162,771 research outputs found

    SINTESIS DAN KARAKTERISASI FILMSELULOSA/GLISEROL DENGAN PENAMBAHAN MINYAK KAYU MANIS (Cinnamomum cassia)SEBAGAI PENGEMAS CABAI

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    Tujuan penelitian ini adalah untuk mengetahui karakterisasi film selulosa dengan penambahan gliserol dan minyak kayu manis berdasarkan karakterisasi uji mekanik, foto permukaan, dan uji ketahanan terhadap air, mengetahui efektivitas film selulosa dengan penambahan gliserol dan minyak kayu manis yang memiliki daya simpan cabai paling baik. Metode yang digunakan yaitu metode casting dan metode coating. Metode casting menggunakan larutan HCl 5% untuk hidrolisis selulosa. Proses pengeringan film selulosa dengan metode casting adalah pada suhu 60oC selama 5 jam. Perbandingan konsentrasi gliserol dan minyak kayu manis yang digunakan dalam pembuatan film selulosa dengan metode coating adalah 3:1; 5:1; 7:1; dan 10:1. Film selulosa hasil sintesis dikarakterisasi menggunakan tensile strength, mikroskop optik, FTIR-ATR, ketahanan terhadap air, dan efektivitas film. Hasil penelitian menunjukkan bahwa perbandingan konsentrasi gliserol dan minyak kayu manis terbaik adalah 3:1 dengan nilai elongasi 21,3843%, modulus young 66,4602 MPa, ketahanan terhadap air 38,86%, foto permukaan yang paling homogen, dan efektivitas film yang paling bai

    A solution concentration dependent transition from self-stratification to lateral phase separation in spin-cast PS:d-PMMA thin films

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    Thin films with a rich variety of different nano-scale morphologies have been produced by spin casting solutions of various concentrations of PS:d-PMMA blends from toluene solutions. During the spin casting process specular reflectivity and off-specular scattering data were recorded and ex situ optical and atomic force microscopy, neutron reflectivity and ellipsometry have all been used to characterise the film morphologies. We show that it is possible to selectively control the film morphology by altering the solution concentration used. Low polymer concentration solutions favour the formation of flat in-plane phase-separated bi-layers, with a d-PMMA-rich layer underneath a PS-rich layer. At intermediate concentrations the films formed consist of an in-plane phase-separated bi-layer with an undulating interface and also have some secondary phase-separated pockets rich in d-PMMA in the PS-rich layer and vice versa. Using high concentration solutions results in laterally phase-separated regions with sharp interfaces. As with the intermediate concentrations, secondary phase separation was also observed, especially at the top surface

    Replacing Color-Blind Casting with Color-Conscious Casting: A New Roadmap to Diversity in Performing Arts

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    The American theatre and film industry has suffered from institutional racism where practices such as whitewashing were common. Beginning in the 1960s and 1970s, the term color-blind casting emerged to supposedly make theatre and film more inclusive and welcoming to people of all ethnicities. However, color-blind casting has done more harm to marginalized communities by disregarding their historical experiences and oppression. Therefore, instead of encouraging color-blind casting in performing arts, the industry should move towards color-conscious casting, a casting technique in which actors’ ethnicities and historical experiences are taken into consideration. The poster will demonstrate the negative aspects of color-blind casting including unequal pay, unacknowledgement of historical racism, and the oppression of actors of color. My poster will present color-conscious casting as the future-thinking roadmap for diversity by acknowledging the role of race in an inclusive performing arts industry. Sources include Johnny Depp\u27s Lone Ranger and Alec Guinness as Prince Faisal.https://ecommons.udayton.edu/stander_posters/3651/thumbnail.jp

    In-situ cross linking of polyvinyl alcohol

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    A method of producing a crosslinked polyvinyl alcohol structure, such as a battery separator membrane or electrode envelope is described. An aqueous solution of a film-forming polyvinyl alcohol is admixed with an aldehyde crosslinking agent a basic pH to inhibit crosslinking. The crosslinking agent, perferably a dialdehyde such as glutaraldehyde, is used in an amount of from about 1/2 to about 20% of the theoretical amount required to crosslink all of the hydroxyl groups of the polymer. The aqueous admixture is formed into a desired physical shape, such as by casting a sheet of the solution. The sheet is then dried to form a self-supporting film. Crosslinking is then effected by immersing the film in aqueous acid solution. The resultant product has excellent properties for use as a battery separator

    Manufacture of DPFC-DMS polymer in the SKG range

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    BPFC-DMS block copolymers were synthesized on a pre-pilot scale (i.e., to 5 Kg lots) and subsequently fabricated into clear, colorless films. Details of the synthesis procedures, property determinations, and film casting techniques are presented. Solubility, viscosity and molecular weight characteristics of the resulting product are reported

