Direct patterning and electrospray deposition through EHD for fabrication of printed thin film transistors

Khan, Saleem,Doh, Yang Hoi,Khan, Arshad,Rahman, Ahsan,Choi, Kyung Hyun,Kim, Dong Soo Elsevier 2011 Current Applied Physics Vol.11 No.1

<P><B>Abstract</B></P><P>This paper presents fabrication of thin film transistors using direct write technology following electrohydrodynamic approach for patterning and spray deposition. In this research colloidal solution of Ag nanoparticles is used for patterning of gate, source and drain contacts, while SiO<SUB>2</SUB> and ZnO colloidal solutions are used for dielectric and semiconductor layers of TFTs using EHD printing technology. For direct patterning, different electrode configurations for inkjet head are used and a new nozzle head is developed for getting stable meniscus and uniform patterning. To minimize the disturbances caused by vertically inserted thin electrode, a hollow conductor is used in new setup, which serves both for ink feed and as an actuation electrode. The new configuration helps in minimizing the extraction voltage for jetting and also repeatability of experiment by keeping fixed parameters of the nozzle head is possible. By using metallic enclosed glass capillary head, conductive pattern lines for gate, source and drain contacts with good uniformity and regular boundaries are printed on glass substrate. Conductive lines having width of around 70μm are achieved with appreciable aspect ratio. A channel length of 50μm and width of 1.5mm is obtained by using EHD direct printing of Ag colloidal solution. Layer thickness of SiO<SUB>2</SUB> achieved is around 300nm while ZnO thickness achieved is around 100nm. A standard deviation in layer thickness of around 25nm for SiO<SUB>2</SUB> and 10nm for ZnO electrosprayed layers is observed. A complete prototype of thin film transistor has been successfully fabricated by using EHD technology in this research. Contact angle analyzer is also used for finding various parameters like contact angle, wetting energy and spreading coefficient of the colloidal solutions which helps in determining the surface properties of the deposited layers. All experiments were performed in ambient conditions and environment.</P> <P><B>Highlights</B></P><P>► Electrohydrodynamic Inkjet steps development for manufacture of thin film transistor. ► Solution based Ag ink for conductive contacts achieving 25 μm channel length and 1.5 mm channel width. ► Electrospray of SiO2 for Dielectric layer around 300 nm thickness. ► Electrospray of ZnO for semiconductor layer around 100 nm thickness.</P>

Influence of weather on the moth catches of Helicoverpa armigera at various cotton-based agro-ecological sites

Khan Muhammad AHSAN,Waseem AKRAM,Faisal HAFEEZ 한국곤충학회 2009 Entomological Research Vol.39 No.3

Pheromones are innate products, exploited for direct population manipulation in the trapping of precise pest density. They demonstrate feasibility and efficiency against Helicopverpa armigera at five different cotton-based agro-ecological sites: river site, vegetable farm, orchard, clean cultivation site, and forest. The data were recorded at 15–20 day intervals from 8 September 2004 to 1 December 2006. The Number of moths caught during the study period demonstrated that the vegetable farm showed the maximum population of moths per trap (0.54), followed by the orchard (0.29), forest (0.19), river (0.15), and clean cultivation site (0.12). During 2004, rainfall (in the orchard and clean cultivation site) and relative humidity (in the clean cultivation site) showed positive and significant correlation with the number of moths caught. During 2005, temperatures played a significant and positive role in population fluctuation of the pest almost at all the selected sites; the minimum temperature was recorded at the vegetable farm and the average temperature was found at the forest site. Rainfall also showed a significant and positive correlation with trapped moths in the vegetable farm, orchard, and clean cultivation site. During 2006, relative humidity showed a significant and negative correlation with the trapped population at all the sites except the river site. Rainfall showed a negative and significant correlation with the pest at the forest site. Relative humidity was the most important aspect at 8.93% causing variation in the trapped population followed by maximum temperature (5.7%), rainfall (1.63%), average temperature (0.74%), and minimum temperature (0.56%).

