bluuebunny/crossref_metadata_2025_split huggingface dataset:
A state-of-the-art review on the effects of particulate contamination and related topics in machine-element contacts
Authors: Nikas G K 
Published: March 2010

Contamination of machine-element contacts by solid particles is a serious problem in all industrial sectors. Particles ranging in size from nanometres to micrometres are responsible for increased wear and for even catastrophic failures of bearings, gears, seals, mechanisms, and machines. The wear such contaminants can cause is abrasion, surface indentation, flaking, and even scuffing, depending on the operating conditions and the mechanical properties of the particulates. The literature on the effects of debris particles in mechanism and machine reliability is voluminous. There are theoretical studies covering the entrainment, entrapment, and passage of particles through concentrated contacts, experimental and theoretical studies on the wear caused in such incidents, studies on the effects of air and lubricant filtration on machine life, and other related research work. The goal is to determine the consequences of having debris particles in a mechanical system and to develop methods to prevent the presence of particles in order to maximize the life expectancy of the system. This article is a review of the related research available in the literature. It covers more than 150 years of research, with the largest volume of work concentrated in the last 30 years. The review discusses over 230 of the most important publications and aims to be a definitive point of reference for the work done up to the year 2009.
Medical Negligence in Italy: The Criminal Inquiry
Authors: Jourdan Stefano , Goulding Julie , Rossi Marco 
Published: March 2010

In the past decade, there has been an exponential increase in legal proceedings against doctors due to allegations of medical negligence. The via crucis of the doctor under investigation for alleged medical negligence in Italy is little known beyond the Alps. The authors hope this paper will bring to the attention of medical and legal colleagues this complex issue of the process followed by the justice machinery in Italy where the criminal route in pursuit of justice is the norm.
Return to Work Following Whiplash and Back Injury: a Review and Evaluation
Authors: Athanasou James A 
Published: March 2010

The purpose of this study is to review the reported return-to-work rates following whiplash and back-injury. The return-to-work rates for the 71 relevant studies that were reviewed varied from 29% to 100% with a median of 67%. The results suggest considerable residual return-to-work potential for persons with whiplash and back injury. Return-to-work rates were substantially higher for motor vehicle (96%) compared to work-related (71%) studies and also considerably higher for whiplash (95%) compared to back injuries (65%). It is suggested that these indices may form potential benchmarks for personal injury claims outcomes. The purpose of this paper is to analyse the published rates of return to work following whiplash and back injury. This criterion of return to work is not without limitations or controversy and Pfingsten, Hildebrandt Leibing, Franz and Saur (1997) noted: “... a high variability exists in data on return-to-work. Results often range from either no return to a very high return rate, with an approximate average of 68% following multimodal treatment procedures...”
Relationships between Carbonization Temperature and Pyrolysis Products from Biomass
Authors: Demirbaş Ayhan 
Published: March 2010

Biomass samples were converted to charcoal and to liquid and gaseous products using pyrolysis process at different temperatures. The yield of charcoal and the chemical composition of charcoal can be calculated as functions of the carbonization temperature. There have been numerous other mathematical models, which were created based on data from the physical or chemical compositions, proximate or ultimate analysis of the biomass fuels. The charcoal components and higher heating values (HHVs) of biomass fuels were correlated with carbonization temperatures. There were highly significant linear correlation between the carbonization temperature of the biomass fuel and the fixed carbon content and HHV of charcoal. The fixed carbon (FC) and HHV (MJ/kg) of the charcoal from biomass as a linear function of carbonization temperature (T, K) was calculated using the following equations: [Formula: see text][Formula: see text] For which square of the correlation coefficients (r2) were 0.9622 and 0.9967, respectively.
Bael Tree Leaves as a Natural Adsorbent for the Removal of Zinc(II) Ions from Industrial Effluents
Authors: Kumar P. Senthil , Kirthika K. , Kumar K. Sathish 
Published: March 2010

