Number Of Processing Factors Research Articles

Formulation Development and Evaluation of Apremilast Nanoemulgel for Enhancing Permeability

Background: Oral apremilast, a selective phosphodiesterase-4 inhibitor, is effective in the treatment of moderate to severe plaque psoriasis and acute psoriatic arthritic disease. According to BCS categorization, it is a class IV medication, which denotes low solubility and lesser permeability through the skin. Objective: The objective of the research is to develop a nanoemulsion that will increase apremilast’s skin permeability. Utilizing a simplex lattice design, an optimised nanoemulsion has been developed, and then transformed into a gel form and created as a nanoemulgel. Method: The nanoemulsion was developed by selecting the oil, surfactant, co-surfactant, and cosolvent, in that order, based on the solubility study, and was then evaluated based on various criteria. Different grades and concentrations of carbopol polymer were used to make nanoemulgel, which was then tested for physicochemical parameters like pH, viscosity, spreadability, extrudability, percentage of drug content, percentage of drug diffusion, skin permeation, and skin retention. For skin irritancy tests, male Wistar albino rats weighing between 200 and 250 g were used to find out how likely it was that apremilast-loaded nanoemulgel would cause skin irritation. Result: The nanoemulsion formulation A5 containing 10% Captex 355 and 40% Smix in a 3:1 ratio of Cremophore RH 40: Labrafil showed the smallest particle size and greatest drug diffusion. In comparison to other formulations of emulgel, the 0.75 % concentration of carbopol 940 produced the best results. Conclusion: A stable nanoemulgel system with apremilast loaded was created, and a number of process factors were assessed. The optimised batch produced repeatable results when evaluated, exhibited no skin irritation, and was shown to be stable after three months at ambient conditions of temperature and humidity.

Регулирование скоростей электроприводов клети толстолистового прокатного стана в режиме формирования «лыжи»

Задача формирования изгиба переднего конца раската в форме «лыжи» является актуальной для электроприводов клетей толстолистовых прокатных станов. Неконтролируемый изгиб раската вверх может привести к повреждению оборудования клети, изгиб вниз - к ударам и застреванию при транспортировке по рольгангу. На основании анализа литературных источников установлено, что причинами неконтролируемого изгиба переднего конца могут быть множество технологических факторов. Основными являются несоответствие скоростей верхнего и нижнего валков, температурный градиент по толщине раската, различие коэффициентов трения и др. Рассогласование скоростей, помимо влияния на форму раската, определяет соотношение моментов электроприводов валков. На примере горизонтальной клети стана 5000 ПАО «Магнитогорский металлургический комбинат» (ПАО «ММК») показано, что при прокатке тяжелых профилей моменты двигателей могут отличаться в три раза. При этом по мере уменьшения толщины раскатов по проходам соотношение нагрузок главных электроприводов верхнего и нижнего валков (ВГП и НГП) меняется на противоположное. Для согласования скоростных и нагрузочных режимов в систему включен регулятор деления нагрузок (РДН). Недостатком является то, что он осуществляет регулирование нагрузок в функции разницы скоростей ВГП и НГП. Представлены осциллограммы, подтвердившие невозможность обеспечения заданного соотношения скоростей в динамическом режиме, возникающем при входе металла в клеть. Для устранения недостатка разработан способ управления электроприводами, согласно которому регулирование скоростей в режиме лыжеобразования осуществляется пропорционально разности сигналов заданий на входах регуляторов скоростей ВГП и НГП. Представлена структурная схема, поясняющая реализацию способа путем включения на вход РДН дополнительного регулятора согласования скоростей. Приведена схема имитационной модели электромеханических систем верхнего и нижнего валков, взаимосвязанных через металл. В результате моделирования установлено, что реализация способа обеспечивает рассогласование скоростей на уровне, близком к заданному, в течение всего времени формирования «лыжи». Алгоритм управления, реализующий разработанный способ, внедрен в АСУ клети стана 5000. Представлены осциллограммы, подтвердившие основные теоретические выводы. Разработанный алгоритм позволяет снизить задание «лыжи» более чем в два раза. За счет этого происходит повышение точности геометрии и сокращение длины изогнутого участка, что обеспечивает меньшее рассогласование моментов двигателей ВГП и НГП и более быстрое их выравнивание. Помимо разгрузки электродвигателей по моменту это обеспечивает повышение их КПД.

Experimental investigations on WEDM process for machining High Manganese steel

ABSTRACT High Manganese steel ASTM A128 is a very hard metal and production of components using a conventional machining process is very difficult and also the quality of the products are not favorable for the efficient function. Wire Electrical Discharge Machining (WEDM) is an emanating approach in the non-conventional machining process to produce intricate products with more accurate and precise. The WEDM process is affected by the number of process factors. Hence, appropriate process factor combination is necessary for achieving economical and quality machining. In this investigation, the process factors which include Peak-current Wire-feed, Open-circuit voltage, and Time-off have been considered and Central Composite Design (CCD) was implemented to layout the exploration. Response Surface Methodology (RSM) was utilized to learn the correlation between process factors and to develop mathematical models for responses which include Surface roughness Ra, Rq and Rz, Hardness, and Material Removal Rate (MRR). Analysis of Variance (ANOVA) scrutiny unveiled that the factor Peak-current is the foremost influencing process factor for MRR and Surface roughness parameters. Open-circuit voltage and Wire-feed are the primary influencing process factors for Hardness. The results of verification test showed that the developed mathematical models were good with sufficient accuracy.

