Vimal Rarh | University of Delhi (original) (raw)

Papers by Vimal Rarh

Journal of forensic chemistry and toxicology, Jun 14, 2019

NFORMATION and Communication Technology (ICT), which encompasses all communication technologies s... more NFORMATION and Communication Technology (ICT), which encompasses all communication technologies such as Internet, wireless networks, cell phones, satellite communications, digital television, etc. has fundamentally changed the way we live now. We find a world of difference in the practices and the procedures of fields such as medicine, travel, tourism, business, banking, engineering as they operate now in comparison to how they operated three decades ago. The impact of ICT on education however has been far less and slow. Though the lack of sufficient funding to purchase technologies has often been cited as a reason for this, the real and the most significant cause has been the lack of motivation among teachers to adopt ICT as teaching tools. But in recent times, factors have emerged that have strengthened and encouraged moves to adopt ICTs in classrooms and learning settings.

Synthetic Communications, 1995

Abstract Palladium catalysed transfer hydrogenation using cyclohexene as the donor is found to de... more Abstract Palladium catalysed transfer hydrogenation using cyclohexene as the donor is found to deprotect readily alcohol benzyl ethers and aliphatic benzyl esters. The phenol benzyl ethers and benzyl benzoates are stable under these conditions.

ut of the two nitration techniques, Vapour-phase nitration is more satisfactory than liquid-phase... more ut of the two nitration techniques, Vapour-phase nitration is more satisfactory than liquid-phase nitration. General rules of vapour phase nitration of alkanes (and cycloalkanes), as given by Hass and Shechter (1947): i. Polynitro compounds are formed only from alkanes of fairly high molecular weight. Smaller alkanes give mainly mono-nitro alkanes. ii. The ease of replacement of the hydrogen atom by nitro group is: tertiary hydrogen > secondary hydrogen > primary hydrogen. At higher temperature, however, the ease of replacement is almost equal. iii. An alkyl group present in the alkane can also be replaced by a nitro-group, i.e, chain fission takes place. For example, isopentane yields nine nitroparaffins. The fission reaction increases as the temperature rises. iv. Oxidation always accompanies nitration, resulting in the formation of nitro-compounds and a mixture of acids, aldehydes, ketones, alcohols, nitrites, nitroso-compounds, nitroolefins, polymers, carbon monoxide and carbon dioxide. Catalysts such as copper, iron, platinum oxide, etc., accelerate oxidation rather than nitration. Mechanism: Proceeds by a free radical mechanism. 2 2 3 2 3 3 HNO CH CH NO CH CH + • − ⎯→ ⎯ • + − ONO CH CH NO CH CH NO CH CH 2 3 2 2 3 2 2 3 2 3 2 3 O CH CH O CH CH 2 3 2 3 In this reaction, the active hydrogen atom is replaced by an amino-methyl group or substituted amino-methyl group: This reaction provides a means of preparing a large variety of compounds, e.g., nitro-amines, diamines, etc.

Current Physical Chemistry, 2019

INFORMATION and Communication Technology (ICT), which encompasses all communication technologies ... more INFORMATION and Communication Technology (ICT), which encompasses all communication technologies such as Internet, wireless networks, cell phones, satellite communications, digital television, etc. has fundamentally changed the way we live now. We find a world of difference in the practices and the procedures of fields such as medicine, travel, tourism, business, banking, engineering as they operate now in comparison to how they operated three decades ago.

Arson is a commonly used term today being used to define a crime involving the deliberate and wil... more Arson is a commonly used term today being used to define a crime involving the deliberate and willful burning of property. The term has originated form an Anglo-French word which means “the act of burning” [1]. According to Indian Penal Code, 1860, sections 435 and 436 relates to definition of arson in India. Also, the data published by National Crime Records Bureau in the year 2016, records the incidence of arson under violent crimes as 2.6%. Moreover, it has also been noted the crimes related to arson has increased from a figure of 9,289 in the year 2014 to 11,196 in the year 2016 [2]. Most of the arson cases reported are initiated with the aid of accelerants which are petroleum based such as petrol or kerosene. Therefore, the existence of vessels capable of having accelerant rouse doubts of arson [3]. Almirall & Furton [4] stated that these samples should then be examined at the laboratory for presence or absence of any accelerant type or ignitable liquid residue. Kirk [5] stated...

