scholarly journals Determination of destruction cause of experimental mill roll of stand roughing group of mill 150.

Author(s):  
I. A. Guzova ◽  
N. A. Hodosovskaya ◽  
I. A. Kovaleva

High quality of purchased resources plays a critical role under the conditions of severe international competition. Raw materials, materials and components are purchase for product production and their quality is an essential part in the production of steel at OJSC “BSW – Management Company of the Holding “BMC” holding». The problem of excessively high level of dynamic loads is especially acute for roughing stands. The main reasons for dynamic overloads are intense transient processes occurring in the rolling cycle, the presence of elastic constraints and gaps in the system, imperfection of electric drive system and errors made during development. Therefore, there is a need for selection of material and manufacturing technology for mill rolls capable to withstand such loads for a sufficiently long period. Investigations of destruction causes of experimental mill roll of stand roughing group of mill 150 of section rolling shop at OJSC “BSW – Management Company of the Holding “BMC” holding were carried out. Main classification features are established based on the analysis of the fracture. The results of metallographic studies of microstructure and chemical composition of central and subsurface zone roll fragments are presented. The reason of destruction of experimental mill roll was discovered – nonconformance of roll material grade with the requirements of technological instructions and normative documentation for rough group of stands No. 1–3

2019 ◽  
Vol 18 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Jian-kai Yang ◽  
Hong-jiang Liu ◽  
Yuanyu Wang ◽  
Chen Li ◽  
Ji-peng Yang ◽  
...  

Background and Objective: Exosomes communicate inter-cellularly and miRNAs play critical roles in this scenario. MiR-214-5p was implicated in multiple tumors with diverse functions uncovered. However, whether miR-214-5p is mechanistically involved in glioblastoma, especially via exosomal pathway, is still elusive. Here we sought to comprehensively address the critical role of exosomal miR-214-5p in glioblastoma (GBM) microenvironment.Methods:The relative expression of miR-214-5p was determined by real-time PCR. Cell viability and migration were measured by MTT and transwell chamber assays, respectively. The secretory cytokines were measured with ELISA kits. The regulatory effect of miR-214-5p on CXCR5 expression was interrogated by luciferase reporter assay. Protein level was analyzed by Western blot.Results:We demonstrated that miR-214-5p was aberrantly overexpressed in GBM and associated with poorer clinical prognosis. High level of miR-214-5p significantly contributed to cell proliferation and migration. GBM-derived exosomal miR-214-5p promoted inflammatory response in primary microglia upon lipopolysaccharide challenge. We further identified CXCR5 as the direct target of miR-214- 5p in this setting.Conclusion:Overexpression of miR-214-5p in GBM modulated the inflammatory response in microglia via exosomal transfer.


2021 ◽  
Vol 22 (9) ◽  
pp. 4961
Author(s):  
Maria Kovalska ◽  
Eva Baranovicova ◽  
Dagmar Kalenska ◽  
Anna Tomascova ◽  
Marian Adamkov ◽  
...  

L-methionine, an essential amino acid, plays a critical role in cell physiology. High intake and/or dysregulation in methionine (Met) metabolism results in accumulation of its intermediate(s) or breakdown products in plasma, including homocysteine (Hcy). High level of Hcy in plasma, hyperhomocysteinemia (hHcy), is considered to be an independent risk factor for cerebrovascular diseases, stroke and dementias. To evoke a mild hHcy in adult male Wistar rats we used an enriched Met diet at a dose of 2 g/kg of animal weight/day in duration of 4 weeks. The study contributes to the exploration of the impact of Met enriched diet inducing mild hHcy on nervous tissue by detecting the histo-morphological, metabolomic and behavioural alterations. We found an altered plasma metabolomic profile, modified spatial and learning memory acquisition as well as remarkable histo-morphological changes such as a decrease in neurons’ vitality, alterations in the morphology of neurons in the selective vulnerable hippocampal CA 1 area of animals treated with Met enriched diet. Results of these approaches suggest that the mild hHcy alters plasma metabolome and behavioural and histo-morphological patterns in rats, likely due to the potential Met induced changes in “methylation index” of hippocampal brain area, which eventually aggravates the noxious effect of high methionine intake.


