105 research outputs found

    Antibacterial activity of some wild medicinal plants collected from western Mediterranean coast, Egypt: Natural alternatives for infectious disease treatment

    Get PDF
    Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the wild plants grown in western Mediterranean coast of Egypt is one of our research goals. In this study, 10 wild plants namely Mesembryanthemum crystallinum, Blackiella aellen, Arthrocnemon glaucum, Atriplex halimus, Thymelaea hirsute, Carduus getulus, Nicotiana glauca, Alhagi maurorum, Atractylis carduus and Echinops spinosissimus were collected from El-Hammam, Burg El Arab and Bahig regions located along the Western Mediterranean coast of Egypt. Hexane and methanol extracts of fresh aerial parts of the plants were screened in vitro for antimicrobial activity against 15 Gram positive and negative pathogenic bacteria. Both methanol and hexane plant extracts showed strong antibacterial activity against at least two pathogenic microorganisms tested. However, hexane extracts generally showed lower activity against microorganisms compared to methanol extracts. The microorganisms’ susceptibility to different extracts did not correlate with the susceptibility or resistance to a particular antibiotic. The results of this study thus support the medical usage of the studied plants and suggest that some of these plants possess antimicrobial properties that can be used to cure infectious diseases.Key words: Egyptian wild plants, antagonism, biological control, phytochemicals, multi-drug resistant

    Evaluation of a compression ignition engine performance and emission characteristics using diesel-essential oil blends of high orange oil content

    Full text link
    In this research, waste stream essential oil such as orange oil is used as a diesel fuel partial replacement to be tested in a diesel engine. Like diesel fuel, orange oil does not contain any oxygen since it is constituted of limonene (a colourless liquid aliphatic hydrocarbon) and has almost similar density. A 6-cylinder diesel engine is operated using various blends of orange and diesel fuel. The engine was operated with three different fuel blends: neat diesel, 74% diesel + 26% orange oil (D74O26) and 59% diesel + 41% orange oil (D59O41). All the orange oil blends produced nearly the same brake power from the engine experiment compared to neat diesel fuel. Furthermore, all orange oil blends emit less particulate matter, and the ‘count mean diameter’ of the emitted particles is also lower than base diesel. Based on the obtained results, these blends can be suggested to be used in a diesel engine

    Heterosis for flower and fruit traits in tomato (Lycopersicon esculentum Mill.)

    Get PDF
    A study was conducted in tomato using an 8 × 8 diallel set excluding reciprocals to quantify the magnitude of heterosis for yield and its five yield components: number of flowers per cluster, number of fruits set per cluster, fruit length, fruit width, fruit weight and fruit yield per plant. Seven accessions and one locally approved variety were crossed in half diallel fashion and the resulting F1 progeny along with their parents were evaluated in a 6 × 6 Tripple Lattice Design at Agricultural Research Institute, Mingora (NWFP), Pakistan during 2007 - 2008 crop season. Highly significant differences were observed among the genotypes for all the studied traits. Highly significant heterosis of positive nature was foundfor flowers per cluster (53.1 and 37.2%), fruits per cluster (38.9%), fruit length (32.7 and 15.5%), fruit weight (48.7 and 45.0%) and yield per plant (34.9%) over the mid and better parents, respectively. Positive significant heterosis was observed for flowers per cluster (7.4%), fruits per cluster (10.0 and 10.0%), fruit length (8.9%), fruit width (8.7 and 7.9%), fruit weight (14.3 and 12.5%), yield per plant (24%) over the mid and better parents, respectively. Four hybrids possessed significantly usefulheterobeltiosis for fruit weight. Three single cross hybrids and four of the parental genotypes were selected for use in subsequent tomato breeding programmes

    State-of-the-Art of Strategies to Reduce Exhaust Emissions from Diesel Engine Vehicles

    Full text link
    Compression ignition engines play a significant role in the development of a country. They are widely used due to their innate properties such as high efficiency, high power output, and durability. However, they are considered one of the key contributors to transport-related emission and have recently been identified as carcinogenic. Thus, it is important to modify the designs and processes before, during, and after combustion to reduce the emissions to meet the strict emission regulations. The paper discusses the pros and cons of different strategies to reduce emissions of a diesel engine. An overview of various techniques to modify the pre-combustion engine design aspects has been discussed first. After that, fuel modifications techniques during combustion to improve the fuel properties to reduce the engine-out emission is discussed. Finally, post-combustion after-treatment devices are briefly discussed, which help improve the air quality of our environment.</jats:p

