Papers by Janan jabbar toma
Hepatology, 1991
ABSTRACT The deposits obstructing 12 biliary endoprostheses were examined by scanning electron mi... more ABSTRACT The deposits obstructing 12 biliary endoprostheses were examined by scanning electron microscopy and analyzed quantitatively by Fourier transform infrared spectroscopy. Calcium palmitate and bilirubinate associated with proteins were found in all the deposits. Apart from the small amount of cholesterol, this composition closely resembled that of brown pigment gallstones and suggested an infectious cause. Facultative aero-anaerobic organisms were found on bacteriological investigation. beta-Glucuronidase activity was only detected in one sample, suggesting that the calcium bilirubinate may have been formed through tissue glucuronidases. In our study, deposit formation was thought to have been caused by the action of bacterial phospholipases (although not measured) rather than beta-glucuronidases.
Polish Journal of Environmental Studies, Dec 17, 2023
In this study, the rainwater qualities in eight sites located in the oil refinery region within E... more In this study, the rainwater qualities in eight sites located in the oil refinery region within Erbil province were evaluated for irrigation and drinking goals. Rainwater specimens (n = 24) were collected once a time on 21 October 2022. The index for quality of water (WQI), Index for irrigation water quality (IWQI), also Heavy Metals Pollution Indice (HPI) were used in the current study to evaluate the rainfall quality for drinking and irrigation purposes. Physical, and chemical parameters and some heavy metals were determined for assessing the quality of rainwater. The results showed that higher turbidity, pH, hardness, magnesium, potassium, and phosphate were recorded in the nearest sites around the polluted region which was considered higher than the guideline of the WHO organization for drinking uses. The value of the studied heavy metals including iron, manganese, lead, cobalt, arsenic, mercury, and cadmium was higher than the permissible value for drinking purposes in all sites. Based on the calculated WQI, 62.5% of sample sites are poor for drinking, and 37.5% of samples are good for drinking. The nearest sites are poor for drinking water in comparison to remote sites from oil refineries. The values of IWQI varied from 74.06 (low restriction) in site 2 to 55.10 (moderate restriction) in site 4 respectively. According to the HPI of the studied area are polluted and unsuitable for drinking purposes according to the HPI index.
Journal of Advanced Laboratory Research in Biology, Oct 1, 2013
The present work is aimed at assessing the water quality index (WQI) for the six well in Erbil ci... more The present work is aimed at assessing the water quality index (WQI) for the six well in Erbil city. This has been determined by collecting groundwater samples and subjecting the samples to a comprehensive physicochemical analysis. For calculating the WQI, the following 8 parameters have been considered: EC, TDS, pH, Alkalinity, Hardness, NO 3 , Ca +2 , Mg +2. The WQI for these samples ranges from 24.825 in Rizgari well No. 1 to 84.048 in Azadi well No. 8. The results indicated that water quality of wells (
Journal of Advanced Laboratory Research in Biology, 2016
Ain Al Kibrit sulfur spring along Tigris River in contrast with two other stations, before and af... more Ain Al Kibrit sulfur spring along Tigris River in contrast with two other stations, before and after the input to the Tigris River were studied. Some chemical, physical parameters (water temperature, pH, EC, alkalinity, total hardness, and sulfate) and total number of phytoplankton were studied during 2003-2004. Samples were taken from the spring, inlet, and outlet along the Tigris River. The results show 5-20 fold differences between stations in almost all parameters, whereas, thermostatic conditions were confirmed in Ain Al Kibrit (24±1). In contrast, the total number of phytoplankton when observed to be fifty folds less in Ain Al Kibrit. This study may be regarded as a first attempt to deal with such factors in this area.
