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Summary: Islam as a universal religion, presents a comprehensive and practical system of ethics for the entire humanity in every field of life. Medical ethics is one of the most important components of this extensive ethics system. Islamic medical ethics is the approach of dealing with and handling the healthcare practice and process according to the Islamic moral system and legislative sources (primarily 'The Quran' and 'Hadith'). It is also adopted and promoted by several international organizations. Islamic ethics endorses the basic principles of biomedical ethics, i.e. Beneficence, non-maleficence, confidentiality, justice, truth-telling, autonomy and informed consent, which have been mainly derived from the "Hippocratic Oath", with some additions and modifications. Moreover, Islamic teachings present some additional moral values over these basic ethical principles. The present manuscript aims to concisely highlight the evolution and history of bio-medical ethics, briefly describe its basic concepts and focus on the influence of teachings, principles and characteristics of Islam on this important aspect of medical practice. In the end, some important relevant topics such as the general responsibilities of the doctor, protection of life, legal status of treatment and status of treatment with prohibited substances, in the light of Islam, are also discussed briefly. [ABSTRACT FROM AUTHOR]

Treatment of Gastro-Esophageal Reflux Disease (GERD) is becoming a challenge. Proton pump inhibitors (PPIs) are commonly prescribed but have many risks, particularly in long-term use. In an earlier pilot study, we have reported benefits of short-term practice of a new life-style, two meals a day with only liquids in between, for management of GERD. Present case report demonstrates benefits of long-term practice of this dietary regimen. A 61 year old patient complaining of night refluxes was diagnosed to have severe GERD with ulcerations at gastroesophageal junction and was advised to take two meals a day with only water, fruit juice, tea, or milk in intervening period. His reflux symptoms improved within fortnight and he remained well for long-time. Endoscopy done after seven years revealed competent and clear gastroesophageal junction. It is concluded that suggested life-style, "Akram's life-style", for GERD is a useful alternate to risky medical and surgical interventions. [ABSTRACT FROM AUTHOR]

The spatial and thermal dispersals of hydroxyl (OH), formaldehyde (CH2O), and other minor species were acquired using various detailed reaction mechanisms in a weak flame of stoichiometric methane and air mixture at ambient pressure. A weak flame was simulated inside a microflow combustor with a prescribed temperature profile that released a very small amount of heat. A wide reaction zone (~ 1 cm) was observed for the methane and air flames compared to the normal/conventional flames. A detailed oxidation analysis was performed based on the normal and weak flame simulations. The computational flame structure was assessed using the experimental results available in the existing literature. Numerical modeling under experimental conditions with various detailed mechanisms predicted a similarly wide reaction zone. However, species production and consumption temperatures varied according to the different mechanisms used in the present study. The GRI mech 3.0 shows a typical two-peak heat release rate profile. The initial breakdown of the fuel is vital for such scattering. The production of OH radicals governs the initial breakdown of fuel at intermediate temperatures. The present investigation is useful for understanding the chemistry of intermediate species in different fuel-air mixtures, especially at intermediate temperatures of 800-1200 K. [ABSTRACT FROM AUTHOR]

In the present computational study, the impact of strut positions and the effect of inlet Mach numbers on the combustion efficiency are investigated in a strut-based supersonic combustor. An experimentally investigated model combustor developed at the German Aerospace Center (DLR) is simulated and validated. Then, a model combustor with three struts placed at different positions is investigated. Two-dimensional, compressible, reacting-flow governing equations are solved along with single-step chemistry reaction and k-ω SST turbulence model using a commercial CFD code FLUENT. The oblique shock from the struts has a profound influence on the mixing and combustion process. The H2O mole fraction, H2 mole fraction contours, and combustion efficiency of various configurations are compared for finding better mixing and flame stabilization. The combustion efficiency reduces when the two struts are located in farther downstream or placed at the same downstream location. At higher Mach numbers, the combustion is delayed, and the mixing of fuel with the supersonic mainstream is incomplete. [ABSTRACT FROM AUTHOR]

Effects of basic amino acids, lysine (Lys) and arginine (Arg), at different levels (0%, 0.5%, and 1%, based on mince weight) on properties of striped catfish (Pangasianodon hypophthalmus) mince gel containing low salt (LS) and high salt (HS) were investigated. Without Lys or Arg addition, HS gel had the higher textural properties including hardness, chewiness, as well as cohesiveness than LS gel (P < 0.05) and the highest values were achieved when 1% Arg was incorporated in both LS and HS gels (P < 0.05). Arg had no effect on acceptability of mince gel. However, whiteness was decreased in HS gel when Arg was applied. Autolysis of gel was lower in HS gel containing Arg. No differences in protein patterns among all gel samples were found. Addition of Arg could increase the gelling ability of both LS and HS mince during heating as evidenced by higher storage modulus (G′) and viscous modulus (G″). Mince gel added with Arg had orderly interconnected structure and their microstructure was finer than that without Arg. Therefore, Arg could be used in LS gel from striped catfish mince, in which quality of gel was equivalent to HS counterpart. Practical Application: Basic amino acid, especially arginine (Arg) with guanidinium group, could increase repulsive force between protein molecules at low‐salt concentration (0.5%). This resulted in high solubilization of muscle proteins, whereas gel formation or gel strength was higher than that containing high salt (2.5% to 3.5%). Thus, Arg could be used for production of fish mince gel containing low salt with lowered health risk. [ABSTRACT FROM AUTHOR]

This study aims at investigating politeness strategies and pragmatic modifiers used by native speakers of Jordanian Arabic to perform the speech act of refusal. The data were collected from 24 hours of recorded conversations taken from different mixed and same-sex conversations by native speakers of Jordanian Arabic. The researchers observed these conversations and utterances that perform the speech act of refusal. The strategies of refusals were analyzed following Beebe, Takahashi, and Uliss-Weltz (1990) model, while pragmatic modifiers were analyzed following House and Kasper (1981) and Blum-Kulka, House, and Kasper (1989). The results of the study showed that the Jordanians used complex strategy more than direct and indirect strategies. The findings showed that Jordanians used many pragmatic modifiers to soften their refusals. The study found that external modifiers were more frequent than other types of pragmatic modifiers. The study also found out that culture affected the use of refusal strategies and pragmatic modifiers. The impact of culture appeared clearly in the fact that Jordanians tended to use Islamic religious expressions to mitigate their utterances. Besides, it seemed that Jordanians preferred complex strategies because they viewed repetition and using more than one strategy as a polite way to save the face of others. [ABSTRACT FROM AUTHOR]

