The Fifth Palestinian International Chemistry Conference

Clarithromycin is a semi-synthetic broad spectrum macrolide antibiotic widely used for theeradication of respiratory tract infections including atypical pneumonias and soft tissueinfections. It is an important substitute for patients exhibiting penicillin sensitivity andallergy.The methods reported previously for the detection of clarithromycin have mainly used lengthysample preparation procedures involving liquid–liquid extraction or solid-phase extractionprior to chromatographic analysis and most of these methods suffer from long run times andrequire large sample volumes. Although these methods offer selective detection ofclarithromycin but they are much more complex than the conventional ultraviolet (UV)detection. Clarithromycin has weak UV absorbance because it lacks a suitable chromophorewhich makes difficult to develop a specific, selective and sensitive method usingspectrophotometry without complexation and derivatization. As a impact of such laboratorypractice, large amounts of waste chemical are produced every day in industrial laboratorieswhich is of great concern throughout the world since long. So it becomes necessary to developalternative strategy which can substitute such traditional methods with clean andenvironmental friendly analytical means involving minimum consumption or replacement oftoxic reagents with the reagents having no or less polluting effects.A rapid, sensitive and environmental friendly analytical method for the direct determinationof clarithromycin in tablet formulations through transmission Fourier Transform Infrared(FT-IR) spectroscopy has been successfully developed for routine quality control analysis. Thismethod avoids any sample pretreatment except grinding or use of any solvent as extraction isno more required. Standards and samples were used in the form of KBr for recording FT-IRspectra. In the final step, chemometric method was used to filter out unmatched spectralfeatures and the converted and filtered spectra were used to build a calibration model basedon partial least square (PLS) using the FT-IR carbonyl region (C=O) from 2965-1662 cm−1.The excellent correlation coefficient (R2) was achieved (0.9999). This method gives maximumAnalytical Chemistry(IYC-2011) 79recovery of 102% and is fully validated. This also fulfills the ever increasing demand ofpharmaceutical industries for developing sensitive, economical, time consuming andenvironmental friendly analytical methods for the quantification of Active PharmaceuticalIngredients (API) while monitoring quality of finished product with total analysis time of lessthan three minutes.

