Evaluation of antibacterial and antioxidant activities of three types of benzoin resin

The benzoin resin is used extensively in traditional medicine for its many reported therapeutic properties. The essential oils of three different types of benzoin resin were extracted using the traditional method in this study. The yield of essential oils of the white, red and gray types of resin was 1.01, 0.92 and 0.54%, respectively. The obtained extracts were tested against two types of pathogenic bacteria, Staphylococcus aureus and Escherichia coli . The tests showed that essential oil of gray type resin is effective against both Escherichia coli (14 mm) and Staphylococcus aureus (11 mm). The antioxidant activity has been also evaluated to compare the efficiency of different type of resin with DPPH· assay. In the DPPH· system, the antioxidant activity of the red resin extract (0.01 μg/mL) was superior to that of the white (27.32 μg/mL) and gray (42.90 μg/mL) extracts, with IC 50 values, respectively.

Thermodynamic Study of Operation Properties Effect on Polymer Electrolyte Membrane Fuel Cells (PEM)

Feasibility Study of Zero Energy Houses: Case Study of Magrun City - Libya

The residential load is one of the largest consumers of the electric energy in Libya that could be supplied by renewable energies. Renewable energy technologies and systems can be a good solution to build “Zero Energy Buildings”. A zero-energy house is proposed for Maqrun city. It is intended to use wind turbine with batteries as a storage system to supply electric energy demand for this house. The intended house average daily electric energy demand is estimated to be 35 kWh/day. Two WECS were selected to supply the energy demand each of size 6 kW. Th energy produced by the selected wind energy conversion system (WECS) is about 23,894 kWh/yr and the expected capacity factor at the site is about 23%. Modeling of energy demand of the house and simulation of its performance was performed using excel sheets and HOMER softare.

Review on solar water heating in Libya

This review paper aims to provide a comprehensive review of the history and the best practices of solar water heaters in Libya. Although Libya is blessed with high solar potential, there is no widespread implementation of this technology due to many reasons such as: the cheap price of both electricity and electric water heaters, lack of clear and systematic policy, and lack of environmental awareness. Th Center for Solar Energy Research and Studies (CSERS) has given attention to this technology since its establishment in 1978, and the solar water heating system field test project is one of the research projects in the Center. Th paper has shown that there was no attention paid to this technology and even to renewable energy in general in the previous years. However, preliminary information clearly shows the importance of continuing research in this field. Numerous valuable information on solar water heating systems from the literature was dedicated and made available for researchers and decision-makers. The studies conducted in this fild for Libya are arranged in this review on the basis of the topic studied: performance evaluation, optimization, on-site measurements and policies and strategies. One of the most important results retrieved from these studies shows that the daily quantity of hot water withdrawn per capita at 45 °C is estimated at around 60 liters. The estimated annual amount of energy consumed for water heating per person is 510 kWh. For an average Libyan family of six persons, the annual amount of energy consumed per dwelling is estimated at about 3060 kWh. The review also presented the history of solar water heaters implementation, manufacturing, and testing facilities for quality control in Libya. The study calls upon the Libyan decision-makers to take their responsibility and put an urgent action plan to help the widespread implementation of solar water heaters in the residential, services, and industrial sectors. Such a plan will surely alleviate the ever-increasing demand for electricity, save fossil fuel reserves and mitigate GHG emissions.

Review on Solar Space Heating - Cooling in Libyan Residential Buildings

This review paper focuses on documenting and studying published papers and works in the field of solar heating and cooling air space in residential buildings. The goal of this survey and documentation is to find out the most important flushing results and conclusions specifically in the fields of using solar energy for space heating, cooling, and ventilation of local residential buildings in Libya. This covers using active and passive solar systems in, achieving thermal human comfort in such buildings leading to reduce electrical energy consumption. This paper also concentrates on applying energy efficiency measures in buildings; planning, design, and construction stages with the use of the principles of energy conservation in buildings. There are several studies comparing traditional with modern house designs in several local cities including both famous old cities of “Ghadames” and “Gharyan”. Several conclusions and recommendations are summarized within the text of this paper.

THE EXPERIENCES OF RECTAL CANCER SURVIVORS WITH STOMA IN WEST JAVA INDONESIA

Source apportionment of fine particulate matter in Houston, Texas: insights to secondary organic aerosols

. Online and offline measurements of ambient particulate matter (PM) near theurban and industrial Houston Ship Channel in Houston, Texas, USA, during May2015 were utilized to characterize its chemical composition and to evaluatethe relative contributions of primary, secondary, biogenic, and anthropogenicsources. Aerosol mass spectrometry (AMS) on nonrefractory PM 1 (PM ≤ 1  µ m) indicated major contributions from sulfate (averaging50 % by mass), organic aerosol (OA, 40 %), and ammonium (14 %).Positive matrix factorization (PMF) of AMS data categorized OA on average as22 % hydrocarbon-like organic aerosol (HOA), 29 % cooking-influencedless-oxidized oxygenated organic aerosol (CI-LO-OOA), and 48 %more-oxidized oxygenated organic aerosol (MO-OOA), with the latter twosources indicative of secondary organic aerosol (SOA). Chemical analysis ofPM 2.5 (PM ≤ 2.5  µ m) filter samples agreed that organicmatter (35 %) and sulfate (21 %) were the most abundant components.Organic speciation of PM 2.5 organic carbon (OC) focused on molecularmarkers of primary sources and SOA tracers derived from biogenic andanthropogenic volatile organic compounds (VOCs). The sources of PM 2.5 OCwere estimated using molecular marker-based positive matric factorization(MM-PMF) and chemical mass balance (CMB) models. MM-PMF resolved nine factorsthat were identified as diesel engines (11.5 %), gasoline engines(24.3 %), nontailpipe vehicle emissions (11.1 %), ship emissions(2.2 %), cooking (1.0 %), biomass burning (BB, 10.6 %), isopreneSOA (11.0 %), high- NOx anthropogenic SOA (6.6 %),and low- NOx anthropogenic SOA (21.7 %). Using availablesource profiles, CMB apportioned 41 % of OC to primary fossil sources(gasoline engines, diesel engines, and ship emissions), 5 % to BB,15 % to SOA (including 7.4 % biogenic and 7.6 % anthropogenic),and 39 % to other sources that were not included in the model and areexpected to be secondary. This study presents the first application of in situ AMS-PMF, MM-PMF, andCMB for OC source apportionment and the integration of these methods toevaluate the relative roles of biogenic, anthropogenic, and BB-SOA. The threesource apportionment models agreed that ∼  50 % of OC is associatedwith primary emissions from fossil fuel use, particularly motor vehicles.Differences among the models reflect their ability to resolve sources basedupon the input chemical measurements, with molecular marker-based methodsproviding greater source specificity and resolution for minor sources. Bycombining results from MM-PMF and CMB, BB was estimated to contribute11 % of OC, with 5 % primary emissions and 6 % BB-SOA. SOA wasdominantly anthropogenic (28 %) rather than biogenic (11 %) orBB-derived. The three-model approachdemonstrates significant contributions of anthropogenic SOA to fine PM. Morebroadly, the findings and methodologies presented herein can be used toadvance local and regional understanding of anthropogenic contributions toSOA.

Source apportionment of fine particulate matter in Houston, Texas: Insights to secondary organic aerosols

Supplementary material to "Source apportionment of fine particulate matter in Houston, Texas: Insights to secondary organic aerosols"

Organosulfates in Atlanta, Georgia: Anthropogenic influences on biogenic secondary organic aerosol formation