Lighter-than-air (LTA) aerial vehicles such as airships and aerostats can be found in various strategic and commercial applications, primarily due to their capability to hover and stealth. The mathematical model of these vehicles helps in understanding their complex dynamics and designing and developing proper stabilisation systems for them. Stability derivatives have been used for developing mathematical models for heavier-than-air aerial vehicles since their introduction. This paper presents a methodology to develop a mathematical model of an aerostat based on stability derivatives. One of the major contributions of this study is the estimation of aerostat's added mass terms expressed as longitudinal stability derivatives due to acceleration of the longitudinal motion variables. A longitudinally decoupled linear mathematical model of a single-tethered aerostat using stability derivatives is investigated in this study. A computational fluid dynamics (CFD)-based analysis of the 3D model of the vehicle is used to obtain the stability derivatives. The methodology presented considers the aerostat and tether models separately before coupling them to create the full model. The stability derivative analysis is carried out using ANSYS Fluent, and the coupled tethered aerostat model is investigated using MATLAB 2020. The negative pitch angle of the aerostat is caused by the selection of the pitching centre as the aerostat centre of volume instead of the tether confluence point. The tension force on the tether, which is proportional to the wind velocity, and aerostat velocity components are found to be stabilised within 200–400 s. [ABSTRACT FROM AUTHOR]

Abstract The experimental measurements and computational predictions of the laminar burning velocity of DME and methane blends with air are reported in the present work. The well documented and validated rectangular diverging channel was used for the measurements. Whereas, one dimensional freely propagating flame simulations were performed using PREMIX code detail reaction mechanisms. The measured experimental data and predictions were successfully validated against the data available at ambient conditions. Then, high temperature burning velocity measurement and predicted data is reported. Influence of mixture equivalence ratios, blend combinations, and initial temperatures are critically analysed and discussed. The detail flame structure variation is also reported with the help of heat release rates, major and minor species profiles, reaction pathways, sensitivity analysis, and fake/pseudo-specie analyses. The addition of DME into methane enhances the reactivity and burning velocity. However, the rate of increase in burning velocity with respect to an increase in initial temperature is higher for pure methane + air mixtures. [ABSTRACT FROM AUTHOR]

Accurate measurement and prediction of laminar burning velocity is important for characterization of premixed combustion properties of a fuel, development and validation of new kinetic models, and calibration of turbulent combustion models. Understanding the variation of laminar burning velocity with thermodynamic conditions is important from the perspective of practical applications in industrial furnaces, gas turbine combustors and rocket engines as operating temperatures and pressures are significantly higher than ambient conditions. With this perspective, a brief review of spherical flame propagation method, counterflow/stagnation burner method, heat-flux method, annular stepwise method, externally heated diverging channel method, and Bunsen method is presented. A direct comparison of power exponents for temperature (α) and pressure (β) obtained from different experiments and derived from various kinetic mechanisms is reported to provide an independent tool for detailed validation of kinetic schemes. Accurate prediction of laminar burning velocities at higher temperatures and pressures for individual fuels will help in closer scrutiny of the existing experimental data for various uncertainties due to inherent challenges in individual measurement techniques. Laminar burning velocity data for hydrogen (H 2 ), gaseous alkane fuels (methane, ethane, propane, n-butane, n-pentane), liquid alkane fuels (n-heptane, isooctane, n-decane), alcohols (CH 3 OH, C 2 H 5 OH, n-propanol, n-butanol, n-pentanol) and di-methyl ether (DME) are obtained from literature of last three decades for a wide range of pressures (1–10 bar), temperatures (300–700 K), equivalence ratios and mixture dilutions. The available experimental and numerical data for H 2 and methane fuels compares well for various pressures and temperatures. However, more experimental and kinetic model development studies are required for other fuels. Comparison of laminar burning velocity data obtained from different measurement techniques at higher initial pressures and temperatures showed significant deviations for all fuels. This suggests to conduct focused measurements at elevated pressure and temperature conditions for different fuels to enable the development of accurate kinetic models for wider range of mixtures and thermodynamic conditions. [ABSTRACT FROM AUTHOR]

Objectives: Prevalence of diabetes mellitus in Arabian Peninsula has risen to a very high level especially in Saudi Arabia (32%). Compliance of diabetic patients' towards therapy is crucial for diabetic management. According to a study conducted at Riyadh, Saudi Arabia 83.4% of uncontrolled glycemic level (HbA1c ≥7%) patients did not follow the recommended dietary plan. Another factor for high rates of un-controlled diabetes was poor compliance to medication. Present study was aimed to investigate awareness of disease and drugs, as well as compliance to medication, dietary control and exercise in diabetic patients reporting to a tertiary hospital at Arar, Saudi Arabia. Study Design: A cross sectional descriptive study. Setting: Diabetic center of Prince Abdul Aziz bin Mossaid hospital, Arar, Saudi Arabia. Period: November and December 2015. Methods: Patients' awareness of disease and drugs, as well as compliance to medication, dietary control and exercise was investigated by using a structured questionnaire. Response to various questions was analyzed using SPSS program version 16. Data was further correlated between variables via Fisher's exact and chi-squared test. Result: Average awareness about disease and drugs was 56.5% and 23%, respectively. Overall compliance rates to medication, dietary control and exercise were 89.3%, 31% & 28.5%, respectively. Positive association was found between awareness to disease/drugs and compliance to therapy. Conclusion: The results of present study and similar studies conducted elsewhere indicate that patients' awareness towards their disease and medication is directly proportional to patients' compliance. Adequate awareness programs should be arranged for better management of diabetes in the community. [ABSTRACT FROM AUTHOR]

