Physical Modeling of the Impeller Construction Impact on the Aluminum Refining Process

Obtaining high-quality aluminum is associated with the use of an effective method of refining, which is argon-purging, in which gas bubbles are introduced into the liquid metal by means of rotary impellers. Various rotary impellers are used in the industry; however, if a newly designed impeller is constructed, it should be tested prior to industrial use. For this purpose, physical modeling is used, which enables the investigation of the phenomena occurring during refining and the selection of optimal processing parameters without costly research carried out in the industry. The newly designed rotary impeller was tested on the physical model of a URO-200 batch reactor. The flow rate of refining gas was: 10, 15 and 20 dm3·min−1, whereas rotary impeller speed was 300, 400 and 500 rpm. The research consists of a visualization test showing the schemes of the gas bubbles’ dispersion level in the liquid metal and experiments for removing oxygen from water, which is an analogue of removing hydrogen from aluminum.

An Overview of Molecular Dynamics Simulation for Food Products and Processes

Molecular dynamics (MD) simulation is a particularly useful technique in food processing. Normally, food processing techniques can be optimized to favor the creation of higher-quality, safer, more functional, and more nutritionally valuable food products. Modeling food processes through the application of MD simulations, namely, the Groningen Machine for Chemical Simulations (GROMACS) software package, is helpful in achieving a better understanding of the structural changes occurring at the molecular level to the biomolecules present in food products during processing. MD simulations can be applied to define the optimal processing conditions required for a given food product to achieve a desired function or state. This review presents the development history of MD simulations, provides an in-depth explanation of the concept and mechanisms employed through the running of a GROMACS simulation, and outlines certain recent applications of GROMACS MD simulations in the food industry for the modeling of proteins in food products, including peanuts, hazelnuts, cow’s milk, soybeans, egg whites, PSE chicken breast, and kiwifruit.

Development on advanced technologies – design and development of cloud computing model

Big Data has been created from virtually everything around us at all times. Every digital media interaction generates data, from computer browsing and online retail to iTunes shopping and Facebook likes. This data is captured from multiple sources, with terrifying speed, volume and variety. But in order to extract substantial value from them, one must possess the optimal processing power, the appropriate analysis tools and, of course, the corresponding skills. The range of data collected by businesses today is almost unreal. According to IBM, more than 2.5 times four million data bytes generated per year, while the amount of data generated increases at such an astonishing rate that 90 % of it has been generated in just the last two years. Big Data have recently attracted substantial interest from both academics and practitioners. Big Data Analytics (BDA) is increasingly becoming a trending practice that many organizations are adopting with the purpose of constructing valuable information from BD. The analytics process, including the deployment and use of BDA tools, is seen by organizations as a tool to improve operational efficiency though it has strategic potential, drive new revenue streams and gain competitive advantages over business rivals. However, there are different types of analytic applications to consider. This paper presents a view of the BD challenges and methods to help to understand the significance of using the Big Data Technologies. This article based on a bibliographic review, on texts published in scientific journals, on relevant research dealing with the big data that have exploded in recent years, as they are increasingly linked to technology

Residual Stresses Control in Additive Manufacturing

Residual stresses are one of the primary causes for the failure of parts or systems in metal additive manufacturing (AM), since they easily induce crack propagation and structural distortion. Although the formation of residual stresses has been extensively studied, the core factors steering their development in AM have not been completely uncovered. To date, several strategies based on reducing the thermal gradients have been developed to mitigate the manifestation of residual stresses in AM; however, how to choose the optimal processing plan is still unclear for AM designers. In this regard, the concept of the yield temperature, related to the thermal deformation and the mechanical constraint, plays a crucial role for controlling the residual stresses, but it has not been duly investigated, and the corresponding approach to control stresses is also yet lacking. To undertake such study, a three-bar model is firstly used to illustrate the formation mechanism of the residual stress and its key causes. Next, an experimentally calibrated thermomechanical finite element model is used to analyze the sensitivity of the residual stresses to the scan pattern, preheating, energy density, and the part geometry and size, as well as the substrate constraints. Based on the numerical results obtained from this analysis, recommendations on how to minimize the residual stresses during the AM process are provided.