Computers ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 63
Author(s):  
Fahd Alhaidari ◽  
Taghreed Zayed Balharith

Recently, there has been significant growth in the popularity of cloud computing systems. One of the main issues in building cloud computing systems is task scheduling. It plays a critical role in achieving high-level performance and outstanding throughput by having the greatest benefit from the resources. Therefore, enhancing task scheduling algorithms will enhance the QoS, thus leading to more sustainability of cloud computing systems. This paper introduces a novel technique called the dynamic round-robin heuristic algorithm (DRRHA) by utilizing the round-robin algorithm and tuning its time quantum in a dynamic manner based on the mean of the time quantum. Moreover, we applied the remaining burst time of the task as a factor to decide the continuity of executing the task during the current round. The experimental results obtained using the CloudSim Plus tool showed that the DRRHA significantly outperformed the competition in terms of the average waiting time, turnaround time, and response time compared with several studied algorithms, including IRRVQ, dynamic time slice round-robin, improved RR, and SRDQ algorithms.


2015 ◽  
Vol 37 (4) ◽  
pp. 459-474 ◽  
Author(s):  
Samantha Evans

Purpose – The purpose of this paper is to examine the interplay between the role of front line managers (FLMs) and their contribution to the reported gap between intended and actual human resource management (HRM). Design/methodology/approach – The findings draw on case study research using 51 semi-structured interviews with managers across two UK retail organisations between 2012 and 2013. Findings – This paper argues that FLMs are key agents in people management and play a critical role in the gap between intended and actual employee relations (ER) and HRM. The research found that these managers held a high level of responsibility for people management, but experienced a lack of institutional support, monitoring or incentives to implement according to central policy. This provided an opportunity for them to modify or resist intended policy and the tensions inherent in their role were a critical factor in this manipulation of their people management responsibilities. Research limitations/implications – The data were collected from only one industry and two organisations so the conclusions need to be considered within these limitations. Practical implications – Efforts to address the gap between intended and actual ER/HRM within organisations will need to consider the role tensions of both front line and middle managers. Originality/value – This research provides a more nuanced understanding of the interplay between FLMs and the gap between intended and actual HRM within organisations. It addresses the issue of FLMs receiving less attention in the HRM-line management literature and the call to research their role in the translation of policy into practice.


Author(s):  
Sunil Chopra

In 2003, ITC responded to the high level of obsolete inventory by shifting risk from finished products to manufacturing and raw materials. This required that their supply chain be much more flexible and responsive than it was in the past. By 2006, changes in the supply chain that included moving manufacturing in-house improved flexibility and responsiveness. Obsolete inventory was significantly reduced and the company was much better at matching supply and demand. Cost, however, continued to be higher than that at third parties. The company had to decide on the appropriate tradeoff between cost and responsiveness when structuring its supply chain.The case illustrates how Wills has changed its supply chain to become more flexible and responsive. This change, however, has come at a cost. The case requires the students to analyze the tradeoff between cost and responsiveness/flexibility to decide on an appropriate level of flexibility/responsiveness. The case also requires the student to understand the relative value of increased flexibility versus increased responsiveness.


Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Milan Houška ◽  
Filipa Vinagre Marques Silva ◽  
Evelyn ◽  
Roman Buckow ◽  
Netsanet Shiferaw Terefe ◽  
...  