Tikrit Journal of Pure Science, 2009
ABSTRACT The studied area is located between Latitude 36° 03' 29"E to 36°10&... more ABSTRACT The studied area is located between Latitude 36° 03' 29"E to 36°10' 45" E and Longitude 43° 30' 29" N to 43° 56' 11" N at south west of Erbil province and extend to north east of Guer town within total length area about (50 km). The drainage patterns are of dendritic type. In present study 48 water samples were collected and analyzed during two periods. 24(20 water samples in Arab-Kand and 4 samples in Greater-Zab river) water samples belonging to the first period (Nov. 2005), and 24(20 water samples in Arab-Kand channel and 4 samples in Greater-Zab river) water samples belonging to the second period (May 2006) in order to calculate biological properties of sewage water along Arab- Kand channel and then determined the effect on Greater- Zab river. The study also includes determination of biological parameters are DO, ( was low especially in second period because of high temperature in comparison with the first period )COD (recorded in both season and also BOD5 are high in both periods because they content high amount of organisms and organic matter )and BOD5(considered as a weak domestic wastewater). Biological indicators are (Coliform and fecal coliform), with huge account of bacteria number in coliform and fecal coliform. Generally the sewage water is unsuitable for human consumption but suitable for building and industries purposes. It is also suitable for irrigation and agriculture with regarding the plant type, and suitable for livestock purposes but in some station unsafe for this purpose due to rising in total account of bacteria.
Iraqi journal of science, Apr 30, 2022
Zygnematales an order of green algae in Shaqlawa District Erbil, Kurdistan Region, Iraq, has been... more Zygnematales an order of green algae in Shaqlawa District Erbil, Kurdistan Region, Iraq, has been studied in eighteen sites, distributed between twelve springs and six along the streams within Shaqlawa district from September2019 to August2020. A total of 116 species belonging to 9 genera were identified. The most dominant genera included Spirogyra and Cosmarium (31, 30) taxa respectively. Out of them, 30 species were recorded for the first time in Iraq. Newly found genera included one species each for Cylindrocystis, Debarya, Hallasia and Staurastrum, nine species belonged to Mougeotia, three species returned to Closterium, and fourteen genera were related to Cosmarium .Growth of Zygnemataceae and Desmids increased in the summer than during the winter season. A brief description as well as the measurement is given for each species.
Govarî zankoî germîan, Apr 1, 2019
Introduction Algae form the main source of food and oxygen for consumer organis ms in water habit... more Introduction Algae form the main source of food and oxygen for consumer organis ms in water habitats, directly affect primary production by forming base level of food chain. And also, it is concluded that the algae have main role in assessing water contamination and clean ing waste water (Bhatt et al. 1999). Algae are one of the more important bio indicators of water quality changes due to their short life spans, speed response to contaminant and easy to determine their nu mbers (Plafkin et al., 1989).Various methods used to classification the lakes and determined the trophic status, the most commonly way depended on productivity by using algae related to trophic state index(Bhatt et al. 1999). Recognition of variances in the quality and quantity of p lankton in lakes contributed to the origin of the trophic system of lake classification. These have been mainly related with the phytoplankton and include the use of a variety of indices and quotients. This field has been developed mainly by European researchers with, as yet, little uses to the waters of North A merica (Chandrashekar et al., 2014). The-trophic status of water bodies is an important aspect in find ing out the water quality. The trophic status means to the level of production in a Lakes as calculated by many factors such as algal co mposition, and chlo rophyll a (Chandrashekar et al., 2014). The chlorophyll-a concentration (hereafter referred to as Chl-a) is an important parameter in evaluating water quality, nutrit ion status and organic pollution extent, provid ing useful in formation for managing water quality (Scherz,1972) and monitoring water pollution (Johson and Harris,1980).Palmer (1 969) also demonstrated that algal assemblages may be used as indicators of clean or contaminated water, similarly My xophycean and Chlorophycean forms have been reported to reflect specific state of aquatic habitats on the basis of Nygaard's indices. The main aim of this investigation to determine the trophic status in Duhok lake depending on variation of algae and application some index to determination its quality.
DOAJ (DOAJ: Directory of Open Access Journals), Jul 1, 2012
Water quality of Duhok Lake was evaluated by Water Quality Index (WQI) technique. A water quality... more Water quality of Duhok Lake was evaluated by Water Quality Index (WQI) technique. A water quality index provides a single number that expresses the overall water quality at a certain location and time based on several water quality parameters. The objective of an index is to turn complex water quality data into information that is understandable and usable by the public. Ten most important parameters such as pH, electrical conductivity (EC), total hardness, total alkalinity, dissolved oxygen (DO), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and sulfate (SO 4) were taken for the calculation of WQI. The result indicated that water quality of Duhok Lake poor in the years 1999, 2000 and is poor in 2009 too. The impact of various anthropogenic activities was evident on some parameters such as the EC, alkalinity and hardness. It is suggested that monitoring of the lake is necessary for proper management. Application of the WQI is also suggested as a very helpful tool that enables the public and decision-makers to evaluate water quality of lakes in Iraq.
