Reduction of Fossil Fuel Usage and Emissions of Diesel Engines by the Application of Quaternary Blends and Varied Fuel Injection Pressures.

The increasing energy demand has led to the exhaustion of mineral fuel resources and an environmental menace. Biodiesel and alcohol, as oxygenated fuels, offer promising potential for diesel engines. Moreover, the deviation in the fuel injection pressure (IP) favors improvement of the engine performance and reduction of flue gases. The contemporary research aims to explore sustainable biofuel that is an alternative to diesel and to achieve cleaner emissions with enhanced engine performance. The experiment involves testing of a diesel engine tank by quaternary blends comprising diesel, sunflower biodiesel, sunflower oil, and alcohol in the volumetric ratio of 50:25:5:20. The IP was varied from 300, 400, 500, to 600 bar at different engine loads of 10 and 20 N m at 1800 rpm of shaft speed. The quality of the quaternary blend was varied by the inclusion of alcohol having different carbon-chain lengths, namely, ethanol, propanol, butanol, heptanol, and decanol. The effect of alcohol inclusion and variation in the IP led to minimal brake-specific fuel consumption and maximal brake thermal efficiency for blended fuel containing 20% propanol, which was 17.39% lower and 8.70% higher than diesel, respectively. The same composition of the fuel blend offered the lowest smoke and CO2 emissions, which were 92.85 and 27.9% lesser than diesel; moreover, 7.36% lower NO x emission than diesel was achieved.

Influence of an Engineered Notch on the Electromagnetic Radiation Performance of NiTi Shape Memory Alloy.

This work explores the influence of a pre-engineered notch on the electromagnetic radiation (EMR) parameters in NiTi shape memory alloy (SMA) during tensile tests. The test data showed that the EMR signal fluctuated between oscillatory and exponential, signifying that the specimen's viscosity damping coefficient changes during strain hardening. The EMR parameters, maximum EMR amplitude, and average EMR energy release rate remained constant initially but rose sharply with the plastic zone radius with progressive loading. It was postulated that new Frank-Read sources permit dislocation multiplication and increase the number of edge dislocations participating in EMR emissions, leading to a rise in the value of EMR parameters. The study of the correlation between EMR emission parameters and the plastic zone radius before the crack tip is a vital crack growth monitoring tool. An analysis of the interrelationship of the EMR energy release rate at fracture with the elastic strain energy release rate would help develop an innovative approach to assess fracture toughness, a critical parameter for the design and safety of metals. The microstructural analysis of tensile fractures and the interrelation between deformation behaviours concerning the EMR parameters offers a novel and real-time approach to improve the extant understanding of the behaviour of metallic materials.

Evaluation of the performance and emission and spectroscopic analysis of an improved soy methyl ester.

Herein, the performance, emission and physiochemical properties of a soy methyl ester (SME) and its combination with methyl oleate (MO) in a common rail direct injection (CRDI) engine were investigated. Moreover, the performance of the engine in terms of brake power (BP), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and NO x emission was assessed to compute the characteristics of the combination of SME with MO; the reasons for using MO in the blending process were the better ignition quality, oxidative stability and low-temperature flow properties of MO, striking a balance between oxidative stability and low flow properties. A remarkable reduction in the BSFC and an increase in the BTE were found in the blended biodiesel (S80-MO20, S70-M30, and S50-M50) as compared to the case of SME. The blended biodiesel was also characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis) and nuclear magnetic resonance (NMR) spectroscopy. In the FTIR spectra, a peak was observed at 1745 cm-1, confirming the presence of a triglyceride ester linkage. Since UV-vis spectroscopy is an affordable technique, herein, it has been employed to detect the presence of conjugated dienes in the oxidized biodiesel. The linear line fitted for absorbance versus the percentage of the blended fuel at 320 nm showed a high coefficient of determination (R 2 = 0.9454). In addition, H NMR spectroscopy was employed to study the oxidative stability of the blended fuel. Different functional groups with their respective peaks (in ppm) are indicated in the NMR spectra.

Sensitization to indigenous pollen and molds and other outdoor and indoor allergens in allergic patients from saudi arabia, United arab emirates, and Sudan.