Management of Fruit Flies (Diptera: Tephritidae) of the Most Perishable Fruits

KHAN, Muhammad Ahsan,Muhammad ASHFAQ,Waseem AKRAM,이종진 한국곤충학회 2005 Entomological Research Vol.35 No.2

Biological nitrogen fixation by the microorganisms in the gut of termites is one of the singularly important symbiotic processes, since termites invariably thrive on nitrogen poor diet. Two isolates of free living aerobic and facultative anaerobic N fixing bacteria were obtained from the guts of fungus cultivating termite, Macrotermes sp. Among the total bacterial isolates from termite gut, the per cents of N fixing aerobes viz., Azotobacter and Beijerinckia spp were 49% and 37% from the salivary gland while facultative N fixing anaerobe viz., Klebsiella and Clostridium contributed (51% and 93%). The free living aerobic bacteria were identified as Azotobacter spp (19×104 CFU mL-1) and Beijerinckia (13.2×104 CFU mL-1) from the salivary gland of the termite; interestingly, foregut, mid gut and hind gut registered a low population of these bacteria. The isolates of Azotobacter were smooth, glistening, vicid in nature, rods, gram negative and cyst forming. Isolates of Beijerinckia sp. produced copious slime, tenacious, rods, gram negative with no cyst formations. Both the isolates emitted green fluorescence and produced acid. Facultative N fixing anaerobes were harbored in the hind gut. The isolates were identified as Klebsiella (20×104 CFU mL-1) and Clostridium pasteurianum 39.1×104 CFU mL-1. Klebsiella were straight rods arranged singly or in pairs, non-motile, gram negative, whereas Clostridium pasteurianum was viscoid, motile with terminal spores. A positive correlation was observed between the extractable of these isolates and soil aggregation. The aggregates formed by the isolates increased soil aeration, porosity, water holding capacity and helped in better plant growth. Thus, the gut microflora of termite, apart from harnessing nitrogen from the atmosphere, also helps improving soil fertility.

Comparison and analysis of patterning based on different ground configurations for polyimide substrate

Saleem Khan(살림칸),Ahsan Rahman(아산라만),Adnan Ali(아드난알리),Arshad Khan(알샤드칸),H. C. Kim(김형찬),J. B. Ko(고정범),Y. H. Doh(도양회),D. S. Kim(김동수),K. H. Choi(최경현) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.4

Does Gender Influence Investment Choice? A Psychosomatic Study of GCC Entrepreneurs

Mohammed Abdul Imran KHAN,Syed Ahsan JAMIL,Shahebaz Sarfaraz KHAN,Meer Mazhar ALI 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.4

Entrepreneurs with behavioral finance biases are more likely to make irrational or financially detrimental decisions. Understanding financial behavior biases can assist in making sound financial decisions. Behavioral finance is a new topic that can assist researchers in better understanding investor behavior and preferences while purchasing and selling stocks. Using measures such as independent t-tests and average Likert five-point scale scores, this study seeks to determine how entrepreneurs make investment decisions and whether gender makes a difference. The study is empirical, and data from 1000 entrepreneurs were collected through convenience sampling. The study’s main findings show that there are numerous factors to consider while investing in stocks, including family planning, children’s education, investment security, and recurring income. Both men and women attempt to invest in many asset classes, but certain investments are extremely risky, while others are low risk. As a result, investors should assess risk based on their age and experience rather than their gender; this indicates that an investment in venture capital has nothing to do with gender but everything to do with the investor’s age.

Correlation between the Profitability and Working Capital Practices: A Case Study in the Gulf Cooperation Council

KHAN, Mohammed Abdul Imran,ALAM, Md. Shabbir,SYED, Ahsan Jamil Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

The ability of entrepreneurs to arrange working capital is the key to maximizing the profitability of small- and medium-sized enterprises and the wealth of entrepreneurs. The study investigates the correlation between entrepreneurs' working capital management and the profitability of SMEs listed on six Gulf Cooperation Council (GCC) stock exchanges between 2019 and 2020. The secondary data is collected from the financial statements of SMEs listed on the six GCC stock exchanges. Actual sample for the research study was a total of 136 small- and medium-sized enterprises selected using purposive sampling methods. Four research models were considered in this analysis, all ending up affecting gross profits. The selected entrepreneurial SMEs were listed on six different Gulf Cooperation Council stock exchanges during 2019-2020. The fixed financial assets ratio, financial debt ratio, and company size are used as control variables and data were analyzed using multiple regression. The research results demonstrate that there is a statistically significant negative correlation between profitability measured by gross profit and cash cycle and the components of the cash cycle (including days of accounts receivable and days of inventory). The study further reveals that there is no significant correlation between gross profit and days of accounts payable.

