Influence of orientation of zones of higher hardness of composite layers on their resistance to wear

Purpose: Experimentally substantiate the influence of the orientation of zones of higher hardness on the wear mechanism of contact surfaces. Design/methodology/approach: Forming of variable composition within the working surfaces of parts is a common way to solve the problem of uneven wear. The tests were aimed at determining the characteristics of the layers surfaced with the orientation of the zones of high hardness. For this different tests and measurements were done. Before the test, samples of 45 steel were surfaced with a preliminary application of titanium carbide paste. Findings: As a result of researches it was found that different ways of the orientation of zones of higher hardness have different influences on the characteristics of a surface. The main conclusion is that the transverse orientation of such zones helps to increase the wear resistance of the surface and to save its original relief. Research limitations/implications: The roughness, wear resistance, zonal hardness, and relief of layers surfaced with the orientation of zones of higher hardness were studied. Practical implications: The results obtained are useful in the field of rolling production and mechanical engineering to avoid the uneven wear of parts and as a result to extend the term of their exploitation. Originality/value: In this paper the model concepts of wear process of surfaces with variable composition and measurements of characteristics of surface considering its local hardening are proposed.

Enhancing Ocean Biogeochemical Models With Phytoplankton Variable Composition

Chlorophyll (Chl) is widely taken as a proxy for phytoplankton biomass, despite well-known variations in Chl:C:biomass ratios as an acclimative response to changing environmental conditions. For the sake of simplicity and computational efficiency, many large scale biogeochemical models ignore this flexibility, compromising their ability to capture phytoplankton dynamics. Here we evaluate modelling approaches of differing complexity for phytoplankton growth response: fixed stoichiometry, fixed stoichiometry with photoacclimation, classical variable-composition with photoacclimation, and Instantaneous Acclimation with optimal resource allocation. Model performance is evaluated against biogeochemical observations from time-series sites BATS and ALOHA, where phytoplankton composition varies substantially. We analyse the sensitivity of each model variant to the affinity parameters for light and nutrient, respectively. Models with fixed stoichiometry are more sensitive to parameter perturbations, but the inclusion of photoacclimation in the fixed-stoichiometry model generally captures Chl observations better than other variants when individually tuned for each site and when using similar parameter sets for both sites. Compared to the fixed stoichiometry model including photoacclimation, models with variable C:N ratio perform better in cross-validation experiments using model-specific parameter sets tuned for the other site; i.e., they are more portable. Compared to typical variable composition approaches, instantaneous acclimation, which requires fewer state variables, generally yields better performance but somewhat lower portability than the fully dynamic variant. Further assessments using objective optimisation and more contrasting stations are suggested.

Compost Produced with Addition of Sewage Sludge as a Source of Fe and Mn for Plants

Direct application of sewage sludge to soil is controversial due to, among others, its highly variable composition, odour, and risks for health. The obtained composts with the addition of sewage sludge were tested for the contents and availability of manganese and iron. Once composts were applied to the soil, their effect on the content and availability of Mn and Fe in soil and bioaccumulation in the plant were determined. The addition of sewage sludge enriched composts with manganese and iron, but did not increase the content of water-extracted forms of Mn and Fe. The compost with addition of biochar had more organic matter-bound forms of Mn and Fe. Composts amended with sewage sludge had lower effect on the amount of Poa pratensis L. biomass than maize straw compost. The content of Mn and Fe in Poa pratensis L. was in the range permissible for biomass used as fodder. Smaller addition of all composts to the soil significantly increased the content of mobile manganese forms; however, neither the type nor the dose had effect on the content of iron mobile forms. There was no significant differences in the content of organic matter-bound forms of Mn and Fe in soil after the application of composts.

New reagent regimes for potash flotation

The article presents the results of the VNII Galurgii’s studies into development of reagent regimes for flotation of potash ores of the Upper Kama deposit in fat solutions of potassium and sodium chlorides. The influence of the temperature of the saline solution and the content of magnesium chloride in it on the efficiency of aliphatic amines—collector of sylvin—was investigated. An alternative ethoxylated sludge collector for flotation de-sludging of potash ores is tested. The effect of a modified sludge depressant obtained by the synthesis of urea and formaldehyde is studied. The developed reagents are tested in full-scale processing of potash ore with variable composition and an increased content of sludge-forming silicate-carbonate and anhydrite water-insoluble impurities have been carried out. It is shown that the process stability and the production performance improve. Application of the sludge depressant in flotation of potash ore of variable composition allows stabilization of sylvin flotation and reduction in potassium chloride loss owing to stimulation of potassium chloride flotation from coarse tailings, which enables the decrease in the sylvin collector consumption and favors improvement of the process performance.