BACKGROUND: : Airborne allergens vary from one climatic region to another. Therefore, it is important to analyze the environment of the region to select the most prevalent allergens for the diagnosis and treatment of allergic patients. OBJECTIVE: : To evaluate the prevalence of positive skin tests to pollen and fungal allergens collected from local indigenous plants or isolated molds, as well as other outdoor and indoor allergens in allergic patients in 6 different geographical areas in the Kingdom of Saudi Arabia (KSA), the United Arab Emirates, and Sudan. MATERIAL AND METHODS: : Four hundred ninety-two consecutive patients evaluated at different Allergy Clinics (276 women and 256 men; mean age, 30 years) participated in this study. The selection of indigenous allergens was based on research findings in different areas from Riyadh and adjoining areas. Indigenous raw material for pollen grains was collected from the desert near the capital city of Riyadh, KSA. The following plants were included: Chenopodium murale, Salsola imbricata, Rumex vesicarius, Ricinus communis, Artiplex nummularia, Amaranthus viridis, Artemisia monosperma, Plantago boissieri, and Prosopis juliflora. Indigenous molds were isolated from air sampling in Riyadh and grown to obtain the raw material. These included the following: Ulocladium spp., Penicillium spp., Aspergillus fumigatus, Cladosporium spp., and Alternaria spp. The raw material was processed under Good Manufacturing Practices for skin testing. Other commercially available outdoor (grass and tree pollens) and indoor (mites, cockroach, and cat dander) allergens were also tested. RESULTS: : The highest sensitization to indigenous pollens was detected to C. murale (32%) in Khartoum (Sudan) and S. imbricata (30%) and P. juliflora (24%) in the Riyadh region. The highest sensitization to molds was detected in Khartoum, especially to Cladosporium spp. (42%), Aspergillus (40%), and Alternaria spp. (38%). Sensitization to mites was also very prevalent in Khartoum (72%), as well as in Abu Dhabi (United Arab Emirates) (46%) and Jeddah (KSA) (30%). CONCLUSIONS: : The allergenicity of several indigenous pollens and molds derived from autochthonous sources was demonstrated. Prevalence studies in different regions of KSA and neighbor countries indicate different sensitization rates to these and other outdoor and indoor allergens.

Increased prevalence of asthma in Saudi Arabia.

BACKGROUND: Bronchial asthma is among the most common chronic illnesses of childhood. A number of reports in the recent past suggest that the prevalence of asthma is increasing globally. OBJECTIVE: To investigate the changing prevalence of asthma in the Kingdom of Saudi Arabia. SUBJECTS AND METHODS: Two populations of schoolchildren between the ages of 8 and 16 years were studied using an internationally designed protocol in 1986 and 1995. The questionnaire used in these studies was very similar to the one used in the International Study of Allergy and Asthma in Childhood. A total of 2,123 school-children in 1986 (Jeddah and Riyadh) and 1,008 schoolchildren in 1995 (Hail and Gizan) were enrolled in the surveys. These cross-sectional studies of randomly selected schoolchildren were statistically analyzed using ANOVA and a Z test. RESULTS: The comparison of data between Riyadh versus Hail (inland desert dry environment) and Jeddah versus Gizan (coastal humid environment) revealed that the prevalence of asthma in the similar populations increased significantly from 8% in 1986 to 23% in 1995 (P < .0001). Likewise, the prevalence of allergic rhinitis also increased from 20% to 25% (P < .003) since 1986. However, no significant change in the prevalence of eczema (from 12% to 13%) was noted between 1986 and 1995. CONCLUSIONS: The study indicates that there was a significant increase in the prevalence of bronchial asthma and, to a lesser extent, in the prevalence of allergic rhinitis in the Kingdom of Saudi Arabia during this 9-year period. The study also revealed increased exposure to environmental factors such as tobacco smoke and indoor animals in Saudi houses. It seems that the continuing changes in contemporary life may well have contributed to the increased prevalence of asthma in the country.

Airborne viable fungi in Riyadh and allergenic response of their extracts.

