bluuebunny/crossref_metadata_2025 huggingface dataset:
Modern dressing based on polymer microfibers with aluminum oxyhydroxide: properties and mechanism of wound healing
Authors: Lozhkomoev A. S. , Kirilova N. V. , Bakina O. V.
Published: December 2020

Objective: to investigate the structure of the new VitaVallis dressing and determine the mechanism of its wound healing effect. Materials and methods. To study the structure of the VitaVallis dressing, transmission and scanning electron microscopy methods were used. The course of the wound process was studied in 60 male mice of the Balb / c line. The healing of a wound defect under the influence of dressings was studied on the model of a “skin flap”. Morphometric evaluation of histological preparations was carried out by computer-aided graphical analysis of samples. Statistical processing of the results was carried out using the parametric (Student's test) and non-parametric (Wilcoxon's test) methods. For analysis, the program Statistica 6.0 was used. Results. The structure of the VitaVallis dressing is randomly spaced polymer fibers with a diameter of 1.0—5.0 microns, on the surface of which nanosheet structures of aluminum oxyhydroxide (AlOOH) are immobilized. In vivo experiments have shown that the use of VitaVallis dressing in the treatment of model wounds in mice promotes accelerated healing and leads to better epidermis organotypic differentiation and accelerates the maturation of granulation tissue. This effect is due to a combination of factors such as: reduction of inflammatory processes due to the removal and retention of wound exudate, including pathogenic microflora, stimulation of marginal epithelization, protection of the formed granulation tissue from drying out and acceleration of its maturation. Conclusion. Analysis of the structure and mechanism of the wound-healing action of the dressing VitaVallis suggests the effectiveness of its use in the local treatment of wounds.
Mathematical model of the 9th version Universal modeling method: features and results of identification
Authors:   Peter the Great St. Petersburg Polytechnic University, Drozdov A. A. , Galerkin Yu. B. ,   Peter the Great St. Petersburg Polytechnic University, Solovyeva O. A. ,   Peter the Great St. Petersburg Polytechnic University, Soldatova K. V. ,   Melbourne University of Technology, Ucehovscy A. A. ,   Peter the Great St. Petersburg Polytechnic University
Published: December 2020

The Universal modeling method is a complex of computer programs for calculating the characteristics and optimal design of centrifugal compressors based on mathematical models of efficiency and head. Practical experience allows improving the mathematical models that underlie the Method. Determining the non-incidence inlet in a blade cascade is an important part of calculating the compressor gasdynamic characteristics. In the 8th version of the Universal modeling method, a formula is used to calculate the direction of the critical stream line, containing an empirical coefficient X. The practice of application has shown that the value of the empirical coefficient changes the amount of losses in the impeller in off-design flow rates. A new scheme for modeling velocity diagrams is proposed. It is made for the stage operation mode corresponding to the zero incidence angle. The successful use of the model for the impeller made it possible to extend it to the vane diffuser and return channel. Several other improvements are made too. A new mathematical model is developed for calculating the flow parameters in the exit nozzles of centrifugal compressor stage. The mathematical model for calculating the flow parameters in the vaneless diffusers is modernized. The applicability boundary of the new model is expanded to a range of diffusers of low consumption stages with a relative width of up to 0,006. The resulting mathematical model is identified by the test results of two family model stages and plant tests of industrial compressors
The influence of blade profile shape of inlet guide vane on performance map of centrifugal compressor stage
Authors:   Omsk State Technical University, Karabanova V. V. , Vanyashov A. D. ,   Omsk State Technical University, Yusha V. L. ,   Omsk State Technical University
Published: December 2020

The object of the study is a centrifugal compressor stage with an inlet guide vane. The performance map of the stage are investigated in the modes of combined regulation by changing the rotor speed and changing the swirl of the flow in front of the impeller by turning the blades of the inlet guide vane. Two variants of the design of the profile of the blades of the inlet guide vane are considered and the method of turning the blades by performance map. As a result of the study, it is found that a profile with a fixed inlet part at large swept angles has a lower loss coefficient, which contributes to an increase in the efficiency of the stage. The effect of regulation to achieve the set point in terms of pressure and flow for the re-profile stage is achieved at lower speeds
Choosing optimal separator design using hierarchy analysis
Authors:   Engineering and Technical Center of LLC «Gazprom dobycha Noyabrsk», Ozherelev D. A. , Shalay V. V. ,   Omsk State Technical University
Published: December 2020

The article describes the possibility of using the «Method of analysis of hierarchies» when choosing the type of separator. These calculation methods are used to determine the vector of priorities and alternatives according to specified criteria, as well as to assess the consistency of expert opinions. The task is set, alternative options and criteria for selecting a separator design are presented. A hierarchical structure is built for various designs of separators. The method of calculation for a variety of indicators that characterize the types of separation equipment is presented. Based on the results presented in accordance with the technical and economic indicators, the optimal design of the separator is determined
Post COVID- 19 protocol of treatment, radiologic examination and infection control in dentistry
Authors: Pooja D Dhole  , Vidya K Lohe  , Ravindra P Kadu  , Swapnil C Mohod  , Mrunal Meshram  , Gaurav A Thakare
Published: December 2020

