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Defence Technology（防务技术） 2019年第6期15卷 949-957页

作者： pratim kumar Dr.K.N.Modi Institute of Engineering and Technology

Research and development of green oxidizers and green fuels as a possible replacement for ammonium perchlorate(NH4ClO4,AP) and hydrazine(N2H4) respectively has been increased considerably in the recent *** and hydrazine are the oxidizer and fuel entities,and used in solid and liquid rocket motors *** is highly toxic and led to adverse health effects,while hydrazine is carcinogenic in *** is in use from the last several decades for rocket and space shuttle propulsion,while hydrazine is used in upper stage liquid propelled rocket ***’s a tough task to replace AP with the currently available green oxidizers;since their ballistic properties are weaker when compared to AP and also they can’t be successfully deployed in a solid rocket motor at present Some important available solid green oxidizers are ammonium nitrate(AN),ammonium dinitramide(ADN),hydroxyl ammonium nitrate(HAN),and hydrazinium nitroformate(HNF).However,AN is one of the cheap and readily available oxidizer,and has great potential to use in solid/liquid rocket *** progress has been envisaged till now,and more progress will be there in the coming future over the development of AN based green energetic materials(GEM’s).A concise overview has been presented over the development of phase stabilized ammonium nitrate(PSAN) and AN/KDN based green oxidizers in the present review paper.

关键词： Green oxidizers Ammonium nitrate(AN) Phase stabilized ammonium nitrate(PSAN) Dinitramide anion(DA) Potassium dinitramide(KDN) Phase stabilizers

An overview on properties,thermal decomposition,and combustion behavior of ADN and ADN based solid propellants

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Defence Technology（防务技术） 2018年第6期14卷 661-673页

作者： pratim kumar Alliance College of Engineering and Design Alliance UniversityBengaluruIndia

Ammonium dinitramide [NH4 N(NO_2)2, ADN] is considered as a possible replacement for ammonium perchlorate(AP) in nearly all kind of solid rocket propulsions in the coming future. The reason to use ADN instead of AP in solid rocket propulsion is because of its harmless combustion products, along with its capacity to generate high specific impulse(Isp). ADN is fairly a new member in the solid oxidizer community and is considered under green energetic material(GEM). Application and feasible utilization of ADN as an oxidizer for composite solid propellants(CSP's) requires complete knowledge of its thermal decomposition processes along with its combustion behavior. A detailed overview on the physical and chemical properties, thermal decomposition, and combustion behavior of ADN and ADN based propellants has been discussed in this paper. Catalytic effect on thermal decomposition, combustion wave structure, and burning rate of ADN is also discussed.

关键词： ADN Green oxidizer Green propellant Thermal decomposition Combustion

Catalytic effects of Cu-Co~* on the thermal decomposition of AN and AN/KDN based green oxidizer and propellant samples

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Defence Technology（防务技术） 2018年第3期14卷 250-260页

作者： pratim kumar Puran Chandra Joshi Rajiv kumar Shelly Biswas Department of Space Engineering & Rocketry Birla Institute of Technology Department of Mechanical Engineering Vidya Vihar Institute of Technology

This paper presents the catalytic effects of Cu-Co~* catalyst on the decomposition of AN and AN/KDN based oxidizer and propellant samples. Ozawa-Flynn-Wall(OFW) iso-conversional method was used for the kinetic studies and to compute the activation energy(Ea) values for various decomposition steps of the prepared oxidizer and propellant samples in the temperature range of 50 e500C. TG-DTG experiments were carried out for both oxidizer and propellant samples at the heating rates of 3, 5, and 10C/min. AN/KDN based oxidizer samples were prepared by an evaporative co-crystallization method. Citric acid sol-gel method was used for the synthesis of Cu-Co~* catalyst. The propellant sample contains HTPB as the fuel binder along with other ingredients such as TDI, DOA, and Glycerol. The Cu-Co~* catalyst was used as 2% by weight to the total weight of catalyzed oxidizer and propellant samples. It was observed from the present study that, Cu-Co~* catalyst helps in reducing the Ea values for AN and AN based propellant samples. However, with the percentage increment of KDN in the AN crystals, Ea value ***, it was observed that Cu-Co~* catalyst stabilizes the initial partial decomposition of KDN.

