bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Investigation Of The Effects Of Fluid Rheological Properties On Three-Dimensional Fracture Propagation
Authors: Ben-Naceur K. , Touboul E. , Roegiers J.E.
Published: March 2010

Abstract

Fluids used in hydraulic fracturing are required to have several characteristics: high viscosity and low leak-off into the formation during the injection, good proppant carrying properties, rapid breakdown during the closure. and easy clean-up during the post stimulation phase, Fluids with complex chemical formulations has been developed to meet those specifications: linear and crosslinked polymeric fluids, energized fluids (foams), gelled acids .. Those fluids depart from newtonian descriptions, and have a history-dependent rheology (to take into account the effects of temperature and shear dependency, with eventually a time-dependency due to the cross-linking process).

The rheology of the fracturing fluids is an essential component in the design of the stimulation treatments, and fluid flow equations dictate the lateral and vertical pressure distribution in the fracture. Algebraic techniques have been used to provide relations, between the fracture parameters (length, width, excess pressure or injection rate) and the fluid rheological description for power law fluids 1.

Introduction

This paper uses a numerical technique for the simulation of three-dimensional propagation of a fracture, and considers the effects of deviation from power-law on the final fracture c:haraderistics. Simpler models (P3DH2) have been developed in the literature, and the previous model provides a tool to validate them. We compare here the vertical growth rates predicted by the fully three-dimensional model with the ones used by a discrete P3DH formulation.

Many fracturing fluids have been shown to deviate from the classical power law representation, and we examine the effects of using some of the more complex rheological models on fracture geometry and proppant placement in the fracture.

The paper finally addresses the problem of the influence of fracture roughness on treatment parameters, and fracturing pressure decline analysis.

FORMULATION AND EQUATIONS

Assuming an isotropic elastic behaviour of the formations, And that the linear fracture mechanics assumption hold, a variational Formulation for the general three-dimensional fracture propagation Equations can be formulated3 by coupling the three sets of equations.

Elasticity

The formulation is based on a finite element formulation of a general boundary integral equation, and has the advantage wrt the classical finite element systems of reducing the dimension of the problem by one:

Equations available in full paper.
An Analytical Model to Predict the Deliverability of a Multiple Fractured Horizontal Well (MFHW)
Authors: Carle D. , Pearson B. , Logan K.
Published: March 2010

The tight gas resource potential in the Western Canadian Sedimentary Basin is enormous. To date, however, it remains relatively unexploited and underdeveloped.

The use of multiply fractured horizontal wells (MFHW) appears to be the "breakthrough" technology needed to economically exploit reasonably thick tight gas zones with effective in-situ permeabilities between 0.1 mD and 0.005 mD. This exploitation technology is already being applied in Europe and, in a more limited extent, in the U.S. Its application in Canada is currently being tested and/or evaluated by several of the larger majors. (This technology also has the potential for enhancing the deliverability of conventional gas.)

An analytical model has been developed to predict the deliverability and production forecast of a multi-fractured horizontal well in a tight gas pool that includes the initial, transient production period. Using the DTC (discounted technical cost) approach to evaluate the economic feasibility of tight gas resources, the majority of the deep, high pressure tight gas evaluated in this study appears to be commercially viable, even at today's gas prices.

Advances In Tight Gas Production Technology

Historically, the development of tight gas reservoirs has involved drilling vertical wells and hydraulically fracturing them, often with the use of large amounts of proppant. These large fracs are known as massive hydraulic fracs (MHF) and typically involved hundreds of thousands or even millions of pounds of proppant.

Quasi government bodies in the United States, such as the Gas Research Institute (GRI) and the Department of Energy (DOE), have been heavily involved in promoting research into the production of tight gas sands (Ref. 1). The GRI and Advanced Resources International (Ref. 2) have highlighted four key new technologies which they believe have the greatest application for the efficient development of tight gas sands:

- 3D Seismic

- Integrated Approaches to Natural Fracture Detection

- Improved Well Completions/Stimulations

- Selected Use of Horizontal Wells

We believe that multiply fractured horizontal wells (MFHW) is one such technology.

Spencer (Ref. 5) surmised that natural fractures played a key role in the production of most tight gas reservoirs so that if the extent and direction of the natural fractures can be predicted and is sufficiently intense and laterally extensive, horizontal and/or multi-lateral wells can be used to promote otherwise uneconomic pay zones. The logical corollary to this is to question whether a network of induced fractures from a horizontal well could be used where the natural fissuring has limited development; and, particularly, where the stress regimes allow the resulting induced fractures to intersect the natural fissuring.
Recovery Of Heavy Oil Using Horizontal Wells And Gravity Drainage With Pressure Maintenance
Authors: Kantzas A. , Marentette D.F. , Erno B.P. , Chatzis T.
Published: March 2010

A series of experiments were performed in physical models saturated with heavy oils of 0.6 to 12.7 Pa.s. The oil was displaced by gravity drainage at constant pressure and it was produced using horizontal wells. The pressure was maintained either using a vacuum pump or by injection of an inert gas at low injection pressures. Computer Assisted Tomography was used for the visualization of the displacement front. Additional gravity drainage tests were performed in long vertical columns and in two dimensional glass micromodels. In this paper a detailed description of the performed experiments is presented. Production characteristics are shown and images of the gravity drainage process are a/so included. The recoveries varied from 20 % to 50 % recovery of the original oil in place. The pressure difference was maintained between 10 and 30 kPa. In the cases where sand parting was not observed, a uniform displacement front was formed. In the cases where parting was observed the experiment was temporarily shut in. Substantial amounts of oil were produced following the shut in period. Temporary shut in was also implemented at gas breakthrough with considerable increase in the oil recovery.