Human need for energy resources is a fact of life. The demand for energy is continuously increasing with time, and is almost reaching a logarithmic relation. Unfortunately, as profitability is masterminding human current practices with energy resources, human being is doing to himself what dinosaurs did to themselves long time ago. Fossil fuels clearly cause global warming through green-house effects. Nuclear energy proves to be a dreadful alternative, as we have plenty to learn from Chernobyl and Fukushima. Bio-fuels, where energy is produced from agricultural products, are at the first glance promising prospect, give no solution. Unfortunately they are proving to be no alternative, as due to profitability interference, they came at the expense of human food. Human being can benefit from energy without hurting future life only by following certain strict strategies. This can be achieved by wise utilization of energy sources and by investing in solar energy resources. To guarantee success, scientific thinking and reason should replace current profitability-based practices. A simple calculation, at least in theory shows that available solar energy resources are 120,000 TW. Less than 0.02% of available resources are sufficient to entirely replace fossil fuels and nuclear power which count to about 24 TW nowadays. To our estimation, if we can utilize incident solar light on one third of Algeria desert, at 10% conversion efficiency, the resulting energy is sufficient to meet current human demands. Quran revelations that Earth has enough resources for human beings are absolutely true ( وقدر فیھا أقواتھا ), if we scientists positively think of these facts. Moreover, solar energy technology needs to be seriously considered as alternative at the global level. Industrialized and developing countries need to work on such areas. Palestine should participate in such technologies for many reasons. Palestine has limited natural resources. Any future development should therefore be based on advanced technology. Such ambitious outlook dictates that Palestine heavily invests in quality teaching and researching in such areas. Materials research is one building block for solar energy technology. The philosophy is simple: we need to develop a technology which intensively demands know-how rather than Plenary resources. In short Palestine should develop a technology based on creativity and invention, starting with advanced materials and their applications in solar energy. Semiconductors (SC) are a very important area of advanced materials. Almost all contemporary technologies rely on SC systems such as p-n junctions (transistors, diodes, PV, PEC, refrigeration, ….). In this plenary, we wish to give one specific example on where Palestinian scientists can target an area of advanced material research and can contribute effectively despite limited resources. Semiconductor research activity has been established in the mid 1990s, and is now housed at SSERL. The activity started with modification of mono-crystalline n-Si and n-GaAs semiconductor surfaces for the purpose of controlling band edge positions. This was for the purpose of tailoring band edge positions to catalyze water splitting (into hydrogen and oxygen) by solar light. The objectives were successfully achieved by graduate students at ANU. To simultaneously achieve stability and efficiency of the SC electrode, other techniques were developed here. Monocrystalline n-GaAs electrodes were enhanced in stability and efficiency using polymeric coatings with electroactroactive ions inside. However, the increasing cost of monocrystalline SC materials affected our objective. Our efforts were then diverted to synthetic thin film SC electrodes. Preparation of enhanced SC materials, in the forms of thin films and nano-scale particles, has then been conducted for the purposes of solar photo-voltaics and for water purification. SSERL researchers have been heavily engaged in preparing and enhancing SC thin films. Nano-thin CdS and CdSe films, deposited onto FTO/glass systems and are currently being used for light-to-electricity conversion processes. Modification of thin films with different techniques shows promising potential in enhancing efficiency and stability. For the first time, ANU researchers were able to stabilize CBD-based CdSe films in PEC processes. Examples of SC research progress at ANU will be highlighted in this presentation. Some technical results and discussions will be presented. This draws inroads for young Palestinian scientists to work on advanced materials while keeping in mind their societal problems. It is also intended to attract the attention of decision makers to put materials R&D as a high priority area in the near future

7-nitro-1-methyl-5-(2 -fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one(Flunitrazepam) is the drug from family of 7-membered heterocyclic compunds 1,4-benzodiazepinones. Although a number of method synthesis of flunitrazepam have beenreported in literature but they suffer because using anhydrous ammonia or dry ammoniagas. [1-4].In this research work the new methods for synthesis of flunitrazepam from 2-flouroacetamidobenzophenone, hexamethylenetetramine (hexamine) and ammonium chloride inethanol as solvent to generate ammonia in situ, will be reported.The results indicate that the best result obtained when the mole ratio of the componentsacetamide:NH4Cl: Hexamine : ethanol in order was as 1.0: 3.5: 2.5 :20-30The structure of products was evaluated by melting point,1H NMR, 13C NMR, 19F NMR,GCMassand IR spectroscopy techniques.

ھدفت الدراسة إلى التعرف على آلیة عمل المعالج الشعبي- العطار- والذي یقوم بمعالجة الأمراض المتنوعة بالأعشاب والمستحضرات الأخرى بالاستناد إلى أمھات الكتب القدیمة والتي كان یستخدمھا الآباء والأجداد في العلاج الشعبي وكذلك تجربة العطار الشخصیة وتجارب الآخرین في العلاج ووصفاتھم في علاج الأمراض والعلل. كما ھدفت الدراسة إلى تعریف القراء بمحتویات دكان العطار- محل العطارة- الصیدلیة الشعبیة والتي تنتشر في كافة المدن الفلسطینیة وخاصة في الأسواق القدیمة ،ولا یزال اسم سوق العطارین موجود في الخلیل والقدس وبیت لحم . اتبعت الدراسة المنھج الوصفي باستخدام المقابلة والزیارة المیدانیة لمحل العطار وكذلك الملاحظة لما یتردد على محل العطار من أشخاص وما یطلبونھ منھ، وفي إثناء جلوسي عند عطار لإجراء مقابلة معھ وفي مدة ساعة تردد على محلھ عشرین شخصا،حیث كان یقطع المقابلة ویلبي طلب الرواد من المرضى والناس العادیین والذین یطلبون وصفات شعبیة سواء لھم أو إلى مرضى آخرین.