ABSTRACT Duplicate samples of some natural waters were taken from twenty four sites within Makhmu... more ABSTRACT Duplicate samples of some natural waters were taken from twenty four sites within Makhmur area including Bakerta, Debaga and Gwer during July and September 2006. The purpose of the study was to investigate the water quality in respect of some physico-chemical parameters. Alkalinity was generally low. A total hardness reached 3400 mg CaCO3.1 -1 . However in all investigated water samples from the wells cations were dominated by calcium.
Journal of Advanced Laboratory Research in Biology, Oct 1, 2013
Water Quality Index (WQI) was applied in Dokan Lake, Kurdistan region, Iraq using ten water quali... more Water Quality Index (WQI) was applied in Dokan Lake, Kurdistan region, Iraq using ten water quality parameters (pH, Dissolved Oxygen, Turbidity, Conductivity, Hardness, Alkalinity, Sodium, Biochemical Oxygen Demand, Nitrate and Nitrite). The relative weight assigned to each parameter ranged from 1 to 4 based on the importance of the parameter for aquatic life. The results indicated that water quality of Dokan Lake declined from Good in the
Passer journal of basic and applied sciences, Dec 1, 2023
The current study was conducted to identify and study the spatial and seasonal variations of diat... more The current study was conducted to identify and study the spatial and seasonal variations of diatoms in some sites in Shaqlawa district in Erbil province for the period from September 2021 to August 2022 and considered the first attempt to identify diatoms in these sites and also considered as an intensive study of the various species of the diatoms under different environmental conditions. Eighteen; sites were selected, of which twelve are in springs, and six of which are along the stream, as well as use indices to evaluate the water quality, such as Shannon Wiener indicators (H), and Jaccard similarity indices (SJ), 57 species of diatoms were identified at eighteen sites, where central diatoms were of two species while pennies diatoms reached fifty-five species. The highest; number of diatoms species was recorded in springs, including site three, and the lower number was identified at site ten. Diatoma; hiemal, D. moniliformis, Fragilaria construes, F. crotonesis, Ulnaria ulna, Cocconeis pediculus, Navicula radiosa, Gyrosigma acuminatum, Nitzschia dubia, Cymbella excise, Gomphonema olivaceous, Surirella oval is considered more dominant than others diatoms species. According to; to Shannon Wiener, indicators (H), a great diversity was obtained in sites 3 and 18. In contrast, lower diversity was observed in sites 5, 10 and 17. According to; to seasons, the maximum diversity was recorded in October-2021, and the minimum variety was calculated in January-2022. The highest similarity rate between Sites 3 and 4 was 29.0%, while the lowest similarity rate between Sites 1 and 10 was 7.9%. Generally, the similarity rate between the sites is considered quiet.
Journal of Environmental Studies, Jun 1, 2011
Samples from two sites of the surface of Dokan Lake were collected monthly over period of 8 month... more Samples from two sites of the surface of Dokan Lake were collected monthly over period of 8 months for physico-chemical analysis of water and investigated algal compositions. In this context, several limnological parameters were evaluated during the period from September 2008 to April 2009. The included physical and chemical parameters were: Air and water temperature, electrical conductivity, total dissolved solids, pH, alkalinity, total hardness, dissolved oxygen, Ca 2+ , Mg 2+ , Na + , K + , SO 4-, Cl-, and the concentrations of nitrite and phosphate. The study revealed that the air and water temperature ranged from 10 to 33 °C and 9 to 30 °C , respectively. Conductivity was in the range of 240-430 µS/cm, TDS was 161 to 280 mg/L, pH range was 7.3 to 8.0. Dissolved oxygen ranged between 5.5 to 9.2 mg/L. Calcium and magnesium concentrations varied from 30 to 52mg/L and 14 to 24 mg/L, respectively. Potassium and sodium ranged between 3.8-6.0 mg/L and 1.1-2.2 mg/L, respectively. Sulfate value varied from 130-224 mg/L and ranged between 18-25 mg/L for chloride. High value of nitrate was recorded. A total of 30 species of algae were recorded of which 14 species belong to Bacillariophyceae, 8 species belong to Chlorophyceae, 5 species to Cyanophyceae, 2 species to Pyrophyta, and one species to Euglenophyceae.