The removal of heavy metal ions from water and wastewater has received a great deal of attention. Although adsorption methods are those most frequently used for the treatment of polluted water, such methods generally employ high-cost adsorbents such as activated carbon. The purpose of the present study was the exploration of the use of natural materials as a low-cost adsorbent in such technological applications. Thus, experiments have been conducted to test the efficiency of bael tree leaves in removing heavy metal ions, viz. Zn(II) ions, from wastewater derived from the electroplating industry. The percentage removal of Zn(II) ions was evaluated under varying experimental conditions, i.e. adsorbent dosage, initial metal ion concentration and contact time. To this effect, batch adsorption experiments were undertaken employing 2 g of 40–50 mesh bael tree leaves as an adsorbent in 100 mℓ of synthetic wastewater containing ca. 10, 20, 30, 40 and 50 mg/ℓ of Zn(II) ions. The initial pH of the synthetic wastewater was ca. 5. The experiments showed that the highest removal rate for Zn(II) ions was 88.58% under optimal conditions. Such Zn(II) ion adsorption followed reversible first-order rate kinetics. Thus, the tree leaves investigated in this study showed a good potential for the removal of Zn(II) ions from synthetic wastewater. The ultimate goal of the work described is the development of inexpensive, readily available, effective metal ion adsorbents from natural waste products as an alternative to existing commercial adsorbents.
Evaluation of an Adsorption–Desorption Process for Concentrating Heavy Metal Ions from Acidic Wastewaters
Authors: Sotomayor Sergio Montes , Montes-Atenas Gonzalo , Garcia-Garcia Francisco , Valenzuela Manuel , Valero Eduardo , Díaz Oscar 
Published: March 2010

Pine bark is a substrate which allows the attachment and de-activation of heavy metal ions, thereby cleansing the host solution. The present work was aimed at studying the removal of binary heavy metal ions from aqueous solutions using pine bark and to explore the possibility of elution as a subsequent stage for releasing and concentrating the metal ions. The application of the method to the cases of Cu(II) and Zn(II) ions is presented. The adsorption of each metal ion separately from binary mixtures onto pine bark was studied. Subsequently, the loaded bark was used to perform elution experiments leading to the concentration of the metal ions and their further retrieval. Tests showed that the adsorption capacity of pine bark towards Cu(II) and Zn(II) ions from a mixture of the same in aqueous solution was almost 0.35 mmol metal ion/g dry bark. The same value was obtained by adding the individual adsorption capacities, determined when each metal ion was adsorbed separately. Cyclic percolation processes resulted in the concentration of the metal ions, showing increases of almost 20- and 10-times for Cu(II) and Zn(II) ions, respectively.
Adsorption of C2H4, C2H6 and CO2 on Cation-exchanged Clinoptilolite
Authors: Aguilar-Armenta Gelacio , Romero-Pérez Álvaro 
Published: March 2010

As a means of assessing their possible applications in the separation and purification of the gases concerned, the adsorption kinetics and equilibrium of pure ethylene (C2H4), ethane (C2H6) and carbon dioxide (CO2) onto untreated natural clinoptilolite/heulandite volcanic tuff (Cp) from Villa de Reyes (San Luis Potosí, México) and onto cation-exchanged clinoptilolite samples (Cp–H and Cp–Na) have been measured over the temperature range 0–240 °C using a glass high-vacuum volumetric device. Some of the results have been compared with those obtained on a commercial synthetic zeolite 4A (CECA). The adsorption rates of the various gases were measured automatically via a custom acquisition data card capable of registering pressure and time data simultaneously. All the samples showed a decreasing adsorption affinity in the order CO2 > C2H4 > C2H6. A very slow adsorption process and a large proportion of irreversible adsorption were observed for both hydrocarbons onto Cp at 20 °C. The irreversible adsorption of C2H4 decreased with increasing temperature, with a small irreversible adsorption being detected at 240 °C. Both Cp at 240 °C and Cp–Na at 0 °C could be promising adsorbents for the separation of C2H4/C2H6 mixtures, while Cp–H may be recommended for the separation at 20 °C at times less than 100 s. The high adsorption selectivity toward CO2 of Cp and Cp–Na at all the experimental temperatures studied enables these samples to be recommenced for the purification of C2H4 and C2H6 contaminated with CO2.
The Use of Eucalyptus Barks for the Adsorption of Heavy Metal Ions and Dyes
Authors: Saliba R. , Gauthier H. , Gauthier R. , Petit-Ramel M. 
Published: March 2010