Utilization of Melt Fracture Phenomenon for the Preparation of Shark Skin Structured Hydrophobic Film

With the application of biomimetic shark skin microstructures with hydrophobicity in microfluidics, sensors and self-cleaning materials, microstructure processing methods are increasing. The preparation process has higher requirements for processing cost and efficiency. In this paper, linear low-density polyethylene (LLDPE) hydrophobic films were prepared with the help of melt fracture phenomenon. The equipment is a self-made single screw extruder. By adjusting the process parameters, the biomimetic shark skin structured LLDPE films with good hydrophobic property can be obtained. The surface microstructure shape of the product is related to kinds of additive, die temperature and screw speed. When AC5 was selected as an additive, the optimal processing parameter was found to be 160 °C die temperature and 80 r/min screw speed. A contact angle of 133° was obtained in this situation. In addition, the influences of die temperature and screw speed on the size of shark skin structure were also systematically investigated in this paper. It was found that the microstructure surface with hierarchical roughness had a better hydrophobic property.

Topography of hippocampal connectivity with sensorimotor cortex revealed by optimizing smoothing kernel and voxel size

Studies of the hippocampus use smaller voxel sizes and smoothing kernels than cortical activation studies, typically using a multivoxel seed with specified radius for connectivity analysis. This study identified optimal processing parameters for evaluating hippocampal connectivity with sensorimotor cortex (SMC), comparing effectiveness by varying parameters during both activation and connectivity analysis. Using both 3mm and 4mm isovoxels, smoothing kernels of 0-10mm were evaluated on the amplitude and extent of motor activation and hippocampal connectivity with SMC. Psychophysiological interactions (PPI) identified hippocampal connectivity with SMC during volitional movements, and connectivity effects from multivoxel seeds were compared with alternate methods; a structural seed represented the mean connectivity map from all voxels within a region, whereas a functional seed represented the regional voxel with maximal SMC connectivity. With few exceptions, the same parameters were optimal for activation and connectivity. Larger isovoxels showed larger activation volumes in both SMC and the hippocampus; connectivity volumes from structural seeds were also larger, except from the posterior hippocampus. Regardless of voxel size, the 10mm smoothing kernel generated larger activation and connectivity volumes from structural seeds, as well as larger beta estimates at connectivity maxima; structural seeds also produced larger connectivity volumes than multivoxel seeds. Functional seeds showed lesser effects from voxel size and smoothing kernels. Optimal parameters revealed topography in structural seed connectivity along both the longitudinal axis and mediolateral axis of the hippocampus. These results indicate larger voxels and smoothing kernels can improve sensitivity for detecting both cortical activation and hippocampal connectivity.

Additive Manufacturing of Wholly Thermoplastic Composites

TLCP reinforced composite has been widely used in different application due to their lightweight, high strength and stiffness, chemical resistance and great recyclability. In this work, TLCP reinforced nylon composite has been developed for using in 3D printing process. TLCP reinforced nylon filaments were generated using dual extrusion, a process by which two single crew extruders are used to individually process two plastics at their optimal processing temperature and pump them directly into a T junction in which a reinforcement material is dispersed throughout a matrix material via a static mixer, then extruded out of a nozzle and cooled in a water bath. Different pumping speeds were controlled via individual gear pumps connected to each extruder. Pump speeds were adjusted to produce 20 wt% TLCP/nylon composite. The filament was then collected and prepared for use in 3D printing.