Current World Environment, Jun 25, 2006
Increasing population and higher levels of human activities including effluent disposals to the s... more Increasing population and higher levels of human activities including effluent disposals to the surface and groundwater resources have made sustainability of resources a very complex task throughout the world 1. Water is known to contain a large numbers of chemical elements .Physical parameters such as temperature, turbidity and current are also known to operate in Lake Ecosystem. The interaction of both the physical and chemical properties of water plays a significant role in the composition, distribution and abundance of aquatic ecosystem. Apart form this, it also gives an insight into the relationships between the organism and their environment and can be used in determining water quality, and productivity of the lake. The physico
Baghdad Science Journal, Jun 1, 2022
In an intensive study of the various species of the Euglenophyceae under different environmental ... more In an intensive study of the various species of the Euglenophyceae under different environmental conditions, the algal samples were collected monthly in twelve springs and six related streams from September 2019 to August 2020 within Shaglawa district-Erbil Province in virgin areas for phycolimnological study. Twenty species of Euglenophyceaen are identified as a new record for the algal flora. These taxa consist of Colacium vesiculosum, Lepocinclis salina and L.wangi, Eutreptia viridis, Euglena chlamydophora, E. clavata, E. geniculata, E. intermedia var klebsii, E. limnophila, E. oblonga, E. sociabilis, E. stellate and E. variabilis, Peranema sacculus, Phacus circumflexus, Ph. dangeardii, Ph. peteloti, Petalomonas mediocanella var disomata, Trachelomonas manginii, and T. volvocina var derephora. All of these new records are described and illustrated as much as possible. According to physicals and chemicals characteristics, water temperature varied from 14.942˚C to 18.475˚C, pH lies on alkaline side of neutrality, electrical conductivity ranged between (627.472-2092.306µs/cm) and high concentration of salinity recorded in Azarian spring.
DOAJ (DOAJ: Directory of Open Access Journals), Sep 1, 2013
Consumers are reacting with water quality problems by buying bottled water which is an expensive ... more Consumers are reacting with water quality problems by buying bottled water which is an expensive solution and only partially resolve the problem. Subsequently, sales of bottled water have increased dramatically in the last ten years; therefore this study was conducted in Erbil city with the major objective of assessing suitability of bottled water quality for drinking purposes through water quality index (WQI) investigation. This was done by subjecting 84 bottled samples collected from different market within 6 months from January to June 2012 to comprehensive physico-chemical analysis using standard methods of analysis. For calculating the WQI, 10 parameters have been considered: Turbidity, Electrical conductivity, Total Dissolved Solids, pH, Alkalinity, Hardness, Calcium, Magnesium, Nitrate and Sulfate. The WQI for these samples ranges from 11.953 to 137.532. Using the water quality index all the bottled samples were classified as excellent to good water they are suitable for drinking purposes except Vauban bottled water which was bad and unsuitable for drinking. A comparison between water quality and the maximum permissible levels depended on the world health organization (WHO) guidelines was reported and discussed. They were varied in composition among the brands and from.
مجلة ديالى للعلوم الصرفة, Apr 1, 2017
Phycology, mycology and physicochemical parameters of some artificial open sand mine ponds in Kal... more Phycology, mycology and physicochemical parameters of some artificial open sand mine ponds in Kalak sub district-Duhok-Iraq were investigated, for a period of six months from July to December-2015. Water samples were collected monthly basis and analyzed for measuring of water temperature, turbidity, pH, electrical conductivity, nitrate, nitrite, ammonium, orthophosphate, dissolved oxygen and biochemical oxygen demand. Concerning algal communities, the results showed that the sixty taxa were identified in samples collected during the study period. They belong to classes Cyanophyceae (18 taxa) with percentage composition of 30%, Chlorophyceae (20 taxa) with percentage composition of 33.3%, Euglenophyceae (2 taxa) with percentage composition of 3.4%and Bacillariophyceae (20 taxa) with percentage composition of 33.3%.According to Shannon-Weiner index, species diversity varied from (2.053to 3.895bits/ind), in pond 3 and in July had the highest diversity were recorded. Concerning to Jaccard similarity index, the highest percentage of similarity to algal community observed between site2 and site 4 reached to 32%. The diatoms were the most noticeable algae in all ponds which represented by Cyclotella, Navicula, Syndra and Cymbella with respect to the frequency of occurrence and number of individuals in all ponds. The diatoms showed their best growths through this study. The dominant of Chlorophyta and Cyanophyta followed by Study algae and fungi interaction in some artificial open sand mine Ponds in kalak sub district-duhok, iraq.