The COVID-19 is an utmost challenge to the health care profession. The medical professionals and system and has recommended different reaction and sorts of solutions found all over the world. As the dental health care professionals deal directly with the oral cavity, their responsibility in avoiding the spread of COVID-19 proves significant. All the usual dental treatment and procedures put on hold into countries which come across COVID-19. During this pandemic, there is a need for planned crucial care which might be delivered by dental professional and auxiliary they should be provided with proper PPE on priority. Dental health care professionals should also be trained to contribute to health care. Quick re-organization of significant health care support is not simple. Dental health care professionals have an ethical duty to lessen the fear of spreading COVID-19 for routine care in dental patients. But they were and are worried concerning the monetary issues. The huge data is online accessible and over societal media, but still, it is hard to recognize research confirmation and supervision; however, ethical conclusions should be made.
Indian Lifestyle With Ayurveda Perspective During Covid-19 Pandemic
Authors: Disha Bhatero  , Punam Sawarkar  , Gaurav Sawarkar
Published: December 2020

Covid-19 is an infectious disease caused by novel Coronavirus. The overall prevalence rate of Covid-19 in Worldwide ( 9.94M )& it is (529 K) & (153 K) in India and Maharashtra. This situation can be considered under JanapadodhwansaVyadhi in Ayurveda. The primary purpose of Ayurveda  is the prevention of the disease in healthy individuals and eradication of disease, which are curable. Immunity comes under the Vyadhikshamatva. Further, Covid-19 infection is correlated with Vataj-Kaphaj Jwara. In Ayurveda Rasayana therapy to boost up immunity (Bala  & Vyadhikshamatva). The present study aimed to explore the concept of infectious disease and its prevention through different lifestyles described in Ayurveda. The above need-based information is collected from various Ayurvedicliterature (Laghutrayee, Bruhatryayi) along with numerous research articles from databases, such as PubMed, Google Scholar. All collected data were depicted in narrative form and tabular manner under different heads. Considering the above aspect in the prevention of Covid-19, the role of Ayurveda intervention may be proved more beneficial in Covid-19. Further, adoption of code of conduct may efficiently overcome the current pandemic situation by maintaining good immunity & implementation of Ahar, Vihar Vidhis, Dincharya, and Rutucharya& Sadvritta  for improving disease resistance.
FENOMENA CAMPUR KODE DALAM NOVEL METROPOP ANTOLOGI RASA KARYA IKA NATASSA (Mixed-codes Phenomenon in the Metropop Novel of Antologi Rasa by Ika Natassa)
Authors: Intan Tania , Handayani Vincentia Tri
Published: December 2020

Penelitian ini dilakukan untuk mengungkap fenomena campur kode di dalam novel Antologi Rasa karya Ika Natassa dengan menggunakan metode deskriptif kualitatif dan pendekatan sosiolinguistik. Kerangka konsep penelitian ini dilandasi oleh referensi teoretis yang mengaitkan sosiolinguistik, bilingualisme-plurilingualisme, dan alih kode-campur kode. Dari data yang dikumpulkan, terdapat wujud campur kode berupa (1) penyisipan kata yang kemudian dibagi atas kelas kata, yaitu nomina, adjektiva, konjungsi, dan interjeksi, (2) penyisipan frasa berupa frasa nominal, frasa preposisional, dan frasa adjektival, (3) penyisipan baster, (4) penyisipan klausa, dan (5) penyisipan idiom. Penelitian juga menunjukkan bahwa para tokoh dan narator di dalam novel Antologi Rasa, yaitu: Keara, Harris, dan Ruly, ditampilkan sebagai sosok-sosok muda metropolitan bilingual yang secara aktif dan konsisten menggunakan kombinasi bahasa Indonesia dan bahasa Inggris untuk berkomunikasi. Para tokoh, terutama Keara dan Harris, tampak sangat leluasa mempraktikkan campur kode, baik saat berbicara dengan tokoh-tokoh lain, maupun ketika bertutur di dalam hati. Penggunaan campur kode dapat dianggap menunjang kategorisasi dan labelisasi novel Antologi Rasa sebagai sebuah karya metropolitan-populer (metropop).This research was conducted to uncover the phenomenon of code mixing in the Ika Natassa’s novel of Antologi Rasa by using descriptive qualitative method and sociolinguistic approach. The frame of research concept  is based on theoretical references that relate sociolinguistics, bilingualism-plurilingualism, with code-mixed-code switching. From the data collected, there are mixed codes in the form of (1) word insertion which is then divided into word classes, namely nouns, adjectives, conjunctions, and interjections, (2) insertion of phrases in nominal phrases, prepositional phrases, and adjunctival phrases, (3) baster insertion, (4) clause insertion, and (5) idiom insertion. The research also shows that the characters and narrators in the novel of Antologi Rasa, namely: Keara, Harris, and Ruly, are shown as bilingual metropolitan young figures who actively and consistently use a combination of Indonesian and English to communicate. The characters, especially Keara and Harris, seem very free to practice code mixing, both when talking to other characters and speaking inwardly. The use of mixed code can be considered to support the categorization and labeling of the Antologi Rasa novel as a popular metropolitan work.
Tingkat Konsumsi Kalsium, Seng, Vitamin E Dan Dismenorea Primer pada Siswi SMA
Authors: Saraswati Putu Datisia Werdi , Suiraoka I Putu , Kusumajaya A.A. Ngurah
Published: December 2020