Pengaruh Komite Audit, Good Corporate Governance dan Whistleblowing System terhadap Fraud Bank Umum Syariah di Indonesia Periode 2016-2019

Fraud relates to fraudulent acts committed deliberately through bank facilities and resulting in losses. Although the role of the audit committee has been established, Good Corporate Governance has generally been well implemented, and has carried out a fairly good internal control function through the Whistleblowing System, the fulfillment of these components has not significantly been able to overcome fraud. Such an interesting condition to be related to the theory of Rezaae and Ajeng Wind. This study is intended to examine the effect of the audit committee, Good Corporate Governance, and the Whistleblowing System on fraud either partially or simultaneously. Sharia Commercial Banks for the period 2016-2019 in Indonesia were selected as the population using saturated sampling techniques, there are 14 Islamic Commercial Banks with 56 units of analysis used in this study. Ordinal logistic regression model was chosen as an analysis technique with SPSS 21 software as an analysis tool. The results of this study indicate that the variable composition of the independent audit committee, tenure of the audit committee and good corporate governance has a significant negative relationship to fraud. Meanwhile, the audit committee meeting variables and the Whistleblowing System have a negative and insignificant effect on fraud. The independent variable composition of the audit committee, audit committee meetings, tenure of the audit committee, Good Corporate Governance, and the Whistleblowing System is able to explain the variation of fraud by 29% while the remaining 71% is explained by other variables outside the research model. The low level of influence may be due to the inadequate follow-up of the audit committee meetings and the lack of independence of the internal auditors in managing fraud reports. So that Sharia Commercial Banks must optimize the function of the anti-fraud division and present the division in holding meetings, as well as increase the independence of the internal auditors in managing reports of suspected fraud that are submitted through the Whistleblowing System.Fraud berkaitan dengan tindakan kecurangan yang dilakukan secara sengaja melalui sarana bank dan mengakibatkan kerugian. Meskipun peranan komite audit telah terbentuk, Good Corporate Governance secara umum telah diterapkan dengan baik, serta menjalankan fungsi pengendalian internal melalui Whistleblowing System yang cukup baik, namun pemenuhan komponen-komponen tersebut tidak secara signifikan mampu mengatasi fraud. Kondisi yang demikian menarik untuk dihubungkan dengan teori Rezaae dan Ajeng Wind. Penelitian ini dimaksudkan untuk menguji pengaruh komite audit, Good Corporate Governance, dan Whistleblowing System terhadap fraud baik secara parsial maupun simultan. Bank Umum Syariah di Indonesia periode 2016-2019 dipilih sebagai populasi dengan menggunakan teknik sampling jenuh, ada 14 Bank Umum Syariah dengan 56 unit analisis yang digunakan dalam penelitian ini. Model regresi logistik ordinal dipilih sebagai teknik analisis dengan software SPSS 21 sebagai alat bantu analisis. Hasil penelitian ini menunjukkan variabel komposisi komite audit independen, masa tugas komite audit dan Good Corporate Governance memiliki hubungan yang negatif signifikan terhadap fraud. Sedangkan variabel rapat komite audit dan Whistleblowing System berpengaruh negatif tidak signifikan terhadap fraud. Variabel independen komposisi komite audit, rapat komite audit, masa tugas komite audit, Good Corporate Governance, dan Whistleblowing System mampu menjelaskan variasi fraud sebesar 29% sedangkan 71% sisanya dijelaskan oleh variabel lain diluar model penelitian. Rendahnya pengaruh yang diberikan tersebut kemungkinan disebabkan oleh kurang optimalnya tindak lanjut dari rapat komite audit yang diselenggarakan serta kurangnya independensi auditor internal dalam mengelola laporan fraud. Sehingga Bank Umum Syariah harus mengoptimalkan fungsi divisi anti fraud dan menghadirkan divisi tersebut dalam penyelenggaraan rapat, serta meningkatkan independensi auditor internal dalam mengelola laporan dugaan fraud yang masuk melalui Whistleblowing System.