Introduction

In the Lloydminster area of west central Saskatchewan and east central Alberta, large reserves of heavy oil exist which can be mobilized at reservoir conditions. Conventional primary production of these reservoirs has utilized mainly vertical wells on relatively large spacings, resulting in recoveries of 5–10 % OOIP. Recent applications of horizontal wells in these reservoirs hold some promise of increasing recoveries, but thin pay intervals, low reservoir pressures and low GOR's limit the effectiveness of recovery mechanisms based on gravity, natural pressure depletion and solution gas drive.

The work described in this paper considers the enhancement of gravity drainage in LIoydminster reservoirs through injection of immiscible gas and production via horizontal wells. In addition to presenting results of lab experiments in various physical models, an extensive review of relevant literature is included.
Electromagnetic Stimulation Of Lloydminster Heavy Oil Reservoirs
Authors: Davison R.J.
Published: March 2010

The paper will present the field test results of two electromagnetic (EM) stimulation projects conducted in the L1oydl1linster heavy oil area. The two wells (AI-1l-48-25 W3M Lashbum and AS-6051-27 W3M Northminster) produce heavy crude from the Sparky formation. Detailed production, electrical and operational data was gathered and analyzed to quantify the effect EM stimulation had on each well's producing characteristics.

77Je main areas covered by the paper include production characteristics (primary and enhanced), inflow performance relationships (primary and enhanced), operational considerations and some of the related economics. The data discussed to this point has been restricted to reservoir heating.

An additional review of a tubing heating electrical configuration test (ran on the Lashbum well) has been included. 17ze viscous nature of the crude oil being produced caused severe rod fall problems. Tubing heating was initiated to reduce the wellbore fluid viscosity and eliminate the rod fall problem. The paper will conclude with a general overview of the EM stimulation process as applied to the Canada Northwest Energy Limited locations and the potential for future applications.

Introduction

The possibility of using electrical energy to heat oil bearing formations has been attempted on several occasions over the past four decades. In general terms, the electrical (and electromagnetic energy) is converted to heat. Three basic types of heating are possible (dielectric, inductive and resistive). This discussion will deal with the resistive heating process.

Canada Northwest Energy et al (CNW) contracted with EOR International (EOR) to field test the process in the Lloydminster area heavy oil formations. A majority of the heavy oil sands around Lloydminster are well suited to the application of electromagnetic (EM) heating. Many of the formations are relatively thin and not well suited for other secondary, tertiary and thermal recovery methods. The EM heating process as applied in the CNW pilot areas creates a heated zone in the near wellbore region. The application of heat significantly reduces the viscosity of the oil, improves the oil/water flow characteristics, and overcomes some forms of formation damage. The end result is an improved pressure profile in the near wellbore region and a corresponding increase in the oil production rate.
Indoor Air Purification by Compost Packed Biofilter
Authors: Ondarts Michel , Hort Cécile , Platel Vincent , Sochard Sabine
Published: March 2010

The interest in Indoor Air Quality (IAQ) has increased this past decade due to better knowledge of this kind of pollution. Recent studies have pointed out the Indoor Air Pollution (IAP) impact on health and associated costs. IAQ improvement can be achieved by removal of pollutant with adapted process. Numerous processes, as sorption or UV photocatalysis, have been studied for IAP treatment. However, IAP specificities, including high number of compounds with different physico-chemical properties at low concentrations, still limit process efficiencies. Competition between pollutants and process selectivity are also common limitations. Biofiltration is commonly used to treat effluents containing numerous compounds at low concentration in composting units or wastewater treatment plants. Moreover, since it uses waste as a filtration medium and avoids the addition of chemical products, biofiltration is a sustainable technology. In this study, biofilter performances for IAP treatment are evaluated. The biofilter is packed with compost, a natural medium which has a large range of microorganisms, good physical properties (water retention, pH) and contains nutrients. The model effluent contains 8 compounds (aldehyde, aromatic, chlorinated, inorganic...), at low concentration (sub-ppmv), chosen for their ubiquity in indoor air, their heterogeneous physical and chemical properties (solubility, vapor pressure, biodegradability) and their potential health risk due to chronic exposures. Biofilter performances were evaluated during 75 days in steady state. Three compounds, undecane, limonene and butyl acetate, could not be quantified during the study, removal efficiencies are close to 100 %. Butanol, formaldehyde and toluene were removed with efficiencies close to 100 % during the first 40 days. After this time, efficiency variations were observed and the removal efficiencies decreased to 55.5, 77.8 and 13.9 % for butanol, formaldehyde and toluene, respectively. The decrease of bed moisture content seems to be the main explanation for these phenomena. Removal efficiencies of 86.3  99.6 % were achieved for nitrogen dioxide. Only trichloroethylene, known as a not easily biodegradable compound, was not removed by the biofilter: only sorption and desorption phenomena were observed during this time for this compound. In these starvation conditions, biomass cannot grow and only a fraction of the biomass can be maintained in the biofilter. However, this non-negligible biomass fraction can have a biological activity and removes the different compounds contained in the model effluent.
Mean Cancer Mortality Rates in Low versus High Elevation Counties in Texas
Authors: Hart John
Published: March 2010