High pressure processing (HPP) is a cold pasteurization technology by which products, prepacked in their final package, are introduced to a vessel and subjected to a high level of isostatic pressure (300–600 MPa). High-pressure treatment of fruit, vegetable and fresh herb homogenate products offers us nearly fresh products in regard to sensorial and nutritional quality of original raw materials, representing relatively stable and safe source of nutrients, vitamins, minerals and health effective components. Such components can play an important role as a preventive tool against the start of illnesses, namely in the elderly. An overview of several food HPP products, namely of fruit and vegetable origin, marketed successfully around the world is presented. Effects of HPP and HPP plus heat on key spoilage and pathogenic microorganisms, including the resistant spore form and fruit/vegetable endogenous enzymes are reviewed, including the effect on the product quality. Part of the paper is devoted to the industrial equipment available for factories manufacturing HPP treated products.


Detritus ◽  
2021 ◽  
pp. 25-31
Author(s):  
Cecilia Matasci ◽  
Marcel Gauch ◽  
Heinz Boeni

Environmental threats are triggered by the overconsumption of raw materials. It is therefore necessary to move towards a society that both reduces extraction and keeps the majority of the extracted raw materials in the socio-economic system. Circular economy is a key strategy to reach these goals. To implement it effectively, it is necessary to understand and monitor material flows and to define hotspots, i.e. materials that need to be tackled with the highest priority. This paper is aimed at determining how to increase circularity in the Swiss economy by means of a Material Flow Analysis coupled with a simplified Life Cycle Assessment. After having characterized material flows, we analyzed two types of hotspots: i) Raw materials consumed and/or disposed at high level, and ii) Raw materials whose extraction and production generates high environmental impacts. The Material Flow Analysis shows that each year 119 Mt of raw materials enter the Swiss economy. Therefrom, 15 Mt are derived from recycled waste inside the country; 67 Mt leave the system yearly; 27 Mt towards disposal. Out of the disposed materials, 56% are recycled and re-enter the socio-economic system as secondary materials. Looking at hotspots; concrete, asphalt, gravel and sand are among materials that are consumed and disposed at high level. Yet, looking at greenhouse gas emissions generated during extraction and production, metals - including the ones in electrical and electronic equipment - as well as textiles are among the categories that carry the biggest burden on the environment per unit of material.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Anna Korus ◽  
Emilia Bernaś ◽  
Jarosław Korus

The aim of this study was to evaluate the quality and health-promoting constituents of several variants of kimchi obtained from Chinese cabbage, kohlrabi, white radish, and cucumbers. The level of dry matter, total soluble solids, ash, total acidity, pH, dietary fiber, and vitamins C, B1, and B2, as well as total polyphenols (TP) and antioxidant activity AA (ABTS, DPPH) in kimchi, were determined. In addition, color parameters were determined ( L ∗ , a ∗ , b ∗ , C ∗ , and h o ). Kimchi with the highest proportion of Chinese cabbage (63%) had the highest levels of dry matter (11.01 g), ash (2.57 g), and vitamins: C, B1, and B2 (51 mg, 52 μg, and 242 μg, respectively), expressed per 100 g of fresh weight. In addition, this product showed the highest total AA of 132.3 μmol Tx/g (ABTS) and 49.7 μmol Tx/g (DPPH) due to its high level of TP (194 mg/100 g). Cucumber-derived kimchi (85%) also had a high content of TP (147 mg/100 g) and high AA of 88.7 μmol Tx/g (ABTS) and 36.3 μmol Tx/g (DPPH). Additionally, stuffed kimchi from kohlrabi (88%) had the highest amounts of total dietary fiber, 3.65 g/100 g fresh weight. In all products, red ( a ∗ ) and yellow ( b ∗ ) were the dominant colors, with values of L ∗ ranging between 32.63 and 53.16. In general, our studies have shown that depending on the raw materials used, kimchi is a good source of dietary fiber but also vitamins and polyphenols.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Manabu Aoki ◽  
Debananda Das ◽  
Hironori Hayashi ◽  
Hiromi Aoki-Ogata ◽  
Yuki Takamatsu ◽  
...  