Metal free carbon nanostructures are desirable materials for wide potential applications in composites, drug delivery, electronic circuits, especially for the silicon industry. The general requirement for the silicon industry for metal free carbon nanotubes is well known. Metals reduce chip lifetime because they react unfavourably with many materials found in circuits. Hence, the use of non-metallic catalysts is desirable for silicon compatibility (and also composites). Recently various investigations have successfully implemented oxide catalyst particles, for example, SiO2, ZrO2, MgO or Al2O3. The use of SiO2 as a catalyst for graphitic nanostructure formation, such as carbon nanotubes and graphene, is particularly attractive for integration into Si based technology. A key question is whether carbide phases form in the reaction. We show the formation of SiC from SiO2 nanoparticles for the synthesis of graphitic carbon nanostructures via chemical vapor deposition (CVD) at 900°C. Our findings point to the carbothermal reduction of SiO2 in the CVD reaction. Moreover, the inclusion of triethyl borate accelerates the carbothermal reduction process improving the availability of SiC species and hence leads to improved yields. The formation of graphitic carbon is best explained through a carbon dissolution mechanism. The studies improve our understanding of the growth mechanisms at play in sp2 carbon formation when using SiO2 catalysts.

Deposition of surface coatings is one of the important approaches in improving the friction and wear properties of surfaces. For instance, self-lubricating coatings such as MoS2- Ti are advantageous in reducing friction. These self-lubricating coatings outperform liquid lubricants in several applications such as vacuum and high temperatures. Wear resistant coatings such as TiB2 are important in reducing wear rate of a material. Even though single layer coatings have a wide range of application their tribological performance may not be sufficient. Hence, coatings that consist of different properties can be prepared as multilayer coatings. These coatings can have different sequence of layers depending on the intended application of the material. In this study, the tribological properties of a graded composite multilayer coating with specific sequence of MoS2:Ti/MoS2:TiBN/TiBN/TiB2/Ti deposited on tool steel substrate was investigated. The coating was deposited by a Closed-Field Unbalanced Magnetron Sputtering technique. The friction and wear properties of the coating were studied at 40°C and 400°C with the help of a high-temperature reciprocating friction and wear tester and wear scars were also analyzed with Scanning Electron Microscope with incorporated Electron Dispersive Spectroscopy. The hardness of the coating was also studied with the help of micro-hardness tester. The experimental results for the tests done at 40°C have shown that the friction coefficient value ranges between 0.02 and 0.034. It has been found that the friction coefficient values were different depending on the deposition parameters used and the coatings deposited at higher substrate bias were found to result in higher friction. The durability of the coating was also found to be dependent on the deposition parameters and the specimen deposited at -150 V substrate bias and 3 % N2 flow has the lowest durability. The friction coefficient and durability of the coatings were found to be highly dependent on temperature. At high temperature, the friction coefficient increases by three folds and the durability decreases significantly. The SEM images of the wear scars have shown that the wear is an adhesive wear type. The hardness of the tool steel surface was also improved with the deposition of the multilayer coating.

