On the effect of spray parameters on CO and NO_x emissions in a liquid fuel fired flameless combustor

Sharma, Saurabh,Kumar, Rohit,Chowdhury, Arindrajit,Yoon, Youngbin,Kumar, Sudarshan Elsevier 2017 Fuel Vol.199 No.-

<P><B>Abstract</B></P> <P>In this paper, numerical and experimental investigations have been carried out to delineate the effect of various spray parameters on CO and NO<SUB>x</SUB> emissions in a combustor operating in flameless combustion mode with kerosene fuel. Thermal input was varied in the range of 20–41kW (Heat release density ∼5–10MW/m<SUP>3</SUP>) with different fuel injectors and various fuel injection pressures. Spray parameters were varied by employing two separate conditions (i) same fuel flow rate with different solid cone pressure swirl spray nozzles (N1 – N4) and injection pressures (2.5–14bar) to achieve varying spray parameters at same thermal input (ii) same fuel injection nozzle at different fuel flow rates and injection pressures (5–13bar) to understand their effect on combustion and emissions. In both the cases, Sauter Mean Diameter (SMD) varied in the range of 34–58μm with spray cone angle varying from 42° to 56° using different nozzles and fuel injection pressures. Tangential air injection helped achieve higher recirculation of hot combustion products in the primary zone of the combustor for all thermal inputs. The finer sprays obtained at higher injection pressures helped achieve improved recirculation and better mixing, resulting in uniform temperature and hence reduced CO and NO<SUB>x</SUB> emissions. The measured CO and NO<SUB>x</SUB> emissions were in the range of 28–70ppm and 2–10ppm for all heat inputs with global equivalence ratio varying from ϕ=0.6 to 1, respectively. Measured acoustic emission levels were in the range of 98–101dB and 104–107dB for the flameless and transition mode respectively. The measured CO, NO<SUB>x</SUB> and acoustic emissions are an order of magnitude smaller those corresponding to conventional combustion mode. It was observed that coarser sprays led to a significant increase in acoustic emissions, relatively non-uniform temperature distribution and higher CO, NO<SUB>x</SUB> emissions during flameless combustion mode.</P>

Effect of NTT on Performance of AODV in a Grid Topology-Based Wireless Ad Hoc Network

Saurabh Sharma,Alok Singh,Rajneesh Kumar Srivastava 한국정보과학회 2022 Journal of Computing Science and Engineering Vol.16 No.3

Routing in wireless ad hoc networks that enable nodes, acting as routers also, to find the best path between source and destination nodes, taking into account cost, is a very challenging task. In the present work, an investigation of performance of AODV routing protocol in a grid topology based ad hoc network by varying the value of node traversal time (NTT) and taking into account absence and presence of Hello messages is reported. A set of metrics, including Average End-to-End Delay, Packet Delivery Ratio, Throughput, Routing Overhead, Route Error Overhead, Normalized Routing Load, Average Hop Count, and Total Number of Received Data Packets, has been used to assess the performance of AODV in the grid network. Performance of AODV routing protocol varies in the value of NTT. Throughput in grid topology, by and large, is observed to decrease with an increase in NTT. However, explicit relations between certain metrics with NTT as well as simulation time could not be traced due to intricacies involved in the combination of states of various links and flows in the grid topology. To have better insights, grid topologies of two, three, and four rows are planned to be investigated in the future.

Accuracy of computed tomographic features in differentiating intestinal tuberculosis from Crohn`s disease: a systematic review with meta-analysis

( Saurabh Kedia ),( Raju Sharma ),( Vishnubhatla Sreenivas ),( Kumble Seetharama Madhusudhan ),( Vishal Sharma ),( Sawan Bopanna ),( Venigalla Pratap Mouli ),( Rajan Dhingra ),( Dawesh Prakash Yadav ) 대한장연구학회 2017 Intestinal Research Vol.15 No.2