Total of 54,89% of childbearing age women in Indonesia experience primary dysmenorrhea. The intake of micronutrients such as Calcium, Zinc, Vitamin E can help in relieving the pain. This study aimed to find out the relationship between the level of calcium, zinc, and vitamin E consumption with the primary dysmenorrhea in female students at SMA Negeri 8 Denpasar. This study used observational research with a cross-sectional approach to support the research. 65 people were taken as samples using the simple random sampling technique. The chi-square was used as the statistical test in this study. The result of the study showed that most of the samples had low-level consumption of Calcium (87,7%), Zinc (78,5%), and vitamin E (95.4%), and 70,8% of the samples had primary dysmenorrhea. Based on the result, there was a relationship between the level of Calcium, Zinc, and Vitamin E consumption with primary dysmenorrhea. The better level of Calcium, Zinc, and Vitamin E consumption, the fewer women will experience dysmenorrhea. It is necessary to provide counseling that is related to alternative dysmenorrhea prevention, especially regarding the role of nutrients that can be used as dysmenorrhea therapy.
Hubungan Unsafe Action dan Unsafe Condition dengan Kecelakaan Kerja pada Pekerja Industri Mebel
Authors: Irkas Adhwa Umniyyah Danur , Fitri Azizah Musliha , Purbasari Ayu Anggraeni Dyah , Pristya Terry Y.R.
Published: December 2020

The furniture industry was one of many industries that are necessities part of human life. The purpose of this study was to analyze the relationship between age, length of work, hours of work, OSH knowledge, unsafe action, and unsafe condition with workplace accidents in furniture industry workers in the Duren Sawit Subdistrict in 2020. The method used in this study was a quantitative analysis method with a cross-sectional study design. The sample in this study were 57 workers. The result obtained using the chi-square test was the variable age, hours of work, and unsafe condition found the value of p-value>0,05 or there was not any relationship. The variable length of work, OSH knowledge, and unsafe action obtained value of p-value<0,05 or there was a relationship. The recommended action for workers and shop owners is to increase awareness in using PPE when working, always maintain cleanliness and implement OSH behavior in the workplace, always obey the rules and remind each other if there are workers who do not obey the rules, and always maintain tidiness at the place and make workplace cleaning efforts more routine.
Analisis Faktor-Faktor yang Mempengaruhi Net Interest Margin Pada Perusahaan Perbankan yang Terdaftar Di Bursa Efek Indonesia Periode 2012-2016
Authors: Asna Widyanto Deny , Wibowo Agung R. Ery , . Alwiyah
Published: December 2020

Penelitian ini bertujuan untuk menguji pengaruh likuditas,modal, efisiensi, ukuranbank dan  Non Performing Loan (NPL) terhadap Net Interest Margin (NIM).Populasi dalam penelitian ini semua  perusahaan  perbankan (Bank Umum) yangtercatat  (Go  Public)  di  Bursa  Efek  Indonesia  (BEI) periode 2012-2016 yangberjumlah 33 bank. Metode  pengambilan  dengan  metode  judgment  sampling, yaitu  salah  satu  bentuk  purposive  sampling. Data  yang digunakan data sekunder dengan analisa data menggunakan analisis regresi linier. Berdasarkan hasilpenelitian diperoleh LDR berpengaruh positif dan signifikan terhadap NIM. EAtidak berpengaruh signifikan terhadap NIM. BOPO tidak berpengaruh signifikanterhadap NIM.Ukuran bank tidak berpengaruh signifikan terhadap NIM. NPLberpengaruh signifikan terhadap NIM.Likuiditas, Modal Efisiensi, UkuranPerusahaan dan Non Performing Loan mempunyai pengaruh signifikan secarabersama-sama terhadap Net Interest Margin (NIM).
Advanced Degradation of Organic Substance in Water Using No-Ferric Fenton Reaction on Titania Nanotube
Authors: Elmakki Tasneem , Zavahir Fathima Sifani , Gulied Mona , Ismail Norhan , Hameed Areeba , Han Dong Suk
Published: December 2020

Highly reactive OH radicals facilitate advanced oxidation processes (AOPs). AOPs are irreplaceable in environmental remediation including but not limited to pollutant degradation. H2O2 leading to OH radicals in iron based fenton systems are well known and few other oxides of alumina and ceria in non-ferrous fenton systems. Majority of studied catalysts materials are in powder form, which limits the catalysts long term applicability in real systems due to separation and regeneration of the catalyst with required catalytic activity, which is costly. In this present work, we have studied anatase phased titania nanotube arrays (TNA) grown on Ti films prepared by an anodization approach for methyl orange (MO) dye degradation under photocatalytic conditions. Key findings reveal long stability of TNAs over fifty reaction cycles in batch process with higher degree of reproducible performance. Complete removal of MO was achieved after six hours of exposure in AM 1.5 G light (equivalent to 1 sun intensity), where hydrogen peroxide accounted for only 1/200th of the amount of initial dye concentration. This superior performance is ascribed to surface oxygen vacancies and Ti3+ sites promoting regeneration of peroxide in the ongoing reaction medium that is consequently transformed to OH radicals. This is further confirmed by the experiments conducted with formic acid, a known hydroxyl radical scavenger, where the dye degradation was observed to be minimal at a near zero rate even after six hours of reaction time, upon measurements with UV-visible spectroscopy. About 38% of the initial dye was oxidized after 1 h into the reaction under light irradiation in a typical system whereas activity was hugely promoted to over 55% when it was coupled with a Pt wire in an electroless process, without supply of additional power. In conclusion, this TNA based new material is highly regarded as environmentally sustainable, easily reusable, non-toxic and commercially viable candidate for real wastewater treatment plants where the treatment plants are usually large tanks constructed in the open space with access to freely available, energetically rich solar power.
Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf
Authors: Al-Thani Jassem A. , Izumi Connor , Yigiterhan Oguz , Al-Ansari Ebrahim Mohd A S , Vethamony Ponnumony , Sorino Caesar Flonasca , Anderson Dan , Murray James W.
Published: December 2020