Polycrystalline CdS/ZnS thin films were prepared by chemical bath deposition (CBD)technique on fluorine-doped tin oxide (FTO) coated glass substrates. Enhancement ofdeposited CdS/ZnS thin film characteristics at solid/liquid interface in photoelectrochemical(PEC) systems was investigated. Deposited CdS/Zns thin films were exposed to differenttreatment methods and different treatment methods and different experimental conditions.The films were heated to desired temperatures (300⁰C, 400⁰C) under air. Cooling of heatedfilms to room temperaturewas achieved by either slow cooling or quenching. Etching of film surface was conductedusingdilute HCI solution. The effect of such treatment on the film photoelectrochemicalcharacteristics was measured by monitoring different parameters, such as: open-circuitvoltage (Voc ), short-circuit current density (Jsc), dark current density-potential (J-V) plots,photo J-V plots, conversion efficiency (η), fill factor (FF), Scanning electron microscopy (SEM),X-ray diffraction, together with electronic absorption and photoluminescence (PL) emissionspectra.The characteristics of CdS/ZnS thin films in PEC systems were enhanced by controllingdifferent experimental conditions, controlling preheating temperatures and controllingcooling rates. The dark- and photo- current densities vs. potential plots were improved byannealing. Cell efficiency, fill factor, short-circuits current densities (Jsc) and SEM resultswere enhanced for the annealed CdS/ZnS films. The best annealing temperature for CdS/ZnSfilms was found to be 300⁰C at which the photo J-V plots and cell efficiency were improvedsignificantly. Slowly cooled electrodes from temperature 300⁰C, gave better dark and photocurrent density vs. potential plots with higher efficiency than their quenched counterparts.SEM measurements were consistent with these findings, and showed better surfaces forNano Technology(IYC-2011) 70slowly cooled CdS/ZnS thin film electrodes. Maximum values of conversion efficiencies wereobtained by slow cooling of preheated CdS/ZnS electrodes cooled from temperature 300⁰Ccompared to that of electrodes cooled from 400⁰C.The effect of coating the CdS/ZnS electrodes with MnP/polysiloxane was also studied. The(Jsc) values of coated CdS/ZnS films (with certain Zn ratios) were significantly enhanced. TheMnP/ploysilocane coating introduces a charge-transfer mediator species that enhancescurrent and electrode stability.

This presentation will focus on using innovative technology in medicinal chemistry, biology, coupled with genomic data to identify the various genes that are implicated in the cause of human diseases. The translation of gene sequence into a 3D protein structure and potential ligand binding pockets on each proposed 3D structure coupled with verification in biologico using innovative techniques (computational chemistry, biology, biological assays, and medicinal chemistry) will be outlined. The utilization of this technology in validating biological targets, pathways, as well as the discovery of novel optimal drug candidates (potency, selectivity, and other physiochemical properties) will be presented. The use of this technology in the discovery of novel treatments amongst a wide range of diseases such as diabetes, obesity, Alzheimer’s, depression, glaucoma, and cancer will be outlined and discussed in this presentation.

In this study, the adsorption of gemifloxacin mesylate (antibiotic) using selected pharmaceutical adsorbents such as activated charcoal and kaolin was investigated spectrophotometrically in terms of initial pH, residence time, initial concentration of drug (adsorbate), weight of adsorbent and temperature. For equilibrium studies, data for adsorption of gemifloxacin mesylate (GEMX) on charcoal were shown to fit Langmuir isotherm whereas, Freundlich isotherm fitted the data very well for the adsorption on kaolin. The maximum adsorption capacity of GEMX were 137mg/g on charcoal compared to 0.04 mg/g on kaolin. This is due to high surface area of charcoal compared to kaolin. The amount adsorbed at equilibrium decreases as adsorbate's concentration increases and increases as the weight of adsorbent increases. pH played a role in the adsorption of GEMX on charcoal which was more in acidic than in basic medium. The maximum adsorption was at pH 6 and at neutral pH for kaolin. Thermodynamics parameters showed that adsorption process was exothermic and spontaneous as ΔHo and ΔGo had negative values. The positive value of ΔSo showed an increase in freedom of molecules with increasing temperature. This study suggests activated charcoal as an effective antidote for cases of GEMX overdose or poisoning. Keywords: adsorption; Gemifloxacin mesylate; Thermodynamics parameters; poisoning.

A new series of substituted 8-fluro-4H-pyrimido[2,1-b] [1,3]benzothiazole-4-ones, substituted 7-methyl-4H-isoxazolo[2,3-a]pyrimidin-4-ones, and substituted 2-methyl-5,6,7,8-tetrahydro- 9H-isoxazolo[2,3-a]pyridopyrimidin-9-ones, compounds I–VII, have been prepared for possible use in medicinal application. The preparation followed condensation of β-keto esters with 2- aminopyridine derivatives, in the presence of polyphosphoric acid. The same technique has also been used to prepare diazepine compounds, VIII–X, by condensation of a γ-keto ester with 2-aminopyridine derivatives. Details of synthetic procedures are shown. The new compounds have been characterized by elemental analysis, GC–MS, FT-IR and NMR spectrometry. Bioactivity of these compounds has been investigated.