PEMBERDAYAAN ANGGOTA PKK KELURAHAN KAUMAN KOTA MALANG DALAM PEMBUATAN FACE MIST EKSTRAK PEGAGAN UNTUK LANSIA

ABSTRAKKegiatan Program Kemitraan Masyarakat ini diawali dengan pengkajian awal terhadap keadaaan di lapangan. Tanaman Pegagan (Centella asiatica) sering digunakan hanya sebagai penutup tanah, Pengkajian awal didapatkan kurangnya pengetahuan masyarakat kelurahan Kauman atas keberadaan dan manfaat pegagan ditandai dengan kurang optimal pengolahan pegagan dalam kosmetik dan obat kulit. Dengan mempertimbangkan potensi pegagan yang besar dalam segi kesehatan, program kepada masyarakat yang bertujuan pemberian edukasi mengenai manfaat pegagan, pengolahan dalam pembuatan face mist sebagai antioksidan dan pelembab kulit lansia. Adanya pemberdayaan terhadap anggota PKK diharapkan nantinya meningkatkan upaya pencegahan dalam mengatasi permasalahan kulit saat menjelang lansia. Maka peningkatan derajat kesehatan khususnya mengenai kulit saat menjelang lansia dapat teratasi dengan pemanfaatan pegagan (Centella asiatica), yang mempunyai manfaat sebagai antioksidan dan pelembab pada sediaan face mist pada kulit. Berkenaan dalam situasi pandemi maka pelaksanaan dilakukan dalam jaringan (daring) dengan menggunakan media zoom dan dilakukan evaluasi dengan metode pre-test dan post test. Hasil post test yang dilakukan dengan nilai rata-rata 83 dapat menjawab pertanyaan dengan benar jika dibandingkan dengan pre test dimana hanya nilai rata-rata 41. Hal ini menunjukkan bahwa pengetahuan anggota PKK Kelurahan Kauman Kota Malang telah meningkat setelah dilakukannya pemberdayaan melalui kegiatan pengabdian kepada masyarakat ini. Kata kunci: pegagan; face mist; Ibu PKK; lansia. ABSTRACTThis activity begins with an initial assessment of the situation in the field. The gotu kola plant (Centella asiatica) is often used only as a ground cover. The initial assessment found that there was a lack of knowledge of the people of the Kauman village on the benefits of gotu kola, which was marked by the less than optimal processing of gotu kola in cosmetics and skin medicine. Taking into account the great potential of gotu kola in terms of health, this program aimed at providing education about the benefits of gotu kola, processing in making face mist as an antioxidant and moisturizing the skin of the elderly. The existence of empowerment of PKK members is expected to increase prevention efforts in overcoming skin problems when approaching the elderly. So the improvement of health status, especially regarding the skin when approaching the elderly, can be overcome by the use of gotu kola (Centella asiatica), which has benefits as an antioxidant and moisturizer in face mist preparations on the skin. With regard to the pandemic situation, the implementation is carried out online (online) using zoom media and evaluation is carried out using pre-test and post-test methods. The results of the post test carried out with an average value of 83 can answer the questions correctly when compared to the pre test where only the average value is 41. This shows that the knowledge of PKK members in Kauman Village, Malang City has increased after empowerment through community service activities. to this society. Keywords: gotu kola plant; face mist; PKK members; elderly.

Technological tests of a multi-seat device for vibro-shock processing of long parts of complex shape

The article deals with the issues related to the possibility of ensuring the indicators of quality of long complex-shaped parts by using vibration-impact processing in the technological process of their manufacturing using a special multi-seat device. The analysis of the design of representatives of long parts and the requirements for the quality of their surface layer, as well as the operational properties, made it possible to formulate the basic requirements for the design of multi-seat tools and develop a prototype for technological tests. The device allows processing two fragments of long parts and was used to establish the possibility of processing full-sized products and to establish optimal processing modes. Elements of the helicopter spars, which have the most complex design in the class of the considered parts, were used as fragments. Particular attention is paid to the processing of the inner surface of a complex shape and variable cross-section. The test results showed the possibility of using a multi-seat device for vibration-impact hardening treatment, which ensures the achievement of the specified parameters of the surface layer: surface roughness and microhardness with high process productivity.

Дослідження якісних показників поляризаційної селекції об’єктів на фоні пасивних завад в поляризаційно-доплерівській радіолокаційній системі

The optimal algorithm of polarization-Doppler selection of targets against the background of passive interference is considered. The polarimetric properties of scattered electromagnetic radiation of objects. The functionally-determined mathematical model of the useful signal, structure and correlation characteristics of the internal radiation of the receiver is determined. The algorithm of optimal processing, synthesized within the method of maximum likelihood, is considered for two limit cases. Algorithmic actions in the processing of passive interference and methods of their compensation are considered and investigated. Based on the obtained results, the expression for the algorithm of compensation of interferences reflected from the earth's surface is written. The obtained algorithm equalizes the variance of the input signals and compensates the residual variance with the help of weight coefficients. On the basis of the developed algorithm the scheme of the structurally simplified optimum compensator of passive disturbances is formed. Feature processing of useful signals in the compensation scheme is investigated. To ensure the adaptability of the generated algorithm, the coefficient of the variance ratio is based on the results coming from the variance meter. It is proposed to introduce quality indicators of polarization object selection on the background of the underlying surface, which combines indicators of efficiency of passive interference compensation and indicators of efficiency of useful signal-processing against the background of internal noise of receivers. The corresponding dependence of the indicators on the correlation coefficients of passive interference of different polarizations, as well as on the coefficients that separately characterize the level of difference in signal intensities and interference in the reception channels. The information value of each indicator of the efficiency of polarization signal selection from the ratio of the input variances, the correlation coefficient of passive interference and the ratio of the input signals is investigated.The obtained results are proposed to be used to improve the quality of polarization selection of objects in ground-based and aerospace-based radar systems.