Real-world performance, durability and reliability of microinverters are critical concerns for microinverter-equipped photovoltaic systems. We conducted a data-driven study of the thermal performance of 24 new microinverters (Enphase M215) connected to 8 different brands of PV modules on dual-axis trackers at the Solar Durability and Lifetime Extension (SDLE) SunFarm at Case Western Reserve University, based on minute by minute power and thermal data from the microinverters and PV modules along with insolation and environmental data from July through October 2013. The analysis shows the strengths of the associations of microinverter temperature with ambient temperature, PV module temperature, irradiance and AC power of the PV systems. The importance of the covariates are rank ordered. A multiple regression model was developed and tested based on stable solar noon-time data, which gives both an overall function that predicts the temperature of microinverters under typical local conditions, and coefficients adjustments reecting refined prediction of the microinverter temperature connected to the 8 brands of PV modules in the study. The model allows for prediction of internal temperature for the Enphase M215 given similar climatic condition and can be expanded to predict microinverter temperature in fixed-rack and roof-top PV systems. This study is foundational in that similar models built on later stage data in the life of a device could reveal potential influencing factors in performance degradation. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to evaluate the suitable rootstock for yield enhancement of Kinnow (Citrus reticulata Blanco) at progeny garden of Citrus Research Institute Sargodha, Pakistan during the year 2002-2011. The seeds of Rough Lemon, Kinnow and Rangpur Lime were sown in nursery during 2002. The seedlings of root stocks were grafted with scion wood of Kinnow mandarin through T-grafting technique during 2004. The grafted plants were transplanted to actual field during September, 2005. Fruit yield was recorded during mid January of three consecutive years (2009, 2010 and 2011). The parameters studied were fruit weight, yield, fruit size, total soluble solids, rind thickness, TSS /acid ratio and juice percentage. The results revealed that rootstocks differ significantly in average fruit weight, fruit size, number of fruits per tree and yield in kg per tree during three successive seasons. Maximum fruit weight (225.12g), diameter (8.02 cm), yield (64.89 kg/plant), rind thickness (0.47 cm), TSS (12.92%), juice (48.11%) and TSS/acid ratio (19.58%) were produced by Rough Lemon rootstock, budded with Kinnow. While these parameters were found minimum in Rangpur Lime rootstocks budded with Kinnow. Results revealed that Rough Lemon rootstock has better effect on the yield and physicochemical characteristic of Kinnow under the prevailing climatic conditions of Sargodha, Pakistan. [ABSTRACT FROM AUTHOR]

In this study, numerical simulations have been carried out to analyze the effect of convective heat transfer on flow separation occurring in a DLP-PAR nozzle. Heat transfer coefficient (0, 200 and 1000 w/m2K) was applied to the nozzle wall to incorporate the cooling effect for different gas inlet temperatures ranging from 1000 to 1500 K. The impact of the cooling effect was analyzed based on nozzle wall temperature and wall static pressure. The wall static pressure distribution also characterizes movement of the separation point. For an inlet temperature of 1000 K, a detailed heat transfer study was carried out for four different nozzle pressure ratios (14, 22, 30 and 40). Significant amount of heat transfer was observed for pressure ratio 14, which in turn had an impact on flow separation. The wall cooling resulted in a shift of the point of separation towards the nozzle exit. For the nozzle pressure ratio of 14, this shift was by about 8.8%, indicating that the flow separation can be delayed by way of cooling for the considered inlet temperature. For higher inlet temperatures, the effect of heat transfer on flow separation seems to be negligible. The current study concludes that the separation point can be controlled by convective cooling for inlet gas temperatures below 1500 K so that the optimal performance of the nozzle can be achieved. [ABSTRACT FROM AUTHOR]

Objective To assess the association between streptococcal throat infection and psoriasis. Patients and methods Total one hundred fourteen (114) patients attending at outpatient and inpatient department of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University, Dhaka were selected for our study. Patients clinically and histopathologically diagnosed as psoriasis were selected as case group and patients with skin diseases other than psoriasis were selected as control group. Results In our study, mean age was 30.73±14.69 years in cases and 26.47±12.64 years in controls. Majority of respondents were diagnosed as chronic plaque psoriasis (51%) among acute guttate psoriasis, guttate flare of chronic plaque psoriasis, deterioration of chronic plaque psoriasis and pustular psoriasis. 19 (30%) patients of psoriasis had sore throat clinically. ASO titer was raised in 65% psoriatics and 19.6% non-psoriatic controls. Majority of cases of guttate psoriasis (86.6%) had raised ASO titer versus 27.2% respective controls. Normal flora was the maximum finding in two groups and Streptococcus pyogenes was the second highest in frequency in both sides. In throat swab culture results of two groups, 15 (23.8%) psoriasis patients and 5 (9.8%) non-psoriatic controls were found positive for S pyogenes. Conclusion Streptococcal throat infection can cause provocation of psoriasis. So, psoriasis patients should be encouraged to report sore throat to their physician and early treatment of streptococcal throat infections might be beneficial in psoriasis. [ABSTRACT FROM AUTHOR]

Nigella sativa (N. sativa) seed has been an important nutritional flavoring agent and natural remedy for many ailments for centuries in ancient systems of medicine, e.g. Unani, Ayurveda, Chinese and Arabic Medicines. Many active components have been isolated from N. sativa, including thymoquinone, thymohydroquinone, dithymoquinone, thymol, carvacrol, nigellimine-N-oxide, nigellicine, nigellidine and alpha-hederin. In addition, quite a few pharmacological effects of N. sativa seed, its oil, various extracts and active components have been identified to include immune stimulation, anti-inflammation, hypoglycemic, antihypertensive, antiasthmatic, antimicrobial, antiparasitic, antioxidant and anticancer effects. Only a few authors have reviewed the medicinal properties of N. sativa and given some description of the anticancer effects. A literature search has revealed that a lot more studies have been recently carried out related to the anticancer activities of N. sativa and some of its active compounds, such as thymoquinone and alpha-hederin. Acute and chronic toxicity studies have recently confirmed the safety of N. sativa oil and its most abundant active component, thymoquinone, particularly when given orally. The present work is aimed at summarizing the extremely valuable work done by various investigators on the effects of N. sativa seed, its extracts and active principles against cancer. Those related to the underlying mechanism of action, derivatives of thymoquinone, nano thymoquinone and combinations of thymoquinone with the currently used cytotoxic drugs are of particular interest. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of N. sativa, its active constituents and their derivatives. [ABSTRACT FROM AUTHOR]

Nigella sativa (N. sativa) seed has been an important nutritional flavoring agent and natural remedy for many ailments for centuries in ancient systems of medicine, e.g. Unani, Ayurveda, Chinese and Arabic Medicines. Many active components have been isolated from N. sativa, including thymoquinone, thymohydroquinone, dithymoquinone, thymol, carvacrol, nigellimine-N-oxide, nigellicine, nigellidine and alpha-hederin. In addition, quite a few pharmacological effects of N. sativa seed, its oil, various extracts and active components have been identified to include immune stimulation, anti-inflammation, hypoglycemic, antihypertensive, antiasthmatic, antimicrobial, antiparasitic, antioxidant and anticancer effects. Only a few authors have reviewed the medicinal properties of N. sativa and given some description of the anticancer effects. A literature search has revealed that a lot more studies have been recently carried out related to the anticancer activities of N. sativa and some of its active compounds, such as thymoquinone and alpha-hederin. Acute and chronic toxicity studies have recently confirmed the safety of N. sativa oil and its most abundant active component, thymoquinone, particularly when given orally. The present work is aimed at summarizing the extremely valuable work done by various investigators on the effects of N. sativa seed, its extracts and active principles against cancer. Those related to the underlying mechanism of action, derivatives of thymoquinone, nano thymoquinone and combinations of thymoquinone with the currently used cytotoxic drugs are of particular interest. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of N. sativa, its active constituents and their derivatives. [ABSTRACT FROM AUTHOR]

