Prognostic Factors in Patients Hospitalized with Diabetic Ketoacidosis

Avinash Agarwal,Ambuj Yadav,Manish Gutch,Shuchi Consul,Sukriti Kumar,Ved Prakash,Anil Kumar Gupta,Annesh Bhattacharjee 대한내분비학회 2016 Endocrinology and metabolism Vol.31 No.3

Background: Diabetic ketoacidosis (DKA) is characterized by a biochemical triad of hyperglycemia, acidosis, and ketonemia. This condition is life-threatening despite improvements in diabetic care. The purpose of this study was to evaluate the clinical andbiochemical prognostic markers of DKA. We assessed correlations in prognostic markers with DKA-associated morbidity andmortality. Methods: Two hundred and seventy patients that were hospitalized with DKA over a period of 2 years were evaluated clinically andby laboratory tests. Serial assays of serum electrolytes, glucose, and blood pH were performed, and clinical outcome was noted aseither discharged to home or death. Results: The analysis indicated that significant predictors included sex, history of type 1 diabetes mellitus or type 2 diabetes mellitus,systolic blood pressure, diastolic blood pressure, total leukocyte count, Acute Physiology and Chronic Health Evaluation II(APACHE II) score, blood urea nitrogen, serum creatinine, serum magnesium, serum phosphate, serum osmolality, serum glutamicoxaloacetic transaminases, serum glutamic pyruvic transaminases, serum albumin, which were further regressed and subjected tomultivariate logistic regression (MLR) analysis. The MLR analysis indicated that males were 7.93 times more likely to have favorableoutcome compared with female patients (odds ratio, 7.93; 95% confidence interval, 3.99 to 13.51), while decreases in meanAPACHE II score (14.83) and serum phosphate (4.38) at presentation may lead to 2.86- and 2.71-fold better outcomes, respectively,compared with higher levels (APACHE II score, 25.00; serum phosphate, 6.04). Conclusion: Sex, baseline biochemical parameters such as APACHE II score, and phosphate level were important predictors of theDKA-associated mortality.

In-Cylinder Spray and Combustion Investigations in a Heavy-Duty Optical Engine Fueled With Waste Cooking Oil, Jatropha, and Karanja Biodiesels

Patel, Chetankumar,Hwang, Joonsik,Chandra, Krishn,Agarwal, Rashmi A.,Bae, Choongsik,Gupta, Tarun,Agarwal, Avinash Kumar ASME International 2019 Journal of energy resources technology Vol.141 No.1

Comparative compression ignition engine performance, combustion, and emission characteristics, and trace metals in particulates from Waste cooking oil, Jatropha and Karanja oil derived biodiesels

Patel, Chetankumar,Chandra, Krishn,Hwang, Joonsik,Agarwal, Rashmi A.,Gupta, Neeraj,Bae, Choongsik,Gupta, Tarun,Agarwal, Avinash Kumar Elsevier 2019 Fuel Vol.236 No.-

<P><B>Abstract</B></P> <P>In the present study, comparison of performance, combustion and emission characteristics of a single cylinder compression ignition (CI) genset engine fueled by biodiesels derived from Waste cooking oil (WCO), Jatropha and Karanja oils vis-á-vis baseline mineral diesel has been carried out. Performance and combustion investigations were carried out at constant engine speed (1500 rpm) and six engine loads (0–100%). WCO biodiesel showed slightly higher heat release rate (HRR) than baseline mineral diesel, while it was slightly lower for Karanja and Jatropha biodiesels. Hydrocarbons (HC) and oxides of nitrogen (NO<SUB>X</SUB>) emissions were lower, while carbon monoxide (CO) emission was relatively higher for biodiesels compared to baseline diesel. Smoke opacity was higher for Karanja and Jatropha biodiesels compared to baseline diesel. WCO biodiesel exhibited comparable smoke opacity with baseline mineral diesel except at full load, where it was relatively lower. Particulates were collected from the engine exhaust on a quartz filter paper using a partial flow dilution tunnel at 50 and 100% engine loads, for trace metal analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES). It was found that trace metals such as Ca, Cu, Fe, K, Mg, Na, Zn and Al showed higher concentrations in particulates from all test fuels, while Ba, Cd, Cr, Mn and Mo showed relatively lower concentrations in the particulates collected.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biodiesels exhibited higher P, HRR<SUB>max</SUB> but shorter CD. </LI> <LI> Biodiesels showed higher smoke opacity due to higher viscosity. </LI> <LI> Lower HC, NOx and trace metals in particulates from biodiesels. </LI> <LI> Trace metals in particulates reduced with increasing engine load. </LI> <LI> Most trace metal concentrations in biodiesel particulates were lower. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