There is controversy as to whether low levels of radiation (i.e., < 5 rem) pose a health risk. This brief inquiry compares archived cancer mortality data in counties having relatively low (0–250 feet above sea level), medium (500–1000 feet above sea level), and high (3000+ feet above sea level) elevations also having corresponding greater natural background levels of radiation respectively. Cancer mortality was found to be lowest in the high elevation counties (mean = 58.2) followed by low elevation counties (67.5) and then medium elevation counties (70.4). Statistically significant differences were found between low -high elevations (p = 0.003), and medium - high elevations (p = 0.010), but not between low and medium elevations (p = 0.5). More rigorous research, with an accounting of confounding variables, is indicated.
Stochastic Threshold Microdose Model for Cell Killing by Insoluble Metallic Nanomaterial Particles
Authors: Scott Bobby R.
Published: March 2010

This paper introduces a novel microdosimetric model for metallic nanomaterial-parti-cles (MENAP)-induced cytotoxicity. The focus is on the engineered insoluble MENAP which represent a significant breakthrough in the design and development of new products for consumers, industry, and medicine. Increased production is rapidly occurring and may cause currently unrecognized health effects (e.g., nervous system dysfunction, heart disease, cancer); thus, dose-response models for MENAP-induced biological effects are needed to facilitate health risk assessment. The stochastic threshold microdose (STM) model presented introduces novel stochastic microdose metrics for use in constructing dose-response relationships for the frequency of specific cellular (e.g., cell killing, mutations, neoplastic transformation) or subcellular (e.g., mitochondria dysfunction) effects. A key metric is the exposure-time-dependent, specific burden (MENAP count) for a given critical target (e.g., mitochondria, nucleus). Exceeding a stochastic threshold specific burden triggers cell death. For critical targets in the cytoplasm, the autophagic mode of death is triggered. For the nuclear target, the apoptotic mode of death is triggered. Overall cell survival is evaluated for the indicated competing modes of death when both apply. The STM model can be applied to cytotoxicity data using Bayesian methods implemented via Markov chain Monte Carlo.
Rehabilitation Following a Minimally Invasive Procedure for the Repair of a Combined Anterior Cruciate and Posterior Cruciate Ligament Partial Rupture in a 15-Year-Old Athlete
Authors: Beecher Michael , Garrison J. Craig , Wyland Douglas
Published: March 2010

Study Design

Case report.

Background

The healing response procedure is a minimally invasive arthroscopic surgical technique used to stimulate healing in the treatment of partial cruciate ligament tears. The purpose of this report is to provide information on the surgical procedure, the postoperative rehabilitation, and the overall functional results in a patient who underwent such a procedure.

Case Description

A 15-year-old male, who sustained a partial tear of both the anterior cruciate and posterior cruciate ligament while playing football, underwent arthroscopic surgical management utilizing a healing response technique. Precautions concerning range of motion and resisted activities were followed postoperatively to protect the healing cruciate ligaments. The postoperative protocol consisted of 3 phases, culminating in return-to-sport training. Treatment incorporated cardiovascular, proprioceptive, strength, power, plyometric, and sport-specific activities. Treatment was progressed based on specific criteria emphasizing proper movement patterns and eccentric control during functional activities.

Outcomes

The patient attended 31 physical therapy sessions over 17 weeks. Strength improved from 3/5 to 5/5, knee range of motion returned to normal, Lower Extremity Functional Scale scores improved from 21/80 to 80/80, and successful outcomes on functional return-to-sport testing allowed the patient to return to competitive athletics.

Discussion

Primary repair of cruciate ligament tears has yielded poor results, and partial cruciate ligament tears may not require complete surgical reconstruction. The healing response technique offers a possible solution for the treatment of partial cruciate ligament tears. A criterion-based postoperative protocol was derived based on current evidence regarding rehabilitation following cruciate ligament reconstruction and evidence regarding lower extremity rehabilitation principles and injury prevention.

Level of Evidence

Therapy, level 4. J Orthop Sports Phys Ther 2010;40(5):297–309. doi:10.2519/jospt.2010.3162
High-resolution ultrasonography in the diagnosis and intraoperative management of peripheral nerve lesions
Authors: Lee Franklin C. , Singh Harminder , Nazarian Levon N. , Ratliff John K.
Published: March 2010

Object

The diagnosis of peripheral nerve lesions relies on clinical history, physical examination, electrodiagnostic studies, and radiography. Magnetic resonance neurography offers high-resolution visualization of structural peripheral nerve lesions. The availability of MR neurography may be limited, and the costs can be significant. By comparison, ultrasonography is a portable, dynamic, and economic technology. The authors explored the clinical applicability of high-resolution ultrasonography in the preoperative and intraoperative management of peripheral nerve lesions.

Methods

The authors completed a retrospective analysis of 13 patients undergoing ultrasonographic evaluation and surgical treatment of nerve lesions at their institution (nerve entrapment [5], trauma [6], and tumor [2]). Ultrasonography was used for diagnostic (12 of 13 cases) and intraoperative management (6 of 13 cases). The authors examine the initial impact of ultrasonography on clinical management.