Alkalinity (Alk) and (dissolved inorganic carbon) DIC were measured on high resolution seawater samples, collected on November 2018 and May 2019 at seven stations in the Exclusive Economic Zone (EEZ) of Qatar. Calculated surface PCO2 averaged 472 matm in 2018 and 447 matm in 2019. Thus, the Arabian Gulf is degassing CO2 at present and will not take up atmospheric CO2 until 2042. Ocean acidification is not yet an issue in the EEZ of Qatar. The elevated PCO2 values are due to CaCO3 formation. Normalized NAlk and NDIC were calculated to remove the impact of increasing salinity. NAlk and NDIC decrease corresponding to a CaCO3/OrgC removal ratio of 2/1. We calculated the nitrate corrected and salinity normalized tracer, Alk*. Values of Alk* were negative, and the change in Alk* relative to Hormuz (DAlk*) indicated that there has been an average decrease of Alk* of -130 mmol kg-1. This decrease is due to CaCO3 formation but previous studies found no evidence for coccolithophorids. One obvious possibility is that Alk removal is due to CaCO3 formation in coral reefs. However, recent study of the composition of particulate matter found that the average particulate Ca concentration was 3.6%, and was easily acid soluble (Yigiterhan et al., 2018). These results suggest that a significant amount of particulate CaCO3 is present in the water column. One hypothesis is that the particulate Ca comes from carbonate rich atmospheric dust. Using Al as a tracer for dust and the average Ca/Al ratio in Qatari dust can only explain about 3% of the particulate Ca. An alternative hypothesis is that particulate CaCO3 may form in the water column due to abiological CaCO3 formation, as proposed recently for the Red Sea (Wurgaft et al., 2016). Precipitation of CaCO3 may be induced by the large inputs of nucleation sites in the form of atmospheric dust.
Feasibility and Cost Optimization study of Osmotic Assisted Reverse Osmosis Process for Brine Management
Authors: Gulied Mona Hersi , Al Nouss Ahmed , ElMakki Tasneem , Zavahir Fathima Sifani , Suk han Dong
Published: December 2020

Due to the excessive demand to desalinate seawater to satisfy the domestic need in Qatar, it was needed to develop safe and cost effective desalination processes with the consideration of stringent regulation for water quality production and wastewater/brine discharge quality. The direct disposal of brines to the environment raised potential negative impact to the aquatic system and therefore the best practice is to minimize the volume of brine production and reuse it for beneficiary application. Several brine-dewatering techniques include both evaporative and non-evaporative approaches, which are capable to dewater high salinity brines with 50-350 g/L of total dissolved solids (TDS). The commonly adopted technology for dewatering brine is mechanical vapor compression that is known for its significant energy consumption up to 25 kWh/m3 of produced water for 50% of water recovery1. Non-evaporative membrane base technologies are a promising approach to dewater brines with minimum energy usage. Osmotically assisted reverse osmosis (OARO) is an advance membrane based technology for energy efficient and high recovery desalination of saline brine. OARO differ from reverse osmosis (RO) by adding saline sweep on permeate side to reduce osmotic pressure difference across the membrane to generate more water flux. The ongoing research work are based on mathematical/numerical approach that focuses on finding the optimum OARO configuration, inlet hydraulic pressure to avoid membrane burst and cost analysis. However, most of these studies are conducted by considering ideal conditions. In this study, an algorithm for simulating OARO process based on MATLAB and Aspen Plus to model membrane calculation and to design process configuration is considered to the effect of concentration polarization (CP) and reverse solute flux (RSF). The objective is to study the effect of inlet feed concentration and flowrate, sweep concentration and flowrate, inlet hydraulic pressure, number of stages, membrane size and characteristics and module configuration flow. In addition, technical economic analysis to evaluate the economic feasibility of OARO process. The stopping criteria of this model is the quality of water permeating at the feasible operating conditions and the cost. This model demonstrated high potential simulating OARO process to be used as a palate form for the user to predict the behavior of the process by varying operating conditions to desired outcomes.
Rational Synthesis, Characterization, and Application of Environmentally‐Friendly (Polymer‐Carbon Dot) Hybrid Composite Film for Fast and Efficient UV Assisted Cd2+ removal from water
Authors: Jlassi Khouloud
Published: December 2020