A study was conducted in the progeny garden of Citrus Research Institute, Sargodha, Pakistan during 2002-2008 to see the effect of various rootstocks on vegetative growth of Kinnow fruit plants. Rootstocks included were: Rough lemon (khatti), Kinnow and Rangpur lime. Seeds of these rootstocks were sown during August, 2002 which were germinated in October, 2002. These were transplanted in the nursery in October, 2003. Seedlings were grafted in September, 2004 and transplanted in the actual field in September, 2005. Maximum plant height (2.48m), spread( 1.95m), scion girth (29.00cm), stock girth (33.50cm) and canopy size (0.25m3) were found in Kinnow plants grafted on Rough lemon stock followed by Kinnow stock (2.11m plant height, 1.79 m spread, 28cm scion girth, 29cm stock girth and 0.11m3 canopy size) during September,2008. Almost similar trend was noted during all other years of study. Conclusively Rough lemon (khatti) proved to be the best vigorous and Rangpur lime dwarf rootstock for Kinnow scion among all tested stocks under Sargodha climatic conditions. [ABSTRACT FROM AUTHOR]

The cytoprotective effect of prostaglandin E1 (PGE1) has been demonstrated experimentally and clinically against hepatic ischemia and reperfusion injury and against the effects of partial hepatectomy in both individual and combined models of noncirrhotic livers. Cirrhotic livers are more vulnerable to ischemia/reperfusion injury during hepatectomy than are noncirrhotic livers, and postoperative malfunctioning complicates life with multiple organ failure. Cirrhotic livers with tumors have mostly been treated conservatively because extended hepatectomy with induced ischemia during surgery is impossible. The purpose of our study was to document postoperative surgical adaptation in inoperable cases with improved survival after extended hepatectomy in a rat model of cirrhosis treated by PGE1. Cirrhosis was induced by intraperitoneal injections of 1% dimethylnitrosamine. The liver was subjected to 15 minutes of total ischemia by occluding the hepatoduodenal ligament. Hepatectomy was performed during ischemia. Pretreatment with PGE1 (0.4 μg/kg/min) (or without it in the controls) was given for 15 minutes by intravenous infusion prior to inducing ischemia and during reperfusion. Portal venous flow (PVF) and liver tissue blood flow (LTBF) were measured during reperfusion. At the end of 60 minutes of reperfusion, venous blood was collected for liver function tests. The animals were followed up regarding survival for 48 hours. The PVF and LTBF were significantly improved in the PGE1 group. The blood chemical analysis indicated that PGE1 significantly suppressed posthepatectomy liver dysfunction. Most importantly, PGE1 treatment markedly improved the survival rate, from 42% in the controls to 75% in the test animals at 24 hours after hepatectomy and from 17% in the controls to 58% in the test animals at 48 hours. We concluded that short-term administration of PGE1 makes extensive hepatectomy possible under ischemic conditions in cirrhotic livers. [ABSTRACT FROM AUTHOR]

d-Allose, one of the rare sugars produced from d-psicose, has been shown to be effective against reperfusion injury after ischemia and partial hepatectomy in cirrhotic rat liver by improving remnant liver blood flow and survival rates, and decreasing liver enzyme levels and liver tissue injury levels. These findings demand further study of the clinical implications of this sugar in view to the advancing fields of liver surgery and transplantation. [Copyright &y& Elsevier]

The present work reports experimentation and numerical simulations of laminar burning velocity, emission analysis, and flame structure of dimethyl ether-hydrogen mixtures. The volumetric hydrogen addition is considered into the DME fuel for a range of mixture equivalence ratios (0.6< ϕ < 1.7). The initial mixture temperature is raised to 373 K at constant atmospheric pressure of 1.0 bar. The heat flux method is utilized to investigate the laminar burning velocity in laminar premixed planar adiabatic flames. The laminar burning velocity (LBV), along with the flame position and emission measurements, are extracted from these flames. The computations were performed with freely propagating flames (LBV, species, sensitivity, etc. data), and the burner stabilizes flames (flame position and emission analysis) for the same mixture and initial conditions using various detailed mechanisms. An emphasis is paid to a newly developed Shrestha mechanism, which includes a radiation model and NO sub-mechanism. Both experimental data and competition results were validated against the pure DME air mixture data available in the existing literature, and further analysis was carried out. It is observed that planar flames can be stabilized only up to a hydrogen addition of 40%. Adding hydrogen enhanced the flame temperature, heat release rates, and burning velocity while reducing the CO and NO emissions. A slight shift of peak burning velocity on the rich side of the equivalence ratio (from 1.05 to 1.2) is observed with hydrogen addition (0–40%). The mixture temperature also enhances the flame temperature and laminar burning velocity. It is interesting to note that hydrogen-added mixtures show a relatively lower dependency on initial mixture temperature. The variation of dominant species and heat release rates are also discussed in detail. The sensitivity analysis is carried out to get information on dominant reactions participating in the combustion of DME hydrogen mixtures. • Influence of H2 content on the LBV of premixed laminar DME flames was measured. • Influence of H2 content on the NOx Emission and temperature was measured. • Study of the flame structure characterized by the HRR and species profiles. • Experimental data compared with simulation results of 5 reaction mechanisms. [ABSTRACT FROM AUTHOR]

