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Disruption of biofilms from sewage pipes under physical and chemical conditioning

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Journal of Environmental Sciences 2009年第1期21卷 120-126页

作者： Charbel mahfoud Antoine El Samrani Rita mouawad Walid Hleihel Rim El Khatib Bruno S. Lartiges Nam Ouani Holy Spirit University of Kaslik(USEK) Faculty of Sciences and Computer Engineering Department of Chemistry and Life SciencesWater and Environment Laboratory. P.B. 446JouniehLebanon Nancy University LEM-ENSG/INPL-CNRSPole de l'Eau15Avenue du CharmoisBP 40-F-54501 Vandoeuvre CedexFrance

Biofilms grown inside two sewage collecting pipes located in industrial and residential areas are studied. Bacterial biomass inside three layers of biofilms was evaluated. Biofilm cohesion under different mixing rate and ionic strength was also investigated. Effects of physical and chemical parameters in the biofilms were evaluated by monitoring turbidity, chemical and biochemical oxygen demands. Extracted organic matter from biofilms was partitioned to polar, aromatic and saturated fractions using activated silica column chromatography. Results revealed that bacterial biomass growth depending on biofilm thickness and stratification. The most loaded stratum in bacteria/biomass was the sewage-biofilm interface stratum that represented 51% of the total bacteria/biomass. Stirring rate and ionic strength of mono- and bivalent salts showed a major influence in biofilm disruption. The stirring time enhanced the exchange dynamic and matter capture between biofilm fragments at the critical stirring rate 90 r/min. Sodium chloride showed the dispersing effect on biofilms in suspension, and decreased the BOD5 （biochemical oxygen demand） beyond the physiological salt concentration.

关键词： biofilms, biochemical oxygen demand (BODs) chemical oxygen demand (COD) biomass ionic strength

Theoretical investigations of electrical transport properties in CoSb3 skutterudites under hydrostatic loadings

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Rare metals 2018年第4期37卷 316-325页

作者： Chongze Hu Peter ni Li Zhan Huijuan Zhao Jian He Terry m. Tritt Jingsong Huang Bobby G. Sumpter Department of mechanical Engineering Clemson UniversityClemson SC 29634 USA Department of mechanical Engineering University of Minnesota-Twin Cities Minneapolis MN 55455 USA montgomery High School Skillman NJ 08558 USA Department of Physics and Astronomy Clemson UniversityClemson SC 29634 USA Center for Nanophase materials Sciences and ComputationalSciences and Engineering Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA

CoSb3-based mark mid-temperature skutterudites have been a benchthermoelectric material under intensive experimental and theoretical studies for decades. Doping and filling, to the first order, alter the crystal lattice constant of CoSb3 in the context of ＂chemical pressure.＂ In this work, we employed ab initio density functional theory in conjunction with semiclassical Boltzmann transport theory to investigate the mechanical properties and especially how hydrostatic loadings, i.e., ＂physical pressure,＂ impact the electronic band structure, Seebeck coefficient, and power factor of pristine CoSb3. It is found that hydrostatic pressure enlarges the band gap, suppresses the density of states （DOS） near the valence band edge, and fosters the band convergence between the valley bands and the conduction band minimum （CBm）. By contrast, hydrostatic tensile reduces the band gap, increases the DOS near the valence band edge, and diminishes the valley bands near the CBm. Therefore, applying hydrostatic pressure provides an alternative avenue for achieving band convergence to improve thermoelectric properties of N-type CoSb3, which is further supported by our carrier concentration studies. These results provide valuable insight into the further improvement of thermoelectric performance of CoSb3-based skutterudites via a synergy of physical and chemical pressures.