Results

Ultrasonography was an effective imaging modality that augmented electrophysiological and other neuroimaging studies. The modality provided immediate visualization of a sutured peroneal nerve after a basal cell excision, prompting urgent surgical exploration. Ultrasonography was used intraoperatively in 2 cases to identify postoperative neuromas after mastectomy, facilitating focused excision. Ultrasonography correctly diagnosed an inflamed lymph node in a patient in whom MR imaging studies had detected a schwannoma, and the modality correctly diagnosed a tendinopathy in another patient referred for ulnar neuropathy. Ultrasonography was used in 6 patients to guide the surgical approach and to aid in intraoperative localization; it was invaluable in localizing the proximal segment of a radial nerve sectioned by a humerus fracture. In all cases, ultrasonography demonstrated the correct lesion diagnosis and location (100%); in 7 (58%) of 12 cases, ultrasonography provided the correct diagnosis when other imaging and electrophysiological studies were inconclusive or inadequate.

Conclusions

High-resolution ultrasonography may provide an economical and accurate imaging modality with utility in diagnosis and management of peripheral nerve lesions. Further research is required to assess the role of ultrasonography in evaluation of peripheral nerve pathology.
Glioma stem cells involved in tumor tissue remodeling in a xenograft model
Authors: Dong Jun , Zhang Quanbin , Huang Qiang , Chen Hua , Shen Yuntian , Fei Xifeng , Zhang Tianyi , Diao Yi , Wu Zicheng , Qin Zhenghong , Lan Qing , Gu Xiaosong
Published: March 2010

Object

Although tissue remodeling plays a crucial role in the tumorigenesis and progression of human gliomas, its mechanisms remain largely uncertain. In the current study, the authors investigated the potential role of human glioma stem cells (hGSCs) in the tissue remodeling of gliomas.

Methods

Transgenic nude mice with ubiquitous green fluorescent protein (GFP) expression were obtained by crossing nontransgenic NC athymic nude mice with the GFP transgenic C57BL/6J mice. As a result, GFP was expressed in essentially all tissues in the offspring. Human glioma stem cells were then orthotopically implanted into the GFP nude mice in an effort to assess the hGSC–host brain interactions and thereby elucidate the roles of tissue remodeling during tumorigenesis and progression of human gliomas.

Results

All of the essential tissues in the GFP transgenic nude mice, including the brain, fluoresced green under an excitation light; therefore, tumor remodeling by hGSCs can be unambiguously distinguished from a bright green background composed of adjacent host GFP-expressing components. This technique enabled the authors to address the following concerns: 1) hGSCs were involved in the invasiveness of gliomas and adjacent stroma degradation of the host. 2) An in vivo study demonstrated that cell fusion occurred between hGSCs and host cells. 3) Vasculogenic mimicry—the formation of patterned, tubular networks of vascular channels by transdifferentiated hGSCs—could be observed. 4) Differentiation mimicry—namely, the differentiation direction of hGSCs bearing multidifferentiation potentials—seemed to be decided by the local host cellular microenviroment.

Conclusions

The results of this study indicated that the GFP transgenic nude mice model with GFP expression in essentially all tissues could be obtained by crossing nontransgenic athymic nude mice with transgenic GFP mice. This model should greatly expand our knowledge of glioma-host interactions. The data indicated that hGSCs might play a decisive role in tissue remodeling of gliomas as well.
Indanylation of o-Cresol with Indene
Authors: Saha Manoranjan , Chakravarty Prashanta , Saha Dipti , Khan Sadia Afrin , Bhuyan M Tafsir Uddin
Published: March 2010

Indanyl o-cresol has been obtained in high yield by the reaction of o-cresol with indene in the presence of p-toluenesulphonic acid as catalyst. The effects of variation of temperature, molar ratio of o-cresol to indene, time of reaction and amount of the catalyst have been investigated on the reaction. The yield of the product increased with the increase of each of the above mentioned parameters. Optimum conditions of the reaction for the production of indanyl o-cresol were temperature, 130°C; molar ratio of o-cresol to indene, 12:1; amount of catalyst, 8% by wt. of o-cresol; time of addition, 2h and time of stirring, 1h. Key words: o-Cresol; Indene; p-Toluenesulphonic acid; Indanyl o-Cresol; Spectral analyses DOI: 10.3329/bjsir.v44i4.4593 Bangladesh J. Sci. Ind. Res. 44(4), 432-434, 2009
A Markov Based Detection for Broadband over Power Line Communications (PLC)
Authors: Morshed M , Sarker P , Roy RC
Published: March 2010

Successful development of Broadband over Power Lines (BPL) is obviously a potential solution for wireless communication systems with the existing infrastructure. Multi-Carrier Code Division Multiple Access (MC-CDMA) with Orthogonal Frequency Division Multiplexing (OFDM) modulation technique is a promising solution for a frequency selective fading with impulsive noises of the PLC channel. A linear iterative receiver with a Finite State Markov Channel (FSMC) model is proposed to remove Multiple Access Interference (MAI) and Inter Symbol Interferences (ISI). In this paper we focused on Maximum Likelihood (ML) feedback detection by introducing FSMC to get significant improvement in Bit Error Rate (BER). This model of the receiver is more robust against Gaussian colored and impulsive noises of the PLC channel. Keywords: FSMC; MC-CDMA; OFDM; MAI; ISI DOI: 10.3329/bjsir.v44i4.4595 Bangladesh J. Sci. Ind. Res. 44(4), 441-444, 2009
Polymetallic Complexes Part LXXXXV Bis-bidentate Donor Azodye Dimeric Complexes
Authors: Mahapatra Bipin Bihari , Patel Nilanchala
Published: March 2010

