Adjustment of precompression force to reduce mixing-time dependence of tablet tensile strength

The effects of mixing conditions, i.e; mixing speed and mixing duration on the mechanical properties of the magnesium based composites were investigated. The hardness, tensile strength and microstructure of composites were studied. It was found that increase of the mixing speed and prolong the mixing time can improved the distribution of SiC particle and mechanical properties of magnesium based composites.

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RIDER distortions in the CODEX experiments

10.5194/mr-2020-23 ◽

2020 ◽

Author(s):

Alexey Krushelnitsky ◽

Kay Saalwächter

Keyword(s):

Time Dependence ◽

Mixing Time ◽

Dipolar Interaction ◽

Quantitative Information ◽

Back Exchange ◽

Rocking Motion ◽

Time Dependencies ◽

Millisecond Time Scale ◽

Rigid Model ◽

Spin Flips

Abstract. CSA and dipolar CODEX experiments enable obtaining abundant quantitative information on the reorientation of the CSA and dipolar tensors on the millisecond-second time scales. At the same time, proper performance of the experiments and data analysis can often be a challenge since CODEX is prone to some interfering effects that may lead to incorrect interpretation of the experimental results. One of the most important such effects is RIDER (Relaxation Induced Dipolar Exchange with Recoupling). It appears due to the dipolar interaction of the observed X-nuclei with some other nuclei, which causes an apparent decay in the mixing time dependence of the signal intensity reflecting not molecular motion but spin-flips of the adjacent nuclei. This may hamper obtaining correct values of the parameters of molecular mobility. In this contribution we consider in detail the reasons, why the RIDER distortions remain even under decoupling conditions and propose measures to eliminate them. Namely, we suggest the additional Z-filter between the cross-polarization section and the CODEX recoupling blocks, which suppresses the interfering anti-phase coherence responsible for the X-H RIDER. The experiments were conducted on rigid model substances as well as microcrystalline 2H/15N-enriched proteins (GB1 and SH3) with a partial back-exchange of labile protons. Standard CSA and dipolar CODEX experiments reveal a fast decaying component in the mixing time dependence of 15N nuclei in proteins, which can be interpreted as a slow overall protein rocking motion. However, the RIDER-free experimental setup provides flat mixing time dependencies meaning that the studied proteins do not undergo global motions on the millisecond time scale.

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Bioplastik Berbasis Galaktomanan Hasil Ekstraski Ampas Kelapa Dengan Campuran Polyvinyl Alkohol

METANA ◽

10.14710/metana.v15i2.24892 ◽

2019 ◽

Vol 15 (2) ◽

pp. 71-78

Author(s):

Nofita Sari ◽

Maudy Mairisya ◽

Riska Kurniasari ◽

Sari Purnavita

Keyword(s):