Eucalyptus barks harvested in Lebanon were used for the adsorption of pollutants such as heavy metal ions and dyes. Washing with water or pretreatment with formaldehyde was performed on the bark powder. The adsorption capacity of this material towards CuII, CrIII, CdII and NiII was evaluated in a batch process for various parameters. The results obtained showed that the retention capacity increased with contact time, pH and initial metal ion concentration but decreased with temperature. The adsorption capacities were 2.61, 0.71, 2.24 and 0.75 mmol/g adsorbent for CuII, CrIII, CdII and NiII, respectively. Eucalyptus barks are also very efficient for the adsorption of dyes (Acid Blue 25, Erichrome Blue Black B and Calmagite) because of interaction between the hydroxy and amino groups of the dyes and the phenolic moities of bark. This adsorption was modified when metal ions had already been adsorbed on to the barks as a result of the formation of a 1:1 complex between the dye and the metal ion. Desorption was achieved by treating with the sodium salt of ethylenediamine-tetraacetic acid (EDTA) for metal ions and by heating at 75°C in aqueous medium for dyes. After desorption, the recycling of the support was tested for potential use as a means of concentrating pollutants.
Examination of the Effectiveness of Physical and Chemical Activation of Natural Bentonite for the Removal of Heavy Metal Ions from Aqueous Solutions
Authors: Banat Fawzi , Al-Asheh Sameer , Abu-Aitah Leena 
Published: March 2010

The ability of physically and chemically activated bentonite to adsorb copper and nickel ions from aqueous solutions was examined under various experimental conditions. Physically activated bentonite was obtained by thermal treatment of the initial material in an oven at 700°C (T-bentonite), while chemically activated bentonite was obtained in two ways, either by treatment of the initial material with sodium dodecyl sulphate (SDS) as an anionic surfactant to give SDS-bentonite or with aluminium hydroxypolycation as a pillaring agent to give Al-bentonite. Batch adsorption tests were undertaken to study the removal of Cu2+ and Ni2+ ions from aqueous solutions using the above-mentioned types of activated bentonite. The adsorption capacity of the bentonites towards both Cu2+ and Ni2+ ions followed the order: Al-bentonite > SDS-bentonite > T-bentonite > natural bentonite. The initial metal concentration, solution pH, temperature and salinity of the solution affected the adsorption capacity towards both metal ions. The uptake of Cu2+ ions increased with an increase in temperature (25–45°C) as well as with an increase in the initial pH of the solution (3–5). The uptake of Cu2+ and Ni2+ ions decreased significantly with an increase in the NaCl and KCl concentrations present in the aqueous solution. Sulphuric acid of 0.1 M concentration was found to be an effective desorbent for bentonite laden with heavy metals.
Energy Technology and Foreign Trade: The Case of Denmark
Authors: Jacobsen Henrik Klinge 
Published: March 2010

This paper address two issues related to energy technology and trade. First it examines the importance of changes in energy technology for long-term trade developments of the Danish manufacturing industry. Secondly the trade potential of a policy to support the development of environmental friendly energy technologies is examined. Energy technologies affect the competitive position of industries through their energy costs. This paper presents an empirical investigation of the Danish industries with respect to the energy intensity and the relative production development of the energy intensive industries relative to the average industry. Another important effect of the change in energy technologies is the competitive option for the industries producing the capital equipment of a specific energy technology. Here the consequences for the Danish wind turbine manufacture and for the manufacture of pipes for district heating can be highlighted. Exports of the environmental friendly technologies are found to be the most important contribution to trade figures in the Danish case.
The Cause of Global Warming
Authors: Gray Vincent 
Published: March 2010