Several procedures are commonly used for water disinfection from bacteria. Examplesare chlorination, peroxide addition, ozonation and UV irradiation. Photodegradation ofmicroorganisms has also been examined. TiO2 and ZnO were examined by researchers forinactivation of Escherichia coli and some other types of bacteria using photo-degradationtechniques.ZnO is a wide band gap (3.2 ev) semiconductor, with limited photo-catalytic applications toshorter wavelengths only, and demands UV region for excitation. However, it has attractedattention as an interesting alternative to TiO2 in dye sensitized solar cells. ZnO has theadvantage of being sensitive to solar UV light.Because only about 4% of the solar spectrum falls in the UV region, ZnO semiconductoris sensitized by dye molecules. Sensitized ZnO catalysts have been investigated for organicpollutant degradation in a safe and simple manner.In this work, ZnO semiconductor nano-particles, combined with safe low cost sensitizer(natural dye anthocyanin) was used to disinfect water from bacteria by photodegrading itwith solar simulator light. The natural dye sensitized ZnO to the visible light, as the dye hassmaller band gap and absorbs in the visible region.Illumination has been constructed by a solar simulator lamp. A pre-contaminated watersample with E-Coli bacteria was treated with the catalyst (ZnO/anthocyanin) under halogenspot lamp. A noticeable decline in bacteria concentration was observed. Contaminatedsamples were treated with naked ZnO, anthocyanin dye, and light source (without anyadditions) separately in control experiments.Up to 90% degradation was achieved by the ZnO/anthocyanin catalyst system undersolar light in 90 minutes. Effect of different parameters on reaction rate and efficiency, suchas temperature, pH, concentration and others were also studied and will be presented.

The self-assembly behavior of Benzotriazoles in aqueous solutions below its solubility limit has been investigated using light scattering techniques. Various light scattering techniques were used to study the aqueous behavior of benzotriazole-1-methanol (BTAOH) and other family members. These studies have revealed the self-assembly of these molecules in water. Results show that Benzotriazoles molecules tend to aggregate in water to form nanoparticles with radius in the range of 25 nm and more. However, a range of sizes was always present in BTAOH solutions even with lower concentrations. Variable temperature DLS studies show that large particles are mainly formed due to the aggregation of smaller ones.

The main purposes of this work are size selective synthesis bimetallic core-shell clusters,such as Mg-Pd cluster with size range (2-10 nm), by using salt reduction-electrochemicalcombine technique, and investigating the effect of varying the preparation parameters, intothe size and structure of the prepared bimetallic clusters, and investigating the hydrogenuptake capacity of these bimetallic nanoparticles.In the proposed project the hydrogen solubility in different metallic clusters with discretesizes should be investigated. Ideal candidates to be researched are surfactant stabilizedclusters, which are tension-free stabilized and have a narrow size distribution. In this projectthe clusters will be Bimetallic (Mg/Pd) core/shell clusters.In this work the preparation of bimetallic core/shell nano-particles will be performed byusing salt reduction-electrochemically combined technique. This method is simple and cheap,other advantages of this method is that nano-particle size can be easily controlled by varyingthe preparation’s parameters, such as Temperature, distance between the electrodes,electrolysis current, and solvents. That means (size selective method).These bimetallic clusters are expected to have a good solubility and capacity to storagehydrogen, and a high stability too. Because both of magnesium and palladium metals have avery high ability to uptake hydrogen atoms and forming hydrated metals. Whereasmagnesium is unstable metal-hydrides formation (has a high enthalpy of formation (MgH2)thus it is stabilized with alloyed by other stable transition metals as Ni or Al, or by formationof bimetallic clusters with one metal be used to enhance the kinetics of hydrogen absorptionby reducing the large activation barrier that magnesium inherently possesses that ispalladium metal.Then we will study the influence effecting on the hydrogen storage in these bimetallicclusters and how we can be able to promoting the adsorption/desorption processes withchanging the size or M-M ratio into core-shell bimetallic clusters.In this work the hydrogen uptake capacity in nano-meterd sized bimetallic clusters withdifferent sized and different structure will be determined isothermally from volumetricsolubility measurements.

