Informatics Publishing Limited

Dipti Verma ¹, Ashish Singla ², Banwari Lal ¹, Priyangshu M. Sarma ¹

Affiliations
1 TERI, Darbari Seth Block, India Habitat Centre, New Delhi 110 003, IN
2 TERI University, 10 Institutional Area, Vasant Kunj, New Delhi 110 070, IN

Abstract

The production of biofuels from synthesis gas that utilizes a wide variety of biomass is an emerging concept, particularly with the focus on biomass-based economy. Biomass is converted to synthesis gas via gasification, which involves partial oxidation of the biomass at high temperature. This route of ethanol or liquid biofuel production has the advantage of utilizing the entire biomass, including the lignin content. Though the technology is yet to be established, there is a major breakthrough in understanding the microbial route of synthesis gas conversion. Acetogenic microorganisms such as Clostridium ljungdahlii, Clostridium aceticum, Acetobacterium woodii, Clostridium carboxidivorans and Clostridium autoethanogenum have already been reported to play a role in the conversion of synthesis gas to ethanol and acetic acid. Poor mass transfer properties of the gaseous substrates and low ethanol yield from these biocatalysts are the major challenges, preventing the commercialization of synthesis gas fermentation technology. This article reviews the existing literature on biomass-derived synthesis gas fermentation into biofuels, specifically ethanol. Special emphasis has been laid on understanding the need of synthesis gas fermentation and its bioconversion into next-generation liquid transport fuels. However, advantages of microbial process over conventional methods and the role of different microorganisms and pathways used have also been described. The article also outlines the challenges and future research directions regarding up scaling and commercialization of synthesis gas fermentation technology.

Keywords

Biomass, Microbial Interventions, Synthesis Gas, Transport Fuels.

Full Text

   

Saurav Dhand ¹, Ashish Singla ¹

Affiliations
1 Department of Mechanical Engineering, Thapar University, Patiala- 147001, Punjab, IN

Abstract

Background/Objectives: Production efficiency is mainly influenced by two factors ─ satisfying customer demands and profit maximization. Some methods for optimizing the production are proposed in the literature, which are computationally expensive. Methods/Statistical Analysis: Production scheduling problem is addressed by using a single objective function and suitable operational constraints. Dual-Phase Simplex method is used to determine the optimal schedule for production and sales. As compared to conventional methods, the current method is found to be computationally inexpensive and easy to implement. The sensitivity analysis is performed to study the effects of parametric variations on the production volume. Findings: The performance of a quality management system, in terms of production efficiency of an organization, is based on the quality of decisions taken at the shop floor. A good production manager must be able to foresee all decision-related discrepancies and adopt preventive measures appropriately. In order to resolve this contradictory requirement, an optimized production scheduling process is generally required, which deals with desired type and quantity of output at minimum cost. A typical case study of Tema (Ghana) based cable manufacturing firm is considered to optimize the production scheduling problem. In this paper, a mathematical model for the optimizing the production of different items having different costs is developed by considering the problem as Linear Programming Problem (LPP). Further, the formed LPP contains mixed type constraints, which are solved using the Dual-Phase Simplex method. It has been found from the literature that the Dual-Phase Simplex method is computationally inexpensive. Moreover, sensitivity analysis is done to observe the effect of break-downs on the production rate. Application/Improvements: The idea proposed in this paper has a wide scope in various physical processes to optimize their parameter values. However, for multi-objective problems the Dual-Phase Simplex method gives invalid results.

Keywords

Production Scheduling, Simplex Method

Full Text

   

Tarun Dagar ¹, Ashish Singla ¹, Varun Garg ¹, Kunal Khanna ¹, S. K. Dhattarwal ¹

Affiliations
1 Department of Forensic Medicine, PGIMS, Rohtak, Haryana, IN

Abstract

The ability to determine whether an individual has fired a firearm is of great significance in the investigation of both homicides and suicides. When the bullet emerges from the barrel of the gun, it is accompanied by a jet of flame, gas, powder, soot, primer residue , metallic particles stripped from the bullet, and vaporized metal from the bullet and cartridge case. These lead to what we know as Gunshot residue (GSR). The most widely used primer compositions contain a mixture of lead, antimony and barium. However, in the mid-1990s, cartridges free of all three metallic elements, primarily because of the threat posed by the 'Lead' constituent of the bullet to the environment as well as to the person firing the weapon due to the gases emitted during discharge of the firearm were introduced in some western countries. However, the availability of such type of ammunition posed a difficulty from the forensics point of view in detection of usual constituents of GSR i.e. lead, antimony and barium from the generally employed tests mentioned above. To deal with the problem of this new “eco-friendly” type of ammunition a new technique is under research called solid phase micro-extraction called as the 'Burleson Test' which can use a tiny amount of residue and uses a new method that can even identify components in newer eco-friendly ammunitions that do not contain lead or the metals other tests used for identifying residue.

Keywords

Gunshot Residue, Detection Technique.

Full Text