Three of the four methods of measuring global temperature show no signs of global warming Proxy measurements (tree rings, sediments etc) for the past 1000 years Weather balloons (radiosondes) for the past 44 years Satellites (MSU Units) for the past 21 years.The fourth method, surface measurement at weather stations, gives an averaged mean global rise of a mere 0.6°C over 140 years, but is intermittent and irregular. Individual records are highly variable, regional, and sometimes, particularly in remote areas, show no change, or even a fall in temperature. It is concluded that temperature measurements carried out away from human influence show no evidence of global warming. The small and irregular rise shown by many surface stations must therefore be caused by changes in their thermal environment over long periods of time, such as better heating, larger buildings, darkening of surfaces, sealing of roads, increases in vehicles and aircraft, increased shielding from the atmosphere and deterioration of painted surfaces.
JI and CDM: Lessons from Pilot Project Assessment
Authors: Begg Katie , Parkinson Stuart 
Published: March 2010

This paper discusses two important issues concerning the use of Joint Implementation (JI) and the Clean Development Mechanism (CDM) under the Kyoto Protocol: — uncertainty in estimates of reductions in greenhouse gas (GHG) emissions; and — contribution to and assessment of sustainable development. The analysis is based on assessments of several operational projects which reduce GHG emissions in countries in transition and developing countries. The projects are concentrated in the energy sector. When considering uncertainty in the estimates of GHG emissions reduction from JI/CDM projects, there are two main issues: construction of the baseline and accuracy of monitoring. Analysis across a range of project types led to estimates of baseline uncertainty which vary from 25% to 60%. Recommendations are made for measures to manage the uncertainty. In terms of contribution to sustainable development, the paper reports analysis of the case study projects in this context and makes recommendations for project aspects which are positive in this respect.
Beauty in the Eye of the Beholder: A Comparison of ‘Green Power’ Certification Programs in Australia, Canada, the United Kingdom and the United States
Authors: Patterson Mary Jane , Rowlands Ian H. 
Published: March 2010

With growing concerns about air quality issues and the continuing restructuring of electricity supply industries world-wide, the prospects for ‘green power’ - that is, environmentally-friendly electricity - are probably better now than they have ever been. What kinds of power are deemed to be ‘green’, however, is the subject of much debate. In an effort to standardise the definition of green power, certification programs are being developed independently by different countries at the national or sub-national level. Effectively, these are the mechanisms by which green power is currently being defined. This article compares the attributes of four certification programs for green power-those in Australia, Canada, the United Kingdom and the United States. The goal is to determine the ways in which these programs are similar, and the extent to which they are different. Though there is no definitive effort to determine which certification program is ‘best’, the key debates surrounding the most contentious parts of green power certification programs are identified and investigated. Accordingly, the policy discussion about the relative merits of different approaches is informed and stimulated.
On Prandtl's Formulas for Supersonic Jet Cell Length
Authors: Powell Alan 
Published: March 2010