Carbon-dots (CDs) are of particular interest in numerous applications. However, their efficiency for heavy metal removal from wastewater was not yet reported. Herein, we rationally synthesized CDs from petroleum-coke-waste via hydrothermal treatment in the presence of ammonia.This drove the formation of outstanding photoluminescent, water-soluble, biocompatible, and high yield of monodispersed sub-5 nm CDs. The CDs are co-doped with high 10 % of N and 0.2 % of S. The as-prepared CDs possess unprecedented photoluminescent properties over broad pH range making these dots unique efficient pH sensors. Chitosan (CH)-CDs hybrid hydrogel nanocomposite film was further prepared as a platform membrane for the removal of Cd2+ metal from wastewater. The prepared CH-CDs membranes show a relatively good mechanical properties, based on stressresistantance and flexibility in order to facilitate handling. The equilibrium state was reached within 5 minutes. Intriguingly, the UV-light illuminations enhanced the Cd2+ removal efficiency of the photoluminescent CDs substantially by four times faster. It was found that adsorption followed pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity at 25̊ C was found to be 112.4 mg g-1 at pH 8. This work paves the way to new applications of CDs in water treatment.
Polymeric Nanocomposites Coatings for the Corrosion Protection of Steel
Authors: Abdou Rana , Alselity Anfal , Shakoor Abdul
Published: December 2020

Corrosion is declared as the primary mechanism for the degradation of infrastructure, failure of metallic materials used in various industries such as pipelines in oil and gas industry, which results in huge economic loss, safety issues, and environmental problems. In this research, polymeric Nano composite smart coatings were synthesized and evaluated for its performance. N-Methyl thiourea was chosen as the core material to be encapsulated in Nano tubes using some experimental techniques. The mode of action of the novel smart coating involved two functional strategies. One is the polymeric matrix that offers physical barrier against corrosion. The other strategy involves the release of the loaded nano containers upon the formation of cracks. Once the release occurs, the methyl thiourea can act as corrosion inhibitor and as self- healing agent. Structural characterization was applied to the loaded nanotubes using SEM, XRD, FITR and TGA analyzer. The performance evaluation of the smart coatings was conducted using gamry device via EIS test which showed the increase in corrosion resistance with time and confirmed the efficiency of the new nano composite smart coatings (NMTU) to perform corrosion inhibition and self-healing on the surface of steel substrate, protecting it from corrosion. It can be so applied in various industries and to machine parts to improve their mechanical and anti-corrosive properties. Future researches for the development of new loaded inhibitors nano containers of higher performance and more environmentally friendly is highly recommended. In addition, it is recommended to try these smart coatings in different applications in (Oil and gas, Automotive, Aerospace, Textile, Manufacturing, Electrical fields).
Fabrication and Testing of Polymeric Membranes for Energy-Efficient Separation of Carbon Dioxide from Flue Gas
Authors: Elhoshee Sara , Taqi Fatima , Alabdullah Amna , Hassan Mohamed , Abouhashem Azza
Published: December 2020

One of the major problems the world is facing nowadays is Global Warming. The main ten Green House Gases (GHGs) include water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The most abundant and dominant greenhouse gas is water vapor but concentration of water vapor depends on temperature and other meteorological conditions, and not directly upon human activities. CO2 is the second-most important one and that is why reduction of CO2 emissions is a vital area of research. Carbon capture and storage (CCS) is a major strategy that can be used to reduce GHGs emission. CCS divides into three methods: pre-combustion capture, oxy-fuel process, and post-combustion capture. Among them, post-combustion capture is the most important one because it offers flexibility and it can be easily added to the operational units. For CO2 capture, various technologies are used which include: absorption, adsorption, cryogenic distillation, and membrane separation. Our research focuses on one of the technologies for post-combustion capture, which is membrane separation. In this research, we fabricated four samples of polymeric membranes with different proportions of the components and then tested them for thermal stability, tensile strength, selectivity and permeability. The membrane can be modified by trying different mixtures of the forming polymers with different percentages. The separated carbon dioxide gas can be used in different applications like fire extinguishers, carbonated beverages or cooling systems. For the future recommendations finding more applications for the use of the separated carbon dioxide gas will benefit the environment and will make this project more successful. The same techniques could be used to fabricate membranes for purifying the methane gas. Further studies must be done to ensure the effectiveness of these membranes when used in the industry.
Distribution and Diversity of Benthic Marine Macroalgae in Islands around Qatar
Authors: Al-AShwal Aisha Ahmed , Al-Naimi Noora , Al-Khayat Jassim , Giraldes Bruno , Al-Omari Najat , Al-Fardi Noora , Sorino Caesar , Abdelbari Ekhlas
Published: December 2020