Optimization of Siderite Ore Sintering Operation Conditions

Research was сarried out on a pilot plant on sintering of various size siderite ore and limonite taken in various ratios. To study impact of a number of process factors on the sintering process performance and the obtained agglomerate quality at the minimum number of the carried out experiments, one of the experiment planning methods was used, and regression equations were derived. With these equations the effect of the ore size, siderite ore and limonite ratio, solid fuel consumption, sintered layer height on the agglomeration unit performance and the agglomerate metallurgical properties was reviewed. The obtained work results have great practical importance, as they allow optimization of siderite ore sintering operation conditions and production of high quality agglomerate. They may be used at a variety of the country agglomeration factories, where siderite ores will be used as iron ore component of the sinter burden.

Effect of Honing Parameters on Generated Surface Quality of Cylinder Liner within Automotive Engine Production

One of the key parameter in evaluation of cylindrical surface quality of the engine liners is surface roughness. A large number of process factors affecting a final surface topography, which has direct impact on fuel consumption and CO2 emission. A suitable choice of honing conditions can results not only to better surface quality, but it can contributes to reducing of environmental impacts in automobile transport. Twelve different engine cylinder liners were machined in various combinations of cutting parameters. Experimental testing was realised on real production machine tool, where process factors were cutting speed, machining allowance and stone pressure of honing tool. All factors have 4 levels and parameters of surface roughness CR, CF, CL were selected as a variables and suitable indicators for surface quality assessment. The results show that influence of the tool stone pressure on honed surface is more significant than effect of cutting speed. Effect of machining allowance is negligible as well.

Improving the yield of steel plates by updating the slab design with statistical models

The purpose of this study was to improve the dimensional accuracy of steel plate by updating the selection of combination parameters for slab design with statistical models. The generalised boosted regression model and the generalised additive models were used to predict the dimensional properties of the combination parameters with process factors. For real-life application, the modelling results were utilised to determine new combination parameter classes containing a larger number of process factors instead of only one. The research increased the knowledge of material sufficiency and the factors behind it. As a result, the new selection procedure is expected to increase yield and reduce the risk of rejection.

Leaching kinetics of ionic rare-earth in ammonia-nitrogen wastewater system added with impurity inhibitors

Ammonia-nitrogen wastewater is produced during the dressing and smelting process of rare-earth ores. Such wastewater includes a very high concentration of NH4+, as well as other ions (e.g., NH4+, RE3+, Al3+, Fe3+, Ca2+, Cl−, and SiO32–) with a pH of 5.4–5.6. Its direct discharge will pollute, yet it can be recycled and used as a leaching reagent for ionic rare-earth ores. In this study, leaching kinetics studies of both rare earth ions and impurity ion Al3+ were conducted in the ammonia-nitrogen wastewater system with the aid of impurity inhibitors. Results showed that the leaching process of rare-earth followed the internal diffusion kinetic model. When the temperature was 298 K and the concentration of NH4+ was 0.3 mol/L, the leaching reaction rate constant of ionic rare-earth was 1.72 and the apparent activation energy was 9.619 kJ/mol. The leaching rate was higher than that of conventional leaching system with ammonium sulfate, which indicated that ammonia-nitrogen wastewater system and the addition of impurity inhibitors could promote ionic rare-earth leaching. The leaching kinetic process of impurity Al3+ did not follow either internal diffusion kinetic model or chemical reaction control, but the hybrid control model which was affected by a number of process factors. Thus, during the industrial production the leaching of impurity ions could be reduced by increasing the concentration of impurity inhibitors, reducing the leaching temperature to a proper range, accelerating the seepage velocity of leaching solution, or increasing the leaching rate of rare earths.

Development and experimental validation of an analytical model to predict the demoulding force in hot embossing

During the demoulding stage of the hot embossing process, the force required to separate a polymer part from the mould should be minimized to avoid the generation of structural defects for the produced micro structures. However, the demoulding force is dependent on a number of process factors, which include the material properties, the demoulding temperature, the polymer pressure history and the design of the mould structures. In particular, these factors affect the chemical, physical and mechanical interactions between a polymer and the replication master during demoulding. The focus of the reported research is on the development and validation of an analytical model that takes into account the adhesion, friction and deformation phenomena to predict the required demoulding force in hot embossing under different processing conditions. The results indicate that the model predictions agree well with the experimental data obtained and confirm that the design of the mould affects the resulting demoulding force. In addition, the applied embossing load was observed to have a significant effect on demoulding. More specifically, the increase in pressure within the polymer raises the adhesion force while it also reduces the friction force due to the decrease in the thermal stress.

The Time Course of Lemma Retrieval in Lexical Decision Tasks

The time course of lemma retrieval was assessed in lexical decision tasks with semantic and syntactic priming using monomorphemic English nouns, verbs, and ambiguous word forms. The results showed distinct processing patterns associated with different syntactic categories. The findings suggest that among other factors lemma retrieval is affected by different types of constraints working on entity/event construal. The findings can be used to propose a view according to which a lemma represents an activation state triggered by a number of processing factors, such as conventionalized conceptual architecture of a lexical item and its relative activation threshold.