Resistance spot welding control based on fuzzy logic

Resistance spot welding is one of the most important welding procedures. Therefore, a lot of research is done in order to increase its cost effectiveness. One of the problems is short electrode life, especially when coated materials are welded. This paper presents a fuzzy logic-based controller which is capable of detecting expulsion and stopping the welding process when it occurs. Consequently, electrodes are spared of unnecessary high stresses which occur when the energy is being poured into the weld region after expulsion. Their life is therefore substantially increased.     

Comparison of self-citation patterns in WoS and Scopus databases based on national scientific production in Slovenia (1996–2020)

Scientometrics - Comparative studies of Web of Science and Scopus databases relate mainly to journal coverage and citation indicators. The aim of this study is to compare self-citation patterns in...     

Relevance for food sciences of quantitative spatially resolved element profile investigations in wheat (Triticum aestivum) grain

Bulk element concentrations of whole grain and element spatial distributions at the tissue level were investigated in wheat (Triticum aestivum) grain grown in Zn-enriched soil. Inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry were used for bulk analysis, whereas micro-proton-induced X-ray emission was used to resolve the two-dimensional localization of the elements. Soil Zn application did not significantly affect the grain yield, but did significantly increase the grain Ca, Fe and Zn concentrations, and decrease the grain Na, P and Mo concentrations; bulk Mg, S, K, Mn, Cu, Cd and Pb concentrations remained unchanged. These changes observed in bulk element concentrations are the reflection of tissue-specific variations within the grain, revealing that Zn application to soil can lead to considerable alterations in the element distributions within the grain, which might ultimately influence the quality of the milling fractions. Spatially resolved investigations into the partitioning of the element concentrations identified the tissues with the highest element concentrations, which is of utmost importance for accurate prediction of element losses during the grain milling and polishing processes.     

The amnion muscle combined graft (AMCG) conduits in nerves repair: an anatomical and experimental study on a rat model

The amnion muscle combined graft (AMCG) conduits showed good clinical results in peripheral nerves gap repair. It combines the human amniotic membrane with autologous skeletal muscle fibres. These results seem attributable to the biological characteristics of human amniotic membrane: Pluripotency, anti-inflammatory and low immunogenicity.We here evaluate the final outcome of nerve regeneration morphologically and functionally, across the AMCG compared to nerve autograft. Fourteen Wistar rats were divided into two groups: In Group A, including 6 rats, the left forelimb was treated performing a 1.5?cm length gap on median nerve that was then reconstructed with a reverse autograft. In Group B, including 8 rats, the gap was reconstructed with AMCG. Functional results were evaluated at 30, 60 and 90 days performing grasping tests. Morphological and stereological analyses were performed at T90 using high-resolution light microscopy and design-based stereology. The AMCG conduits revealed nerve fibres regeneration and functional recovery. Functional recovery was observed in both groups with AMCG conduits group showing lower values and a regeneration of median nerves with more myelinated fibres with the same axon size, but thinner myelin than the autograft group. Though the autograft remains the gold standard to restore wide nerve gaps, the AMCG conduit has proved to be effective in enabling nerve regeneration through a critical rat’s nerve gap of 15?mm. These findings empirically support the great clinical results obtained using AMCG conduit to restore traumatic nerve’s gap from 3 to 6?cm of mixed forearm nerves.

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Improving multimodal web accessibility for deaf people: sign language interpreter module

The World Wide Web is becoming increasingly necessary for everybody regardless of age, gender, culture, health and individual disabilities. Unfortunately, there are evidently still problems for some deaf and hard of hearing people trying to use certain web pages. These people require the translation of existing written information into their first language, which can be one of many sign languages. In previous technological solutions, the video window dominates the screen, interfering with the presentation and thereby distracting the general public, who have no need of a bilingual web site. One solution to this problem is the development of transparent sign language videos which appear on the screen on request. Therefore, we have designed and developed a system to enable the embedding of selective interactive elements into the original text in appropriate locations, which act as triggers for the video translation into sign language. When the short video clip terminates, the video window is automatically closed and the original web page is shown. In this way, the system significantly simplifies the expansion and availability of additional accessibility functions to web developers, as it preserves the original web page with the addition of a web layer of sign language video. Quantitative and qualitative evaluation has demonstrated that information presented through a transparent sign language video increases the users’ interest in the content of the material by interpreting terms, phrases or sentences, and therefore facilitates the understanding of the material and increases its usefulness for deaf people.     

Solid catalysts for the production of fine chemicals: the use of ALPON and hydrotalcite base catalysts for the synthesis of arylsulfones

α#x2010;phenylsulfonylcinnamononitrile and derivatives as well as α-phenylsulfonylchalcone have been obtained by condensation of phenylsulfonylacetonitrile and phenylsulfonylacetophenone with benzaldehyde and 4-substituted benzaldehydes, using solid base catalysts with different basic strengths. Cs-exchanged X zeolite showed low activity for the above reactions, while high-surface-area MgO and MgO–Al₂O₃ mixed oxides derived from hydrotalcite were active and selective catalysts. An optimum basicity was observed with MgO–Al₂O₃ with the atomic ratio Al/(Al+Mg) between 0 and 0.20, showing the increase in basicity when introducing Al in the MgO structure. Nitridation of a high-surface-area aluminophosphate gives active and selective catalysts for the above reactions. The activity per unit surface area for the less demanding reaction between sulfonylacetonitrile and benzaldehyde is directly proportional to the level of nitridation. However, formation of α-phenylsulfonylchalcone, which is a more demanding reaction, does not increase linearly but goes through a maximum with the nitrogen content of the solid, showing the heterogeneity of active sites on ALPONs and the decrease in the activity coefficient of the basic sites when the density of N atoms increases. This revised version was published online in July 2006 with corrections to the Cover Date.     

Parameter optimization for the enzymatic hydrolysis of sunflower oil in high-pressure reactors

This study is concerned with the hydrolysis of sunflower oil in the presence of lipase preparation Lipolase 100T (Aspergillus niger lipase). Supercritical carbon dioxide was used as a solvent for this reaction. In a high-pressure stirred tank reactor operated in a batch mode, the effects of various process parameters (temperature, pressure, enzyme/substrate ratio, pH, and oil/buffer ratio) were investigated to determine the optimal reaction rate and conversion for the hydrolysis process. The optimal concentration of lipase was 0.0714 g/mL of CO₂-free reaction mixture, and the highest conversions of oleic acid (0.193 g/g of oil phase) and linoleic acid (0.586 g/g of oil phase) were obtained at 50°C, 200 bar, pH=7, and an oil/buffer ratio of 1∶1 (w/w).     

Fecal excretion and the clearance of alpha 1-antitrypsin in patients with Crohn's disease

In previous work we defined the normal values of faecal alpha-1 antitrypsin (A1ATF) and their plasmatic clearance (CLAT) in 25 healthy patients. The aim of the present study is to compare these previous results with new results obtained when we applied this test to 30 patients with Crohn's disease (CD). We also show the good performance of the mentioned tests as indicators of the intestinal inflammatory activity. We compare the values of A1ATF and CLAT of healthy patients with those of CD patients. We also compare the Crohn's Disease Activity Index (CDAI) and Simple Index between active and inactive CD patients. Our results show significant differences between A1ATF excretion and CLAT as measured in healthy and CD patients. The relationship between those parameters could be explained by the equation CLAT = 0.325 x A1ATF. Active and inactive CD patients only differ significantly with respect to their leucocytes and C reactive protein values. In our group the A1ATF excretion is larger in CD patients with colonic disease.