关键词： CoSb3 skutterudite Hydrostatic loadingsmechanical properties Electronic structure Seebeckcoefficient Thermoelectrics

Validation of <sup>226</sup>Ra and <sup>228</sup>Ra measurements in Water Samples Using Gamma Spectrometric Analysis

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Journal of Water Resource and Protection 2013年第8期5卷 53-57页

作者： Hanan m. Diab waleed m. Abdellah Nuclear and Radiological Regulatory Authority Cairo Egypt

Radium isotopes can be analyzed by different analytical methods based on gamma spectrometric measurements or alpha spectrometry. An improved method was developed to determine radium isotopes from water using gamma spectrometry after radiochemical separation. The Radium was selectively extracted from acidified samples using co-precipitation procedure with iron hydroxide and followed by precipitation of radium as radium sulphate Ba(Ra)SO4. The precipitate Ba(Ra)SO4 was filtered through the millipore filter paper, dried and weighed to calculate chemical yield. 226Ra and 228Ra activities were measured using low-background gamma spectrometry in water samples. Radium was pre-concentrated from environmental samples by co-precipitation with BaSO4. The amounts of 226Ra and 228Ra on the sample were obtained by gamma-ray spectrometry for the 351 keVγ-ray from 214Pb and for the 911 keV γ-ray from 228Ac, both in radioactive equilibrium with precursors, respectively. The accuracy, selectivity, traceability, applicability and minimum Detectable Activity (mDA) of the technique were discussed. also, the effect of physical and chemical characteristics of the water samples such as TDS, pH, soluble species, sulphate and bicarbonate that effect on the radium determination were taking into consideration. The method has been validated with a certified reference material supplied by the International Atomic Energy Agency and reliable results were obtained. The radiochemical yields for radium were 70% - 90% and recovery was 97% and 80% for 226Ra and 228Ra, respectively.

关键词： Radium Isotopes Gamma-Ray Spectrometry Water Analysis

Hemodynamics in the immediate post-transplantation period in alcoholic and viral cirrhosis

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World Journal of Gastroenterology 2010年第5期16卷 608-612页

作者： waleed K al-Hamoudi Saleh alqahtani Puneeta Tandon Samuel S Lee Gastroenterology Unit(59) College of MedicineKing Saud UniversityPO Box 2925Riyadh 11461 Saudi Arabia Gastroenterology unit King Faisal Specialist Hospital&Research CenterJeddah 21499Saudi Arabia alberta Liver Transplantation Program University of AlbertaEdmontonAlbertaT6G 2X8 Canada Liver Unit University of CalgaryCalgary AlbertaT2N 4N1Canada

AIm:To study the hemodynamics in the immediate post transplant period and compare patients with alcoholic vs viral cirrhosis. mETHODS:Between 2000-2003,38 patients were transplanted for alcoholic cirrhosis and 28 for postviral *** rate(HR),central venous pressure(CVP), mean arterial pressure(mAP),pulmonary capillary wedge pressure(PCWP),cardiac index(CI),systemic vascular resistance index(SVRI),pulmonary artery pressure(PAP),and pulmonary vascular resistance index(PVRI)were measured immediately and 24 h post transplantation. RESULTS:Hyperdynamic circulation persisted at 24 hfollowing transplantation with an elevated CI of 5.4± 1.3 L/(min×m 2 )and 4.9±1.0 L/(min×m 2 )in the viral and alcoholic groups,respectively,and was associated with a decreased *** the first 24 h, there was a significant decrease in HR and increase in mAP;the extent of the change was similar in both *** CVP,PCWP,and SVRI increased,and CI decreased in the viral patients,but not the alcoholic *** showed a lower PVRI(119±52 dynes/(cm 5 ×m 2 )vs 166±110 dynes/(cm5×m2),PmmHg vs 24±7 mmHg,Pmpared to the viral group at 24 h. CONCLUSION:Hyperdynamic circulation persists in the immediate post-transplant period with a faster improvement in the viral *** patients have a more pronounced pulmonary vasodilatation.

关键词： Hemodynamics Cirrhosis alcohol Viral allograft

Systematic Survey on Big Data Analytics and Artificial Intelligence for COVID-19 Containment

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Computer Systems Science & Engineering 2023年第11期47卷 1793-1817页

作者： Saeed m.alshahrani Jameel almalki waleed alshehri Rashid mehmood marwan albahar Najlaa Jannah Nayyar Ahmed Khan Department of Computer Science College Computing and Information TechnologyShaqra UniversityShaqraSaudi Arabia Department of Computer Science College of Computer in Al-LithUmm Al-Qura UniversityMakkahSaudi Arabia High-Performance Computing Center King Abdulaziz UniversityJeddahSaudi Arabia

