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Unraveling the role of dual Ti/Mg metals on the ignition and combustion behavior of HTPB-boron-based fuel

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Defence Technology（防务技术） 2024年第2期32卷 134-143页

作者： Arijit debnath Yash Pal Sri Nithya Mahottamananda Djalal Trache School of Aeronautical Science Hindustan Institute of Technology and ScienceChennai 603103India Department of Aerospace Engineering B S Abdur Rahman Crescent Institute of Science and TechnologyChennai 600048India Energetic Materials Laboratory(EMLab) Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj El-Bahri16046AlgiersAlgeria

Metal additives play an essential role in explosive and propellant formulations. Boron(B) is widely used in propellant applications owing to its high energetic content. The addition of B to explosives and propellants increases their energy density, making them more efficient and powerful. Nevertheless, B forms oxide layers on its surface during combustion, slowing down the combustion rate and reducing rocket motor efficiency. To overcome this issue, other metal additives such as aluminum(Al), magnesium(Mg),and titanium(Ti) are revealed to be effective in boosting the combustion rate of propellants. These additives may improve the combustion rate and therefore enhance the rocket motor’s performance. The present study focused on preparing and investigating the ignition and combustion behavior of pure hydroxyl-terminated polybutadiene(HTPB)-B fuel supplemented with nano-titanium and nanomagnesium. The burn rates of HTPB-B fuel samples were evaluated on the opposed flow burner(OFB)under a gaseous oxygen oxidizer, for which the mass flux ranges from 22 kg/(m^(2)·s) to 86 kg/(m^(2)·s). The addition of Ti and Mg exhibited higher regression rates, which were attributed to the improved oxidation reaction of B due to the synergetic metal combustion effect. The possible combustion/oxidation reaction mechanism of B-Mg and B-Ti by heating the fuel samples at 900℃ and 1100℃ was also examined in a Nabertherm burnout furnace under an oxygen atmosphere. The post-combustion products were collected and further subjected to X-ray diffraction(XRD) and field emission scanning electron microscopy(FE-SEM) analyses to inspect the combustion behavior of B-Ti and B-Mg. It has been observed that the B oxide layer at the interface between B-Ti(B-Mg) is removed at lower temperatures, hence facilitating oxygen transfer from the surroundings to the core B. Additionally, Ti and Mg decreased the ignition delay time of B, which improved its combustion performance.

关键词： Boron B_(2)O_(3) Opposed flow burner Combustion Magnesium

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Effect of TiB_(2)Addition on Microstructure and Mechanical Properties of AA8009 Alloy Fabricated by Laser Additive Manufacturing

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 67-77页

作者： Xinxing Xiong Sijie Yu Pei Wang Junfang Qi Haichao Li Xulei Wang Michael Ryan debajyoti Bhaduri Rossitza Setchi Additive Manufacturing Institute Shenzhen UniversityShenzhen518060China Henan Key Laboratory of High Performance Carbon Fiber Reinforced Composites Institute of Carbon Matrix CompositesHenan Academy of SciencesZhengzhou450046China School of Materials Science and Engineering Shanghai University of Engineering ScienceShanghai201620China School of Materials Science and Engineering Zhengzhou University of AeronauticsZhengzhou450046China High-Value Manufacturing Research Group School of EngineeringCardiff UniversityCardiffCF243AAUK

The research involves the addition of 5 vol.%TiB_(2)particles into AA8009 alloy powder to synthesize TiB_(2)/AA8009 composite parts produced via laser powder bed fusion(LPBF).The addition of the TiB_(2)particles causes the TiB_(2)/AA8009 composites with and without annealing have lower compressive strength than AA8009 alloy due to the change of the strengthening *** results further indicated that solid solution strengthening was the main strengthening mechanism of the LPBF AA8009 alloy at room temperature whereas Orowan strengthening became the primary strengthening factor after annealing at 673 *** contrast,Orowan strengthening always remained the main strengthening mechanism for the TiB_(2)/AA8009 composite,irrespective of the annealing *** addition,after annealing of the LPBF parts at 673 K,the compressive yield strength(CYS)of the unblended AA8009 alloy specimens had a~2.5 times greater reduction(from 705±16 to 459±30 MPa)compared to that of the composite TiB_(2)/AA8009 samples(from 466±23 to 368±3 MPa).Therefore,TiB_(2)particles can suppress the drop in yield strength of LPBF AA8009 alloy below 673 K,providing a theoretical and experimental basis for the applications of both LPBF AA8009 and TiB_(2)/AA8009 alloys at low and medium temperatures.