    Techno-economic analysis and physicochemical properties of Ceiba pentandra as second-generation biodiesel based on ASTM D6751 and EN 14214

    Full text link
    © 2019 by the authors. Processing biodiesel from non-edible sources of feedstock seems to be thriving in recent years. It also has also gathered more attention than in the past, mainly because the biodiesel product is renewable and emits lower pollution compared to fossil fuels. Researchers have started their work on various kinds of biodiesel product, especially from a non-edible feedstock. Non-edible feedstocks such as Ceiba pentandra show great potential in the production of biodiesel, especially in the Southeast Asia region because the plants seem to be abundant in that region. Ceiba pentandra, also known as the Kapok tree, produces hundreds of pods with a length of 15 cm (5.9 in) and diameter 2-5 cm (1-2 in). The pods consist of seeds and fluffin the surrounding areas inside the pod, which itself contains yellowish fibre, a mixture of cellulose and lignin. The seeds of Ceiba pentandra can be used as feedstock for biodiesel production. The study for Ceiba pentandra will involve techno-economic, as well as a sensitivity analysis. Moreover, the study also shows that the techno-economic analysis of a biodiesel processing plant for 50 ktons Ceiba pentandra with a life span of 20 years is around 701millionwith3.7yearsofthepaybackperiod.Besidesthat,thisstudyalsoshowsthedifferencesinoperatingcostandoilconversionyield,whichhastheleastimpactonrunningcost.Byimprovingtheconversionprocessescontinuouslyandbyincreasingtheoperationaleffciency,thecostofproductionwilldecrease.Inaddition,thestudyalsoexplainsthedifferencesoffinalpricebiodieselanddieselfossilfuel,bothshowingdissimilarscenariossubsidyandtaxation.Biodieselhasasubsidyof701 million with 3.7 years of the payback period. Besides that, this study also shows the differences in operating cost and oil conversion yield, which has the least impact on running cost. By improving the conversion processes continuously and by increasing the operational effciency, the cost of production will decrease. In addition, the study also explains the differences of final price biodiesel and diesel fossil fuel, both showing dissimilar scenarios subsidy and taxation. Biodiesel has a subsidy of 0.10/L and $0.18/L with a total tax exemption of 15%. The value was obtained from the latest subsidy cost and diesel in Malaysia. Finally, further research is needed in order to fully utilize the use of Ceiba pentandra as one of the non-edible sources of biodiesel

    Production process and optimization of solid bioethanol from empty fruit bunches of palm oil using response surface methodology

    Full text link
    © 2019 by the authors. This study aimed to observe the potential of solid bioethanol as an alternative fuel with high caloric value. The solid bioethanol was produced from liquid bioethanol, which was obtained from the synthesis of oil palm empty fruit bunches (PEFBs) through the delignification process by using organosolv pretreatment and enzymatic hydrolysis. Enzymatic hydrolysis was conducted using enzyme (60 FPUg-1 of cellulose) at a variety of temperatures (35 °C, 70 °C, and 90 °C) and reaction times (2, 6, 12, 18, and 24 h) in order to obtain a high sugar yield. The highest sugars were yielded at the temperature of 90 °C for 48 h (152.51 mg/L). Furthermore, fermentation was conducted using Saccharomyces cerevisiae. The bioethanol yield after fermentation was 62.29 mg/L. Bioethanol was extracted by distillation process to obtain solid bioethanol. The solid bioethanol was produced by using stearic acid as the additive. In order to get high-quality solid bioethanol, the calorific value was optimized using the response surface methodology (RSM) model. This model provided the factor variables of bioethanol concentration (vol %), stearic acid (g), and bioethanol (mL) with a minus result error. The highest calorific value was obtained with 7 g stearic acid and 5 mL bioethanol (43.17 MJ/kg). Burning time was tested to observe the quality of the solid bioethanol. The highest calorific value resulted in the longest burning time. The solid bioethanol has a potential as solid fuel due to the significantly higher calorific value compared to the liquid bioethanol

    Performance and Emission Parameters of Homogeneous Charge Compression Ignition (HCCI) Engine: A Review