Gabapentin which is chemically known as 1-aminomethyl-1-cyclohexaneacetic acid and its structure is shown below is a very well known pharmaceutical drug useful for the treatment of epilepsy and other cerebral disorders. The medicine suffers form several disadvantages and low bioactivity. This presentation covers an overview about the drug synthesis, application and new ways of structure modification that could enhance the bioactivity of Gabapentin and reduces it side effects. The suggested chemical modification of Gabapentin is expected to increase its permeability to blood brain barrier.

In our research, we are going to synthesis different nanoparticles in a range of 3 to 20 nmselectively with very narrow size distribution, using chemical preparation methods, which canbe carried out either by electrochemical technique or by salt reduction technique. Thenanoparticles will be stabilized in a matrix. Two different stabilizing matrix will be used:polymer and surfactant matrix.We will study the magnetic properties using the Magnetic susceptibility system MS2 atdifferent temperatures.The effect of the stabilizing matrix and the effect of reducing the size into the nano-range onthe magnetic properties will be investigated.The magnetic properties nanoparticles will depend on both the structure and the size of thenanoparticles, and will be affected by the type of the stabilizing matrix.The narrow size distribution of the nanoparticles will enhance the magnetic properties ofnanoparticles.

Single-walled carbon nanotubes (SWNT) are considered to be a potential material for next generation nano-electronics because of their physical and electrical properties. Their potential as key components for devices has already been proven in different applications including, field-effect transistors and logic circuits. For such applications, it’s essential to synthesis SWCNT with controlled spatial position, orientation, alignment, yield and electronic type. One promising synthesis technique used for synthesizing horizontally or vertically aligned SWCNT is chemical vapor deposition (CVD). Using this method, different approaches to grow and control oriented SWNTs horizontally aligned on substrates have been explored, including low gaseous fluxes, electric fields, and selectively cut single crystal substrates such as ST-cut and AT-cut quartz. An important goal behind many of these studies is to control the density of the grown SWNT. Thermal annealing of the substrates prior the CVD process is an often implemented step to improve yield. Nevertheless, the role of the annealing step has not been fully investigated. In this study we systematically investigate the effect of the annealing step on the morphology and smoothness of the used ST-cut quartz substrates, in order to provide excellent conditions for high nucleation yields and allow for unhindered growth leading to long tubes (> 100μm). In addition, the surface morphology is shown to affect the size distribution of the catalyst nanoparticles which in turn affects their propensity to nucleate SWNT. The ratio of the metals (Fe:Co) in the catalyst mix is shown to be a less important parameter for the high yield synthesis of horizontally aligned SWNT on ST-cut quartz. The successful transfer of the grown SWCNTs onto other surfaces without incurring damage is also demonstrated.