Abdominal computed tomography (CT) can noninvasively image the entire gastrointestinal tract and assess extraintestinal features that are important in differentiating Crohn`s disease (CD) and intestinal tuberculosis (ITB). The present meta-analysis pooled the results of all studies on the role of CT abdomen in differentiating between CD and ITB. We searched PubMed and Embase for all publications in English that analyzed the features differentiating between CD and ITB on abdominal CT. The features included comb sign, necrotic lymph nodes, asymmetric bowel wall thickening, skip lesions, fibrofatty proliferation, mural stratification, ileocaecal area, long segment, and left colonic involvements. Sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio (DOR) were calculated for all the features. Symmetric receiver operating characteristic curve was plotted for features present in >3 studies. Heterogeneity and publication bias was assessed and sensitivity analysis was performed by excluding studies that compared features on conventional abdominal CT instead of CT enterography (CTE). We included 6 studies (4 CTE, 1 conventional abdominal CT, and 1 CTE+conventional abdominal CT) involving 417 and 195 patients with CD and ITB, respectively. Necrotic lymph nodes had the highest diagnostic accuracy (sensitivity, 23%; specificity, 100%; DOR, 30.2) for ITB diagnosis, and comb sign (sensitivity, 82%; specificity, 81%; DOR, 21.5) followed by skip lesions (sensitivity, 86%; specificity, 74%; DOR, 16.5) had the highest diagnostic accuracy for CD diagnosis. On sensitivity analysis, the diagnostic accuracy of other features excluding asymmetric bowel wall thickening remained similar. Necrotic lymph nodes and comb sign on abdominal CT had the best diagnostic accuracy in differentiating CD and ITB. (Intest Res 2017;15:149-159)

Reduced graphene oxide modified smart conducting paper for cancer biosensor

Kumar, Saurabh,Kumar, Suveen,Srivastava, Saurabh,Yadav, Birendra K.,Lee, Seung H.,Sharma, Jai G.,Doval, Dinesh C.,Malhotra, Bansi D. Elsevier 2015 Biosensors & bioelectronics Vol.73 No.-

<P><B>Abstract</B></P> <P>We report results of the studies relating to the fabrication of a paper based sensor comprising of poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and reduced graphene oxide (RGO) composite. The effect of various solvents like methanol, ethylene glycol and H<SUB>2</SUB>SO<SUB>4</SUB> on the electrical conductivity of PEDOT:PSS coated Whatman paper has been investigated. The conductivity of this solution processed conducting paper significantly increases from ~1.16×10<SUP>−4</SUP> Scm<SUP>−1</SUP> up to ~3.57×10<SUP>−2</SUP> Scm<SUP>−1</SUP> (~300 times) on treatment with ethylene glycol. The observed significant increase in electrical conductivity is due to conformational rearrangement in the polymer and is due to strong non-covalent cooperative interaction between PEDOT and the cellulose molecules. Further, incorporation of RGO into the conducting paper results in improved electrochemical performance and signal stability. This paper electrode is a promising alternative over the expensive conventional electrodes (ITO, gold and glassy carbon), that are known to have limited application in smart point-of-care (POC) devices. This low cost, flexible and environment friendly conducting paper based biosensor utilized for cancer biomarker (carcinoembryonic antigen, CEA) detection reveals high sensitivity of 25.8µAng<SUP>−1</SUP> mLcm<SUP>−2</SUP> in the physiological range, 1–10ngmL<SUP>−1</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Solution processed reduced graphene oxide modified conducting paper sensor is reported for cancer detection. </LI> <LI> This paper sensor is exceptionally low cost, flexible and disposable. </LI> <LI> It exhibits high sensitivity of 25.8µAng<SUP>−1</SUP> mLcm<SUP>−2</SUP> in the detection range of 1–10ngmL<SUP>−1</SUP> for cancer biomarker (carcinoembryonic antigen, CEA) detection. </LI> <LI> This conducting paper electrode is a promising alternative over the expensive conventional electrodes (ITO, gold and glassy carbon) for application to POC devices. </LI> </UL> </P>

Orbital IgG4 Disease: Imaging Findings on 68Ga-DOTANOC PET/CT

Saurabh Arora,Nishikant A. Damle,Rachna Meel,Sanjay Sharma,Seema Sen,Chandrasekar Bal,Kanak Lata,Sneha Prakash,Divya Yadav,Meivel Angamuthu 대한핵의학회 2019 핵의학 분자영상 Vol.53 No.6

Immunoglobulin G4 (IgG4)–related diseases are a spectrum of systemic inflammatory conditions of unknown etiology, which are characterized by infiltration of tissues by IgG4 plasma cells and sclerosing inflammation (Cheuk and Chan Adv Anat Pathol 17:303–32, 2010). Although this condition was initially described in relation to autoimmune pancreatitis, now it has been reported in almost every organ system of body (Zen and Nakanuma Am J Surg Pathol 34:1812–9, 2010, Masaki et al. Ann Rheuma Dis 68:1310–5, 2009). Orbital involvement by IgG4 disease can involve extraocular muscles (EOM), lacrimal glands, conjunctiva, eyelids, infraorbital nerve, orbital fat, and nasolacrimal system (McNab and McKelvie. Ophthal Plast Reconstr Surg 31:167–78, 2015, Katsura et al. Neuroradiology 54:873–82, 2012). The basis of using 68Ga-DOTANOC PET/CT in IgG4 orbital disease is the known expression of somatostatin receptors in chronic inflammatory cells (Cuccurullo et al. Indian J Radiol Imaging 27:509-16, 2017) and also avidity shown previously in other IgG4-related diseases (Cheng et al. Clin Nucl Med 43:773-6, 2018).