关键词：催化氧化剂催化效果热分解 Cu 燃料取样 TG-DTG 催化剂

Combustion performance studies of aluminum and boron based composite solid propellants in sub-atmospheric pressure regimes

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Propulsion and Power Research 2019年第4期8卷 329-338页

作者： pratim kumar Mayank Varshney Aniket Manash Department of Aerospace Engineering and Applied Mechanics IIESTShibpurHowrahWest Bengal711103India Indian Institute of Technology(Indian School of Mines) DhanbadJharkhand862004India Aryabhatta Center for Nanoscience&Technology AKUPatnaBihar800001India

The aim of present study is to investigate the burning rate,ignition delay,and flame characteristics of ammonium perchlorate(AP)-hydroxyl terminated poly-butadiene(HTPB)[AP/HTPB]based composite propellants(CSP's)in sub-atmospheric pressure regimes(13 kPae100 kPa).Several fuels and catalyzed were used to evaluate their effects on the combustion characteristics of AP based propellants in sub-atmospheric pressure *** fuels,aluminum(Al)and boron(B)were selected as metallic and non-metallic fuel *** in catalyst,butyl ferrocene(B.F.)and ferric oxide(F.O.)were selected as liquid and solid catalyst *** from these,other ingredients that were used are di-octyl adipate(DOA),toluene di-isocyanate(TDI),and *** article throws some light on the burning rate and ignition delay properties for these new classes of prepared propellant *** subatmospheric pressures,all propellants are susceptible to irregular burning with the ejection of soot's,fumes,and unburned *** catalyzed propellants can sustain its combustion up to the lowest pressure.

关键词： AP/HTPB Metallic/non-metallic fuel Catalyst Sub-atmospheric pressure Burning rate Base-bleed

Identification of parameter to assess cracking resistance of asphalt mixtures subjected to aging and moisture conditioning

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第2期9卷 293-304页

作者： Bhaskar pratim Das Anjan kumar Siddagangaiah Department of Civil Engineering Indian Institute of Technology GuwahatiGuiuahati 781039India

This study comprehensively evaluated different parameters based on tensile strength testing to assess the cracking resistance of asphalt mixtures subjected to aging and moisture *** this purpose,two sources of aggregates were selected to produce hot and warm mix asphalt *** mixtures were subjected to short term and long term aging,three levels of moisture conditioning(freeze thaw cycles),and tested at two temperatures(15℃and 25℃).The load-displacement data was used to determine the fracture work density,fracture energy,toughness index,cracking resistance index,cracking tolerance index,and rate dependent cracking *** was noticed that moisture conditioning increased the variability of the different *** cracking tolerance index and rate dependent cracking index parameter had a much higher coefficient of variation(Co V)with a maximum value close to 50%.Indirect tensile strength,fracture energy,and fracture work density appropriately captured the effect of moisture on cracking resistance of *** cracking resistance index,cracking tolerance index,and rate dependent cracking index increased with an increase in the moisture conditioning *** Statistical analysis showed that tensile strength,fracture work density,and fracture energy were significantly influenced by different aging and moisture conditions *** energy showed better association with fatigue life of asphalt mixtures subjected to three freeze-thaw cycles compared to tensile ***,the fatigue life prediction models showed that both indirect tensile strength and fracture energy significantly influence the fatigue life of asphalt mixtures subjected to aging and moisture conditioning.