    Full text link
    Strict emission regulations and demand for better fuel economy are driving forces for finding advanced engines that will be able to replace the conventional internal combustion engines in the near future. Homogeneous charge compression ignition (HCCI) engines use a different combustion technique; there are no spark plugs or injectors to assist the combustion. Instead, when the mixtures reach chemical activation energy, combustion auto-ignites in multiple spots. The main objective of this review paper is to study the engine performance and emission characteristics of HCCI engines operating in various conditions. Additionally, the impact of different fuels and additives on HCCI engine performance is also evaluated. The study also introduces a potential guideline to improve engine performance and emission characteristics. Compared to conventional compression ignition and spark ignition combustion methods, the HCCI combustion mode is noticeably faster and also provides better thermal efficiency. Although a wide range of fuels including alternative and renewable fuels can be used in the HCCI mode, there are some limitation/challenges, such as combustion limited operating range, phase control, high level of noise, cold start, preparation of homogeneous charge, etc. In conclusion, the HCCI combustion mode can be achieved in existing spark ignition (SI) engines with minor adjustments, and it results in lower oxides of nitrogen (NOx) and soot emissions, with practically a similar performance as that of SI combustion. Further improvements are required to permit extensive use of the HCCI mode in future.</p

    State-of-the-Art of Establishing Test Procedures for Real Driving Gaseous Emissions from Light- and Heavy-Duty Vehicles

    Full text link
    Air pollution caused by vehicle emissions has raised serious public health concerns. Vehicle emissions generally depend on many factors, such as the nature of the vehicle, driving style, traffic conditions, emission control technologies, and operational conditions. Concerns about the certification cycles used by various regulatory authorities are growing due to the difference in emission during certification procedure and Real Driving Emissions (RDE). Under laboratory conditions, certification tests are performed in a ‘chassis dynamometer’ for light-duty vehicles (LDVs) and an ‘engine dynamometer’ for heavy-duty vehicles (HDVs). As a result, the test drive cycles used to measure the automotive emissions do not correctly reflect the vehicle’s real-world driving pattern. Consequently, the RDE regulation is being phased in to reduce the disparity between type approval and vehicle’s real-world emissions. According to this review, different variables such as traffic signals, driving dynamics, congestions, altitude, ambient temperature, and so on have a major influence on actual driving pollution. Aside from that, cold-start and hot-start have been shown to have an effect on on-road pollution. Contrary to common opinion, new technology such as start-stop systems boost automotive emissions rather than decreasing them owing to unfavourable conditions from the point of view of exhaust emissions and exhaust after-treatment systems. In addition, the driving dynamics are not represented in the current laboratory-based test procedures. As a result, it is critical to establish an on-road testing protocol to obtain a true representation of vehicular emissions and reduce emissions to a standard level. The incorporation of RDE clauses into certification procedures would have a positive impact on global air quality

    Optimization of cerbera manghas biodiesel production using artificial neural networks integrated with ant colony optimization

    Full text link
    © 2019 by the authors. Optimizing the process parameters of biodiesel production is the key to maximizing biodiesel yields. In this study, artificial neural network models integrated with ant colony optimization were developed to optimize the parameters of the two-step Cerbera manghas biodiesel production process: (1) esterification and (2) transesterification. The parameters of esterification and transesterification processes were optimized to minimize the acid value and maximize the C. manghas biodiesel yield, respectively. There was excellent agreement between the average experimental values and those predicted by the artificial neural network models, indicating their reliability. These models will be useful to predict the optimum process parameters, reducing the trial and error of conventional experimentation. The kinetic study was conducted to understand the mechanism of the transesterification process and, lastly, the model could measure the physicochemical properties of the C. manghas biodiesel

    Performance Evaluation Effect of Nb2O5 Particulate on the Microstructural, Wear and Anti-corrosion Resistance of Zn–Nb2O5 Coatings on Mild Steel for Marine Application

    Get PDF
    In this study, we developed Zn–Nb2O5 composite coatings from sulfate bath for wear and corrosion performance on mild steel by electrodeposition technique. The effect of Nb2O5 particulate on the Zn–Nb2O5 properties was investigated. The particle volume fraction was varied within between 10 and 20 wt%. The structural properties of the composite coatings were characterized using scanning electron microscope equipped with energy-dispersive spectrometer. The hardness and wear of the composite coating were measured with diamond base microhardness indenter tester and sliding CETR reciprocating wear testers, respectively. The corrosion properties were examined in 3.65% NaCl using AUTOLAB 101 Metrohm potentiostat–galvanostat with linear polarization technique. The results showed that average hardness value of 192.6 and 200.6 HV and passivation potential of 4.39E?08 and 5.30E?08(X) were obtained for the 10–20 wt% Nb2O5 particulate on the Zn–Nb2O5 coatings. The wear performance improves by 63.4% as against the control sample. In all, this study established that up to 20 wt% of Nb2O5 in Zn–Nb2O5 composite coating significant corrosion, wear and microhardness propagation resistance of mild steel was attained
    corecore