REVIEW OF REGULATED, UNREGULATED AND PARTICULATE EMISSIONS FROM BIODIESEL FUELLED COMPRESSION IGNITION ENGINES

Chetankumar Patel,Joonsik Hwang,배충식,Avinash Kumar Agarwal 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.6

Compression-ignition (CI) engines have been utilised in transport and power generation sectors due to their excellent thermal efficiency, robustness and durability. However, the rapid depletion of crude oil reserves and environmental concerns have forced CI engines to be powered by alternative and environment-friendly renewable fuels. Biodiesel, which contains ~10 % (w/w) oxygen in its fuel molecules, has become a popular alternative fuel for CI engines. Biodiesel can be stored similar to mineral diesel. Hence it does not require a separate fuel distribution infrastructure. The fuel properties of biodiesel are very close to mineral diesel; hence conventional CI engines can be fueled with biodiesel/blends without major modifications in the engine hardware/software. It is also widely known that biodiesel in CI engines brings significant benefits of lower emissions such as unburned hydrocarbons, carbon monoxide, and particulate matter (PM). Since biodiesel is considered an attractive alternative fuel, there are many attempts to produce and utilise biodiesel in different applications from various feedstocks such as soybean, rapeseed, and waste cooking oil. Hence, it is necessary to understand the effects of biodiesel feedstocks and engine applications (operating conditions, engine type, etc.) on regulated and unregulated emissions. This paper reviews effects of biodiesel on regulated/unregulated/particulate matter (PM) emissions based on numerous experimental research studies in open literature conducted on a variety of engines using different biodiesels.

Investigations on air-fuel mixing and flame characteristics of biodiesel fuels for diesel engine application

Hwang, Joonsik,Bae, Choongsik,Patel, Chetankumar,Agarwal, Rashmi A.,Gupta, Tarun,Kumar Agarwal, Avinash Elsevier 2017 APPLIED ENERGY Vol.206 No.-

<P>In this study, the spray and combustion phenomena of biodiesels were investigated in a constant volume combustion chamber (CVCC). Mineral diesel was used as a baseline fuel and biodiesels derived from waste cooking oil, Karanja oil, and Jatropha oil were utilized to investigate the effect of fuel properties on spray and combustion processes. Experiments were performed at high temperature and pressure conditions in order to simulate the atmospheric environment of a diesel engines. Test fuels were injected at an injection pressure of 80 MPa using a common-rail equipped solenoid injector. Macroscopic evaporation characteristics were analyzed by high-speed shadowgraphy technique under evaporating conditions. The representative droplet size distribution and Sauter mean diameter (SMD) were measured using the Phase Doppler Interferometry (PDI) technique, which was applied to study the spray atomization characteristics of the fuels. The air-fuel equivalence,ratio in the spray was calculated using mathematical correlations. The quantitative estimations of soot generation in the spray flames were compared using Hue number analysis. From the shadowgraphy images, the biodiesels showed slower air-fuel mixing characteristics than the baseline diesel due to their inferior volatility. While diesel evaporated abruptly after the fuel injection, the biodiesels showed dense liquid regions in the center of the spray plume. Biodiesels also exhibited larger SMD than the baseline mineral diesel in the fuel spray because of their higher density, viscosity, and surface tension. Despite having poor spray atomization characteristics, the calculated equivalence ratio of biodiesels was lower than that of the baseline diesel. This trend was attributed to the oxygen content of biodiesel. The flame luminosity and visible spray flame duration of biodiesels were lower than those of diesel, while the biodiesel spray flames exhibited lower sooting tendency than the baseline diesel.</P>

HRTEM evaluation of primary soot particles originated in a small-bore biofuel compression-ignition engine

Hwang, Joonsik,Hirner, Felix Sebastian,Bae, Choongsik,Patel, Chetankumar,Gupta, Tarun,Agarwal, Avinash Kumar Pergamon 2019 Applied thermal engineering Vol. No.

<P><B>Abstract</B></P> <P>Nanostructure of soot particles from a small-bore compression-ignition engine was investigated by high-resolution transmission electron microscopy (HRTEM). Four test fuels namely conventional diesel, waste cooking oil (WCO) biodiesel, Jatropha biodiesel, and Karanja biodiesel were studied. Lacey carbon TEM grids were utilized to capture soot particles from engine exhaust gas. An in-house image processing algorithm was developed to measure primary particle diameter, fringe length, fringe tortuosity, and fringe spacing. The HRTEM image revealed the presence of thicker absorbed hydrocarbon layers surrounding biodiesel soot primary particles than those of diesel soot. The primary particle size of WCO biodiesel was smaller than diesel, on the other hand, Jatropha biodiesel and Karanja biodiesel showed slightly larger particles. In terms of nano-structure analysis, WCO biodiesel and Jatropha biodiesel particles exhibited shorter fringe length than diesel, while the Karanja biodiesel particles showed the longest fringe length of 0.91 nm. Fringe tortuosity of biodiesels was smaller than diesel because of relatively lower portion of core area, where highly curved fringes existed. The soot particles from biodiesels exhibited larger fringe spacing than diesel, especially the Karanja biodiesel showed the longest fringe spacing of 0.67 nm compared to 0.55 nm in case of diesel.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biodiesel fuels showed higher particulate matter emissions than diesel fuel. </LI> <LI> High viscosity biodiesel fuels showed unburned hydrocarbon layer in primary particles. </LI> <LI> WCO biodiesel showed the smallest primary particle diameter among the tested fuels. </LI> <LI> Biodiesel fuels had larger fringe spacing compared to that of diesel. </LI> </UL> </P>

