Environmental Effects Caused by Utilising Copper Mine Tailings in Various Geotechnical Applications – A Review

Based on the available literature this paper evaluates the environmental effects of copper mine tailings (CMT) when used as structural fill material in various geotechnical applications. Leaching of heavy metals from the CMT is considered as the vital factor hindering its wider acceptability among researchers and engineers. Therefore, apart from physical and chemical characteristics, due consideration was given to assess the leachability of CMT when used as structural fill in various geotechnical applications like subgrade, embankment, fill and reclamation. From the literature review, it was found that CMT seems to be satisfying the criteria meant for structural fill. Leachability test results show that only a very few elements concentration exceeded the limits in un-stabilized form. Stabilized CMT performed better by bringing down the concentration well below the permissible limits in all the application types. This encourages the utilization of CMT in structural fills and shows that environmental impacts are within the limits prescribed in standards.

Methods for increasing the wear resistance of heavy loaded metal-polymer tribosystems

Methods of increasing the wear resistance and reliability of friction units are generating considerable interest being a vital factor in transport, mechanical engineering, and other fields of technology. The solution of the given problem is impossible without the creation of self-regulating structures on the friction contact surfaces. We strongly believe that this problem can be solved by creating multicomponent functional layers (hereafter MFL) on tribocontact.

Vehicle Routing Problem in Relief Supply under a Crisis Condition considering Blood Types

Despite the advances achieved in Medical Sciences, no substitute has been found for blood as a vital factor. Therefore, preparing sufficient and healthy blood in crisis conditions is a challenge that health systems encounter. Along with examining the conducted investigations in this field, the main contribution of current research is to develop a biobjective Mixed-Integer Linear Programming (MILP) model for relief supply under crisis condition. For this purpose, this paper proposes a model for routing of bus blood receiver under crisis conditions considering different blood groups. Besides, hours of unnecessary travel by bloodmobiles (buses) between each blood station (BS) and the crisis-stricken city for dispatching the collected blood is prevented thanks to considering a helicopter. The mentioned model has two objectives: maximizing the amount of blood collected by bloodmobiles and minimizing the arrival time of the blood receiver buses and a helicopter to a crisis-stricken city after the collected blood is used up. The model is coded by CPLEX software, and the results obtained from solving the model indicate that, without considering a helicopter, the demand is not supplied within the critical period after crisis. Given that blood cannot be artificially produced, its primary resource is blood donors. Concerning the importance of this issue under crisis conditions, this research investigates the relief vehicles’ routing problem, including bus and helicopter, in a crisis considering supply and transfer of different blood groups to a crisis-stricken city for maximum relief supply and blood transfer within the shortest period.

A Crystalline Tri-thorium Cluster: When Metal σ-Aromaticity Just Isn’t Enough

Very recently, Liddle and coworkers extended the range of aromaticity to a record seventh row of the periodic table by successful isolation of the crystalline actinide cluster 3 containing at its heart the σ-aromatic tri-thorium ring. In this study we prove that the authors have misinterpreted the experimental Raman spectrum of 3, which eventually led to the wrong conclusions about the role of the σ-aromatic tri-thorium bonding in the synthesized cluster. We demonstrate that the thorium-thorium bond in 3 is not very different from the already known extremely weak actinide-actinide bonds, and the marginal σ-aromatic stabilization in the Th3 ring makes it hardly distinguishable from ordinary non-aromatic rings. Also, we show that the multicenter charge-shift bonding in the Th3Cl6 cage is a vital factor that determines the uniqueness and remarkable thermodynamic stability of 3. By clarifying the misleading conclusions of the original Nature paper and drawing special attention to the essential stabilizing role of actinide-halogen charge-shift bonding, this study may have broader implications for understanding the chemistry of actinides and future attempts to design and synthesize new stable actinide complexes.

A STOCHASTIC MODEL FOR ESTIMATION OF EXPECTED TIME TO RECRUITMENT WHEN THE THRESHOLD HAS GENERALIZED EXPONENTIATED GAMMA DISTRIBUTION

In any organization a number of factors are required to generate production activities and the manpower is the most vital factor. The manpower requirements may increase in course of time due to increase in production activities or due to depletion of manpower at random time points. Hence recruitment is to be made whenever the total demands for manpower crosses the so called threshold level. In this paper an estimate of the expected time to recruitment is derived under the assumption that the threshold level is a random variable which follows the Generalized Exponentiated Gamma distribution. The variances also found out. The results are substantiated with numerical examples

RCAN1 Reduces FBXW7β Transcription by Inhibiting Calcineurin/NFAT Signaling Pathway