Synthesis of Tetrazolo[1,5-a]quinoxaline based Azetidinones & Thiazolidinones as Potent Antibacterial & Antifungal Agents

Kumar, Shiv,Khan, S.A.,Alam, Ozair,Azim, Rizwan,Khurana, Atul,Shaquiquzzaman, M.,Siddiqui, Nadeem,Ahsan, Waquar Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

4-Chlorotetrazolo[1,5-a]quinoxaline (III) was synthesized by azide (2+3) cycloaddition of 2,3-dichloroquinoxaline (II). Compound (III) on further refluxing with hydrazine hydrate furnished 4-hydrazinotetrazolo[1,5-a]quinoxaline (IV). Further refluxing of (IV) with different aromatic aldehydes in methanol yielded corresponding Schiff's bases V(a-j). Various 4-aminotetrazolo[1,5-a]quinoxaline based azetidinones VII(a-j) were synthesized by stirring the compounds V(a-j), at low temperature, with equimolar mixture of chloroacetylchloride & triethylamine in dry benzene, while 4-aminotetrazolo[1,5-a]quinoxaline based thiazolidinones VIII(a-j) were synthesized by refluxing Schiff's bases V(a-j) with thioglycolic acid in oil-bath. The structures of all the compounds were confirmed on the basis of $^1H$-NMR & FT-IR spectral data. All the newly synthesized compounds were screened for in-vitro antimicrobial activity against E. coli, S. aureus, K. pneumoniae & P. aeruginosa & antifungal activity against C. albicans. Few of them have exhibited the promising activity.

Discovery of Novel 1,4-Benzodioxane Containing Thiazolidinone Derivatives as Potential Antihepatotoxic Agent

Khalilullah, Habibullah,Khan, Shamshir,Ahsan, Mohamed Jawed,Ahmed, Bahar Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.2

In continuance of our search for newer antihepatotoxic agents some novel thiazolidinone derivatives containing 1,4-benzodioxane ring system were synthesized starting from 2,3-dihydro-1,4-benzodioxane-2-carbohydrazide. The synthesized compounds were evaluated for antihepatotoxic activity against $CCl_4$-induced hepatotoxicity in rats. Among them some compounds have shown significant antihepatotoxic activity comparable to standard drug silymarin.

Correlation between the Profitability and Working Capital Practices: A Case Study in the Gulf Cooperation Council

Mohammed Abdul Imran KHAN,Md. Shabbir ALAM,Ahsan Jamil SYED 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

The ability of entrepreneurs to arrange working capital is the key to maximizing the profitability of small- and medium-sized enterprises and the wealth of entrepreneurs. The study investigates the correlation between entrepreneurs’ working capital management and the profitability of SMEs listed on six Gulf Cooperation Council (GCC) stock exchanges between 2019 and 2020. The secondary data is collected from the financial statements of SMEs listed on the six GCC stock exchanges. Actual sample for the research study was a total of 136 small- and medium-sized enterprises selected using purposive sampling methods. Four research models were considered in this analysis, all ending up affecting gross profits. The selected entrepreneurial SMEs were listed on six different Gulf Cooperation Council stock exchanges during 2019–2020. The fixed financial assets ratio, financial debt ratio, and company size are used as control variables and data were analyzed using multiple regression. The research results demonstrate that there is a statistically significant negative correlation between profitability measured by gross profit and cash cycle and the components of the cash cycle (including days of accounts receivable and days of inventory). The study further reveals that there is no significant correlation between gross profit and days of accounts payable.

Discovery of Novel 1,4-Benzodioxane Containing Thiazolidinone Derivatives as Potential Antihepatotoxic Agent

Habibullah Khalilullah,Shamshir Khan,Mohamed Jawed Ahsan,Bahar Ahmed 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.2

In continuance of our search for newer antihepatotoxic agents some novel thiazolidinone derivatives containing 1,4-benzodioxane ring system were synthesized starting from 2,3-dihydro-1,4-benzodioxane-2-carbohydrazide. The synthesized compounds were evaluated for antihepatotoxic activity against CCl4-induced hepatotoxicity in rats. Among them some compounds have shown significant antihepatotoxic activity comparable to standard drug silymarin.