The purpose of this work was to perform the phytochemical and antimicrobial activity evaluation of the water-immiscible solvent extracts of Olive tree leaves (Olea europaea L., Family: Oleaceae). Seven sample extracts of the leaves of O. europaea were obtained using dichloromethane (DCM), dichloroethane (DCE) along with their mixtures with chloroform (CH), and ethyl acetate (EA). The phytochemical studies were carried out using the standard procedures. Serial plate dilution technique was used to perform the antimicrobial activity of the extracts. The phytochemical tests revealed the presence of steroids, terpenoids, saponins and flavonoids in all extracts of olive leaves. The 1:1 mixture of ethyl acetate and dichloromethane (EA:DCM) exhibited equivalent MIC (20 μgml-1, 100%) values concerning Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa with respect to ofloxacin (MIC = 20 μgml-1, 100%). Similarly, the 1:1 mixture of ethyl acetate and dichloroethane (EA:DCE) exhibited equivalent MIC (20 μgml-1, 100%) values concerning E. coli and P. aeruginosa with respect to ofloxacin (MIC = 20 μgml-1, 100%). The 1:1 mixture of EA:DCM and EA:DCE showed moderate antifungal activity (MIC = 20 μgml-1, 75%) with respect to fluconazole against Aspergillus niger and Candida albicans. The water immiscible solvent extracts showed more potent antimicrobial activity than the water extract of the olive leaves, which might be because of the presence of the lipophilic compounds in the water immiscible solvent extracts of the olive leaves. It is also expected that by increasing the concentration of ethyl acetate in EA:DCM & EA:DCE solvent system may further provide better MIC values. [ABSTRACT FROM AUTHOR]

The effect of hydrogen (H 2) addition in the laminar burning velocity (LBV) of n-butane-air at elevated temperatures is described in this paper. For various equivalence ratios (ϕ), ranging from 0.7 to 1.3, LBV was measured for 20%, 40% and 60% H 2 addition to n-butane using a preheated mesoscale diverging channel technique. Using this experimental technique, LBV measurements were conducted for unburnt mixture temperature up to 450 K. The maximum burning velocity has been obtained at equivalence ratio 1.1 for all the mixture conditions. The LBV results at atmospheric condition for n-butane-hydrogen-air mixture were obtained by extrapolating the experimental data at elevated temperatures. "Heat flux method" experimental setup was used for measuring the LBV of n-butane-hydrogen-air mixture at atmospheric condition. The results obtained for LBV at atmospheric conditions with the two different methods at 0%, 20%, 40% and 60% H 2 composition in n-butane were found to be in good agreement. The experimental results of LBV for n-butane were compared with the numerical predictions using USC mech II, Aramco mech 2.0 and LLNL reaction mechanisms. The numerical predictions of LBV using Aramco mech 2.0 shows good agreement with experimental data at rich, lean and stoichiometric mixture conditions. • The effect of H 2 addition in the LBV of n-butane is studied. • LBV at elevated temperatures is measured using diverging channel setup. • Temperature exponent decreases with addition of hydrogen. [ABSTRACT FROM AUTHOR]

A numerical study on the structure of the laminar premixed flames established on perforated plate burners is performed. Three dimensional numerical simulations are performed on different perforated plate geometries, under various operating conditions, using methane reaction mechanism consisting 36 species and 253 reactions. The comparison of numerical results of inline and staggered configurations of perforated plate burner models show that the flame interaction has significant role in the structure and stabilization of perforated burner flame. The flame structure, flame height and the standoff distances are studied for both inline and staggered configurations at fuel lean and rich conditions. The flame standoff distance and the flame height found to be higher for staggered configuration in comparison to the inline configuration. The flame structure is studied for different hole-to-hole distances. The numerical results show an increase in flame base curvature with an increase in hole-to-hole distance for both inline and staggered configurations. The flame thickness reduces with an increase in hole-to-hole distance for both inline and staggered cases. The effect of recirculation and flame base curvature causes the flame base to get stabilized at a higher distance in staggered configuration in comparison to the inline configuration. [ABSTRACT FROM AUTHOR]

Vertical Axis Wind Turbines (VAWTs) have proven to be suitable for changing wind conditions, particularly in urban settings. In this paper, a 2D URANS (Unsteady Reynolds-Averaged Navier Stokes) numerical analysis is employed for an H-Darrieus VAWT. A turbulent domain is created through systemically randomising the inlet velocity to create macro-turbulence in front of the VAWT. The parameters for spatial and temporal randomisation of velocity and its effects on the turbine performance are studied for a mean free stream velocity, U∞ = 10 m/s, and a tip speed ratio (TSR) of 4.1. The mean Coefficient of power (Cp) for randomised fluctuation of 2 m/s and half-cycle randomisation update frequency is 0.411 and for uniform inlet velocity is 0.400. The Cp vs. Tip Speed ratio plot suggests that the optimal tip speed ratio for operation is around 4.1 for this particular wind turbine of diameter 1 m, chord 0.06 m, and NACA 0018 airfoils. The effect of randomisation for tip speed ratio λ = 2.5, 3.3, 4.1, and 5.3 on the performance of the turbine is studied. Turbine wake recovers at a faster rate for macro-turbulent conditions and is symmetric when compared to wake generated by uniform velocity inlet. The maximum velocity deficit for a distance behind the turbine, x/d = 8 at TSR (λ) = 4.1 is 46% for randomised inlet and 64% for uniform inlet. The effect of randomisation for λ = 2.5 to 5.3 on the performance of the turbine is analysed. A time-varying gust based on International Electrotechnical Commission (IEC) Extreme Operating Gust is used to study the effect of fluctuating wind conditions in a turbulent environment. Since real-time conditions often exceed gust factors mentioned by IEC, winds with large gust factors such as 1.50, 1.64, and 1.80 are analysed. With an increase in gust amplitude, Ugust = 6 m/s to Ugust = 12 m/s on a free stream velocity of U∞ = 10 m/s, the mean Cp decreases from 0.41 to 0.35 since the wind turbine operates under tip speed ratios outside optimal range due to large fluctuations in incoming velocity. [ABSTRACT FROM AUTHOR]

Film cooling as applied to rocket nozzles is analyzed numerically with emphasis on the assessment of the effect of the mixing of coolant with the hot stream. Cooling performance, as characterized by cooling effectiveness, is studied for three different coolants in the three-dimensional, turbulent flow field of a supersonic convergent-divergent nozzle operating with a hot stream temperature of 2500 K over a range of blowing ratios. The coolant stream is injected tangentially into the mainstream using a diffuser-type injector. Parameters influencing the effectiveness, such as coolant injector configuration and mixing layer, are analyzed. Thermal and species mixing between the coolant and the mainstream are investigated with regard to their impact on cooling effectiveness. The results obtained provide insight into the film cooling performance of the gases and the heat transfer characteristics associated with these three gases. An injector taper angle of 30° results in the most effective cooling among the configurations considered (0°, 15°, 30° and 45°). Mixing of the coolant with the hot stream is examined based on the distributions of velocity, temperature and species. The higher values of cooling effectiveness for Helium are attributed to its thermophysical properties and the reduced rate of mixing with the hot stream. The results further indicate that through optimization of the blowing ratio and the coolant injector configuration, the film cooling effectiveness can be substantially improved. [ABSTRACT FROM AUTHOR]

