Search results for "grinding"
showing 10 items of 31 documents
Preparation and Characterization of Composites Materials with Rubber Matrix and with Polyvinyl Chloride Addition (PVC)
2020
An important problem that arises at present refers to the increase in performances in the exploitation of the conveyor belts. Additionally, it is pursued to use some materials, which can be obtained by recycling rubber and PVC waste, in their structure. Thus, the research aimed at creating conveyor belts using materials obtained from the recycling of rubber and PVC waste. Under these conditions, conveyor belts were made that had in their structure two types of rubber and PVC, which was obtained by adding in certain proportions of reclaimed rubber and powder obtained from grinding rubber waste. In order to study the effect of adding PVC on properties, four types of conveyor belts were made, …
Making by Grinding: Mechanochemistry Boosts the Development of Halide Perovskites and Other Multinary Metal Halides
2019
Mechanochemical synthesis has recently emerged as a promising route for the synthesis of functional lead halide perovskites as well as other (lead‐free) metal halides. Mechanochemical synthesis presents several advantages with regards to more commonly used solution‐based processes such as an inherent lower toxicity by avoiding organic solvents and a finer control over stoichiometry of the final products. The ease of implementation, either through the use of a simple mortar and pestle or with an electrically powered ball‐mill, and low amount of side products make mechanochemical synthesis appealing for upscaling the production of halide perovskites. Due to the defect tolerance of lead halide…
Nanomanufacturing/Nanotechnology
2017
This chapter provides comprehensive knowledge regarding the fabrication of nanoproducts and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques, such as nanomachining (ultra-precision) and new trends in improving nanoprocesses taking into account AFM, laser beam machining, electron beam machining processes are overviewed. The background of nanomachining processes, including typical machining operations such as turning, milling and grinding and different construction materials (metallic and nonmetallic), is outlined. The physical mechanisms responsible for the transition from brittle to ductile regime machining are explained. Mo…
Investigation of the phase transitions occurring during and after the dehydration of xylazine hydrochloride monohydrate.
2014
This paper reports an investigation of a complex solid state phase transition where two inter-converting polymorphs (X and A) of the pharmaceutical molecule xylazine hydrochloride formed and transformed during and after the dehydration of its monohydrate (H). The crystal structures of all three forms were compared. During the investigation of this solid state phase transition it was determined that the dehydration of H produced either a pure X form, or a mixture of the X and A forms. The phase composition depended on the sample preparation procedure and the experimental conditions. It was found that grinding of the hydrate enhanced the formation of polymorph X as a product of dehydration, w…
Controlled temperature grinding under modified atmosphere for Almond (Prunus Dulcis) paste production
2011
The quality of the raw material and the processing conditions have a great influence on the nutritional properties of finished products. This research is focused on almond paste production and aims at developing a new production process to deliver the high nutritional content of the raw almonds into the finished product. Raw almonds are composed mainly of fats (approx. 50%) and proteins (approx. 25%), and are particularly rich in omega 6 fatty acids, and are hence exposed to denaturation and oxidation phenomena during the traditional grinding/homogenization process. The study involved the analysis of six different local cultivars based upon the main nutritional indicators (protein content, …
Controlled temperature grinding under modified atmosphere for Almond (Prunus Dulcis)paste production
2010
The research is focused on almond paste production and aims at developing a new production process to deliver the high nutitional content of the raw almonds into finished product
Chromatography with dense gases
1992
A capillary restrictor for supercritical fluid chromatography (SFC) with CO2 was made by using a micro torch and fine emery cloths or grinding blocks. This restrictor could be drawn out either directly from the end of the analytical capillary column, or from a short piece of any capillary, which was then connected to the analytical column by standard techniques. It was found that the base current of a flame ionisation detector (FID) depends strongly on the position of the capillary end with respect to the FID flame tip and on the CO2 grade, of course. Best results have been achieved at around 5 to 7 mm distance between the restrictor and the flame tip ends, and using SFC grade CO2.
Recyclable and Light-Adaptive Vitrimer-Based Nacre-Mimetic Nanocomposites.
2021
Nacre's natural design consists of a perfect hierarchical assembly that resembles a brick-and-mortar structure with synergistic stiffness and toughness. The field of bioinspired materials often provides attractive architecture and engineering pathways which allow to explore outstanding property areas. However, the study of nacre-mimetic materials should not be limited to the design of its architecture but ought to include the understanding, operation, and improvement of internal interactions between their components. Here, we introduce a vitrimer prepolymer system that, once integrated into the nacre-mimetic nanocomposites, cures and cross-links with the presence of Lewis acid catalyst and …
Tērvetes pilskalna akmens lejamveidnes
2017
No analizētajām Tērvetes pilskalna 25 lejamveidnēm 2 ir pusfabrikāti. 10 veidnēs liets metāls, 11 bijusas nelietotas, 2 veidnēm lietosana nav nosakāma. 10 veidnes bija t.s. vāciņi - veidnes apģērba apsuvju un piekariņu aizmugures iegūsanai. Septiņas veidnes bijusas apvērsamās - ar ielietnēm akmens plāksnīsu augsā un apaksā. Akmens plāksnītes - lejamveidnes izgatavosanas procesā ir slīpētas un atsevisķos gadījumos pulētas. Veiddobumi pārsvarā izgriezti ar nazi.---The article analyses 25 finished and semi-manufactured stone casting moulds found at the hill-fort of Tērvete, dated to the 11th–13th century. In terms of construction they all are two-part moulds. Ten moulds have been used for cast…
Comparison of Post-Weld Treatment of High-Strength Steel Welded Joints in Medium Cycle Fatigue
2010
This paper presents a comparison of three post-weld treatments for fatigue life improvement of welded joints. The objective is to determine the most suitable post-weld treatment for implementation in mass production of certain crane components manufactured from very high-strength steel. The processes investigated are: burr grinding, TIG dressing and ultrasonic impact treatment. The focus of this investigation is on the so-called medium cycle area, i.e. 10 000-500 000 cycles and very high stress ranges. In this area of fatigue design, the use of very high strength steel becomes necessary, since the stress range can exceed the yield-strength of ordinary structural steel, especially when consi…