At cold areas where there are heavy snow fall, mass number of people are covered by avalanche and... more At cold areas where there are heavy snow fall, mass number of people are covered by avalanche and are needed for individualization. Sometimes it is also important in cases where criminals often hide their weapons inside the ice or snow, and these evidences or weapons may often contain the fingerprint of the victim or the culprit. As for this we need to develop fingerprint for the identification and individualization of the culprit or the victim.Thus, this present study has been conducted to give an overview of the current fingerprints methods available to assimilate the outcome of the visualisation of the latent fingerprint and to find out the best method suitable for the development of latent fingerprint on non porous surfaces (aluminium and plastic) at different low temperature (-5 C,-1 C, 0 C, 1 C, 5 C). 80 samples were taken, out of which 16 samples (8 for aluminium, 8 for plastic) were taken for each different temperature which was developed with both physical and chemical meth...

CONTENTS Acidity of Alpha Hydrogens Acidity of β-dicarbonyl Compounds Hydrogen-Deuterium Exchange... more CONTENTS Acidity of Alpha Hydrogens Acidity of β-dicarbonyl Compounds Hydrogen-Deuterium Exchange Alkylation of Enolate Anions Alkylation Reactions of Enolate Anions Regioselectivity in Enolate Anion Formation and Reaction Keto-enol tautomerism of Ethyl Acetoacetate Equilibrium of keto-enol Mixtures Enolisation Modern Theories of Tautomerism Position of Equilibrium in keto-enol Tautomerism Factors affecting the Enol Content Synthesis of Ethyl Acetoacetate: the Claisen Condensation Alkylation of Diethyl Malonate and Ethyl Acetoacetate Alkylation of 1,3-Dithianes Alkylation and Acylation of Enamines Enamines, Enols and Enolate Ions

Polymers for Advanced Technologies

Current Physical Chemistry

Journal of forensic chemistry and toxicology, Jun 14, 2019

NFORMATION and Communication Technology (ICT), which encompasses all communication technologies s... more NFORMATION and Communication Technology (ICT), which encompasses all communication technologies such as Internet, wireless networks, cell phones, satellite communications, digital television, etc. has fundamentally changed the way we live now. We find a world of difference in the practices and the procedures of fields such as medicine, travel, tourism, business, banking, engineering as they operate now in comparison to how they operated three decades ago. The impact of ICT on education however has been far less and slow. Though the lack of sufficient funding to purchase technologies has often been cited as a reason for this, the real and the most significant cause has been the lack of motivation among teachers to adopt ICT as teaching tools. But in recent times, factors have emerged that have strengthened and encouraged moves to adopt ICTs in classrooms and learning settings.

Synthetic Communications, 1995

Abstract Palladium catalysed transfer hydrogenation using cyclohexene as the donor is found to de... more Abstract Palladium catalysed transfer hydrogenation using cyclohexene as the donor is found to deprotect readily alcohol benzyl ethers and aliphatic benzyl esters. The phenol benzyl ethers and benzyl benzoates are stable under these conditions.

