numbers, and the capillary vessels were smaller in diamater (2–5 µm) and more in numbers. There were granules including amount of melanin pigment at the apical part of the pleats. These granules were fewer and scattered randomly on the basal part of the pleats. As a result, pecten oculi in the stork, which is a migrating bird, were determined to be similar to those of other diurnal birds. Microsc. Res. Tech. 76:963–967, 2013. © 2013 Wiley Periodicals, Inc.