Baghdad Science Journal, 2017
This study is conducted in order to, investigate the trophic state of Duhok Lake Dam located with... more This study is conducted in order to, investigate the trophic state of Duhok Lake Dam located within Duhok city, Iraq. Water samples are collected seasonally from three monitored sites during 2011. The parameters used for assessing water quality and trophic status level include: water temperature, pH, EC, TDS, DO, BOD 5 , nutrients, Secchi disk transparency, and chlorophyll a. The results reveal that DO is above 5 mg.l-1 in all sites, BOD 5 value is within permissible level for domestic uses. Water quality considered as a hard type. High sulfate concentration is recorded during the study period. Trophic state shows that water type is classified as mesotrophic during autumn season, while it is regarded as eutrophic in other seasons. TDN/TDP ratio suggests that phosphorus is a limiting factor for algal growth. Based on IWQI, the water type is classified as excellent type for irrigation purpose.
Open Journal of Ecology, 2013
Al-Nahrain journal of science, Sep 1, 2021
Monthly samples of algae collected in eighteen sites of springs and streams through September-201... more Monthly samples of algae collected in eighteen sites of springs and streams through September-2019 till August-2020during morning till afternoon in Shaqlawa district within Erbil Province, Kurdistan Region of Iraq. Eleven various kinds of algae were identified for first time in Iraqi inland water, distributed to three genera of blue-green algae, which include Marssoniella elegans, Pseudoanabaena catenata, Cyanotheca aeroginosa, also in Pyrrophyta identified four new species genera include Gymnodium inversum, Woloszynskia tenuissima, Peridinium goslaviense, Hemidinium naustum and Xanthopyta recorded three species were Ophiocytium arbuscula, Ophiocytium parvulum, Tetraedriella polychloris while Cryptophyta only have one species was Cryptomonas reflex. According to physicals and chemicals characteristics, water temperature varied from 14.942 o C to 18.475 o C, pH lies on alkaline side of neutrality, electrical conductivity ranged between (627.472-2092.306 s/cm) and high concentration of salinity recorded in Azarian spring, higher value of calcium and magnesium recorded in Azarian and Benwan springs were 294.84 mg/L and 106.578 mg/L respectively. Lower value of nitrate and phosphate reported in Sard and Piawan springs, while lower value of sulfate observed in Prenga spring.
Diyala Journal for Pure Science, 2016
The present study describes the algal assemblages at 3 sites within Erbil wastewater channel whic... more The present study describes the algal assemblages at 3 sites within Erbil wastewater channel which extended from southwest of Erbil city with their elongation for more than 50 km effluent discharges into Greater Zab River, with particular reference to abundance, distribution and periodicity were investigated in the samples collected. A total of 56 taxes was identified belongs to 3 divisions, among them 26 taxa were belong of Bacillariophyta, 18 taxa were Cyanophyta and 12 taxa were Chlorophyta. The seasonality of algal assemblage was decreased at 3 sites within Erbil wastewater channel in January and February-2011. The dominate genera among non-diatoms were, Oscillatoria, Merismopedia Chroococcus, Ulothrix, Scendesmus and Spirogyra whereas among the diatoms were Navicula, Syndra, Gomphonema, and Fragilaria, have been studied, in addition to many environmental parameters such as water temperature, pH, electrical conductivity (EC), phosphate, sulfate, nitrate dissolved oxygen and BOD5 were evaluated to explain the effect of these parameters on algal distribution in waste water channel in Erbil city. Keyword: Erbil wastewater channel, Algae, community structure. Algal Survey in Wastewater Channel of Erbil City, Iraq Yahya Ahmed Shekha Janan Jabbar Toma Yadi Omer Mustafa AlBarzingy 40 Vol: 12 No:4 , October 2016 ISSN: 2222-8373 قارعلا ,ليبرأ ةنيدم يراجم ةانق يف بلاحطلا حسم هخيش دمحأ ىيحي اموت رابج نانج يجنزربلا ىفطصم رمع ىداي ةيئيبلا مولع مسق مولعلا ةيلك حلاص ةعماج نيدلا ليبرأ ةصلاخلا تاعمتجم ةيلاحلا ةساردلا فصت يف بلاحطلا 3 بونج نم دتمت يتلا ليبرأ ةنيدم يف يحصلا فرصلا هايم ةانق لخاد عقاوم نم رثكأ ىلا ةلئاسلا تايافنلا فيرصتل كلذو ةنيدم برغ 50 عيزوتو ةرفو ىلإ ةصاخ ةراشإ عم ،ىلعلاا بازلا رهن ىلا مك نم بلاحطلا دجاوتو للاخ يرحتلا اهنع يف تانيعلا صيخشت مت .