Extending into the Arabian Gulf, Qatar is surrounded by a number of islands mostly scattered by the eastern coastline. With the unique physical characteristics of the Gulf, which is a highly saline sea with high seawater temperatures, there is an urge need to investigate the macroalgae living in such harsh environment. Macroalgae plays an important role in the food web as they are primary producers and providers of food for other organisms. They also provide shelter and habitat in the marine ecosystem for herbivorous fish and other invertebrate animals. Additionally, macroalgae plays an outstanding role in reducing CO2 from the atmosphere and increasing the level of dissolved oxygen in their immediate environment. However, there are few studies on marine macroalgae in Qatar and no previous studies found related to macroalgae from the islands around Qatar. The present work contributes to the macroalgae research by providing the first survey of distribution and diversity of benthic marine macroalgae in islands around Qatar. The marine benthic green, red and brown macroalgae of intertidal and subtidal in marine zone areas around Qatar were collected during Qatar’s Islands project, which started 2018. The collected macroalgae are documented and a total of 67 species of macroalgae are recorded for all islands around Qatar, 24 Chlorophyta (Green algae), 25 Rhodophyta (Red algae) and 18 species Phaeophyta (Brown algae). The Red algae are dominant taxon in term of species richness, accounting for an average of 37% of the species at all study sites. The islands which had more species are Al-Beshaireya 58 Species, Al-Aaliya 53 Species, Sheraouh 48 Species, Janan 43 Species and Bu Felaita 37 Species. Our results show that islands located at eastern and southeastern coast of Qatar have more diversity of algae species than those located at the western and northwestern coast.
Adhesion Improvement between Polyethylene and Aluminium using Eco-Friendly Plasma Treatment
Authors: Al-Gunaid Taghreed Abdulhameed , Popelka Anton
Published: December 2020

Lamina made of low density polyethylene (LDPE) and Aluminium (Al) is used widely in many applications, especially in food packaging (TetraPak containers). However, it's found that the adhesive bond between LDPE-Al is low due to the hydrophobic surface of LDPE. Therefore, there is a strongly need for surface modification of LDPE. Corona discharge, which is considered as an atmospheric pressure plasma technique was used in this research to treat LDPE surface by adding polar functional groups (e.g. hydroxyl, carbonyl, and carboxyl groups) into the exposed non-polar surface which led to increase surface free energy and then greater wettability and a smaller contact angle, and finally the adhesion between LDPE-Al improved significantly.
A Preliminary Checklist of the Ants (Hymenoptera: Formicidae) of Qatar
Authors: AlHajri Salma , Agosti Donat
Published: December 2020

The State of Qatar is a small peninsula located in the northeastern part of the Arabian Peninsula. It is classified as a subtropical desert with an extreme harsh climatic conditions in summer and mild winter. Information on Formicidae of Qatar as well as its insect fauna is poorly documented. So far only six species of Formicidae (ants) belonging to five genera have been recorded from Qatar. At least 300 ant species have been recorded from the Arabian Peninsula (Collingwood et al., 2011). For instance, Collingwood and Agosti (1996) reported a list of 265 ant species in Saudi Arabia. Moreover, Collingwood et al. (2011) published a list of 126 ant species in UAE and Sharaf et al. (2018a) recorded 123 ant species from Oman. This indicates a significant gap regarding our knowledge of the ant fauna and their diversity in Qatar. This study provides the first taxonomic survey of the ant fauna of Qatar. Ant specimens were collected by using aspirator, direct hand collection, litter sifting and pitfall traps during the period of April 2015 to March 2019 from 43 sites around the country. In the present study, 45 species are newly recorded for the ant fauna of the state of Qatar increasing the total number of ant species from Qatar to 51 species, including one additional subfamily, and 16 additional genera.
Investigation and Biological Control of Toxigenic Fungi and Mycotoxins in Dairy Cattle Feeds
Authors: Alasmar Reem Moath , Jaoua Samir
Published: December 2020

Mycotoxins, the secondary fungal metabolites are important contaminants of food and feed. Among the other contaminants, aflatoxin B1 (AFB1) and OTA are frequently detected in the animal feed product. In the present study, the mixed dairy cow feed products were collected from the supermarkets in Qatar and analyzed for the presence of AFB1 and OTA. Yeast strains were isolated and tested for their biological control activities against aflatoxigenic and ochratoxin fungi. We demonstrated that local 15 yeasts isolates have important antifungal potential activities through the synthesis of volatile organic compounds (VOC) that are able to act against the mycotoxigenic fungi and their synthesis of the mycotoxins. Two Yeast strains (4&2) isolated from fermented food, have shown a great antifungal inhibition growth in-vitro as well as spores inhibition and mycotoxins synthesis.
Linking Soil Chemical Parameters and Fungal Diversity in Qatar
Authors: Adenan Sakeenah , Oja Jane , Abdel-Fattah Talaat , Alatalo Juha
Published: December 2020

Given the vast expanse of Qatar’s dryland ecosystems, agricultural productivity and soil stability is highly dependent on the diversity of soil microbiota. The soil environment is a heterogeneous habitat shaped by various components like chemical (organic matter, salinity and nutrients) and biological (fungal diversity and vegetation) properties that form multitudes of different microhabitats. Soil microbial diversity changes along environmental gradients. It is hypothesized that a “stable” microhabitat is one that is inhabited by a large diversity of established microorganisms that are best adapted to the niche. Microorganisms like fungi serve as the underlying biological drivers for biochemical processes within the soil. The key objective of this study is to evaluate the fungal diversity and abundance present within the Qatari soil using molecular-based tools and evaluate potential relationships between the identified fungal communities with chemical properties of the habitat. We found that the composition of fungi and AMF varied between different habitats around Qatar. Despite the lack of significant differences in the measured soil chemical parameters between sampled sites, it is evident that AMF species are more abundant than compared to that of other fungal species in most of the study sites; thus, suggesting that other factors like land use may also be an essential component explaining the variation in fungal communities.
Synthesis of High-Antifouling and Antibacterial Ultrafiltration Membranes incorporating Low Concentrations of Graphene Oxide
Authors: Alkhouzaam Abedalkader Ibraheem , Qiblawey Hazim , Khraisheh Majeda
Published: December 2020