关键词： Laser powder bed fusion AA8009 alloy Microstructure Mechanical properties

Post-urethroplasty complications in hypospadias repair: a systematic review and meta-analysis comparing, polydioxanone and polyglactin sutures

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World Journal of Pediatric Surgery 2024年第1期7卷 1-9页

作者： Nitinkumar Borkar Charu Tiwari debajyoti Mohanty Tridip Dutta Baruah Manoj Mohanty C K Sinha Pediatric Surgery All India Instituteof Medical Sciences-RaipurRaipurChhattisgardhIndia General Surgery All India Institute of Medical Sciences-RaipurRaipurChhattisgardhIndia Pediatric Surgery All India Institute of Medical Sciences-BhubaneswarBhubaneswarOrissaIndia St George's University of London LondonUK

Background Polyglactin(PG)and polydioxanone(PDS)sutures are extensively used based on the surgeon's *** development of post-reconstruction urethrocutaneous fistula(UCF)is variably attributed to the choice of suture material for *** meta-an alysiscompares complications of hypospadia srepair using PGand PDS *** The systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses *** authors conducted thorough searches in databases including MEDLINE,EMBASE,CENTRAL,Scopus,Google Scholar,and clinical trial *** measures included UCF,meatal stenosis,wound infection,urethral stricture,glans dehiscence,and overall *** analysis was used with fixed or random-effect models to find the pooled risk ratio and I2 *** The criteria for inclusion were met by five comparative studies with the inclusion of 1244 children *** analysis failed to show a statistically significant difference in the incidence of meatal stenosis,urethral stricture,wound infection,and total complications using PG and PDS ***,it showed a reduction in the incidence of UCF with PDS suture hypospadias repairs(risk ratio=0.66,95%Cl 0.48 to 0.92).Conclusions PDS sutures are associated with decreased incidence of UCF than PG after hypospadias *** incidence of meatal stenosis,urethral stricture,wound infection,and total complications was not affected by the type of suture material used for *** implications This meta-analysis suggests decreased incidence of UCF when PDS sutures are used for hypospadias repair which may impact the choice of suturematerialforrepair.

关键词： complications wound suture

Tubularized incised plateurethroplasty and grafted tubularized incised plate urethroplasty: systematic review, metaanalysis and trial sequential analysis

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World Journal of Pediatric Surgery 2024年第1期7卷 10-19页

作者： Nitinkumar Borkar Charu Tiwari Abhijit Nair debajyoti Mohanty C K Sinha Jai Kumar Mahajan Paediatric Surgery All India Institute of Medical Sciences-RaipurRaipurChhattisgardhIndia Department of Anaesthesiology Ibra HospitalbraOman General Surgery All India Institute of Medical Sciences-RaipurRaipurChhattisgardhIndia Paediatric Surgery St George's University Hospitals NHS Foundation TrustLondonUK Pediatric Surgery PGIMERChandigarhIndia