Twelve dimeric complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with two new bis-bidentate donor azodye ligands, 4,4'-bis (2'-hydroxy-3',5'-dinitrophenylazo) diphenylsulphone and 4,4'-bis (2'-hydroxy-5'-nitrophenylazo) diphenylsulphone has been synthesized. The structure elucidation of the complexes was made basing upon analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, and X-ray diffraction (powder pattern) data. Antifungal activities of the ligands and a few complexes were also studied. The cobalt (II) and nickel (II) complexes are found to be octahedral, copper (II) complexes are distorted octahedral and a tetrahedral stereochemistry has been suggested to Zn (II), Cd (II) and Hg (II) complexes. Key words: Polymetallic complexes; Azodye complexes; Multidentate ligands. DOI: 10.3329/bjsir.v44i4.4596 Bangladesh J. Sci. Ind. Res. 44(4), 445-452, 2009
A study to Establish a Protocol for Cultivation of Jatropha curcas Linn
Authors: Rahman MM , Banu LB , Uddin MN , Begum MM
Published: March 2010

Survival rate of stem cutting, vegetative and reproductive growth studies were performed with Jatropha curcas. Plant species were collected from different topographical regions of Bangladesh viz. Chittagong, Sylhet, Jessore and Thakurgaon. No organic, inorganic fertilizer or plant hormone were used in this experiment. Results of the study revealed that best performance in respect of vegetative growth and reproductive growth was found in field condition. The study also showed that survival rate of stem cutting is highest in pot. The maximum survival rate (42.7%) for stem cutting was found during the month of March. Stem cutting collected from Chittagong showed best performance. The results suggested that genome collection and cultivation of Jatropha curcas performed best in summer season, specifically from March to early April, which is unusual to other plants in our country. It also suggested that to cultivate J. curcas in level land like Dhaka, steam cutting should be collected from hilly areas of Bangladesh like Chittagong district for more survival rate of plants. Key words: Jatropha curcas; growing season; fertilizer; soil pH; survival percentage. DOI: 10.3329/bjsir.v44i4.4598 Bangladesh J. Sci. Ind. Res. 44(4), 457-460, 2009
Fish Drying in Chalan Beel Areas
Authors: Samad MA , Galib SM , Flowra FA
Published: March 2010

A study on fish drying in Chalan Beel areas was conducted between August 2006 and February 2007. Field survey was carried out in Atrai, Singra, Tarash, and Bhangura Upazilas adjacent to Chalan Beel to assess the fish drying status. Twenty six fish were used for drying including five major fish species for large scale drying and remaining species were mixed with major species, mostly of damaged physically. Majority (89.3%) dry fish farmers brought raw fishes from local fish markets or landing centers. Washing of raw fish was done by beel water and poor quality salts were used for salting (rate: 50-250 g / kg fish) in most cases. Majority drying were done by spreading raw fishes on bamboo rack without any protection measure from insects or dust. Finally, maximum dried products were carried to Sayadpur (Nilphamary) dry fish wholesale market by the dry fish farmers or other middlemen. Key Words: Chalan Beel; Fish drying; Dry fish farmer; Raw fish; Marketing DOI: 10.3329/bjsir.v44i4.4599 Bangladesh J. Sci. Ind. Res. 44(4), 461-466, 2009
Studies on the Production of Gasoline from Heavy oil (furnace oil) by Thermal Cracking
Authors: Jamal MS , Ismail Mohammad , Miah M Yunnus , Haque M Naimul , Banik Sujit Kumar
Published: March 2010

Heavy fuel oil (furnace oil) was thermally cracked by thermal cracker under different parametric conditions such as cracking temperature, molar ratio of heavy oil to diesel and cracking time to optimize the yield of the final product. In this thermal cracking process, the yield was gradually increased with the increase in temperature and time. After a certain temperature and time no significant increase in yield was observed. Thermo gravimetric analysis (TGA) was done to observe the percentage of weight loss with increasing temperature. The obtained cracked oil was fractionated by atmospheric vacuum distillation unit. Products obtained from different experiments under different conditions showed almost similar physico-chemical properties. Optimization was done on the basis of yield (%wt). The optimum yield (56.2%) of light petroleum fraction (gasoline) was obtained under the following experimental conditions: cracking temperature: 445°C; molar ratio of furnace oil to diesel 95:05; and cracking time: 30 min. The properties such as density, water content, ash content, pour point, flash point, viscosity, range of boiling point, sulphur content, carbon residue, octane number etc. of the obtained light petroleum fraction were found almost similar to that of the commercial grade gasoline. Key words: Furnace oil; Thermal cracking; Gasoline; Thermo gravimetric analysis. DOI: 10.3329/bjsir.v44i4.4601 Bangladesh J. Sci. Ind. Res. 44(4), 473-478, 2009
Genetic variation in walnuts (Juglans regia and J. sigillata; Juglandaceae): Species distinctions, human impacts, and the conservation of agrobiodiversity in Yunnan, China
Authors: Gunn Bee F. , Aradhya Mallikarjuna , Salick Jan M. , Miller Allison J. , Yongping Yang , Lin Liu , Xian Hai
Published: March 2010