Real jet fuels have hundreds of individual hydrocarbon species with varying physical and chemical properties. Surrogate fuels containing mixtures of a small number of components have been developed to emulate the behaviors of the parent fuels. Often surrogates are derived solely based on the gas-phase combustion behavior and thus are not constrained to match physical phenomena, such as atomization and vaporization. Thus, these fuels can subsequently exhibit different behaviors than the parent fuel they are designed to emulate, especially when introduced in a two-phase system. This work explores the ability of selected established and newly developed/proposed surrogate jet fuels to mimic the properties necessary for the two-phase conversion process, including the vaporization behavior of real fuel spray. The droplet lifetime/vaporization dynamics is measured using a single droplet levitating device (acoustic levitator). The newly developed surrogates show a satisfying emulation of the parent jet fuel's physical and chemical properties, including SMD, CN, LHV, MW, and vaporization evolution. Most notably, the binary solution consisting of n-dodecane and toluene predicted the physical and chemical properties of the parent fuel closely, with a total maximum deviation from the selected targeted fuel properties ∼12.6% compared to ∼52% of the well-established previously developed Dooley 1st surrogate. [ABSTRACT FROM AUTHOR]

Chevron nozzles, which are characterized by the serrations at the nozzle exit, are widely used for suppressing jet noise in aircraft engines. The noise suppression is accomplished by the enhanced mixing of the exhaust streams, which, in turn, is a result of the streamwise vorticity induced by the serrations. The present study focuses on the numerical modeling of the acoustic field in a compressible jet issuing from a chevron nozzle at a Mach number of 0.8. The study evaluates the effectiveness of turbulence modeling approaches of Large Eddy Simulation and Detached Eddy Simulation methods and compares them with the less computationally intensive Unsteady Reynolds Averaged Navier–Stokes (URANS) formulation. The Ffowcs Williams–Hawkings noise model was used to predict the overall sound pressure level in the far field. The LES predictions of the acoustic signature were found to match well with the experimental data, whereas the URANS model grossly underpredicted the sound pressure levels in the compressible jet flow field. [ABSTRACT FROM AUTHOR]

Discusses the application of reverse logic in the study of the philosophy of God. Types of logic; Discussion on reverse logic and God; Status of the attempt to define God through logic.

The present study reports the effect of hydrogen addition on combustion characteristics of LPG–air mixtures for different mixture compositions, temperatures and pressures. Numerical simulation has been carried out using USC Mech II reaction mechanism, consisting of 111 species and 784 reactions. It is found that, variation of the flame speeds were relatively small for various compositions of LPG–air mixtures used. Thus 50% propane – 50% butane mixture is considered for the present work. The effect of volumetric H 2 addition on laminar flame speed and ignition delay of selected LPG (50% propane + 50% butane) air mixtures is then studied for hydrogen addition ratio varying from 0 < R H < 0.5 and over a wide range of mixture equivalence ratio. Also, the investigation is carried out for mixture temperature up to 450 K and pressure ranging from 1 to 10 bar. A parabolic variation of laminar flame speed is observed with equivalence ratios giving peak value for slightly rich mixture. A linear correlation has been observed for the flame speed as a function of hydrogen addition, R H at all the conditions studied. Whereas, power law correlation has been proposed for the hydrogen added LPG–air mixture, to understand the dependency of laminar flame speed on temperature and pressure. A generic correlation has been proposed to study the combined effect of temperature and pressure on laminar flame speed. [ABSTRACT FROM AUTHOR]

Characteristics of microjet hydrogen diffusion flames stabilized near extinction are investigated numerically. Two-dimensional simulations are carried out using a detailed reaction mechanism. The effect of burner wall material, thickness, and thermal radiation on flame characteristics such as flame height and maximum flame temperature are studied. Results show that the flame stabilizes at lower fuel jet velocities for quartz burner than steel or aluminum. Higher flame temperatures are observed for low conductive burners, whereas the flame length increases with an increase in thermal conductivity of the burner. Even though thermal radiation has a minor effect on flame characteristics like flame temperature and flame height, it significantly influences the flame structure for low conductive burner materials. The burner tip and its vicinity are substantially heated for low conductive burners. The effect of burner wall thickness on flame height is significant, whereas it has a more negligible effect on maximum flame temperature. Variation in wall thickness also affects the distribution of H and HO2 radicals in the flame region. Although the variation in wall thickness has the least effect on the overall flame shape and temperature distribution, the structure near the burner port differs. [ABSTRACT FROM AUTHOR]

AbstractMethicillin resistance in staphylococci is conferred by the acquisition in its chromosome of the mecAgene, which is located on a mobile genetic element called staphylococcal cassette chromosome mec(SCCmec). Genetic type of SCCmecis defined by combination of mecgene complex class and cassette chromosome recombinase gene (ccr) allotype. In this study, we analyzed genetic diversity of the SCCmecin 11 Staphylococcus haemolyticusstrains and a Staphylococcus sciuristrain, which were recently isolated from clinical specimens in Bangladesh. Among these strains, only two S. haemolyticusstrains were proved to have the known types of SCCmec, that is, SCCmecV (class C2 mec–ccrC) and VII (class C1 mec–ccrC). Five S. haemolyticusstrains were assigned two unique mec–ccrgene complexes combination; that is, class C1 mec–ccrA4B4(four isolates) and class A mec–ccrC(one isolate). In the remaining four S. haemolyticusstrains with class C1 mec, no known ccrallotypes could be detected. A single S. sciuristrain with class A meccomplex carried a ccrAgene belonging to a novel allotype designated ccrA7, together with ccrB3. The ccrA7gene in the S. sciuristrain showed 61.7%–82.7% sequence identity to the ccrAgene sequences published so far, and 75.3% identity to ccrA3, which is a component of the type 3 ccrcomplex (ccrA3-ccrB3) in methicillin-resistant Staphylococcus aureus. The results of the present study indicated that mecgene complex and ccrgenes in coagulase-negative staphylococci are highly divergent, and distinct from those of common methicillin-resistant S. aureus. Identification of the novel ccrA7allotype combined with ccrB3suggested an occurrence of recombination between different ccrcomplexes in nature. [ABSTRACT FROM AUTHOR]