ABSTRACTDarunavir (DRV) has bimodal activity against HIV-1 protease, enzymatic inhibition and protease dimerization inhibition, and has an extremely high genetic barrier against development of drug resistance. We previously generated a highly DRV-resistant HIV-1 variant (HIVDRVRP51). We also reported that four amino acid substitutions (V32I, L33F, I54M, and I84V) identified in the protease of HIVDRVRP51are largely responsible for its high-level resistance to DRV. Here, we attempted to elucidate the role of each of the four amino acid substitutions in the development of DRV resistance. We found that V32I is a key substitution, which rarely occurs, but once it occurs, it predisposes HIV-1 to develop high-level DRV resistance. When two infectious recombinant HIV-1 clones carrying I54M and I84V (rHIVI54Mand rHIVI84V, respectively) were selected in the presence of DRV, V32I emerged, and the virus rapidly developed high-level DRV resistance. rHIVV32Ialso developed high-level DRV resistance. However, wild-type HIVNL4-3(rHIVWT) failed to acquire V32I and did not develop DRV resistance. Compared to rHIVWT, rHIVV32Iwas highly susceptible to DRV and had significantly reduced fitness, explaining why V32I did not emerge upon selection of rHIVWTwith DRV. When the only substitution is at residue 32, structural analysis revealed much stronger van der Waals interactions between DRV and I-32 than between DRV and V-32. These results suggest that V32I is a critical amino acid substitution in multiple pathways toward HIV-1’s DRV resistance development and elucidate, at least in part, a mechanism of DRV’s high genetic barrier to development of drug resistance. The results also show that attention should be paid to the initiation or continuation of DRV-containing regimens in people with HIV-1 containing the V32I substitution.IMPORTANCEDarunavir (DRV) is the only protease inhibitor (PI) recommended as a first-line therapeutic and represents the most widely used PI for treating HIV-1-infected individuals. DRV possesses a high genetic barrier to development of HIV-1’s drug resistance. However, the mechanism(s) of the DRV’s high genetic barrier remains unclear. Here, we show that the preexistence of certain single amino acid substitutions such as V32I, I54M, A71V, and I84V in HIV-1 protease facilitates the development of high-level DRV resistance. Interestingly, allin vitro-selected highly DRV-resistant HIV-1 variants acquired V32I but never emerged in wild-type HIV (HIVWT), and V32I itself rendered HIV-1 more sensitive to DRV and reduced viral fitness compared to HIVWT, strongly suggesting that the emergence of V32I plays a critical role in the development of HIV-1’s resistance to DRV. Our results would be of benefit in the treatment of HIV-1-infected patients receiving DRV-containing regimens.


2017 ◽  
Vol 18 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Shinji Yamasaki ◽  
Tuyen Danh Le ◽  
Mai Quang Vien ◽  
Chinh Van Dang ◽  
Yoshimasa Yamamoto

AbstractEmergence and spread of antimicrobial-resistant bacteria, including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, have become serious problems worldwide. Recent studies conducted in Vietnam revealed that ESBL-producing E. coli are widely distributed in food animals and people. CTX-M-9 and CTX-M-1 are the most prevalent β-lactamases among the identified ESBLs. Furthermore, most of the ESBL-producing E. coli isolates were multi-drug resistant. Residual antimicrobials such as sulfamethoxazole, trimethoprim, sulfadimidine, cephalexin, and sulfadiazine were also detected at a high level in both animal meats and environmental water collected from several cities, including Ho Chi Minh city and Can Tho city. These recent studies indicated that improper use of antimicrobials in animal-originated food production might contribute to the emergence and high prevalence of ESBL-producing E. coli in Vietnam. Although clonal ESBL-producing E. coli was not identified, CTX-M-55 gene-carrying plasmids with similar sizes (105–139 kb) have been commonly detected in the ESBL-producing E. coli strains isolated from various food animals and human beings. This finding strongly suggests that horizontal transfer of the CTX-M plasmid among various E. coli strains played a critical role in the emergence and high prevalence of ESBL-producing E. coli in Vietnam.


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