Artificial Intelligence(AI)has gained popularity for the containment of COVID-19 pandemic *** AI techniques provide efficient mechanisms for handling pandemic *** methods,protocols,data sets,and various validation mechanisms empower the users towards proper decision-making and procedures to handle the *** so many tools,there still exist conditions in which AI must go a long *** increase the adaptability and potential of these techniques,a combination of AI and Bigdata is currently gaining *** paper surveys and analyzes the methods within the various computational paradigms used by different researchers and national governments,such as China and South Korea,to fight against this *** process of vaccine development requires multiple medical *** process requires analyzing datasets from different parts of the *** learning and the Internet of Things(IoT)revolutionized the field of disease diagnosis and disease *** accurate observations from different datasets across the world empowered the process of drug development and drug *** overcome the issues generated by the pandemic,using such sophisticated computing paradigms such as AI,machine Learning(mL),deep learning,Robotics and Bigdata is essential.

关键词： COVID-19 IoT artificial intelligence big data coronavirus deep learning robotics machine learning

Effect of Brine Discharge From al-Dur RO Desalination Plant on the Infauna Species Composition in the East Coast of Bahrain

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management Studies 2019年第6期7卷 609-623页

作者： Anwar al-Osaimi Thamer Salim ali waleed al-Zubari Humood Naser ministry of Education Kuwait Arabian Gulf University ManamaKingdom of Bahrain University of Bahrain ZallaqKingdom of Bahrain

The GCC countries have been experiencing an accelerated socio-economic development process since the 1970s,resulting in rapid demographic and urbanization growth and associated with rapidly increasing municipal water *** meet these demands’quantity and quality,the GCC countries resorted to ***,the GCC countries collectively possess the largest desalination capacity in the world(~45%),and based on the current urbanization trends,it is expected that current rates in desalination capacity growth will continue in the ***,desalination has a number of environmental externalities on the marine,and their severity will depend on various factors(i.e.,site-specific).The objective of the present study is to investigate the impacts of the brine water discharged by al-Dur RO desalination plant on the coastal infauna benthic species composition in the east coast of *** samples were collected from 10 locations selected at different distances from the discharge *** species composition of infauna was investigated using univariate analysis and multivariate *** results showed an extreme elevation in temperature(>38℃)and hypersaline waters(>55‰)at locations nearby the discharge outlet,and also at bottom waters of depths more than 3 m during the high and low tide cycles in both seasons with exceptional levels in *** main groups of benthic infauna identified are represented by Polychaeta(12 taxa),Bivalves(4 taxa),Gastropod(2 taxa),and Amphipod(3 taxa)including 256 *** univariate analysis indicated spatial variations in infauna species composition where the lower diversity indices were found at locations close to the discharge outlet and at Station 5 where noticeable vertical differences were observed indicating exceptional elevation of hypersaline waters with lesser extent of temperature at bottom ***,the highest species diversity indices characterized the most offshore *** infauna speci

关键词： RO desalination univariate analysis multivariate analysis infauna species diversity Bahrain

Highly transmitted silver nanowires-SWCNTs conductive flexible film by nested density structure and aluminum-doped zinc oxide capping layer for flexible amorphous silicon solar cells

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Journal of materials Science & Technology 2022年第31期126卷 152-160页

作者： Shunliang Gao Xiaohui Zhao Qi Fu Tianchi Zhang Jun Zhu Fuhua Hou Jian ni Chengjun Zhu Tiantian Li Yanlai Wang Vignesh murugadoss Gaber A.m.mersal mohamed m.Ibrahim Zeinhom m.El-Bahy mina Huang Zhanhu Guo The Key Laboratory of Semiconductor Photovoltaic Technology at Universities of Inner mongolia Autonomous Region College of Physical Science and TechnologyInner Mongolia UniversityHohhot 010021China Department of Electronic Science and Technology School of Electronic Information and Optical EngineeringNankai UniversityTianjin 300350China Advanced materials Division Engineered Multifunctional Composites(EMC)Nanotech LLCKnoxvilleTN 37934United States Integrated Composites Laboratory(ICL) Department of Chemical and Bimolecular EngineeringUniversity of TennesseeKnoxvilleTN 37996United States Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt College of materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China