Walnuts are a major crop of many countries and mostly cultivated in large‐scale plantations with few cultivars. Landraces provide important genetic reservoirs; thus, understanding factors influencing the geographic distribution of genetic variation in crop resources is a fundamental goal of agrobiodiversity conservation. Here, we investigated the role of human settlements and kinship on genetic variation and population structure of two walnut species: Juglans regia, an introduced species widely cultivated for its nuts, and J. sigillata, a native species cultivated locally in Yunnan. The objectives of this study were to characterize sympatric populations of J. regia and J. sigillata using 14 molecular markers and evaluate the role of Tibetan villages and kin groups (related households) on genotypic variation and population structure of J. regia and J. sigillata. Our results based on 220 walnut trees from six Tibetan villages show that although J. regia and J. sigillata are morphologically distinct, the two species are indistinguishable based on microsatellite data. Despite the lack of interspecific differences, AMOVAs partitioned among villages (5.41%, P = 0.0068) and kin groups within villages (3.34%, P = 0.0068) showed significant genetic variation. These findings suggest that village environments and familial relationships are factors contributing to the geographic structure of genetic variation in Tibetan walnuts.
Ecological and geographic modes of species divergence in wild tomatoes
Authors: Nakazato Takuya , Warren Dan L. , Moyle Leonie C.
Published: March 2010

Understanding the role of geography and ecology in species divergence is central to the study of evolutionary diversification. We used climatic, geographic, and biological data from nine wild Andean tomato species to describe each species’ ecological niche and to evaluate the likely ecological and geographical modes of speciation in this clade. Using data from >1000 wild accessions and publicly available data derived from geographic information systems for various environmental variables, we found most species pairs were significantly differentiated for one or more environmental variables. By comparing species’ predicted niches generated by species distribution modeling (SDM), we found significant niche differentiation among three of four sister‐species pairs, suggesting ecological divergence is consistently associated with recent divergence. In comparison, based on age‐range correlation (ARC) analysis, there was no evidence for a predominant geographical (allopatric vs. sympatric) context for speciation in this group. Overall, our results suggest an important role for environmentally mediated differentiation, rather than simply geographical isolation, in species divergence.
Rice pinch to war thrown nation: an overview of the rice supply chain of Sri Lanka and the consumer attitudes on government rice risk management
Authors: De Silva DAM , Yamao M
Published: March 2010

Rice is staple for 2 million people in war thrown nation devastated by tsunami. This is the second year running in which production increased in real terms through out past has failed to keep pace with population growth. The harvest has also been hit by floods and unusual wet weather. Time series forecasting analysis based on the secondary data was carried out to identify the past, present and future trends of rice production, prices and self sufficiency level. Focus group discussions and field observations used to construct the rice trading pattern. Primary data on consumer attitudes on government rice risk management obtained through the field survey. The study locations include both major rice growing areas (Hambantota, Anuradhapura and Pollonnnaruwa) as well as important consumer hubs (Colombo, Ratnapura, Galle, Matara and Hambantota). Cultivated and harvested land extends and yield have positive increasing trend while simple time series modeler explains the increasing trend of retail prices. Private sector is playing a very important role in rice marketing channel where government intervention is minimal. Behavior of the rice processors has direct impact on the availability of rice and the pricing in dome market. Consumers have negative attitudes on government rice risk management and they are not confident on state intervention. Key words: Rice; Sri Lanka; time series forecasting; consumer attitudes. DOI: 10.4038/jas.v4i2.1647 The Journal of Agricultural Sciences, 2009, vol. 4, no. 2 pp.77-96
Occupational stress among farming people
Authors: Ramesh AS , Madhavi C
Published: March 2010

During the last 25 years, agricultural sector has gone through lot of changes and it also found to be one of the potential areas for stress. Greater use of automation technology, more use of organic production, decrease price for agricultural products and new complicated legislations have made the life of farmers more stressful one. In this study an attempt is made to find out the potential factors which cause stress and made the life of farming community more miserable. Results have clearly indicated that the occupation farming leads to stress due to financial, weather, work overload, social interaction and farm hassles. It is inferred that all the selected dimensions are producing either high or medium level of stress to farming people. It is also found that stress due to financial factors is found to be slightly higher than other stresses. Key words: farm stress; financial stresses; weather; farm hassles; social interaction DOI: 10.4038/jas.v4i3.1650 The Journal of Agricultural Sciences, 2009, vol. 4, no. 3 pp.115-125
Statement of consensus on Family Medicine in Africa
Authors: Mash Robert , Reid Steve
Published: March 2010

Family Medicine is an emerging speciality in sub-Saharan Africa and yet potential interest in the contribution of Family Medicine to health, primary care and district health services is limited by the lack of a regional definition. Governments, health departments and academic institutions would benefit from a clearer understanding of Family Medicine in an African context.The 2nd African Regional WONCA (World Organisation of Family Doctors) Conference, held in Rustenberg, South Africa in October 2009, engaged participants from sub-Saharan Africa in the development of a consensus statement on Family Medicine. The consensus statement agreed to by the conference defined the contribution of Family Medicine to equity, quality and primary health care within an African context, as well as the role and training requirements of the family physician. Particular attention was given to the contribution of women in Family Medicine.
Continuous dependence on the data for nonlinear elliptic equations via symmetrization
Authors: Betta Maria Francesca , Mercaldo Anna
Published: March 2010

