Observation of saturation transfer characteristics in solution processed vertical organic field-effect transistors (VOFETs) with high leakage current

M.A. Mohd Sarjidan,Ahmad Shuhaimi,W.H. Abd. Majid 한국물리학회 2018 Current Applied Physics Vol.18 No.11

Unlike ordinary organic field-effect transistors (OFETs), saturation current is hardly to be found in vertical OFETs (VOFETs). Moreover, the fabrication process of patterned sourced for VOFETs is quite complex. In this current work, a simple solution processed VOFET with directly deposited intermediate silver source electrode has been demonstrated. The VOFET exhibits a high leakage current that induces an inversion polarity of its transistor behavior. Interestingly, a well-defined saturation current was observed in the linear scale of transfer characteristic. The VOFET operated with high-current density>280 mA/cm2 at Vd=5 V. Overview potential of the fabricated device in display application is also presented. This preliminary work does open-up a new direction in VOFET fabrication and their application.

Growth Optimization of a Probiotic Candidate, Bifidobacterium Pseudocatenulatum G4, in Milk Medium Using Response Surface Methodology

Stephenie, W.,Kabeir, B.M.,Shuhaimi, M.,Rosfarizan, M.,Yazid, A.M. Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.2

Bifidobacterium pseudocatenulatum G4, a wild strain isolated from infant stools that has previously exhibited probiotic characteristics, was used in this study. The aim of this research was to improve the growth potential of this strain in milk-based medium. An initial screening study using a $2^3$ full factorial design was carried out to identify the impact on biomass production of the various components of the medium which were skim milk, yeast extract, and glucose. Statistical analysis suggested that yeast extract had a significant positive effect on viable cell count whereas glucose had a negative effect. Response surface methodology (RSM) was then applied to optimize the use of skim milk and yeast extract. A quadratic model was derived using a $3^2$ face-centered central composite design to represent cell mass as a function of the two variables. The optimized medium composition was found to be 2.8% skim milk and 2.2% yeast extract, w/v. The optimized medium allowed a maximum biomass of 9.129 $log_{10}cfu/mL$, 3.329log units higher than that achieved with 10% skim milk, which is the amount commonly used. The application of RSM resulted in an improvement in the biomass production of this strain in a more cost-effective milk medium, in which skim milk use was reduced by 71.8%.

Influence of pH and Impeller Tip Speed on the Cultivation of Bifidobacterium Pseudocatenulatum G4 in a Milk-Based Medium

Stephenie, W.,Kabeir, B.M.,Shuhaimi, M.,Rosfarizan, M.,Yazid, A.M. Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.5

Biomass production of Bifidobacterium pseudocatenulatum G4 in a milk-based medium was carried out in a 2- and 10-L stirred tank fermenters. The effects of impeller tip speed (0.28, 0.56, and 0.83 m/s) and pH control (6.0, 6.5, and 7.0) on the biomass production were investigated. The growth performance in the 2-L fermenter was significantly improved when the impeller tip speed was heId constant at 0.56 m/s and the pH was controlled at 6.5. These conditions yielded a maximum biomass of $1.687{\times}10^9cfu/mL$, a maximum specific growth rate of $0.504 h^{-1}$, a biomass productivity of $9.240{\times}10^7 cfu/mL{\cdot}h$, and a biomass yield of $9.791{\times}10^{10} cfu/g$ lactose. The consumption of milk lactose resulted in the accumulation of 7.353 g/L acetic acid and 6.515 g/L lactic acid, with an acetic:lactic ratio of 1.129. Scale-up of the fermentation process to a 10-L fermenter based on a constant impeller tip speed of 0.56 m/s yielded reproducible results with respect to biomass production and cell viability.

Profiling of Recovery Efficiencies for Three Standard Protocols (FDA-BAM, ISO-11290, and Modified USDA) on Temperature-Injured Listeria monocytogenes

( Hai Yen Lee ),( Lay Ching Chai ),( Chai Fung Pui ),( Woan Chwen Wong ),( Shuhaimi Mustafa ),( Yoke Kqueen Cheah ),( Zuraini Mat Issa ),( Mitsuaki Nishibuchi ),( Ra Du Son ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.9

There have been a number of studies conducted in order to compare the efficiencies of recovery rates, utilizing different protocols, for the isolation of L. monocytogenes. However, the severity of multiple cell injury has not been included in these studies. In the current study, L. monocytogenes ATCC 19112 was injured by exposure to extreme temperatures (60oC and -20oC) for a one-step injury, and for a two-step injury the cells were transferred directly from a heat treatment to frozen state to induce a severe cell injury (up to 100% injury). The injured cells were then subjected to the US Food and Drug Administration (FDA), the ISO-11290, and the modified United States Department of Agriculture (mUSDA) protocols, and plated on TSAyeast (0.6% yeast), PALCAM agar, and CHROMAgar Listeria for 24 h or 48 h. The evaluation of the total recovery of injured cells was also calculated based on the costs involved in the preparation of media for each protocol. Results indicate that the mUSDA method is best able to aid the recovery of heat-injured, freeze-injured, and heat-freeze-injured cells and was shown to be the most cost effective for heat-freeze-injured cells.