Indium tin oxide(ITO)is widely used in transparent conductive films(TCFs);however,several disadvan-tages,such as high cost and toxicity of indium,limit its ***,it is necessary to develop other materials that can replace *** nanowires or single walled carbon nanotubes(SWCNTs)have attracted considerable interest owing to their unique electrical,optical,and thermal stabilities,and thus,they are ideal for transparent electrodes for flexible or stretchable *** this study,we develop a novel architecture of composite TCFs on a polyethylene naphthalate(PEN)flexible ***,the silver nanowires-SWCNTs films with nested density structure were fabricated through ultrasonic spraying technology by varying the spraying *** achieving enhanced transmittance,we combined the larger irregular grids and holes with fewer nanowires stacked in the longitudinal direction,more optical chan-nels,and good carrier ***,aluminum-doped zinc oxide(AZO)was used as capping to the structure for enhancing the optical properties of the *** silver nanowires-SWCNTs/AZO(ASA)bilayer was obtained in the optimized architecture,which showed superior optoelectronic performance to that shown by commercial ITO with a high optical transmittance of 92%at the wavelength of 550 nm and low sheet resistance of 17/*** the specially structured conductive film,the significant improvement in the transmittance and uniformity of the sheet resistance was attributed to the effective nanowire junc-tion contact compared to that in ordinary structure of silver nanowires,which reduced the mean density of small clusters of *** with the silver nanowires-SWCNTs films,the ASA bilayer film exhibited excellent resistance to boiling,mechanical bending(10,000 cycles),and CO_(2)***,the sheet resistance of ASA changed slightly after the tape tests,thereby illustrating a strong adhesion to the PEN substrate after the enclosure of ***

关键词： Silver nanowires-SWCNTs Nested density TCFs Flexible substrate Photovoltaic devices

Variation in pore distribution along sample length in sintered 7xxx aluminum alloy

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Transactions of Nonferrous metals Society of China 2016年第8期26卷 2019-2028页

作者： Xi-ni YUAN[[ S.m.AmINOSSADATI m.QIAN Research Institute Baoshan Iron & Steel Co. Ltd. Shanghai 201900 China State Key Laboratory of Development and Application Technology of Automotive Steels (BaoSteel) Shanghai 201900 China

An experimental and computational fluid dynamics (CFD) numerical study of the sintering of an al?7Zn?2.5mg?1Cu alloy in flowing nitrogen was presented. Three rectangular bars with dimensions of 56 mm × 10 mm × 4.5 mm each, equally spaced 2 or 10 mm apart, were sintered in one batch at 620 °C for 40 min in a tube furnace. The pore distribution in the selected cross section of sintered samples was found to be dependent on the sample separation distance and the distance from the cross section examined to the sample end. A three-dimensional (3D) CFD model was developed to investigate the nitrogen gas behavior near each sintering surface of the three samples during isothermal sintering. The variation in porosity in the cross section of each sintered sample along sample length was found to be closely related to the nitrogen gas flow field near the sintering surfaces.

关键词： aluminum alloy sintering pore distribution nitrogen computational fluid dynamics (CFD) modeling

Position-sensitive detectors based on two-dimensional materials

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Nano Research 2021年第6期14卷 1889-1900页

作者： Wenhui Wang Junpeng Lu Zhenhua ni School of Physics and Key Laboratory of mEmS of the ministry of Education Southeast UniversityNanjing211189China

Two-dimensional(2D)materials have attracted great attention in optoelectronics because of their unique structure,optical and electrical *** high-performance photodetectors and implementing their applications are eager to promote the development of 2D ***-sensitive detector(PSD)is an optical inspection device for the precise measurements of position,distance,angle,and other relevant physical *** is a widely used component in the fields of tracking,aerospace,nanorobotics,and so ***,PSD is also a photodetector based on the lateral photovoltaic effect(LPE).This article reviews recent progress in high-performance PSD based on 2D *** high-sensitive photodetectors and LPE involved in 2D photodetectors are firstly ***,we introduce the research progress of PSD based on 2D materials and analyze the carrier dynamics in different device ***,we summarize the functionalities and applications of PSD based on 2D materials,and highlight the challenges and opportunities in this research area.

关键词： two-dimensional(2D)materials graphene photodetector lateral photovoltaic effect position-sensitive detector heterojunction