关键词： Cracking resistance Aging Moisture Warm mix additive Fatigue life

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Geochemistry and hydrocarbon source rock potential of shales from the Palaeo-Mesoproterozoic Vindhyan Supergroup, central India

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Energy Geoscience 2023年第3期4卷 276-295页

作者： Arvind kumar Singh Partha pratim Chakraborty Birbal Sahni Institute of Palaeosciences 53 University RoadLucknow226007India Department of Geology University of DelhiNew Delhi110007India Hiroshima Institute of Plate Convergence Region Research Hiroshima UniversityHigashi-Hiroshima7398526Japan

With increase in shale gas exploration, inorganic and organic geochemical investigations of shale have become extremely important. Here, we explore the six argillaceous (shale) intervals (Arangi, Koldaha, Rampur, Bijaygarh, Rewa and Sirbu shale) from Son valley sector, Vindhyan Basin with an aim to understand provenance conditions, palaeoclimate, tectonic setting and hydrocarbon generation potential. Whole rock geochemistry indicates Vindhyan sediments derived from felsic source(s) except for Sirbu shale that indicates additional influx of mafic rocks with differentiated felsic source. A comparative study of Vindhyan shale rare earth elements (REEs) points to Mahakoshals and Chhotanagpur gneissic complex (CGC) as probable sediment provenance for Vindhyan sediments. CIA analysis, after necessary corrections for K-metasomatism, suggests evolution in weathering and palaeoclimate indicating a transformation from moderate weathering conditions with warm and humid climate during lower Vindhyan deposition to intense weathering conditions with hot and humid climate during upper Vindhyan deposition. Trace (La/Y vs. Sc/Cr) and REE analysis indicates passive margin setting for Vindhyan sediments whereas a wide range spanning passive to active continental margin setting is also inferred using (Th-Sc-Zr/10) and (Th–La-Sc) ternary diagrams. However, these tectonic discriminant diagrams lack in explaining rift- or sag-related origin of any intracratonic basin such as the Vindhyan Basin. The total organic carbon (TOC) content in Vindhyan shales ranges from 0.29% to 8.44%. The thermally liberated hydrocarbon (S1) values range from 0.01 to 0.18 mg HC/g rock (milligram hydrocarbon per gram of rock sample), whereas hydrocarbon from cracking of the kerogen (S2) shows values ranging from 0.04 to 0.47 mg HC/g rock. Based on modified Van Krevelen correlation (HI vs. Tmax) diagram, organic matter from Arangi and Bijaygarh shales is characterized as thermally mature, Type III kerogen of gas

关键词： Shale geocheristry Provenance Organic matter Hydrocarbon potential VIndhyan basin

An unusual cause of dyspnoea complicating right upper abdominal swelling

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World Journal of Gastroenterology 2006年第25期12卷 4109-4111页

作者： Sanjay kumar Mandal Partha pratim Chakraborty Rana Bhattacharjee Subhasis Roy Chowdhury Shounak Majumdar Department of Medicine Medical College Kolkata88College StreetKolkataWest BengalIndia

A middle aged, non-addict male presented with right upper abdominal pain and swelling with respiratory distress. Examination revealed central cyanosis, bipedal pitting edema with prominent epigastric and back veins. Liver was enlarged, tender, spanned 20 cm without any splenomegaly or ascites. Other systems were clinically normal. Laboratory investigations showed polymorphonuclear leucocytosis with slightly deranged liver function. Abdominal ultrasonography showed an abscess in the right lobe of the liver with compressed inferior vena cava （IVC）, middle and left hepatic veins. Arterial blood gas （ABG） documented hypoxia with orthodeoxia and air-contrast echocardiography was suggestive of an intrapulmonary shunt. A diagnosis of hepato-pulmonary syndrome （HPS） was made with near normal liver function secondary to amebic liver abscess. It reversed completely following successful treatment of the liver abscess.