Tracer Accumulation in Relation to Venous Thrombus on 18F-DOPA PET/CT in a Case of Persistent Hyperinsulinemic Hypoglycemia of Infancy

Saurabh Arora,Nishikant Avinash Damle,Averilicia Passah,Rajni Sharma,Harish Goyal,Shreedharan Thankarajan Arunraj,Priyanka Gupta,Manisha Jana 대한핵의학회 2019 핵의학 분자영상 Vol.53 No.2

18F-DOPA PET/CT is commonly done in patients with persistent hyperinsulinemic hypoglycemia of infancy (PHHI) to look for any focal lesion in the pancreas.We present the findings in a 20-day-old neonate with PHHI who underwent 18F-DOPA PET/CT. The scan showed diffuse uptake in the pancreas with no focal lesion, physiologic excretion into the genito-urinary system, and interestingly tracer accumulation was seen in the inferior vena cava and ilio-femoral veins which is a non-physiological site for tracer accumulation. The uptake corresponded to a large venous thrombus which was confirmed by a venous Doppler.

Effectiveness of Inorganic Nitrogen on Kojic Acid Production from Fungi Aspergillus sp. BU20S

Sharma Sumit,Singh Shikha,Sarma Saurabh Jyoti 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.4

Kojic acid is a valuable compound that contributes to various therapeutic and cosmetic applications. Organic nitrogen partially contributes to fermentation and mostly prefers cell growth as well as increases production costs. This study aims to fi nd the eff ect of low-cost inorganic nitrogen in the form of ammonium chloride on kojic acid production from fungal isolate Aspergillus sp. BU20S. A 3.63-times increase in the kojic acid (4.43 ± 0.47 g/L) was found when only the ammonium chloride was supplemented in glucose (10 g/L) medium than other minimal salts. The product formation was 2.52 ± 0.56 g/L in ammonium chloride as compared to 2.02 ± 0.06 g/L yeast extract after 10 days. The carbon/nitrogen ratio (C/N) was found optimal as 15 (molecular C/N: 23.58) which gives a high titer of 5.17 ± 0.84 g/L from 10 g/L of glucose. At this optimal molecular nitrogen value, the nitrogen supplement cost can be reduced by 93–99% compared to yeast extract. The antimicrobial potential of kojic acid purifi ed from the fermented broth was also studied against methicillin-resistant Staphylococcus aureus (MRSA). The purifi ed kojic acid showed a ~ 20 mm zone of inhibition at a 2.5 mg dose loaded over 7.4 × 10 9 CFU/ mL of MRSA. This study concludes that only ammonium chloride is a suffi cient inorganic nitrogen source to produce kojic acid and is useful in reducing production costs. The purifi ed kojic acid is also an eff ective antimicrobial agent.

Addition of computed tomography chest increases the diagnosis rate in patients with suspected intestinal tuberculosis

( Saurabh Kedia ),( Raju Sharma ),( Sudheer Kumar Vuyyuru ),( Deepak Madhu ),( Pabitra Sahu ),( Bhaskar Kante ),( Prasenjit Das ),( Ankur Goyal ),( Karan Madan ),( Govind Makharia ),( Vineet Ahuja ) 대한장연구학회 2022 Intestinal Research Vol.20 No.2