The allergenicity and antigenicity of various airborne fungi isolated from the atmosphere of Riyadh were studied. Protein nitrogen contents were estimated and found to range from 0.9 mg ml(-1) for Cladosporium to 2.1 mg ml for Aspergillus extracts. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis for those extracts exhibited a number of protein bands of higher molecular weight between 13 and 80 kDa for Alternaria, Ulocladium, Penicillium, Aspergillus and Cladosporium. Extracts in both aqueous and lyophilized forms were sterilized and tested for diagnostic skin prick test in 100 consecutive patients having bronchial asthma and allergic rhinitis. Overall, 13% of patients reacted positively to fungal extracts, revealing allergic sensitization to these fungi. These findings necessitate further investigation as regards the purification and characterization of these local extracts for better diagnostic use in patients in Saudi Arabia.

Seasonal incidence of airborne fungal allergens in Riyadh, Saudi Arabia.

Aerobiological studies to evaluate allergenic fungal spores in the atmosphere of Riyadh were conducted. Burkard personal volumetric sampler were operated as volumetric 'viable' spore traps at two different sites (Al-Batha, a more developed area in the south and Al-Ulia, a less developed area in the north) in Riyadh. Twice a week samplings were carried out over a period of 12 month. The seasonal fluctuations of the most frequent fungi were plotted as 'major' components. The dominant species at the two sites were members of the genera Alternaria, Aspergillus, Cladosporium, Penicillium and Ulocladium. Drechslera, Fusarium, Rhizopus and Stachybotrytis species were minor components or sporadic. Seasonal variations of the total colonies were significantly (p < 0.05) different. They showed higher concentrations in the winter season and the lowest in summer. The Al-Batha site was always higher in spore concentrations than the Al-Ulia site. The results provide valuable information for the diagnosis and prophylaxis of allergic diseases due to airborne fungi.

Human sensitization to Prosopis juliflora antigen in Saudi Arabia.

BACKGROUND: Allergenicity to Prosopis juliflora pollen antigen has been reported from only a few countries, including the US, South Africa, India and Kuwait. In some parts of Saudi Arabia, species of Prosopis have been introduced by the millions as roadside ornamentation. There appear to be four flowering seasons during which pollen grains float in all directions. However, the role of Prosopis pollen as the sensitizing and/or triggering agent of allergic asthma and/or rhinitis in the Kingdom has never been evaluated. PATIENTS AND METHODS: A total of 473 allergic patients suffering from bronchial asthma in four different geographical regions (Abha, Qassim, Hofuf and Gizan), and attending allergy clinics and chest disease centers of university and Ministry of Health hospitals in the region were tested for immediate hypersensitivity reaction to Prosopis juliflora allergens. Airborne pollen grains at one center were also studied for one full year, using volumetric sampling techniques. RESULTS: A total of 76.1% patients in Qassim, 37.5% in Gizan, 29% in Abha and 11% in Hofuf reacted positively to Prosopis antigen. Multiple sensitivities to other pollen antigens were detected in all patients. The level of airborne Prosopis pollen detected in Gizan exceeded 90 grains m -3 of air. CONCLUSION: In view of the documented evidence of Prosopis-involved allergenicity, the role of Prosopis pollen as a sensitizing factor in Saudi Arabia has been confirmed. However, the cause of elicitation of symptoms in many multiple sensitive patients, together with the question of cross-reactivities, needs thorough and detailed investigation. In vitro confirmation of all positive results is also required to incriminate Prosopis as one of the major allergens in parts of Saudi Arabia.

Airborne Alternaria spores: Potential allergic sensitizers in Saudi Arabia.

BACKGROUND: In order to investigate the role of airborne Alternaria spp. in the sensitization of individuals having respiratory allergy symptoms, particularly bronchial asthma, an aerobiologic and clinical (diagnostic) study was conducted at several centers in Saudi Arabia. MATERIALS AND METHODS: Airborne Alternaria spores were studied at four different centers in Riyadh, Jeddah and Al-Khobar, including three years at one site. Skin prick tests (SPT) were conducted on a total of 616 allergic individuals attending allergy clinics at six different hospitals in Abha, Qassim, Gizan, Jeddah, Hofuf and Makkah regions. RESULTS: Alternaria spores constituted between 1.9%-9.6% of the total fungal air spora, and the maximum concentration exceeded 5x10 2 spores per m3 of air in Jeddah, followed by 4.9x102 spores per m3 in Al-Khobar. Mean weekly and monthly concentration of Alternaria fluctuated, reaching up to 150 spores per m 3 and 60 spores per m 3, respectively. Quantitative regional variations were also recorded. IgE-mediated SPT reactivities conducted on allergic patients resulted in an overall 21.6% positive reactions, showing mild, moderate and strong wheal and erythema. CONCLUSION: The findings reveal that Alternaria spores are prevalent as a major component in the outdoor environment of the Kingdom, with peaks in April and October. The overall 21.6% positive SPT reactions indicate the sensitization level or cross-reactive sensitivity to Alternaria allergens. The study suggests that airborne Alternaria can be a potential allergic sensitizer in susceptible individuals and can be a risk factor in sensitized individuals with symptoms of bronchial asthma and allergic rhinitis in the Kingdom of Saudi Arabia.