    An Experimental and Numerical Study of the Film Casting Process

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    Film casting is a common industrial process used to produce polymeric films. During film casting, a polymer melt is extruded through a flat die before rapid cooling on a chill roll. The chill roll velocity is faster than the velocity at which the melt exits the die, thus the polymer melt is stretched and oriented in an extensional flow. The material properties and processing conditions have a significant impact on the process and the final thermal/mechanical properties of the film produced. Optimization of industrial scale film casting processes is still greatly dependent on trial and error methods. Therefore, this work is motivated primarily by the vision of the Center for Advanced Engineering Fibers and Films (CAEFF) to provide industry partners with computer-aided simulation methods for the design and optimization of future film casting processes. This work is unique in that it employs an integrated experimental and modeling research approach towards the investigation of the film casting process. Experimentally, we study the film development in the air-gap between the die and the chill roll, and the final film properties. The modeling uses parameters such that the physical conditions under which the film casting experiments are conducted are identical to the experiments. The model inputs are directly derived from the rheological and thermal characterization of the polymeric materials used in the experiments. Therefore, this work provides a comprehensive set of experimental data, coupled with some simulations, which contribute towards a more detailed understanding of the film casting process. In this work, we experimentally investigate the impact of material properties (such as polymer viscosity) and process conditions (such as die temperature, draw ratio and air-gap length) on the film formation process in the region between the die exit and the chill roll. Experiments are conducted using polypropylene, and a full thermal and rheological characterization of these materials is used both to interpret the experimental results and to provide parameters for the subsequent simulations. The effect of secondary processing steps, such as uniaxial stretching, on film strength, orientation and crystallinity is also studied. Finally, the measured width, temperature and velocity profiles are compared to model predictions. The machine direction (vx) and transverse direction (vy) velocity components are measured as a function of position in the air-gap. We believe that these are the first pointwise measurements of the vy velocity component in film casting using the LDV technique. The vy velocity component is a result of the film neck-in, and is seen to decrease from the film edges to the centerline. Calculated centerline strain rates are found to depend on the draw ratio due to the effects of the resistance to flow as the film cools near the chill roll and the tension applied to the film as draw ratio is increased. An increase in the die temperature, or a decrease of the material molecular weight, causes an increase in film neck-in due to the reduced resistance to flow. Increasing the air-gap length also increases the neck-in. This is due to the reduction of the strain rate (Deborah number) as the air-gap length is increased. Increasing the draw ratio results in an increase in the temperature drop in the air-gap region. This observation is due to improved heat transfer from the film as a result of the decrease in film thickness as draw ratio is increased. Temperature maps show a minimum in the temperature in the central portions of the film, as the chill roll is approached, due to the formation of edge beads at the film edges. The Primary film samples produced on the take-up roll are found to possess the mesomorphic crystalline morphology of isotactic polypropylene. This is attributed to the quenching action of the chill roll. Increasing the draw ratio slightly increases the crystalline content of the Primary film due to the decrease in the film temperature at the chill roll. Uniaxial stretching increases the moduli of the film due to the increase in film orientation and the effect on the film crystalline morphology. The stretching conditions also impact the film properties. The wealth of experimental data generated during the course of this work is employed in the verification of the CAEFF FISIM 2D Cast Film Model. The experimental results are used as an indicator of the success of the model in capturing the primary physical characteristics of the film casting process. Using model parameters obtained directly from the thermal and rheological characterization of the polymer materials, and identical process variables to the experiments, we find that the model captures the qualitative effect of draw ratio, die temperature and polymer viscosity on the film geometry. The model also predicts the temperature drop and velocity profiles in the web

    SINTESIS DAN KARAKTERISASI FILM SELULOSA-PEG (Polyethylene Glycol) 400 DENGAN PENAMBAHAN MINYAK ADAS SEBAGAI PENGEMAS BUAH DAN SAYUR

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    Penelitian ini bertujuan untuk 1) mengetahui karakteristik film selulosa terbaik dengan penambahan PEG 400 dan minyak adas berdasarkan karakterisasi menggunakan uji mekanik, foto permukaan, dan uji ketahanan air, 2) mengetahui hasil efektivitas film selulosa terbaik dengan penambahan PEG 400 dan minyak adas terhadap daya simpan cabai. Pembuatan film selulosa menggunaan 2 metode yaitu metode casting dan metode coating. Pembuatan film selulosa-PEG 400 dengan metode casting menggunakan pelarut HCl 5% dan dikeringkan di dalam oven pada suhu 50 selama 5 jam. Sedangkan metode coating digunakan untuk membuat film selulosa-PEG 400, film selulosa-minyak adas, dan film selulosa PEG 400-minyak adas dengan berbagai variasi minyak adas dan PEG 400. Variasi minyak dan pemlastis yang digunakan yaitu 3:1, 5:1, 7:1, 10:1, dan 15:1 . Pada metode coating, pengeringan film dilakukan dengan cara diangin-anginkan. Film selulosa-PEG 400 metode casting memliki tekstur rapuh, kasar, tidak transparan, berwarna coklat. Sedangkan film selulosa yang dibuat dengan metode coating berbentuk lembaran transparan berwarna putih kecoklatan. Hasil uji sifat mekanik dan ketahanan air menunjukkan film selulosa terbaik yaitu film selulosa PEG 400-minyak adas pada komposisi 7:1. Film selulosa ini memiliki nilai persen perpanjangan saat putus 13,9351% , kuat tarik 25,2311 Mpa, modulus young 181,061 Mpa, dan nilai ketahanan air sebesar 27,45%. Hasil uji efektivitas menunjukkan bahwa film selulosa PEG 400-minyak adas 7:1 mampu memperpanjang umur simpan cabai. Cabai yang dikemas selama 38 hari memiliki perubahan fisik yaitu tekstur kusut dan agak kering, warna cabai merah, tidak tumbuh jamur, dan tidak busuk

    Location Decisions in a Changing Labour Market Environment

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    We study the location of various film-related services (such as camera rental, casting agencies or pyrotechnic services), the main determinant of interest being the human capital specificity. We show that firms which supply services with a lower firm specificity locate farther away from one another, and argue that it can be concluded that the "poaching" argument (fear of employees leaving for a competitor in large regional labour markets) has greater practical weight than the Marshallian labour pooling mechanismagglomeration, film industry, flexible specialisation, labour pooling, poaching, regional labour markets, turnover
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