اهعمج مت يتلا 56 عون ةثلاث ىلا يمتنت بعش يتلااك و ، 26 لا ىلا دوعت اهنم عون تاموتياد و ، 18 دوعت عون ةقرزملا رضخلا بلاحطلل و 12 دقو .رضخلا بلاحطلا ىلا دوعت عون يف ةيبلحطلا تاعمجت دادعا ضفخنا 3 ا فرصلا هايم ةانق لخاد عقاوم طابشو يناثلا نوناك يرهش يحصل 2011 سانجلاا . اهتسارد مت يتلا ةدئاسلا ريغل يه تاموتيادلا Oscillatoria , Merismopedia Chroococcus ، Ulothrix , Scendesmus و Spirogyra تناك تاموتايدلا نيب نيح يف Navicula, Syndra, Gomphonema, Fragilaria ةضومحلا ةجرد، ،ءاملا ةرارح ةجرد لثم ةيئيبلا لماوعلا نم ديدعلا ىلإ ةفاضلإاب ،اهصيخشت مت يتلا اهمييقت مت يتلا نيجسكولال يويحلا بلطتملاو باذملا نيجسكولأا، تارتنلا، تاتيربكلا، تافسوفلا، يئابرهكلا ليصوتلا، ق يف بلاحطلا عيزوت ىلع لماوعلا هذه ريثأت حيضوتل كلذو .ليبرأ ةنيدم يف يحصلا فرصلا هايم ةان تاملك ةيحاتفم : ةيعمتجملا ةبيكرت ،بلاحطلا ،ليبرأ يراجم ةانق Introduction Water is a common element in lives of all peoples and societies. Water has been foundation of many great civilization and today is essential for the agriculture, economic and industrial activity that helps societies and develop (1). The pollution of water sources happens through point and non-point source. Non-point source pollution is more ambiguous which cannot be related to a specific point for example, pesticides and fertilizers application to agriculture fields (2). The problem of water pollution occurs when substances are added to the water that affect its chemical composition and threaten the human health and ecosystem (2). Agricultural land, sewage effluent, debris, runoff from urban areas, and animal waste, are found to be responsible for the increased number of microorganisms found in water (3). Wastewater is the largest disposal problem associated with waste and by-product production, being typically Algal Survey in Wastewater Channel of Erbil City, Iraq Yahya Ahmed Shekha Janan Jabbar Toma Yadi Omer Mustafa AlBarzingy 41 Vol: 12 No:4 , October 2016 ISSN: 2222-8373 several tones of water per person per year (4). Physical, chemical and biological parameters are important characters to recognized wastewater quality (5). The phytoplankton play an important role in aquatic ecosystems. They are the primary producers, thus they are the first link in the food chain, and often cause nuisance condition to the environment (6). As stated by (7) algal flora is an important indicator of water pollution and bloom in water bodies receiving agriculture waste, domestic water and household waste. Algae particularly diatoms are generally accepted as one of the most suitable bioindicators of aquatic ecosystem for water quality monitoring and organic pollution (8). Specific algae grows in specific environments and therefore, their distribution pattern, periodicity and productivity are different vary from water to water body. However, algal species, community structure, fine spatial distribution and biomass vary day to day, season to season as affected by environmental factor (9). Although, the composition of phytoplankton community has been changed little in the past 10 years especially, Cyanophyta because they are extremely very stress to environmental conditions (10).The objective of this work is to analyze of the physical, chemical variables and algal composition of…
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Papers by Janan jabbar toma