Tensile Strength ◽

Water Resistance ◽

Mixing Time ◽

Extraction Process ◽

Synthetic Polymer ◽

Polymer Materials ◽

Natural Polymer ◽

Optimum Conditions ◽

Short Time ◽

Degradation Time

Penelitian ini bertujuan untuk mendapatkan kondisi optimum yang meliputi luas permukaan dan jumlah solven pada proses ekstraksi galaktomanan dari ampas kelapa terhadap yield yang dihasilkan dan mendapatkan kondisi optimumpada proses pembuatan bioplastik yang meliputi jumlah sorbitol dan waktu pencampuran terhadap karakteristik bioplastik yang meliputi ketebalan, ketahanan air, kuat tarik, elongasi, waktu degradasi dan morfologi.Bioplastik merupakan plastik yang dapat diuraikan oleh mikroorganisme dalam waktu yang singkat, sehingga lebih ramah lingkungan dibandingkan plastik konvensional.Bioplastik terbuat dari bahan polimer alami seperti pati, selulosa atau lemak.Penelitian pembuatan bioplastik ini berbasis dari galaktomanan ampas kelapa dan PVA. Galaktomanan merupakan polimer alami yang memiliki kemampuan membuat lapisan film.Polyvinyl alkohol (PVA) merupakan polimer sintetik namun memiliki sifat mudah larut dalam air sehingga dapat digunakan sebagai bahan campuran pembuatan bioplastik. PVA juga mampu meningkatkan elastisitas dan kuat tarik bioplastik. Penelitian ini menghasilkan bioplastik dengan ketebalan terbaik 0,18 mm dan prosentase ketahanan air tertinggi 74,76%. Tensile strength bioplastik terbaik dengan nilai 7,55 MPa, sedangkan prosentase elongation terbaik 46,81%. Bioplastik pada penelitian ini memiliki titik leleh (MP) 120°C dan terdegradasi sempurna dalam 24 jam. This study aims to obtain optimum conditions which are including surface area and amount of solvent in the galactomannan extraction process from coconut pulp to the produced yield and obtaining the optimum conditions in the bioplastic manufacturing process which are included the amount of sorbitol and mixing time of the bioplastic characteristics including thickness, water resistance, tensile strength, elongation, degradation time and morphology. Bioplastics are plastics that can be decomposed by microorganisms in a short time, making them more environmentally friendly than conventional plastics bioplastics made from natural polymer materials such as starch, cellulose, or fat. The research in making bioplastics was based on galactomannan coconut pulp and PVA. Galactomannan is a natural polymer that can make film layers. Polyvinyl alcohol (PVA) is a synthetic polymer but has properties that are soluble in water so it can be used as a mixture of bioplastics. PVA is also able to increase the elasticity and strong pull of bioplastics. This study produced bioplastics with the best thickness of 0,18mm and the highest percentage of water resistance in 74,76%. The best bioplastic tensile strength at 7,55 MPa value, while the best percentage of elongation 46,81%. Bioplastics in this study had a melting point (MP) of 120 ° C and were degraded correctly in 24 hours.

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Effects of Mixing Parameters on Tensile Strength of TPU/NR Blends

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.291-294.2654 ◽

2013 ◽

Vol 291-294 ◽

pp. 2654-2656

Author(s):

Nor Azwin Ahad ◽

Sahrim Hj Ahmad ◽

Norazwani Muhammad Zain

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Natural Rubber ◽

Polymer Blends ◽

Mixing Time ◽

Thermoplastic Polyurethane ◽

Mixing Times ◽

Melt Mixing ◽

Mixing Parameters ◽

The Poor

The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) were prepared via melt mixing technique, at four different blending temperature at range 180°C - 210°C and mixing times of 8, 10, 12, 14 min. The effects of both mixing parameters on tensile strength of the blends were investigated. The blend of 85TPU15NR shows the maximum tensile strength at 180°C and 10 min mixing. The viscosity of the polymer blends will decrease as the temperature increased. The movements of molecules are more worthy because of the poor molecules interaction. The increasing of mixing time will increase the compatibility of the blends and also increase in mechanical properties. Mixing time and mixing temperature are important parameters in acquiring blends having optimum mechanical properties.

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Dependence of Punch Sticking on Compaction Pressure—Roles of Particle Deformability and Tablet Tensile Strength

Journal of Pharmaceutical Sciences ◽

10.1016/j.xphs.2017.04.059 ◽

2017 ◽

Vol 106 (8) ◽

pp. 2060-2067 ◽

Cited By ~ 15

Author(s):

Shubhajit Paul ◽

Kunlin Wang ◽

Lisa J. Taylor ◽

Brendan Murphy ◽

Joseph Krzyzaniak ◽

...

Keyword(s):

Tensile Strength ◽

Compaction Pressure ◽

Tablet Tensile Strength

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Processing of Clay/Epoxy Nanocomposites with A Three-Roll Mill Machine

MRS Proceedings ◽

10.1557/proc-740-i3.7 ◽

2002 ◽

Vol 740 ◽

Cited By ~ 17

Author(s):

Asma Yasmin ◽

Jandro L. Abot ◽

Isaac M. Daniel

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Mixing Time ◽

Clay Content ◽

Epoxy Nanocomposites ◽

Clay Particles ◽

Roll Mill ◽

Short Period ◽

Mixing Techniques ◽

Xrd And Tem

ABSTRACTIn the present study, a three-roll mill machine was used to disperse/exfoliate the nanoclay particles in an epoxy matrix. The compounding process was carried out with varying mixing time and concentrations of clay particles (1 to 10 wt.%). It was found that the longer the mixing time, the higher the degree of intercalation. Mechanical properties, XRD and TEM were used to characterize the nanocomposites. Elastic modulus was found to increase with increasing clay content, however, the tensile strength was not found to vary accordingly. Compared to conventional direct and solution mixing techniques, the compounding of clay/epoxy nanocomposites by a three-roll mill was found to be highly efficient in achieving higher levels of intercalation/exfoliation in a short period of time and also environmentally friendly.

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