Background/Aims: Intestinal tuberculosis (ITB) is difficult to diagnose due to poor sensitivity of definitive diagnostic tests. ITB may be associated with concomitant pulmonary tuberculosis (PTB) which may remain undetected on chest X-ray. We assessed the role of contrast enhanced computed tomography (CECT) chest in detecting the prevalence of active PTB, and increasing the diagnostic yield in patients with suspected ITB. Methods: Consecutive treatment naïve patients with suspected ITB (n=200) who underwent CECT chest (n=88) and had follow-up duration>1 year were recruited in this retrospective study (February 2016 to October 2018). ITB was diagnosed in the presence of caseating granuloma, positive acid fast stain or culture for Mycobacterium tuberculosis on biopsy, presence of necrotic lymph nodes (LNs) on CT enterography or positive response to anti-tubercular therapy. Evidence of active tuberculosis on CECT-chest was defined as presence of centrilobular nodules with or without consolidation/miliary nodules/thick-walled cavity/enlarged necrotic mediastinal LNs. Results: Sixty-five of eighty-eight patients (mean age, 33.8±12.8 years; 47.7% of females) were finally diagnosed as ITB (4-caseating granuloma on biopsy, 12-necrotic LNs on CT enterography, 1-both, and 48-response to anti-tubercular therapy) and 23 were diagnosed as Crohn’s disease. Findings of active TB on CECT chest with or without necrotic abdominal LNs were demonstrated in 5 and 20 patients, respectively. No patient with Crohn’s disease had necrotic abdominal LNs or active PTB. Addition of CECT chest in the diagnostic algorithm improved the sensitivity of ITB diagnosis from 26.2% to 56.9%. Conclusions: Addition of CECT chest significantly improves the sensitivity for definite diagnosis in a patient with suspected ITB. (Intest Res 2022;20:184-191)

OpCloudSec: Open cloud software defined wireless network security for the Internet of Things

Sharma, Pradip Kumar,Singh, Saurabh,Park, Jong Hyuk Elsevier 2018 Journal of Computer Communications Vol.122 No.-

<P><B>Abstract</B></P> <P>Cutting-edge cloud frameworks will require a paradigm shift in regards to how they are built and managed. Traditional management and control platforms face significant challenges in terms of security, reliability, and flexibility that these cutting-edge frameworks must deal with. On the other hand, Distributed Denial of Service (DDoS) attacks have become a weapon of choice for cyber-terrorists, cyber-extortionists, and hackers. Recently, the simplicity of programmability in Software-Defined Networking (SDN) makes it a good platform for the implementation of various initiatives that includes decentralized network management, dynamic topology changes, and application deployment in a multi-tenant data center environment. Motivated by the capabilities of SDN, we are proposing a mitigation architecture for security attacks that incorporates a highly programmable monitoring network so as to make it possible to identify attacks. It has a flexible control structure to quickly define the reaction of attacks and particular side, and we show how SDN can be used as a key application in the cloud IoT. We evaluated the performance of our proposed architecture and compared it with the existing models to obtain various performance measures. The results of our evaluation show that our OpCloudSec architecture model can efficiently and effectively meet the security challenges created by the new network paradigm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present the integration of SDN and cloud computing, which are applied into the IoT environment for efficient and better security management. </LI> <LI> We propose a mitigation architecture for security attacks that incorporates a highly programmable monitoring network to empower the identification of attacks. </LI> <LI> It has a flexible control structure to quickly define the reaction of attacks and particular side and show how SDN can be used as a key application in the cloud IoT. </LI> <LI> We performed a simulation study using real network traces. The outcomes showed that when it comes to dealing with new challenges, our OpCloudSec proposal is successful. </LI> <LI> The detection algorithm is quick enough for performing deduction line packages and accomplishes a high identification rate. </LI> </UL> </P>

DistBlockNet: A Distributed Blockchains-Based Secure SDN Architecture for IoT Networks

Sharma, Pradip Kumar,Singh, Saurabh,Jeong, Young-Sik,Park, Jong Hyuk Institute of Electrical and Electronics Engineers 2017 IEEE communications magazine Vol.55 No.9

<P>The rapid increase in the number and diversity of smart devices connected to the Internet has raised the issues of flexibility, efficiency, availability, security, and scalability within the current IoT network. These issues are caused by key mechanisms being distributed to the IoT network on a large scale, which is why a distributed secure SDN architecture for IoT using the blockchain technique (DistBlockNet) is proposed in this research. It follows the principles required for designing a secure, scalable, and efficient network architecture. The DistBlockNet model of IoT architecture combines the advantages of two emerging technologies: SDN and blockchains technology. In a verifiable manner, blockchains allow us to have a distributed peer-to-peer network where non-confident members can interact with each other without a trusted intermediary. A new scheme for updating a flow rule table using a blockchains technique is proposed to securely verify a version of the flow rule table, validate the flow rule table, and download the latest flow rules table for the IoT forwarding devices. In our proposed architecture, security must automatically adapt to the threat landscape, without administrator needs to review and apply thousands of recommendations and opinions manually. We have evaluated the performance of our proposed model architecture and compared it to the existing model with respect to various metrics. The results of our evaluation show that DistBlockNet is capable of detecting attacks in the IoT network in real time with low performance overheads and satisfying the design principles required for the future IoT network.</P>