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Tooling device design for vibration-assisted high speed shaping of PMMA
Md. Golam Mostofa,J. H. Noh,김화영,안중환,D. B. Kang 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.8
PMMA optical components that are used as one of the most important parts of high precision equipments and machines are increasingly replacing the glass due to the various advantages of PMMA. Especially in Light Guide Panels, the PMMA sheet that is used in Liquid Crystal Displays plays an important role in scattering the incident light and requires very fine machining as the sheet is directly related to the optical characteristics of the panels. The High Speed End milling and High Speed Shaping processes that are widely adopted and applied to the precise machining of Light Incident Plane still have quality problems, such as cracks, breakages, poor waviness,and straightness. This paper presents the tooling device design for machining a Light Incident Plane through vibration-assisted High Speed Shaping for increasing the optical quality by minimizing the above-mentioned problems. The cutting tool and the tool post presented in this paper are designed by the authors to increase the magnitude of the cutting stroke by adopting the resonant frequency without weakening the stiffness and to reduce vibrations during even high speed feeding. The dynamic characteristics of the cutting tool and the tool post are evaluated through simulation and experiment as well. The results reveal very appropriate dynamic characteristics for vibration-assisted High Speed Shaping.
Mostofa Mahmud HASAN(Mostofa Mahmud HASAN ),BM Sajjad HOSSAIN(BM Sajjad HOSSAIN ),Md. Abu SAYEM(Md. Abu SAYEM ),Mahnaz AFSAR(Mahnaz AFSAR ) 한국유통과학회 2022 유통과학연구 Vol.20 No.11
Purpose: The purpose of this study was to determine the effect of agricultural exports and imports on economic growth in Bangladesh and propose an upgraded and customized model of the supply chain for agribusiness growth in Bangladesh to achieve plain sailing and systematic operation and financial gains at home and abroad. Research design, data, and methodology: All data in the research have been collected from secondary sources. Gross domestic product was used as the dependent variable and exports and imports of agricultural products were used as independent variables. Pairwise Granger causality was utilized to see the impact of the variable responsible for the economic growth in Bangladesh and the causal relationship between the variables analyzed was measured using Johansen co-integration test. Results: From the empirical analysis, the researchers observed that agricultural commodity imports and exports have a unidirectional impact on economic growth in Bangladesh and a long-run causal link with economic growth in Bangladesh. The suggested supply chain model of agnbusiness aids in achieving smooth operations, systematic management, and monetary gains both domestically and internationally. Conclusions: This paper contnbutes to the development of a more effective and profitable agribusiness supply chain in Bangladesh systematically through their theoretical and practical implications.
Duration of Preservation Affect the Quality of Chilled Black Bengal Buck Semen
Md Gulshan Anowar Pradhan,Md Saidur Rahman,Woo-Sung Kwon,Dipendra Mishra,Md Mostofa Kamal,Mohammad Musharraf Uddin Bhuiyan,Mohammed Shamsuddin 韓國受精卵移植學會 2013 한국동물생명공학회지 Vol.28 No.2
The study focuses on the quality assessment of Black Bengal buck semen preserved at chilled condition. In this in vitro trial, collected semen from Black Bengal bucks was preserved at chilling temperature (4▲5줛) in tris-glucosecitrate yolk medium of 1:5 ratios for four days. Artificial Vagina (AV) method was utilized to collect semen from buck. General evaluation of semen includes the color, mass activity and density were measured by direct visual examination. However, computer-assisted sperm analysis (CASA) and phase contrast microscopy were used to figure out the motility (%), hyper-activated (HYP) motility (%) and number of abnormal spermatozoa (%) initially, and at every 24 h intervals. The result revealed that spermatozoa preserved at chilling temperature showed significantly (P<0.05) lower motility and HYP motility with the progression of preservation. The number of phenotypically abnormal spermatozoa significantly (P<0.05) increased following preservation. Although significant positive correlation (r=0.945; P<0.05) was existed between % motile and % HYP motile spermatozoa however, the % of morphologically abnormal spermatozoa was negatively correlated with % motile (r=긏0.997; P<0.05) and % HYP motile spermatozoa (r=긏0.946; P<0.01). Therefore, we concluded that the quality of chilled semen progressively losses its viability and doesn…t remain useable after certain period of preservation with respect to its motility and morphology.