There is paucity of data from developing countries on the efficacy and safety of imatinib mesylate in chronic myeloid leukemia (CML). The primary objective of this study was to document complete and partial cytogenetic responses to imatinib in all phases of CML. Secondary objectives included evaluations of complete hematologic response, safety, time to progression, and survival.Two hundred seventy‐five patients in all phases of CML who received treatment with imatinib from January 2001 to December 2005 were included in the study. All patients had on bone marrow or BCR‐ABL positive in peripheral blood by polymerase chain reaction.After a median follow‐up of 18 months, major cytogenetic responses (Ph <35%) in chronic phase (CP), accelerated phase (AP), and blastic phase (BP) were documented in 61%, 57%, and 28% of patients, respectively. A complete cytogenetic response was observed in 39.4%, 35.7%, and 14.3% of patients in CP, AP, and BP, respectively; and a complete hematologic response was observed in 90%, 86%, and 30%, respectively. The median time to progression at 18 months was 91% in CP and 68% in AP. The overall survivals in CP, AP, and BP at 18 months was 92%, 74%, and 38%, respectively.Impressive hematologic, cytogenetic, and molecular responses to imatinib were observed, similar to the responses reported in patients from Western countries. Patients had good compliance, toxicity was limited, and overall quality of life was improved markedly. The results indicated that the biology of CML is not different in patients from developing countries. Cancer 2007 © 2007 American Cancer Society. [ABSTRACT FROM AUTHOR]

The current work presents computational investigations of biogas-hydrogen blends' combustion characteristics for various thermo-physical conditions relevant for practical combustor applications. The numerical simulations were performed using 0-D SENKIN and 1-D PREMIX codes, whereas chemical kinetics is modelled using the GRI Mech 3.0 mechanism. Biogas composition represented by 60CH 4 /40CO 2 % (v/v) is blended with different H 2 concentration varying from 0 to 50% (v/v) in the fuel. The effect of initial temperature and pressure on ignition delay, laminar flame speed (S u), flame temperature (T ad), species concentrations (C i), and heat release rate profiles is investigated. The results showed that GRI-Mech 3.0 predictions are in good agreement with the available experimental ignition delay data for CH 4 /CO 2 -air mixture for stoichiometric ambient condition (P = 0.1 MPa and φ = 1). For the high-temperature oxidation, GRI-Mech 3.0 has accurately predicted S u available from literature for pure biogas (R H = 0.0) under a wide range of equivalence ratios (φ = 0.7–1.4) for ambient conditions. The computational analysis was then extended for R H ranging from 0.0 to 0.5 over a wide range of equivalence ratio (φ) = 0.7–1.4, initial temperatures (T) = 300–600 K and initial pressures (P) = 0.1–7.0 MPa. These results obtained were used to develop a new analytical correlation for the laminar flame speed (S u = S u o (φ , R H ) T T u α (φ) P P u β (φ , R H ) ) in terms of operating conditions. The results show that hydrogen addition to the biogas improves both the flame speed and ignition delay. The extent of reduction in flame speed due to elevation of initial pressure is a linear function of hydrogen addition to biogas. Furthermore, the sensitivity analysis was studied to assess the influence of hydrogen added to the biogas using laminar flame speed sensitivity coefficient (σ). The understanding of these mixtures' combustion characteristics at given initial conditions leading to feasibility conformity of optimal blends of biogas/hydrogen mixtures for the design improvement of practical combustors is discussed. • New analytical correlation for biogas/H 2 -air S u (= S u o (φ , R H ) ( T T u ) α (φ) ( P P u ) β (φ , R H ) ) for combustor relevant conditions. • 5 to 10 times reduction in ignition delay with 10–50% H 2 addition to biogas (60CH 4 /40CO 2). • 2 to 3 times increase laminar flame speed (S u) with 10–50% H 2 addition to biogas. • 2 to 3 times increase in HRR peak with 50% H 2 addition to biogas (T = 300 & 600 K). • 1.5 to 2 times increase in peak H and OH peak radials with 50% H 2 addition to biogas. [ABSTRACT FROM AUTHOR]

The energy crisis has forced researchers to look for various non-conventional energy sources. Wind energy is one of the potential sources, and researchers have invested resources in developing different kinds of wind turbines. Vertical axis wind turbines (VAWT) have received less attention than their horizontal-axis counterparts. A helical-bladed VAWT is preferred because it makes perfect sense as an improvement in design, as they have higher azimuth angles of power generation capabilities. This paper studies the effects of the helix angle of blades in the aerodynamic performance of VAWT using 3D numerical simulations. Three different helix angles of 60°, 90°, and 120° of a three-bladed VAWT operating across different tip speed ratios were studied. Turbulence is modelled using a four-equation transition SST k-ω model (shear stress transport). The 60° helical-bladed VAWT was found to be better performing in comparison with all other helical-bladed and straight-bladed VAWT. The ripple effects on the shaft are also analysed using a standard deviation plot of the moment coefficient generated by a single blade over one complete cycle of its rotation. It was observed that the greater the helix angle, the lower the standard deviation. The paper also tries to analyse the percentage of power generated by each quartile of flow and the contribution of each section of the blade. Ansys FLUENT was employed for the entire study. A comparative study between different helical-bladed VAWT and straight-bladed VAWT was carried out along with wake structure analysis and flow contours for a better understanding of the flow field. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the molecular characteristics of hereditary multiple osteochondromas (HMO) in a subset of Jordanian patients with a focus on the genetic variants of exostosin (EXT1)/(EXT2) and their protein expression. Patients with HMO and their family members were included. Recorded clinical characteristics included age, sex, tumors number and location, joint deformities and associated functional limitations. Mutational analysis of EXT1 and EXT2 exonic regions was performed. Immunohistochemical staining for EXT1 and EXT2 was performed manually using two different commercially available rabbit anti-human EXT1 and EXT2 antibodies. A total of 16 patients with HMO from nine unrelated families were included, with a mean age of 13.9 years. A total of 75% (12/16) of the patients were male and (69%) (11/16) had a mild disease (class I). EXT mutation analysis revealed only EXT1 gene mutations in 13 patients. Seven variants were detected, among which three were novel: c.1019G>A, p. (Arg340His), c.962+1G>A and c.1469del, p. (Leu490Argfs*9). Of the 16 patients, 3 did not harbor any mutations for either EXT1 or EXT2. Immunohistochemical examination revealed decreased expression of EXT1 protein in all patients with EXT1 mutation. Surprisingly, EXT2 protein was not detected in these patients, although none had EXT2 mutations. The majority of Jordanian patients with HMO, who may represent an ethnic group that is infrequently investigated, were males and had a mild clinical disease course; whereas most patients with EXT1 gene mutations were not necessarily associated with a severe clinical disease course. The role of EXT2 gene remains a subject of debate, since patients with EXT1 mutations alone did not express the non-mutated EXT2 gene. [ABSTRACT FROM AUTHOR]