Background Hypospadias is one of the most common genital birth *** are around 300 various techniques available for the repair of *** study aims to compare the reported outcomes of Tubularized incised plate urethroplasty(TIP)and Grafted TIP(GTIP)repair in children undergoing primary *** This meta-analysisadhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,and we framed our research question using the population,intervention,control and outcomes *** conducted comprehensive electronic searches across various databases,employing a Boolean search strategy with predefined search *** randomized controlled trials(RCTs)were included for quantitative *** Totally,10 RCTs met our inclusion criteria for quantitative *** results indicated that urethrocutaneous fistula,glans dehiscence,and stricture rates were comparable between the two *** incidence of meatal stenosis was found to be significantly lower in the GTIP group with a relative risk(RR)of 0.32(95%confidence interval(Cl)0.15 to 0.67).Conclusion The coucomes UCF,glans dehiscence,and stricture rates were comparable between the two ***,the incidence of meatal stenosis was found to be significantly lower in the grafted TIP *** terms of operative time,our quantitative synthesis demonstrated that the TIP group had a shorter operative time than the GTIP group with significant heterogeneity.

关键词： plate grafted analysis

Mapping COVID-19 in India:Southern states at the forefront of new JN.1 variant

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Asian Pacific Journal of Tropical Medicine 2024年第1期17卷 1-3页

作者： Rabin debnath Arshdeep Singh Kushal Seni Anjali Sharma Viney Chawla Pooja A Chawla Department of Pharmaceutical Chemistry ISF College of PharmacyG.T RoadGhal KalanMogaPunjab142001India Department of Pharmaceutical Analysis ISF College of PharmacyG.T RoadGhal KalanMogaPunjab142001India University Institute of Pharmaceutical Sciences and Research Baba Farid University of Health SciencesFaridkotPunjabIndia

A new variant,JN.1,stemming from the omicron subvariant BA.2.86,garnered the attention of the World Health Organization(WHO)as a"variant of interest."Despite its rapid global spread,especially in the US,Canada,France,Singapore,Sweden[1],and the UK,JN.1 is considered to pose minimal *** vaccinations are believed to remain effective against *** WHO underscores the importance of maintaining immunization records amid co-occurring respiratory illnesses,and epidemiologists recommend monitoring hospitalizations,particularly in areas with low vaccination rates.

关键词： Canada Mapping spite

REMnO3（RE=Pr,Nd,Sm,Eu,Gd） perovskite as efficient catalysts for oxygen reduction reaction

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Journal of Rare Earths 2024年第11期42卷 2078-2087页

作者： Rakesh Ranjan Mahalik Siba Soren Ipsha Hota A.K.debnath K.P.Muthe Purnendu Parhi Department of Chemistry Ravenshaw University Technical Physics Division Bhabha Atomic Research Centre

Rare earth metal based perovskite emerges as important catalytic material for energy production and *** ABO3type materials are now the focus of research in the field of oxygen reduction and evolution ***,in this work we evaluated the oxygen reduction properties of the synthesized one-dimensional REMnO3（RE=Pr,Nd,Sm,Eu and Gd）.The one-dimensional REMnO3prepared by the hydrothermal synthesis route results in pure phase perovskite on *** perovskite was characte rized with X-ray diffraction,Fourier transform-infrared（FT-IR）,field emission-scanning electron microscopy（FE-SEM）,transmission electron microscopy（TEM） and X-ray photoelectron spectroscopy（XPS）.The oxygen reduction reaction activities were investigated with the help of electrochemical workstation that consists of three-electrode system immersed in 0.1 mol/L KOH electrolyte solution saturated with *** Koutechy-Levich plot obtained from rotating ring disk electrode shows all the prepared catalysts follow 4e-processes during oxygen *** effect of "A" site cation variation in REMnO3 on oxygen reduction reaction is ***3showed better onset potential for oxygen reduction reaction among the prepared rare earth ***3having high RE:Mn ratio（A-site rich co mpositions） promotes oxygen reduction reaction（ORR） *** the perovs kites showed good oxygen reduction property with high stability and methanol tolerance.