In 1904 Prandtl developed a pioneering small perturbation theory to obtain the well-known “Prandtl Formula” λ = 1.306 d√(( wm/ c)2 − 1) for the wavelength (cell length) of an almost perfectly expanded circular supersonic jet, uniform everywhere and notably so on the bounding streamlines, where d = jet diameter, wm/ c = mean (unperturbed) speed (Mach number) of the jet. To relate to experiment and possibly provide a means of estimating jet speed from cell length measurements, he very tersely made a comparison of the results of his formula with those of Emden's formula, λ = 0.88 d√( R - Rc). This was based on extensive experiments with choked jets, with R = pressure ratio (critical value Rc), He rewrote his formula as λ = 1.306 dw√(( w/c)2 − 1), called herein “Prandtl's Formula II, where now dw = minimum diameter of the nozzle duct, i.e. exit diameter for Emden's choked jets, but the throat diameter of the convergent-divergent nozzle of uniform supersonic jets. He rewrote the foregoing equation, “my relationship,”” clearly considering that the nozzle exit diameter dw for the fully expanded flow would vary (according to the one-dimensional gas flow equations) so as to be consistent with the pressure ratio in Emden's formula. Unfortunately these simple but important notational changes for the comparison were made without comment and appear to have been totally ignored. Then converting his Formula II into Emden's form gave the well-known λ = 1.2 d√( R - Rc), a good approximation over a wide range of R. This fully satisfied Prandtl's objective, the discrepancy (1.2 vs. 0.88) being a constant factor easily taken into account, its magnitude apparently being of no particular significance considering the radically different jet flow structures. The coefficient 1.306 was improved to 1.22 by Pack who was able to compute up to 40 terms of the series solution, for which Prandtl had taken just the first term. Pack also provided the full series solution for the two-dimensional case. The circumstances of the origin of these formulas and their subsequent history over the next half-century are discussed in some detail, but a more general discussion of cell length is beyond the scope of this account.
Vortex Sound with Special Reference to Vortex Rings: Theory, Computer Simulations, and Experiments
Authors: Kambe Tsutomu 
Published: March 2010

This is a review paper on vortex sound with special reference to vortex rings and sound emission detected in experimental tests. Any unsteady vortex motion excites acoustic waves. From the fundamental conservation equations of mass, momentum and energy of fluid flows, one can derive a wave equation of aerodynamic sound. The wave equation of acoustic pressure can be reduced to a compact form, called the equation of vortex sound. This equation predicts sound generation by unsteady vortex motions. On the other hand, based on the matched asymptotic expansion (using the multipole expansions), one can derive a formula of wave pressure excited by time-dependent vorticity field localized in space. The theoretical predictions are compared with experimental observations and direct computer simulations. The systems considered are, head-on collision or oblique collision of two vortex rings, vortex-cylinder interaction, vortex-edge interaction, and others. Scaling laws of the pressure of emitted sound are predicted by the theory and compared with experimental observations. Comparison between theories and observations shows excellence of the theoretical predictions. Direct numerical simulations are reviewed briefly for sound generation by collisions of two vortex rings and that by a cylinder immersed in a uniform stream ( aeolian tones). Vortex sound in superfluid is also reviewed about experimental observations and computational studies on the basis of the Gross-Pitaevski equation.
Computational Investigation of Flow Fields and Erosion in a Dimpled Channel
Authors: Alhajeri M. H. , Alhajeri H. Alhamad 
Published: March 2010

A numerical prediction of flow in a dimpled channel is reported. The flow regimes considered cover a wide range of Reynolds numbers, which range from 380 to 99000 and which are equivalent to a range of inlet velocities from very low (0.072 m/s) to very high (60 m/s). In this study, calculations were made using the standard k-e model with standard wall function. The drag coefficient, skin friction drag, pressure drag, and pressure distribution around a dimple were investigated. As the velocity increased, the drag coefficient decreased until the velocity exceeded 45 m/s, after which it increased. Furthermore, the pressure drag and skin friction drag depend on the velocity. Particles with a density of 2440 kg/m3 and a diameter of 100 microns were tracked through the domain to estimate the frequency, velocity, and angle of impact of the particles and to estimate the resulting erosion rate. It was found that the maximum erosion rate occurred between 40 and 65 degrees from the leading edge of the dimple. Furthermore, a computational study of the flow fields of three dimples in an in-line arrangement is presented. This study showed that similar flow behaviours exist between the first and second dimples and that the flow behaviours are identical between the second and third cylindrical dimples.