Growth Optimization of a Probiotic Candidate, Bifidobacterium pseudocatenulatum G4, in Milk Medium Using Response Surface Methodology

A. M. Yazid,W. Stephenie,B. M. Kabeir,M. Shuhaimi,M. Rosfarizan 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.2

Bifidobacterium pseudocatenulatum G4, a wild strain isolated from infant stools that has previously exhibited probiotic characteristics, was used in this study. The aim of this research was to improve the growth potential of this strain in milk-based medium. An initial screening study using a 23 full factorial design was carried out to identify the impact on biomass production of the various components of the medium which were skim milk, yeast extract, and glucose. Statistical analysis suggested that yeast extract had a significant positive effect on viable cell count whereas glucose had a negative effect. Response surface methodology (RSM) was then applied to optimize the use of skim milk and yeast extract. A quadratic model was derived using a 32 face-centered central composite design to represent cell mass as a function of the two variables. The optimized medium composition was found to be 2.8% skim milk and 2.2% yeast extract, w/v. The optimized medium allowed a maximum biomass of 9.129 log10 cfu/mL, 3.329 log units higher than that achieved with 10% skim milk, which is the amount commonly used. The application of RSM resulted in an improvement in the biomass production of this strain in a more cost-effective milk medium, in which skim milk use was reduced by 71.8%.

Influence of pH and Impeller Tip Speed onthe Cultivation of Bifidobacterium pseudocatenulatum G4 in a Milk-Based Medium

A. M. Yazid,W. Stephenie,B. M. Kabeir,M. Shuhaimi,M. Rosfarizan 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.5

Biomass production of Bifidobacterium pseudocatenulatum G4 in a milk-based medium was carried out in a 2- and 10-L stirred tank fermenters. The effects of impeller tip speed (0.28, 0.56, and 0.83 m/s) and pH control (6.0, 6.5, and 7.0) on the biomass production were investigated. The growth performance in the 2-L fermenter was significantly improved when the impeller tip speed was held constant at 0.56 m/s and the pH was controlled at 6.5. These conditions yielded a maximum biomass of 1.687 × 109 cfu/mL, a maximum specific growth rate of 0.504 h-1, a biomass productivity of 9.240 × 107 cfu/mL·h, and a biomass yield of 9.791 × 1010 cfu/g lactose. The consumption of milk lactose resulted in the accumulation of 7.353 g/L acetic acid and 6.515 g/L lactic acid, with an acetic:lactic ratio of 1.129. Scale-up of the fermentation process to a 10-L fermenter based on a constant impeller tip speed of 0.56 m/s yielded reproducible results with respect to biomass production and cell viability.

TikTok: Startup from the Stage of the Ideation to the One of the Growth

RAMZI SALLEM,SAEEDA AL HARA'MI,ASHWAQ AL SHUHAIMI,MANAR AL MUKHAINI,SUMAYA AL-QANOOBI Academy of Asian Business (AAB) 2022 Academy of Asian Business Review Vol.8 No.2

Nowadays, social networks and vines have become a necessity for all of us to make from our smartphones a real tool of education and entertainment. With an exponential growth in terms of the application download reaching actually about 1.8 billion active users and revenues estimated to more than 10 billion dollars in the end of 2022, The “TikTok” application is becoming not only a social phenomenon, but it is also the new serious competitor of big digital startup like Facebook, Instagram and YouTube. Thus, the current case study aims to analyze the “Tik Tok” company, a world-famous vine, which is considered as a very successful Asian startup. Based in China, this startup has recently achieved remarkable performance in a multidimensional level: Technological, commercial, and financial. Interested by this case, an effort of analysis was made to understand the growth stages of that global application, its critical milestones, and its crucial turning point: the COVID 19 pandemic which was detected as the “good wind” to the development of that startup. After a strategic diagnosis made through a SWOT analysis, we found many elements that constitute the value proposition, the competitive advantage, and the key success factors of that company. These findings are very important in terms of the added value to young people, merchants, and nascent entrepreneurs. The traced strategies that it has developed to overcome difficult challenges are very didactic and instructive to the community of digital startuppers to be inspired from the reasons behind the success of that Asian company, and to gain knowledge about the evolving market through technology.