Regulator of calcineurin 1 (RCAN1), a crucial endogenous regulator of calcineurin, is implicated in multiple important physiological and pathological processes. Aberrant expression of RCAN1 is commonly found in brains of patients with Down syndrome (DS) or Alzheimer’s disease (AD), accounting for impaired neurodevelopment in DS and neuronal degeneration in AD, respectively. However, the mechanism of RCAN1 in brain development and neurodegeneration remains unclear. FBXW7 functions as vital factor in neurodevelopment and neurodegeneration via mediating proteasomal degradation of its substrates. Deficiency of FBXW7 contributes to impaired neurodevelopment and accelerating neurodegeneration. Here, we show that increased RCAN1 reduces the level of β isoform of FBXW7 (FBXW7β). RCAN1 inhibits FBXW7β transcription in a calcineurin dependent manner. Potential NFAT binding sites are identified within the promoter of FBXW7β, and NFAT is also demonstrated to activate the promoter activity of FBXW7β. In summary, our work implies that RCAN1 can regulate FBXW7β expression by inhibiting FBXW7β transcription via calcineurin/NFAT signaling pathway. It could provide more understanding on the mechanism of FBXW7 regulation and suggest a potential mechanism on functional implication of RCAN1 with impaired brain function in some neurodevelopmental and neurodegenerative diseases.

Changes in Physicochemical Properties and Qualities of Red Brown Rice at Different Storage Temperatures

The effects of storage temperature on the physicochemical properties and qualities of red brown rice were investigated in this study. The samples were vacuum-packed in nylon/polyethylene pouches and stored at 15 °C, 25 °C and 35 °C for 12 weeks. The moisture content decreased as storage time was prolonged. Rice stored at 15 °C and 25 °C had a lower falling range of water content compared to the samples stored at 35 °C. Free fatty acid values increased fastest when samples were stored at a high temperature, and the rise can be effectively delayed at low temperatures. The pH of residual cooking water and adhesiveness decreased, while the heating water absorption rate and hardness increased during storage for red and brown rice. Low-field nuclear magnetic resonance results indicate that water molecules migrated, the binding force of H protons became stronger and the bonds between molecules became closer with increased storage duration. Temperature had an obvious correlation with starch granules and protein structure, characterized by a scanning electron microscope and Fourier transform infrared spectroscopy. Low temperatures significantly retarded those changes. The results indicate that storage temperature is a vital factor affecting the physicochemical properties and qualities of red brown rice and provided reference and theoretical basis for the actual storage of red brown rice.

Satisfaction and Loyalty in Local Food Festival: Do Switching Barriers Matter?

In food tourism context, attracting customers and provision of satisfaction is of necessity. In accord with the call for empirical evidence within the extant literature, this study examines switching barriers and its role as moderator on the relationship between satisfaction and customer loyalty, at a food festival in Delhi, India. Switching barriers can be a vital factor for attracting more tourists into organized festivals, if implied adequately and maintained on a controlled manner. Creating switching barriers can be an effective approach for obtaining long-term visitors from marketing and tourism aspects. A questionnaire was designed specifically using related measures based on the literature. Various regression models were applied to estimate switching barriers’ effects and to further analyze our hypotheses. Interaction plot exhibited suppressing effect of switching barriers on the relationship between customer satisfaction and customer loyalty. The results of this study found that the role of switching barriers is not merely statistically significant, but requires critical attention from organizers. JEL Classification: M3, M30, M31, M37, M39

The factors influencing technological entrepreneurship in nanotechnology businesses

PurposeTechnological entrepreneurship has been a very significant topic in recent decades. It has a crucial role in economic modernization and growth. The need for technological entrepreneurship is because technology-based industries are expanding rapidly and are replacing traditional industries. Therefore, this study aimed at identifying the factors affecting the success of technological entrepreneurship in Iranian nanotechnology businesses.Design/methodology/approachThe research was conducted through mixed method. The participants in the qualitative section included 17 university experts and executive managers in the field of nanotechnology in Iran, and 75 nanotechnology business managers participated in the quantitative section. The interview and questionnaire were used to collect information. In order to measure and fit the models, the confirmatory factor analysis method and PLS3 software were used.FindingsThe results indicated that the key factors affecting the success of the technological entrepreneurship process in nanotechnology were classified into five general categories: organizational, environmental, institutional, individual and technology factors. Moreover, it was shown that all these dimensions had a positive and significant effect on technological entrepreneurship. In addition, the organizational dimension has an essential role.Originality/valueCompanies' ability to engage technological entrepreneurship is a vital factor in human resource management and strategic management. However, technological entrepreneurship in Iranian nanotechnology businesses has not been involved integrally in the context of companies.