We prove the continuous dependence on the data of weak solutions to Dirichlet problem for nonlinear elliptic equations with a first order term and datum in dual spaces of classical Sobolev spaces. We deduce uniqueness results.
Subelliptic Hamilton–Jacobi equations: the coercive stationary case
Authors: Biroli Marco
Published: March 2010

We prove the existence uniqueness and comparison results for a (Lipschitz) viscosity solution for an Hamilton−Jacobi equation on a Carnot group.
Polymer‐Supported, Carbon Dioxide‐Protected N‐Heterocyclic Carbenes: Synthesis and Application in Organo‐ and Organometallic Catalysis
Authors: Pawar Gajanan Manohar , Buchmeiser Michael R.
Published: March 2010

The synthesis of a resin‐supported, carbon dioxide‐protected N‐heterocyclic carbene (NHC) and its use in organocatalysis and organometallic catalysis are described. The resin‐bound carbon dioxide‐protected NHC‐based catalyst was prepared via ring‐opening metathesis copolymerization of 1,4,4a,5,8,8a‐hexahydro‐1,4,5,8‐exo,endo‐dimethanonaphthalene (DMNH6) with 3‐(bicyclo[2.2.1]hept‐5‐en‐2‐ylmethyl)‐1‐(2‐propyl)‐3,4,5,6‐tetrahydropyrimidin‐1‐ium‐2‐carboxylate (M1), using the well‐defined Schrock catalyst Mo[N‐2,6‐(2‐Pr)2‐C6H3](CHCMe2Ph)(OCMe3)2 and was used for a series of organocatalytic reactions, i.e., for the trimerization reaction of isocyanates, as well as for the cyanosilylation of carbonyl compounds. In the latter reaction, turn‐over numbers (TON) up to 5000 were achieved. In addition, the polymer‐supported, carbon dioxide‐protected N‐heterocyclic carbene served as an excellent progenitor for various polymer‐supported metal complexes. It was loaded with a series of rhodium(I), iridium(I), and palladium(II) precursors and the resulting Rh‐, Ir‐, and Pd‐loaded resins were successfully used in the polymerization of phenylacetylene, in the hydrogen transfer reaction to benzaldehyde, as well as in Heck‐type coupling reactions. In the latter reaction, TONs up to 100,000 were achieved. M1, as a non‐supported analogue of poly‐M1‐b‐DMNH6, as well as the complexes PdCl2[1,3‐bis(2‐Pr)tetrahydropyrimidin‐2‐ylidene]2 (Pd‐1) and IrBr[1‐(norborn‐5‐ene‐2‐ylmethyl)‐3‐(2‐Pr)‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidine](COD) (Ir‐1) were used as homogeneous analogues and their reactivity in the above‐mentioned reactions was compared with that of the supported catalytic systems. In all reactions investigated, the TONs achieved with the supported systems were very similar to the ones obtained with the unsupported, homogeneous ones, the turn‐over frequencies (TOFs), however, were lower by up to a factor of three.
Resorcin[4]arene‐Derived Mono‐ and Diphosphines in Suzuki Cross‐Coupling
Authors: El Moll Hani , Sémeril David , Matt Dominique , Toupet Loïc
Published: March 2010

Three resorcin[4]arene cavitands (1–3) having either one or two resorcinolic C‐2 atoms substituted by a CH2PPh2 podand arm were assessed in the Suzuki arylation of aryl bromides with phenylboronic acid. Using P:Pd ratios of 2:1 and operating in dioxane at 100 °C with a catalyst loading of 0.001 mol% resulted in highly efficient catalytic systems. For example, TOFs up to 34570 mol(converted ArBr)⋅mol(Pd)−1⋅h−1 were obtained with the proximally‐disubstituted cavitand 3 when using 4‐bromotoluene as substrate. The performance was shown to vary in the following order: monophosphine 1<diphosphine 2<diphosphine 3 (where 2 is the distally disubstituted cavitand). A comparison of the catalytic properties of monophosphine‐cavitand 1 with those of benzyldiphenylphosphine and o‐anisylmethyldiphenyl phosphine suggests that 1 functions as a hemilabile phosphine, the oxygen atoms close to the phosphorus atom behaving as donors able to temporarily increase the electron density on the metal and/or favour the formation of mono‐ligand Pd(0) species.
Catalytic Dicyanative 5‐exo‐ and 6‐endo‐Cyclization Triggered by Cyanopalladation of Alkynes
Authors: Arai Shigeru , Koike Yuka , Nishida Atsushi
Published: March 2010

A stereoselective dicyanative 5‐exo‐ and 6‐endo‐cyclization using various enynes has been investigated. The mode of cyclization is critically controlled by the structure of the substrates. For example, N‐allyl derivatives prefer 5‐exo‐cyclization, while methacryloyl amides are transformed to the corresponding lactams with tetra‐substituted carbons at the alpha‐position via 6‐endo‐cyclization. Both reactions include syn‐cyanopalladation to carboncarbon triple bonds in the initial step, and sequential cyclization followed by reductive elimination in one operation enables the construction of the highly functionalized nitrogen heterocycles. The scope of suitable substrates and a proposed mechanism are also described.
Ionische Flüssigkeiten für Spezialaufgaben – von der Katalyse bis zur Analytik
Authors: Giernoth Ralf
Published: March 2010