ut of the two nitration techniques, Vapour-phase nitration is more satisfactory than liquid-phase... more ut of the two nitration techniques, Vapour-phase nitration is more satisfactory than liquid-phase nitration. General rules of vapour phase nitration of alkanes (and cycloalkanes), as given by Hass and Shechter (1947): i. Polynitro compounds are formed only from alkanes of fairly high molecular weight. Smaller alkanes give mainly mono-nitro alkanes. ii. The ease of replacement of the hydrogen atom by nitro group is: tertiary hydrogen > secondary hydrogen > primary hydrogen. At higher temperature, however, the ease of replacement is almost equal. iii. An alkyl group present in the alkane can also be replaced by a nitro-group, i.e, chain fission takes place. For example, isopentane yields nine nitroparaffins. The fission reaction increases as the temperature rises. iv. Oxidation always accompanies nitration, resulting in the formation of nitro-compounds and a mixture of acids, aldehydes, ketones, alcohols, nitrites, nitroso-compounds, nitroolefins, polymers, carbon monoxide and carbon dioxide. Catalysts such as copper, iron, platinum oxide, etc., accelerate oxidation rather than nitration. Mechanism: Proceeds by a free radical mechanism. 2 2 3 2 3 3 HNO CH CH NO CH CH + • − ⎯→ ⎯ • + − ONO CH CH NO CH CH NO CH CH 2 3 2 2 3 2 2 3 2 3 2 3 O CH CH O CH CH 2 3 2 3 In this reaction, the active hydrogen atom is replaced by an amino-methyl group or substituted amino-methyl group: This reaction provides a means of preparing a large variety of compounds, e.g., nitro-amines, diamines, etc.

Current Physical Chemistry, 2019

INFORMATION and Communication Technology (ICT), which encompasses all communication technologies ... more INFORMATION and Communication Technology (ICT), which encompasses all communication technologies such as Internet, wireless networks, cell phones, satellite communications, digital television, etc. has fundamentally changed the way we live now. We find a world of difference in the practices and the procedures of fields such as medicine, travel, tourism, business, banking, engineering as they operate now in comparison to how they operated three decades ago.

Arson is a commonly used term today being used to define a crime involving the deliberate and wil... more Arson is a commonly used term today being used to define a crime involving the deliberate and willful burning of property. The term has originated form an Anglo-French word which means “the act of burning” [1]. According to Indian Penal Code, 1860, sections 435 and 436 relates to definition of arson in India. Also, the data published by National Crime Records Bureau in the year 2016, records the incidence of arson under violent crimes as 2.6%. Moreover, it has also been noted the crimes related to arson has increased from a figure of 9,289 in the year 2014 to 11,196 in the year 2016 [2]. Most of the arson cases reported are initiated with the aid of accelerants which are petroleum based such as petrol or kerosene. Therefore, the existence of vessels capable of having accelerant rouse doubts of arson [3]. Almirall & Furton [4] stated that these samples should then be examined at the laboratory for presence or absence of any accelerant type or ignitable liquid residue. Kirk [5] stated...

At cold areas where there are heavy snow fall, mass number of people are covered by avalanche and... more At cold areas where there are heavy snow fall, mass number of people are covered by avalanche and are needed for individualization. Sometimes it is also important in cases where criminals often hide their weapons inside the ice or snow, and these evidences or weapons may often contain the fingerprint of the victim or the culprit. As for this we need to develop fingerprint for the identification and individualization of the culprit or the victim.Thus, this present study has been conducted to give an overview of the current fingerprints methods available to assimilate the outcome of the visualisation of the latent fingerprint and to find out the best method suitable for the development of latent fingerprint on non porous surfaces (aluminium and plastic) at different low temperature (-5 C,-1 C, 0 C, 1 C, 5 C). 80 samples were taken, out of which 16 samples (8 for aluminium, 8 for plastic) were taken for each different temperature which was developed with both physical and chemical meth...

CONTENTS Acidity of Alpha Hydrogens Acidity of β-dicarbonyl Compounds Hydrogen-Deuterium Exchange... more CONTENTS Acidity of Alpha Hydrogens Acidity of β-dicarbonyl Compounds Hydrogen-Deuterium Exchange Alkylation of Enolate Anions Alkylation Reactions of Enolate Anions Regioselectivity in Enolate Anion Formation and Reaction Keto-enol tautomerism of Ethyl Acetoacetate Equilibrium of keto-enol Mixtures Enolisation Modern Theories of Tautomerism Position of Equilibrium in keto-enol Tautomerism Factors affecting the Enol Content Synthesis of Ethyl Acetoacetate: the Claisen Condensation Alkylation of Diethyl Malonate and Ethyl Acetoacetate Alkylation of 1,3-Dithianes Alkylation and Acylation of Enamines Enamines, Enols and Enolate Ions

Polymers for Advanced Technologies

Current Physical Chemistry