Pharmaceutical pollution is one of the most serious types of environmental pollution, that attracts increasing attention & lead research studies in recent years. Because of their great impact on aquatic life, soil & under ground water as emerging aquatic micro pollutants that have possibly been affecting the ecological system. It could have major implications on plants, wildlife and humans who may be directly & indirectly be responsible of this type of pollution. In this study two antibacterials were selected, oxytetracycline & doxycycline as examples of pharmaceuticals that are released into the environment, both are marketed in the Palestinian market either for human pharmaceutical industry or the veterinary one. In this research the adsorption behavior of both pharmaceuticals on soil, the effect of organic matter, the effect of magnesium chloride hepta hydrate addition on polluted soil, in addition their effect on characteristics of under ground water, all were studied using the UV-Vis spectrophotometry. The results showed that increasing organic matter increases the adsorption of oxytetracycline more than doxycycline, also showed that the composition of oxytetracycline complex with magnesium ion was more stable than doxycycline complex with magnesium. The study also revealed a higher concentration of doxycycline in leachate water from the soil than those of oxytetracycline, because doxycycline has higher solubility in water. It also showed a decrease of the concentrations for both substances over time in leachate water due to degradation. The degradation of both pharmaceuticals in soil & water would be produced by other substances may be harmful, as the threat of their presence in the soil and groundwater would increase the resistance of bacteria in the soil, in another words that would affect the natural properties of soil and groundwater as well.

In this study, we intend to introduce a new technique to prepare nano-sized films of CdS for the purpose of light-to-electricity conversion processes. In order to evaluate the new systems, their photo electrochemical (PEC) characteristics have been compared with conventional counterparts, in addition, their optical and structural characteristics such as SEM and XRD have been studied and compared with conventional counterparts. The nano-sized films were prepared by different techniques, namely: electrochemical (EC), chemical bath (CB) and electrochemical followed by chemical bath (EC/CB) deposition techniques. The latter technique describes the new preparation technique for CdS nano particles. All films were deposited onto fluorine-doped tin oxide-coated glass substrates (FTO/Glass). The different types of films were compared with each other by monitoring different parameters, such as: open-circuit voltage (Voc), current density (Jsc), photo (J-V) plots, efficiency and stability. Poly crystalline CdS thin films, prepared by different techniques, were modified by annealing and slow cooling to enhance PEC characteristics. The effect of treatment on film characteristics has been studied by: photo (J-V) plots, efficiency, and stability. Annealing and slow cooling showed higher conversion efficiency for each preparation technique compared with un-treated films. SEM and XRD results for prepared CdS films were consistent with the efficiency results for each preparation technique before and after modification. Annealing and slow cooling increased the grain size of CdS nano particle and consequently, increased the efficiency. CdS thin films prepared by EC/CB technique, before annealing, showed higher efficiency than films prepared by EC, but lower than CB systems. After annealing, the EC/CB prepared systems showed higher efficiency than either EC or CB prepared counterparts. The results show that the new preparation technique gives new thin films with higher efficiency and stability than earlier conventional prepared.

Certain cyanobacteria change the tetrapyrrole pigments attached to phycoerythrin inresponse to the color of light available. These tetrapyrrole pigments consist ofphycoerythrobilin (PEB) and phycourobilin (PUB) which are structural isomers PEB andPUB differ in the position of one double bond and are therefore isobaric but have differentUV-absorbance spectra. Each phycobiliprotein may have several bilin pigments attached tovarious cysteine residues. Researchers purify microgram amounts of protein to performHPLC-UV-VIS experiments to identify the pigments utilized by the organism. The pigmentsattached to phycoerythrins produced in green vs blue light in Synechococcus RS 9916 havenot been determined. This work utilizes the CID fragmentation patterns of differentbilipeptides in conjunction with UV-absorbance to facilitate pigment attachment siteidentifications.

Nitrate & nitrite contamination of surface and ground water has become one of the most serious environmental problems all over the world. Therefore simple and economic processes to purify water from those contaminants based on agricultural wastes are proposed. Carbon has been prepared here based on solid olive stones, using different routes. Different carbon batches were then activated by different techniques. ZnCl2, H3PO4 and NaHCO3 were all used for activation under different treatment conditions. The resulting activated carbon surface was characterized by SEM and surface area measurement. Carbon activated by ZnCl2 effectively adsorbed nitrate and nitrite ions from pre-contaminated water samples. Different methods of preparation and activation showed significant effects on the activated carbon adsorption efficiencies, which paralleled their porosities, surface textures and surface areas. Effect of different parameters on adsorptions processes such pH, concentration and others will be presented.