Performance and emission evaluation of a small-bore biodiesel compression-ignition engine

Hirner, Felix Sebastian,Hwang, Joonsik,Bae, Choongsik,Patel, Chetankumar,Gupta, Tarun,Agarwal, Avinash Kumar Pergamon Press 2019 Energy Vol.183 No.-

<P><B>Abstract</B></P> <P>This study investigates the influence of biodiesels on combustion and emission characteristics in a common-rail equipped small-bore single-cylinder diesel engine. The engine experiments were performed using waste-cooking-oil (WCO), Jatropha-oil, and Karanja-oil derived biodiesels. Conventional diesel was utilized as a baseline fuel. The test engine was operated at a speed of 1200 rpm and an indicated mean effective pressure of 0.5 MPa. The fuels were injected at fuel injection pressures (FIPs) of 40, 80, and 120 MPa. At the same time, the fuel injection timing was varied from −15 crank angle degrees (CAD) after top dead center (aTDC) to −3 CAD aTDC. Experimental results showed that ignition delay was directly correlated to the cetane number and had more significant effect at higher FIPs. The peak of in-cylinder pressure increased as the injection timing was advanced, due to longer ignition delay. Biodiesels showed relatively lower or equal level of nitrogen oxides (NOx) emissions compared to conventional diesel. This was mainly due to lower combustion efficiency showing high amount of smoke, HC, and CO emissions from incomplete combustion. However, for the WCO biodiesel, smoke, HC, and CO emissions could be significantly improved than other biodiesel thanks to better atomization and air-fuel mixing process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Jatropha and Karanja biodiesel had shorter ignition delays than diesel. </LI> <LI> Diesel and WCO biodiesel showed higher portion of pre-mixed combustion. </LI> <LI> Smoke, CO, and HC emissions from biodiesels were higher than diesel. </LI> <LI> In most conditions, biodiesel fuels showed lower NO<SUB>x</SUB> emissions than diesel. </LI> </UL> </P>

Nanostructure characterization of soot particles from biodiesel and diesel spray flame in a constant volume combustion chamber

Hirner, Felix Sebastian,Hwang, Joonsik,Bae, Choongsik,Patel, Chetankumar,Gupta, Tarun,Agarwal, Avinash Kumar Elsevier Ltd 2019 Fuel Vol.235 No.-

<P><B>Abstract</B></P> <P>This study investigates the effect of biodiesel fuels on morphological characteristics of soot particles from spray flame in a constant volume combustion chamber. The experiments were carried out under simulated diesel engine condition. The auto-ignition of injected fuel was carried out at an ambient pressure of 5 MPa and ambient temperature of 978.15 K. The soot particles were captured with a transmission electron microscope (TEM) grid inside the flame by thermophoretic effect. They were characterized as primary particle diameter, graphene layer (fringe) length, fringe tortuosity, and fringe spacing based on the image processing from original TEM image. Three different kinds of biodiesel fuels, waste cooking oil biodiesel, Jatropha biodiesel and Karanja biodiesel were used in the test. Conventional diesel fuel was utilized as a baseline fuel for the comparison. The tested fuels were injected with injection pressures of 40, 80, and 120 MPa by means of common-rail injection system. The experimental result showed that all of the biodiesel fuels had smaller primary particle diameter than that of conventional diesel regardless of injection pressures. The soot particles from biodiesel fuels were also distinguished showing characteristically shorter fringe length and lower tortuosity. These experiments unveiled a correlation between the nano-structural parameters for the early stage of oxidation inside the flame.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Regardless of fuel, primary particle diameter was decreased as the injection pressure increased. </LI> <LI> Primary particle diameter of biodiesel fuels was 1–2 nm smaller than that of diesel. </LI> <LI> Biodiesel primary particles were consisted of lower fringe tortuosity and spacing layers. </LI> <LI> Shorter fringe length in combination with lower tortuosity led to the smallest fringe spacing. </LI> </UL> </P>