Ovulation Synchronization in Water Buffaloes Guided by Milk Progesterone ELISA
Md. Nazmul Hoque,Anup Kumar Talukder,Md. Mostofa Kamal,Ajit Kumar Jha,Farida Yeasmin Bari,Mohammed Shamsuddin 사단법인 한국동물생명공학회 2011 한국동물생명공학회지 Vol.26 No.2
Ovulation synchronization (ovsynch) has proved to increase the number of insemination in cattle by overcoming the problems of heat detection. The aim of this study was to do ovsynch in water buffaloes where heat detection is a major reproductive problem and to determine the conception rates after timed artificial insemination (TAI). Twenty cyclic buffaloes at ≥60 days postpartum were selected by examining 24 unobserved estrus buffaloes based on milk progesterone assay (progesterone concentration ≥1.0 ng/ml) from the Mymensingh district of Bangladesh. Ovsynch treatment regimen was started irrespective of the stage of estrous cycle. Gonadorelin (500μg) was injected intramuscularly at Day 0 followed by Alfaprostol (8 mg) at Day 7. A second injection of Gonadorelin was given at Day 9 and TAI was done with frozen semen from Mediterranean buffalo bulls at 16~20 hours of the second Gonadorelin injection. Milk progesterone ELISA at Day 10~12 post AI confirmed ovulation in 16 out of 20 (80%) buffaloes (progesterone concentration ≥1.0 ng/ml). High progesterone concentration (≥1.0 ng/ml) at Day 10~12 and Day 22~24 of AI showed pregnancy in six out of 20 (30%) buffaloes. Pregnancy was further confirmed by ultrasonography at Day 40 in these six buffaloes. In conclusion, ovsynch followed by TAI could be applied in cyclic buffaloes for overcoming the estrus detection problems; however, more studies are needed to increase the conception rate.
Ovulation Synchronization in Water Buffaloes Guided by Milk Progesterone ELISA
Hoque, Md. Nazmul,Talukder, Anup Kumar,Kamal, Md. Mostofa,Jha, Ajit Kumar,Bari, Farida Yeasmin,Shamsuddin, Mohammed 韓國受精卵移植學會 2011 한국동물생명공학회지 Vol.26 No.2
Ovulation synchronization (ovsynch) has proved to increase the number of insemination in cattle by overcoming the problems of heat detection. The aim of this study was to do ovsynch in water buffaloes where heat detection is a major reproductive problem and to determine the conception rates after timed artificial insemination (TAI). Twenty cyclic buffaloes at 60 days postpartum were selected by examining 24 unobserved estrus buffaloes based on milk progesterone assay (progesterone concentration 1.0 ng/ml) from the Mymensingh district of Bangladesh. Ovsynch treatment regimen was started irrespective of the stage of estrous cycle. Gonadorelin (500 ) was injected intramuscularly at Day 0 followed by Alfaprostol (8 mg) at Day 7. A second injection of Gonadorelin was given at Day 9 and TAI was done with frozen semen from Mediterranean buffalo bulls at 16~20 hours of the second Gonadorelin injection. Milk progesterone ELISA at Day 10~12 post AI confirmed ovulation in 16 out of 20 (80%) buffaloes (progesterone concentration 1.0 ng/ml). High progesterone concentration ( 1.0 ng/ml) at Day 10~12 and Day 22~24 of AI showed pregnancy in six out of 20 (30%) buffaloes. Pregnancy was further confirmed by ultrasonography at Day 40 in these six buffaloes. In conclusion, ovsynch followed by TAI could be applied in cyclic buffaloes for overcoming the estrus detection problems; however, more studies are needed to increase the conception rate.
Duration of Preservation Affect the Quality of Chilled Black Bengal Buck Semen
Pradhan, Md. Gulshan Anowar,Rahman, Md. Saidur,Kwon, Woo-Sung,Mishra, Dipendra,Kamal, Md. Mostofa,Bhuiyan, Mohammad Musharraf Uddin,Shamsuddin, Mohammed The Korean Society of Embryo Transfer 2013 한국동물생명공학회지 Vol.28 No.2
The study focuses on the quality assessment of Black Bengal buck semen preserved at chilled condition. In this in vitro trial, collected semen from Black Bengal bucks was preserved at chilling temperature ($4{\sim}5^{\circ}C$) in tris-glucosecitrate yolk medium of 1:5 ratios for four days. Artificial Vagina (AV) method was utilized to collect semen from buck. General evaluation of semen includes the color, mass activity and density were measured by direct visual examination. However, computer-assisted sperm analysis (CASA) and phase contrast microscopy were used to figure out the motility (%), hyper-activated (HYP) motility (%) and number of abnormal spermatozoa (%) initially, and at every 24 h intervals. The result revealed that spermatozoa preserved at chilling temperature showed significantly (P<0.05) lower motility and HYP motility with the progression of preservation. The number of phenotypically abnormal spermatozoa significantly (P<0.05) increased following preservation. Although significant positive correlation (r=0.945; P<0.05) was existed between % motile and % HYP motile spermatozoa however, the % of morphologically abnormal spermatozoa was negatively correlated with % motile (r=-0.997; P<0.05) and % HYP motile spermatozoa (r=-0.946; P<0.01). Therefore, we concluded that the quality of chilled semen progressively losses its viability and doesn't remain useable after certain period of preservation with respect to its motility and morphology.