关键词： A-a O2 gradient Air contrast echocardiography Hepato-pulmonary syndrome Orthodeoxia Amoebic liver abscess

Poncet's disease: An unusual presentation of tuberculosis in a diabetic lady

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World Journal of Clinical Cases 2015年第4期3卷 385-388页

作者： Partha pratim Chakraborty Sayantan Ray Chitra Selvan Rana Bhattacharjee Sanjay kumar Mandal Department of Endocrinology IPGMER and SSKM Hospital Department of General Medicine Medical College and Hospital

Authors describe a 53-year-old woman who presentedto their diabetes clinic with a three week history of multiple painful and swollen joints. She had been diagnosed with type 2 diabetes 5 years back. On examination, both knee joints and left ankle were swollen. A soft tissue swelling appeared over the medial end of the left clavicle few days later. Rheumatoid arthritis, collagen vascular diseases and other common causes of polyarthritis were ruled out by appropriate investigations. Non steroidal anti-inflammatory drugs failed to give satisfactory pain relief and the arthritis persisted. Conventional cultures of synovial fluid samples including cultures for tuberculosis were negative. Computed tomography showed a space occupying lesion involving the left sternoclavicular joint. Fine needle aspiration from the lesion was performed and acidfast bacilli were demonstrated in the smear using ZiehlNeelsen stain. The explanation of her arthritis was therefore tuberculous arthritis in left sternoclavicular joint and reactive arthritis in the rest of the joints. A diagnosis of Poncet's disease was considered in her case. We treated her with standard anti-tuberculosis drugs and the arthritis resolved within a few days. She remained symptom-free at her 2 years' follow-up.

关键词： Poncet’s disease Diabetes Tuberculous arthritis Reactive arthritis Acid-fast bacilli

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Choking or Epilepsy

Journal of Forensic Science and Medicine 2016年第1期2卷 57-59页

作者： Raktim pratim Tamuli Debarshee Chakraborty Nayan kumar Das Braja Gopal Das Department of Forensic Medicine and Toxicology Tezpur Medical CollegeTezpur epartment of Forensic Medicine and Toxicology Gauhati Medical CollegeGuwahatiAssamIndia

Choking is a form of asphyxia caused by an obstruction within the air passage usually between the pharynx and bifurcation of the *** is commonly associated with alcohol intoxication,neurological injury,or *** is almost always *** and homicidal chokings are ***,in the present case,the dead body of a 29‑year‑old male was brought by the local police to the mortuary of Gauhati Medical College and Hospital,Guwahati for medico‑legal autopsy,who as reported,was mysteriously found dead on his *** complete and thorough autopsy,the cause of death was opined to be due to asphyxia as a result of antemortem choking,following impaction of the food bolus in the laryngotracheal *** person had a history of a single episode of seizure(epilepsy)about 1 month back.

关键词： Asphyxia choking epilepsy food bolus

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沥青混合料疲劳寿命的新现象学模型研究

中外公路 2018年第3期38卷 288-296页

作者：冯新军杨强赵弘正 Nikhil Saboo Bhaskar pratim Das Praveen kumar 长沙理工大学交通运输工程学院湖南长沙410004

该文对印度公路和道路运输部所规定的3种级配沥青混合料进行了四分点疲劳试验,并评价了其疲劳寿命。试验采用应变控制模式,加载为频率10Hz的正弦加载,温度为20℃。所有混合料的空隙率都控制在(4.0±0.2)%,同时对沥青混合料进行了马歇尔... 详细信息

该文对印度公路和道路运输部所规定的3种级配沥青混合料进行了四分点疲劳试验,并评价了其疲劳寿命。试验采用应变控制模式,加载为频率10Hz的正弦加载,温度为20℃。所有混合料的空隙率都控制在(4.0±0.2)%,同时对沥青混合料进行了马歇尔残留稳定度和间接拉伸强度的测试以评价其性能。在此基础上,提出了一个评价沥青混合料疲劳寿命的新现象学模型。试验研究表明:弹性改性沥青疲劳寿命最长,并且具有最低的应变敏感性。塑性改性沥青混合料太脆导致在高应变水平下表现较差,SMA的疲劳寿命比密级配沥青混合料的疲劳寿命高近5倍。新的模型不仅与试验结果高度吻合,而且在统计上也比传统模型更加可靠。

关键词：疲劳模型沥青材料沥青混合料