Membrane treatment for wastewater treatment is one of the promising solutions to affordable clean water. It is a developing technology throughout the world and considered as the most effective and economical method available. However, the limitations of membranes’ mechanical and chemical properties restrict their industrial applications. Graphene Oxide (GO) is one of the materials that have been recently investigated in membrane water treatment sector. In this work, ultrafiltration polysulfone (PSF) membranes with high antifouling properties were synthesized by incorporating different loadings of GO. High-oxidation degree GO had been synthesized using modified Hummers’ method. The synthesized GO was characterized using different analytical techniques including (FTIR-UATR), Raman spectroscopy, and CHNSO elemental analysis that showed high oxidation degree of GO represented by the its oxygen content (50 wt.%). Morphology and hydrophilicity of membranes were investigated using SEM, AFM and contact angle analyses and showed clear effect of GO on PSF morphology and better hydrophilicity of GO-based membranes caused by the hydrophilic nature of GO and its high oxygen content. Separation properties of the prepared membranes were investigated using a cross-flow membrane system. Biofouling and organic fouling resistance of membranes were tested using bovine serum albumin (BSA) and humic acid (HA) as model foulants. It has been found that GO based membranes exhibit higher antifouling properties compared to pure PSF. When using BSA, the flux recovery ratio (FRR %) increased from 65.4 ± 0.9 % for pure PSF to 86.9 ± 0.1 % with loading of 0.1 wt.% GO in PSF. When using HA as model foulant, FRR increased from 87.8 ± 0.6 % to 95.6 ± 4.2 % with 0.1 wt.% of GO in PSF. The pure water permeability (PWP) decreased with loadings of GO from 181.7 L.m-2.h-1.bar-1 of pure PSF to 181.1 and 167.4 L.m-2.h-1.bar-1 with 0.02 and 0.1 wt.% GO respectively. Furthermore, GO based membranes exhibited effective antibacterial performance against Halomonas aquamarina compared to pristine PSF. It can be concluded from the obtained results that incorporating low loading of GO could enhance the antifouling and antibacterial properties of PSF hence improving its lifetime and reuse.
Micromodel Study on Pore Scale Mechanisms associated with Permeability Impairment in Porous Media
Authors: Nishad Safna , Al-Raoush Riyadh
Published: December 2020

Recently, researchers have been attracted towards the gas production from hydrate bearing sediments considering its abundance in marine continental margins and persisting demand for alternate energy. Dissociation of hydrate into gas and water is the preliminary technique for gas production in hydrate bearing sediments. Expanded fluid volume and gas pressure upon dissociation detach the fines from the grain surface and result in pore throat entrapment. Migration of fines associated with gas flow greatly influence the alteration of permeability of the sediment by clogging pore throats in the flow path. A pore-scale visualization study was implemented to provide a clear insight into the actual mechanisms associated with mobilization and clogging of fines during two-phase flow through a microfluidic chip. Carboxylate modified polystyrene latex particles deposited in the porous media were migrated during drainage with CO2 gas. The detachment of fine particles from the grain surfaces was observed and were retained on the new interface; gas-water interface. The images and videos captured during the experiment were helpful in observing additional pore scale mechanisms responsible for permeability impairment in the porous media. Interface pinning, deformation and resistance to coalescence were found to be other mechanisms in addition to pore clogging.
Development of In-Situ Sensors for CO2 to Fuel Process
Authors: Houkan Mohammad , Shehata Omar , Kannan Karthik , Cabibihan John-John , Abdullah Aboubakr M. , Sadasivuni Kishor Kumar
Published: December 2020

Conversion of CO2 into fuel is an interesting and promising field. However, the conversion yield is hard to measure during the conversion process. Here, we have developed two techniques to measure the amount of CO2 while the reaction is taking place. First method is colorimetry, where a chemical is added to the solution, and it changes color depending on the resulting product. The second method is the atomization of the resulting solution. Thereafter, the results were measured by a gas sensor. The prepared sensors are cost effective and portable to use.
Development of PLA Fibers as an Antimicrobial Agent with Enhanced Infection Resistance using Electrospinning/Plasma Technology
Authors: Mahmoud Abdelrahman , Naser Mohammed , Abdelrasool Mahmoud , Jama Khalid , Hussein Mohamed , Abdulkareem Asma , Kasak Peter , Popelka Anton
Published: December 2020

