76 research outputs found
Guidelines to the implementation of printing vocational schools in Nigeria
This study is concerned with the implementation of printing vocational high schools in Nigeria. It has been too long a wait for the implementation of vocational schools in printing. The methodology of this study is based on the information gathered through personal interviews. The head of the schools teaching printing, the production manager, or the president or vice president of printing companies in both New York City and Rochester responded to the questions that appear in appendices C and D. For details see Tables 1 through 10. Also library research was employed to obtain background information on the American voca tional program such as justifications for their needs. Library resources provided information on the existence of similar programs in a developing nation. The training of young men and women should be transferred from the individual printers or Masters because of its disadvantages, including the lack of uniformity of training, the lack of standar dization, and self-interest. Vocational education could be the answer to the formal education of Graphic Arts (printing), and the printing industry. The government should gear its effort toward the establishment of at least one school of printing for experimentation in each of the nineteen states in the federation. The success of the implementation is of benefit to all. Some of the future national problems will be solved to a greater extent by the provision of craftsmen to the industry. The study is not peculiar to the printing industry but also could be used as a model for other trades. In the short run, little effort will be needed to train young people for entrance into the printing field. In the long run, it will pay for itself. Courses and content, type of equipment, etc. are recommended. If these recommendations are strictly adhered to, most of the prob lems will be solved. Courses of instruction should include the following: Introduction to Graphic Occupation, Prepress Operation, Presswork for both Letterpress and Lithographic Process of Printing, Bindery Operations, Preparation for Employment, and Co-op (work-study program) . Committees include the National Technical Committee for Printing Education, Curriculum Committee, Industrial Committee and the Parents\u27 Body. These committees should advise and administer the implementa tion of these printing schools. The federal government, the printing industry and the public are therefore called upon to see the need of vocational high schools for printing in Nigeria. The result of the study shows that the vocational printing high school is satisfactory as an entry level to the printing industry. Schools train better than individual printers, therefore, we should not wait indefinitely for the implementation of the vocational print ing school at the high school level in Nigeria. If the United States had waited as long as we are waiting, we should be categorized together as the Third World
Development of a Sludge Dewatering Filter and Utilization of Dried Sludge in Brick Making
These A dewatering filter was designed and constructed to dewater sludge collected from Eleyele waterworks using slow sand filtration. Washed sand passing through sieve mesh size of 1.18 mm was used as the filter media. The flow rate of the filtrate was monitored for six (6) days and readings were taken at 30-minute intervals for 6 hours after each sludge loading of 15 L. The dewatered and dried sludge was investigated for use as brick material. The sludge and laterite samples were characterized using Atomic Absorption Spectroscopy. The major chemical components of the sludge and laterite samples were silicon, aluminium and iron oxides. The laterite soil sample consisted of 60.47% SiO2, 17.77% Al2O3 and 8.18% Fe2O3 while the sludge sample consisted of 52.98% SiO2, 29.46% Al2O3 and 3.63% Fe2O3. Batching method by weight was used in mixing the materials in the ratios of sludge at 0%, 15% and 30% to produce laboratory scale bricks with dimensions of 70 mm by 70 mm by 70 mm and the properties of the bricks were investigated. The average compressive strength of the laterite bricks with dried sludge content of 0%, 15% and 30% were 3.15 N/mm2, 3.08 N/mm2 and 2.64 N/mm2, respectively. The results of this research demonstrated that a locally constructed sludge dewatering filter can be used to thicken waterworks sludge and laterite-sludge can be made from dewatered water works sludge.Keywords—Compressive strength, bricks, filter, media slow sand filtration, waterworks sludg
Actin remodeling in regulated exocytosis: toward a mesoscopic view
Cellular communication relies on fusion of secretory vesicles with the plasma membrane, following dynamic events that change the micro- and nanoscale environment of the approaching vesicles in the vicinity of docking sites. Visualization of fine cortical actin network structures and their interactions with vesicle and plasma membrane has recently been facilitated by the development of new imaging technologies. Consequently, a greater understanding is emerging of the role of the cortical actin network on controlling secretory vesicles as they undergo docking, priming, and fusion in exocytic hot spots. In this review, we propose a mechanistic framework underpinning the mesoscopic properties of the cortical actin and discuss how molecular coupling of these pleiotropic effects orchestrate every single step of regulated exocytosis
Need for speed: Super-resolving the dynamic nanoclustering of syntaxin-1 at exocytic fusion sites
Communication between cells relies on regulated exocytosis, a multi-step process that involves the docking, priming and fusion of vesicles with the plasma membrane, culminating in the release of neurotransmitters and hormones. Key proteins and lipids involved in exocytosis are subjected to Brownian movement and constantly switch between distinct motion states which are governed by short-lived molecular interactions. Critical biochemical reactions between exocytic proteins that occur in the confinement of nanodomains underpin the precise sequence of priming steps which leads to the fusion of vesicles. The advent of super-resolution microscopy techniques has provided the means to visualize individual molecules on the plasma membrane with high spatiotemporal resolution in live cells. These techniques are revealing a highly dynamic nature of the nanoscale organization of the exocytic machinery. In this review, we focus on soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) syntaxin-1, which mediates vesicular fusion. Syntaxin-1 is highly mobile at the plasma membrane, and its inherent speed allows fast assembly and disassembly of syntaxin-1 nanoclusters which are associated with exocytosis. We reflect on recent studies which have revealed the mechanisms regulating syntaxin-1 nanoclustering on the plasma membrane and draw inferences on the effect of synaptic activity, phosphoinositides, N-ethylmaleimide-sensitive factor (NSF), α-soluble NSF attachment protein (α-SNAP) and SNARE complex assembly on the dynamic nanoscale organization of syntaxin-1
Subdiffractional tracking of internalized molecules reveals heterogeneous motion states of synaptic vesicles
Arterial Function in patients with diabetes mellitus undergoing coronary artery bypass grafting
Control of neurotransmission by diffusional properties of a presynaptic plasma membrane protein - syntaxin1A
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