Seit einigen Jahren haben ionische Flüssigkeiten (ionic liquids, ILs) wegen ihrer einzigartigen Eigenschaften als Lösungsmittel für chemische Transformationen die Aufmerksamkeit vieler Chemiker erregt. Dieser Kurzaufsatz konzentriert sich auf den Einsatz von so genannten “task‐specific”, also anwendungsorientierten ionischen Flüssigkeiten, deren Rolle über die eines Lösungsmittels hinaus geht. Vielfältige Anwendungsmöglichkeiten finden sich z. B. in den Bereichen der Katalyse, der Synthese, der Gasabsorption oder der Analytik.
Religion and mental health: theory and research
Authors: Levin Jeff
Published: March 2010

This article provides an overview of psychiatric and mental health research on religion. First, conceptual models of religion and of mental health used throughout this literature are described. Second, published empirical research in this field is summarized, including findings from epidemiologic, clinical, and social and behavioral investigations. Third, promising theoretical perspectives for understanding a putative religion–mental health connection are elaborated. These are based on respective behavioral, biological, psychodynamic, and transpersonal interpretations of existing research findings. Copyright © 2010 John Wiley & Sons, Ltd.
Practical stability and asymptotic stability of positive fractional 2D linear systems
Authors: Kaczorek Tadeusz
Published: March 2010

A new concept of the practical stability of the positive fractional 2D linear systems is proposed. Necessary and sufficient conditions for the practical stability and the asymptotic stability of the positive fractional 2D systems are established. It is shown that the checking of the practical stability and the asymptotic stability of positive fractional 2D linear systems can be reduced to testing the stability of corresponding 1D positive linear systems. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Stabilization for a class of complex interlaced systems using asymptotical gain
Authors: Ye Huawen , Kang Jianling , Liu Guoping , Gui Weihua
Published: March 2010

This paper addresses the stabilization problem of a class of interlaced systems that are not in a strict‐feedforward form and contain some severe nonlinear terms. Bounded control laws in a fractional form are explicitly constructed. The feature of stability analysis allows the closed‐loop system, when it is proven to have no finite escape time, to employ the asymptotical gain, which is obtained from an input‐to‐state stable (ISS) subsystem, to calculate the severe nonlinear terms, and the related estimate in turn guides the assignment of small controls. Together with the use of the passivity theory and the ISS‐based stability criterion, the proposed method requires no small gain analysis although the asymptotical gain is used, and differs from the state‐dependent saturation scheme since the controls do not include saturation functions. As an application, a new stabilizing control law is presented for the well‐known friction ball‐and‐beam system. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
LMI based stability and stabilization of second‐order linear repetitive processes
Authors: Dabkowski Pawel , Gałkowski Krzysztof , Datta Biswa , Rogers Eric
Published: March 2010

This paper develops new results on the stability and control of a class of linear repetitive processes described by a second‐order matrix discrete or differential equation. These are developed by transformation of the second‐order dynamics to those of an equivalent first‐order descriptor state‐space model, thus avoiding the need to invert a possibly ill‐conditioned leading coefficient matrix in the original model. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Testing (non‐)linearity of distributed‐parameter systems from a video sequence
Authors: Rafajłowicz Ewaryst , Rafajłowicz Wojciech
Published: March 2010

The aim of the paper is to propose a statistical test for testing (non‐) linearity of nD systems described by partial differential equations. The test is based on using a sequence of 2D observations provided by a camera, which are converted into observed modes of the system and compared to the modes that are expected when the system is linear. A theoretical correctness of the test is proved for a certain class of nonlinear systems. An application of the theory is illustrated by testing linearity of the process of cooling a copper plate. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Eight new and three recalculated orbits for binaries
Authors: Cvetković Z. , Novaković B.
Published: March 2010

In this paper new orbital elements are given for eleven binaries. For eight of them, WDS 00003–4417 = I 1477, WDS 00106–7313 = I 43 AB, WDS 00366+5609 = A 914, WDS 00519–4343 = I 47, WDS 01315+1521 = BU 506, WDS 01577+4434 = A 1526, WDS 08144–4550 = FIN 113 AB and WDS 08291–4756 = FIN 315 Aa‐Ab, the orbital elements are calculated for the first time. For three of them, WDS 04422+2257 = MCA 16 Aa‐Ab, WDS 08275–5501 = FIN 116 and WDS 14567–6247 = FIN 372, the orbital elements are recalculated. One of the eleven binaries, MCA 16 Aa‐Ab, was discovered by McAlister in 1980 by speckle interferometry and four pairs were discovered by Finsen between 1929 and 1960. For these five pairs, all measured separations are less than 0″.4 and most of the observations were done by using the interferometric techniques. The orbital periods calculated here are between 39 and 270 years. The remaining six pairs were discovered between 1878 and 1926 and most of the observations are visual. They have longer orbital periods, between 384 and 1637 years. In addition to the orbital elements the masses, dynamical parallaxes, absolute magnitudes and ephemerides for the next five years are also given in this paper (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)