Humans are vulnerable and easily prone to all kind of injuries, diseases, and traumas that can be damaging to their tissues (including its building unit, cells), bones, or even organs. Therefore, they would need assistance in healing or re-growing once again. Medical scaffolds have emerged over the past decades as one of the most important concepts in the tissue-engineering field as they enable and aide the re-growth of tissues and their successors. An optimal medical scaffold should be addressing the following factors: biocompatibility, biodegradability, mechanical properties, scaffold architecture/porosity, precise three-dimensional shape and manufacturing technology. There are several materials utilized in the fabrication of medical scaffolds, but one of the most extensively studied polymers is polylactic acid (PLA). PLA is biodegradable thermoplastic aliphatic polyester that is derived from naturally produced lactic acid. PLA is characterized with its excellent mechanical properties, biodegradability, promising eco-friendly, and excellent biocompatibility. PLA can be fabricated into nanofibers for medical scaffolds used through many techniques; electrospinning is one of the widely used methods for such fabrication. Electrospinning is a favorable technique because in the preparation of scaffolds, some parameters such as fiber dimensions, morphology, and porosity are easily controlled. A problem that is associated with medical scaffolds, such as inflammation and infection, was reported in many cases resulting in a degradation of tissues. Therefore, a surface modification was thought of as a needed solution which mostly focuses on an incorporation of extra functionalities responsible for the surface free energy increase (wettability). Therefore, plasma technique was a favorable solution for the surface treatment and modification. Plasma treatment enables the formation of free radicals. These radicals can be easily utilized for grafting process. Subsequently, ascorbic acid (ASA) could be incorporated as anti-inflammatory and anti-infection agent on the plasma pretreated surface of scaffolds.
Pilot Scale Osmotic Concentration Process for Reducing Wastewater Volumes from Gas Processing Facilities in Qatar
Authors: Jalab Rem , Awad Abdelrahman M. , Nasser Mustafa S. , Minier-Matar Joel , Adham Samer
Published: December 2020

Over the past 10-15 years, there has been increasing attention in the development of forward osmosis (FO) technology as a low-energy technical solution to wastewater treatment through the exploitation of the natural osmosis phenomenon across semi-permeable membrane. The significant energy benefit arises in applications where direct recovery of the permeate product from the draw solution (DS) is obviated such as in osmotic concentration (OC) process. In the current research, an OC FO-based pilot-scale unit was applied for wastewater volume reduction from oil and gas processing facilities in Qatar. The pilot unit uses seawater of 40 g/L salinity as a DS and wastewater generated during oil and gas operations as a feed. This feed water is of comparatively low conductivity (2 g/L salinity), making it unusually suited to treatment by OC. Based on FO technology principles, the feed gets concentrated at lower volume with the water permeation through the membrane, meanwhile the water transfer to DS side dilutes it. The diluted DS could be directly discharged into the ocean; so the energy intensive step of DS recovery is entirely eliminated. Two FO membranes (Toyobo and NTU) of hollow fiber configuration were tested to assess their performance and fouling propensity on both synthetic and real wastewaters. Results demonstrated that the membrane-based process can achieve feed water recoveries up to 90% without any scaling issues. Achieved water flux ranges between 1.5 to 12 LMH for feed recoveries between 60 and 90% using a constant dilution rate of the draw solution. Above all, the pilot unit maintained stable water flux of 1.62 and 6 LMH using at 75% feed recovery for over 48 hours of continuous operation Toyobo and NTU membranes respectively.
Shear Behavior of Fiber Reinforced Concrete Beams with Basalt FRP Reinforcing Bars and Glass FRP Stirrups
Authors: AL-Hamrani Abathar , Alnahhal Wael
Published: December 2020

The State of Qatar suffers from a harsh environment in the form of high temperature that prevails almost all year round in addition to severe humidity and coastal conditions. This exposure leads to the rapid deterioration and the reduction of the life span of reinforced concrete (RC) infrastructure. The full functionality and safe use of the infrastructure in such environments can only be maintained by holistic approaches including the use of advanced materials for new construction.With the developments in materials science, the advanced composites, especially fiber reinforced polymer (FRP) materials are becoming viable alternatives to the traditional construction materials. Having superior durability against corrosion, versatility for easy in-situ applications and enhanced weight-to-strength ratios compared to their counterpart conventional materials, FRPs are promising to be the future of construction materials. More recently, FRP composites made of basalt FRP (BFRP) have been introduced as an alternative to traditional steel reinforcement at a price comparable to glass fibers of about $2.5–5.0 per kg, which is significantly lower than carbon fibers. BFRP bars are characterized by their corrosion resistance, greater strain at failure than carbon fibers, and better chemical resistant than glass fibers, particularly in a strongly alkaline environment. Knowing that FRP bars are anisotropic materials with weaker strength in the transverse direction compared with the longitudinal direction, and having a relatively low modulus of elasticity compared with steel reinforcement, it is important to investigate the concrete contribution to shear strength for beams reinforced with BFRP bars. In addition, due to the elastic performance of the FRP reinforcing bars compared with steel bars, FRP bars fail in a brittle manner. Moreover, concrete itself is a brittle material. Previous investigations have shown that using discrete fibers in concrete increases its ductility due to the large compressive strains exhibited at failure. Therefore, basalt macro-fibers is proposed in this study. A total of 14 concrete beam specimens were tested under four point loading until failure. The parameters investigated included the reinforcement ratio (2rb, 3.1rb, and 4.53rb, where rb is the balanced reinforcement ratio), the span to depth ratio (a/d=2.5, and a/d=3.3), the spacing between stirrups (S1=170mm, and S2=250mm) and the basalt fiber volume fraction (0%, 0.75% and 1.5%). Test results clearly showed that both BFRP bars and basalt macro-fibers can be used as sustainable and eco-friendly alternative materials in Concrete Structures in Qatar.