House dust mite allergens in Saudi Arabia: Regional variations and immune response.

In order to assess the causative extrinsic allergic factor(s) in school-age children diagnosed as having bronchial asthma and allergic rhinitis, and to qualitatively and quantitatively evaluate the presence of house dust mites (HDMs) in the homes of these children in Saudi Arabia, a study analyzing mite contents in 165 samples collected from patientsâ indoor environment was conducted. The dust samples were collected from four regions of Saudi Arabia, showing variation in their geography and climate. Immunochemical assays were performed using ALK reagents by ELISA technique. A total of 462 children were also tested using skin prick test (SPT) method for IgE-mediated reactions to HDMs. The samples from the Central dry region revealed a very low amount of the potent house dust mites (Dermatophagoides pteronyssinus and D. farinae, the two dominant species in various parts of the world). The samples from the Southern mountainous region contained a very high concentration of Der p I (84,000 ng/g of dust), while the Western coastal region showed a high concentration of Der f I (up to 22,000 ng/g). The mid-Western agricultural region did not exhibit any significant level of either Der p I or Der f I. The maximum level of D. pteronyssinus detected in the Central dry region was 106 ng/g of dust. The data exhibit both qualitative and quantitative variations of HDMs in the three regions and may be attributed to variation in geography and climate, particularly humidity of the regions, which vary significantly. Riyadh in the Central region is considered to have low humidity (<40%), while humidity in the Western coastal region, Jeddah, and the Southern region of Abha is comparatively higher, which helps house dust mites thrive. SPT results in these regions with house dust mite allergens (in addition to other common inhalant allergens) also revealed a considerable number of IgE-mediated reactions, consistent with the frequency of house dust mites in the region. Though more data are being accumulated on the subject to conduct a statistical comparison and more skin tests are underway in the Southern region, the study suggests the presence of at least two HDMs as well as qualitative diversity and quantitative variation of house dust mites in Saudi Arabia. The study also indicates, with a considerable number of IgE-mediated reactions, the possible influence of mites in the allergic manifestations of many patients, which is not only common, but increasing in parts of the country.

Cladosporium as an airborne allergen in Saudi Arabia.

Airborne mold monitoring in three cities in Saudi Arabia has documented the presence of Cladosporium in high concentrations. The spore counts reached threshold levels for sensitization at Jeddah and Al-Khobar with prominent seasonal variations. The concentration in Riyadh (central region) showed levels with minor fluctuationgs and a minor peak towards the month of Novermber. Indoor monitoring also revealed the presence of Cladosporium. Ten species of Cladosporium were idenified with C. sphaerospermum, C. herbarum, C. cladosporoides and C. macrocarpum being most prevalent. The species are relevant in relation to extracts for diagnosis. Skin testing of asthmatic children in Riyadh and Makkah revealed reactivities to Cladosporium extract of 5.8% and 31.3%, respectively. This indicates that Cladosporium may be an important allergen in the region that necessitates further biochemical and immunochemical studies to confirm the allergic impact of the species of Cladosporium prevalent in the region.

A comparative study of immediate skin test reactivity to inhalant allergens in asthmatic children of two different regions in Saudi Arabia.