关键词： Electrocatalytic activity Oxygen reduction reaction (ORR) Perovskite Rare earths REMnO3 SmMnO3

Computer vision-based six layered ConvNeural network to recognize sign language for both numeral and alphabet signs

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Biomimetic Intelligence & Robotics 2024年第1期4卷 45-58页

作者： Muhammad Aminur Rahaman Kabiratun Ummi Oyshe Prothoma Khan Chowdhury Tanoy debnath Anichur Rahman Md.Saikat Islam Khan Department of Computer Science and Engineering Green University of BangladeshDhakaBangladesh Department of Computer Science and Engineering National Institute of Textile Engineering and Research(NITER)Constituent Institute of Dhaka UniversityDhakaBangladesh Department of Computer Science and Engineering Mawlana Bhashani Science and Technology UniversityTangailBangladesh

People who have trouble communicating verbally are often dependent on sign language,which can be difficult for most people to understand,making interaction with them a difficult *** Sign Language Recognition(SLR)system takes an input expression from a hearing or speaking-impaired person and outputs it in the form of text or voice to a normal *** existing study related to the Sign Language Recognition system has some drawbacks,such as a lack of large datasets and datasets with a range of backgrounds,skin tones,and *** research efficiently focuses on Sign Language Recognition to overcome previous *** importantly,we use our proposed Convolutional Neural Network(CNN)model,“ConvNeural”,in order to train our ***,we develop our own datasets,“BdSL_OPSA22_STATIC1”and“BdSL_OPSA22_STATIC2”,both of which have ambiguous backgrounds.“BdSL_OPSA22_STATIC1”and“BdSL_OPSA22_STATIC2”both include images of Bangla characters and numerals,a total of 24,615 and 8437 images,***“ConvNeural”model outperforms the pre-trained models with accuracy of 98.38%for“BdSL_OPSA22_STATIC1”and 92.78%for“BdSL_OPSA22_STATIC2”.For“BdSL_OPSA22_STATIC1”dataset,we get precision,recall,F1-score,sensitivity and specificity of 96%,95%,95%,99.31%,and 95.78%***,in case of“BdSL_OPSA22_STATIC2”dataset,we achieve precision,recall,F1-score,sensitivity and specificity of 90%,88%,88%,100%,and 100%respectively.

关键词： Conv NeuralSign language CNN Static Feature extraction Convolution2D Fully connected layer Dropout

Modified Chaplygin Gas with Variable G and Λ

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Chinese Physics Letters 2011年第11期28卷 289-292页

作者： Ujjal debnath Department of Mathematics Bengal Engineering and Science UniversityShibpurHowrah-711103India

We consider a modified Chaplygin gas with the gravitational constant G and the cosmological constantΛ.The trivial solution describes decelerating phase to accelerating phase of the *** non-static with constant equation of state describes the inflationary *** static universe,GandΛmust be formed arbitrarily,and for static universe with constant equation of state,GandΛshould be constant.

关键词： solution trivial constant

Rhyolites in continental mafic Large Igneous Provinces: Petrology,geochemistry and petrogenesis

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Geoscience Frontiers 2021年第1期12卷 53-80页

作者： Mahesh Halder debajyoti Paul Sarajit Sensarma Department of Earth Sciences Indian Institute of Technology KanpurKanpur 208016India Centre of Advanced Study in Geology University of LucknowLucknow 226007India

We present a detailed review of the petrological and geochemical aspects of rhyolite and associated silicic volcanic rocks(up to 20 vol%of all rocks)reported to date from twelve well known Phanerozoic continental mafic Large Igneous Provinces(LIPs).These typically spread over900℃.Rhyolites formed by significant crustal contribution are characterized by strong negative Nb-Ta anomalies,absence of clinopyroxene phenocrysts,and are likely to have a magma temperature<900℃.Geochemical signatures suggest rhyolite melt generation in the plagioclase stability field with a minor fraction originating from lower crustal depths.A large part of the compositional variability in rhyolites,particularly the SrNd-Pb-O isotope ratios,suggests a significant role of continental crust(upper crustal melting or AFC)in the evolution of these silicic rocks in the continental mafic LIPs.

关键词： Large Igneous Province Silicic rock Rhyolite Geochemistry Petrogenesis AFC

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