The effect of hydrocarbon addition on tip opening of lean and stoichiometric hydrogen-air flames is studied computationally by performing two-dimensional numerical simulations. The numerical study reveals that the flame tip of the H 2 -air burner stabilized flame is open at lean and stoichiometric mixture conditions. The flame tip closes upon hydrocarbon addition. The tip closing is mainly affected by preferential diffusion of the multi-component mixture and the stretch effects. In the addition of light hydrocarbon (CH 4), the tip closing starts at a higher percentage of hydrocarbon addition in H 2 -air flames. Whereas, upon the addition of heavy hydrocarbons such as propane and butane in H 2 -air flames, tip closing starts with a lesser amount of hydrocarbon addition. Temperature, OH mole fraction and heat release rate have been investigated, focusing on the flame structure at the tip. The tip opening regime diagram for H 2 –CH 4 -air, H 2 –C 3 H 8 -air and H 2 –C 4 H 10 -air mixtures are presented. • Effect of hydrocarbon addition on the tip opening of H 2 -air flames is studied. • Addition of hydrocarbon increases the intensity of burning at the tip. • Tip opening is strongly depended on preferential diffusion for HC-H 2 -air flames. • Tip closing occurs earlier by adding higher hydrocarbons compared to CH 4 addition. • Tip opening regime is presented for lean and stoichiometric HC-H 2 -air flames. [ABSTRACT FROM AUTHOR]

This study's objective was to emphasize the renewable lignocellulosic biomasses' energy potential by thermally describing them. The TG/DTG/DTA procedures were used to examine the thermal pyrolysis behavior of coffee wastes (CW), date seeds (DSM), prickly pears (PP), and two blends (50%CW/50%DSM and 33.3%CW/33.3%DSM/33.3%PP by weight), and their physico-chemical compositions were identified and assessed. The activation energy (E) of all tested samples was predicted using iso-conversional models like Friedman (FR), Starink (ST), Kissinger-Akahira-Sunose (KAS), and Ozawa-Flynn-Wall (OFW), and the frequency factor (A) was calculated based on the acquired (E) values utilizing the chemical reaction mechanisms (C1–C8). SEM, EDX, and FTIR techniques were used to examine the microstructure, mineralogy, and functional group present in the studied samples. Every DTG profile displayed a rightward shift when the heating rate (β) rose to higher temperatures. The difference in the average activation energy (E a v ) values between the ST, OFW, and KAS models, except for the blend (1), does not surpass 5 k J / m o l e. Increases in the (β) value, particularly for blends, were significantly correlated with increases in the maximum pyrolysis rate ( − R P), pyrolysis index (C P I), pyrolysis stability index (R W), and volatile release index (D d e v ). The Δ G a v discrepancies between the results from all kinetic models for all samples varied from 1 to 7 k J / m o l e. A little potential energy barrier was noticed when comparing the (E a v) to the average enthalpy ( Δ H a v ). [Display omitted] • Co-pyrolysis of coffee, date seed, and prickly pear wastes was explored for the first time. • Four iso-conversional models were applied to estimate pyrolysis kinetic parameters. • The blend (33.3%CW/33.3%DSM/33.3%PP) showed the best pyrolysis properties • E av compared to ΔH av revealed a slight potential energy barrier. • High −R P , CPI, R W and D dev indicated easily pyrolysis and combustion. [ABSTRACT FROM AUTHOR]

Abstract For the past few decades flapping wing aerodynamics has attracted a great deal of research interest from both the aeronautical and biological communities pertaining to the development of MAVs. The objective of this study is to examine and understand the effect of non-dimensional plunge amplitude and reduced frequency on propulsive performance of NACA 4-digit airfoil series and to examine the performance characteristics of square plunge motion and trapezoidal plunge motion. Two dimensional flow simulations around plunging symmetric aerofoils were performed using FLUENT. The simulations were carried out at Reynolds number of 20000 using incompressible laminar, NS solver. The reduced frequency (k) was varied from 0.5–5 and the plunging amplitude (h) was varied from 0.25–1.5. The plunging motions to the aerofoils were provided through UDFs. The effect of variation of k and h on the thrust coefficient (C T), power-input coefficient (C P) and propulsive efficiency (η) is studied. C T value is maximum for square plunge profile for all the airfoils. However, for a given value of h , with the increase in k , C T increases with increasing thickness of the airfoil and reaches a maximum value for airfoil thickness of NACA0018 and then starts decreasing. With varying h and k , it was observed that the propulsive efficiency reached a peak value and the peak shifts to higher h and k with increasing airfoil thickness. From the above study, it was concluded that airfoil thickness played a major part in influencing the thrust generation at low Strouhal number. However, at high Strouhal numbers airfoils showed diverse trends with respect to thrust generation. Sinusoidal plunging motion was more efficient but generated less thrust when compared to square and trapezoidal plunging motions. [ABSTRACT FROM AUTHOR]

The laminar burning velocity of CO 2 /N 2 diluted stoichiometric dimethyl ether (DME) air mixtures is determined experimentally at atmospheric pressure and elevated mixture temperatures using a mesoscale high aspect-ratio diverging channel with inlet dimensions of 25 mm × 2 mm. In this method, planar flames at different initial temperatures (T u ) were stabilized inside the channel using an external electric heater. The magnitude of burning velocities was acquired by measuring the flame position and initial temperature. The mass conservation of the mixture entering the inlet and the stationary planar flame front is applied to obtain the laminar burning velocity. Laminar burning velocity at different initial mixture temperatures is plotted with temperature ratio ( T u / T u , o ) , where a reference temperature (T u,o ) of 300 K is used. Enhancement in the laminar burning velocity is observed with mixture temperature for DME-air mixtures with CO 2 and N 2 dilutions. A significant decrease in the burning velocity and slight increase in temperature exponent of the stoichiometric DME-air mixture was observed with dilution at same temperatures. The addition of CO 2 has profound influence when compared to N 2 addition on both burning velocity and temperature exponent. [ABSTRACT FROM AUTHOR]