The skin test reactivities to various inhalant allergens in asthmatic children from two different regions in Saudi Arabia were compared. One hundred-twenty subjects each from the Central and Western regions, representing different environmental features, were selected. Prick test reactivity to 24 common allergens were analyzed and compared. Seventy-one (59.2%) patients from Riyadh (Central region) showed positive skin reactions to one or more allergens, while 87 (72.5%) reacted positively to different allergens from Makkah (Western region). The distribution of skin test sensitivity revealed striking differences in the two groups. The most prominent were reactions to the house dust mite (D. farinae) which amounted to 56.3% and to fungal allergens, 31.3% in asthmatics from the Western region, while reactions to the same allergens in subjects from the Central region were 10% and 5.8%, respectively. Similarly, marked variations were noted with pollen grain allergens with 9.3% in Central region and 15.4% in the Western region. The study indicates the presence of different allergen profiles in the two regions and suggests the influence of climatic and environmental factors and their impact on sensitization of susceptible subjects.

An aerobiological survey of allergens in al Khobar, Saudi Arabia.

A nationwide aerobiologic study is in progress in Saudi Arabia using Burkard 7-day volumetric spore traps to determine the major airborne allergens and their seasonal patterns. Eights months readings have been completed at Al-Khobar, an important coastal city on the Arabian Gulf. Pollen levels showed a double season. An autumnal peak reached its maximum in October rising sharply from the low summer values before falling during the short winter then rising again in springtime. Both local and imported flora were represented with chenopodiaceae, grasses and Ambrosia as the most common botanical groups, identification of the most significant individual species is still in progress. Fungal spores also show distinctive seasonal patterns. In descending rank order from the most common genera were Cladosporium, Ustilago, Alternaria, with Chaetomium and Ulocladium as consistent but minor components. Basiodiospores and Ascospores represented less than 10% of the total spore population, indicative of the dry nature of the climate. Desert dust added an important irritant to the Saudi atmosphere but a major contaminating factor to the aerobiological material being analysed.

The basidiomycete ganoderma and asthma: collection, quantitation and immunogenicity of the spores.

Ganoderma fungal spores are a major component of the Auckland air-spora. Previous studies of ganoderma involvement in allergic asthma and rhinitis were extended by locating the sporophores (fruiting bodies) in the Auckland area and systematically collecting the ejected spores. Maximum production by one sporophore was 5 gram dry weight of spores in one week, equivalent to 11 billion spores. We have estimated that between 400 and 1200 sporophores would account for previously reported levels of ganoderma spores collected from the air by Burkhard spore traps. Both whole spores and extracts of spores were strongly immunogenic in rabbits. Of the 115 asthma patients who were skin prick tested with a variety of fungal extracts, 32 (28%) were positive to one or more fungi. Of these, 18 (16%) reacted positively to ganoderma extracts. A theory proposing how ganoderma might contribute to allergic hyperreactivity in susceptible patients is developed.

Allergy to basidiospores: immunologic studies.

Fruiting bodies of larger basidiomycetous fungi were collected over a 15 month period from natural habitats and a total of 67 different antigenic extracts were prepared from spores or tissue, in buffered saline, pH8, and standardised at 1:50 and 1:10 (W/V) concentrations. A number of heterogeneous and diagnosed allergic patients were tested by skin prick test method with the extracts of either individual species or mixtures of related species. Up to 22% patients reacted positively, indicating their possible IgE mediated reactions and the allergenic potency of the species involved. The potential allergenicity of many of these genera and/or species has not been reported previously. The findings suggest that basidiospores could be a possible major factor for the high respiratory allergy incidence in the Auckland region and necessitate further investigation.

Fungal allergy and respiratory disease.

An aerobiological study of three different localities of the Auckland region using Burkard volumetric spore traps was conducted for a 12 month period from September 1979 to August 1980. High counts were recorded of various types of fungal spores of both unknown and recognised potential allergens but the basidiospore group was dominant at all sites forming greater than 50% of the total air spora. Seasonal periodicities as well as regional variations in spore concentrations of five generic group viz Ganoderma, Leptosphaeria, Cladosporium, Alternaria and Aspergillus-Penicilium were recorded. These exhibited summer and/or autumn peaks. The diel periodicities recorded for Ganoderma and Leptosphaeria were of nocturnal type. Cladosporium was diurnal and Aspergillus-Penicillium did not display any clear periodicity. The hospital admissions of acute asthma sufferers were recorded for the period January 1979 to December 1980. The seasonal pattern of airborne basidiospores of the region and the pattern of acute asthma admissions indicate a close relationship between the two.