Investigating the Effect of Mechanical Activation Parameters on Structural Changes and Leaching Rate of Molybdenite Concentrate

AbstractIn this research, mechanical activation (MA) was employed for leaching rate improvement of molybdenite concentrate in nitric acid media. These experiments were performed in two groups: with and without aluminum oxide (alumina). A full factorial design was used for each group of experiments. Leaching rate increment up to 5 times was observed only in 2hours activation procedure. XRD analysis demonstrated structural disordering in activated MoS2. TEM images showed that particle size has been reduced to nanoscale. The initial powder size was 80% between 2-44μm and dropped to about 10nm and 140nm in MA experiments with and without alumina, respectively. This size reduction would be the main reason of leaching rate enhancement which is more achievable in MA in presence of alumina. The results demonstrate that alumina has a motivating effect in activation procedure to achieve a nanostructure molybdenite. Analysis of variance revealed milling speed is the main parameter in MA without alumina, while, ball to powder ratio is the most important factor in MA procedure in presence of alumina on leaching rate

The evolution of food security: where are we now, where should we go next?

Food security is one of the most challenging topics globally; however, the concept of food security has taken on additional dimensions that are general and are less detailed. This study aims to identify the intellectual structure of food security research and the changes in this structure. This paper analyzed 3169 documents from the Web of Science database through a bibliometric review. A review of the published documents shows an increasing trend over the past 46 years. In accordance with co-occurrence analysis, 125 keywords were grouped into five clusters: food security and sustainable development; food security and socioeconomic factors; food security policy and governance; coping strategies for poverty, inequality, and hunger; and modern food security management. This study identifies four streams within food security research: sustainability and environmental, socioeconomic, cultural, and political factors. The paper concludes that even though food security might investigate many significant areas, other new dimensions should still be considered. Further gaps in the literature emerge that present avenues for future research directions. Reviewing indicators and techniques of food security assessment and identifying high-risk groups should be a priority

Forensic investigation of cross platform massively multiplayer online games: Minecraft as a case study

Minecraft, a Massively Multiplayer Online Game (MMOG), has reportedly millions of players from different age groups worldwide. With Minecraft being so popular, particularly with younger audiences, it is no surprise that the interactive nature of Minecraft has facilitated the commission of criminal activities such as denial of service attacks against gamers, cyberbullying, swatting, sexual communication, and online child grooming. In this research, there is a simulated scenario of a typical Minecraft setting, using a Linux Ubuntu 16.04.3 machine (acting as the MMOG server) and Windows client devices running Minecraft. Server and client devices are then examined to reveal the type and extent of evidential artefacts that can be extracted

Cutaneous Leishmaniasis in Bam: A Comparative Evaluation of Pre- and Post- Earthquake Years (1999-2008)

Background: The recent devastating earthquake of December 26 in Bam, 2003 created various risk factors; caused a sharp increase in incidence of anthroponotic cutaneous leishmaniasis (ACL) cases and reached to an epidemic proportion. The objective of this study was to evaluate the status of ACL cases five years before the earthquake compared to the cases occurred five years after the earthquake (1999-2008). Methods: Status of disease was assessed retrospectively for the five years before the earthquake and prospectively for the five years after the earthquake. Identification was confirmed by smear and polymerase chain reaction (PCR). Results: The mean annual incidence of ACL for the period from 1999 to 2003 was 1.9 per 1000 comparing to post earthquake period, which was 7.6 per 1000. Most of the infection was in individuals of <20 years, more frequently in females before the earthquake, whilst in contrast, there was a progressive rise in the number of cases, significantly in male individuals of >20 years (P< 0.0001) in post earthquake era. The anatomical distribution of lesions considerably changed during the two periods. Most of the cases were limited to three zones within the city prior to the earthquake, whereas it was spread throughout different zones after the earthquake. PCR indicated that the CL was due to Leishmania tropica in the city. Conclusion: The results strongly suggest that in natural disasters such as earthquakes various precipitating factors in favor of disease will be created, which in turn provide a suitable condition for propagation of the vector and the transmission of the parasite

Fuzzy pattern tree for edge malware detection and categorization in IoT

The surging pace of Internet of Things (IoT) development and its applications has resulted in significantly large amounts of data (commonly known as big data) being communicated and processed across IoT networks. While cloud computing has led to several possibilities in regard to this computational challenge, there are several security risks and concerns associated with it. Edge computing is a state-of-the-art subject in IoT that attempts to decentralize, distribute and transfer computation to IoT nodes. Furthermore, IoT nodes that perform applications are the primary target vectors which allow cybercriminals to threaten an IoT network. Hence, providing applied and robust methods to detect malicious activities by nodes is a big step to protect all of the network. In this study, we transmute the programs' OpCodes into a vector space and employ fuzzy and fast fuzzy pattern tree methods for malware detection and categorization and obtained a high degree of accuracy during reasonable run-times especially for the fast fuzzy pattern tree. Both utilized feature extraction and fuzzy classification which were robust and led to more powerful edge computing malware detection and categorization method

Patient-reported health outcomes in long-term lung transplantation survivors

During the last three decades lung transplantation (LTx) has become a proven modality for increasing both survival and health-related quality of life (HRQoL) in patients with various end-stage lung diseases. Most previous studies have reported improved HRQoL shortly after LTx. With regard to long-term effects on HRQoL, however, the evidence is less solid. This prospective cohort study was started with 828 patients who were on the waiting list for LTx. Then, in a longitudinal follow-up, 370 post-LTx patients were evaluated annually for up to 15 years. For all wait-listed and follow-up patients, the following four HRQoL instruments were administered: State-Trait Anxiety Inventory, Zung Self-rating Depression Scale, Nottingham Health Profile, and a visual analogue scale. Cross-sectional and generalized estimating equation (GEE) analysis for repeated measures were performed to assess changes in HRQoL during follow-up. After LTx, patients showed improvement in all HRQoL domains except pain, which remained steady throughout the long-term follow-up. The level of anxiety and depressive symptoms decreased significantly and remained constant. In conclusion, this study showed that HRQoL improves after LTx and tends to remain relatively constant for the entire life span

Calculation of the efficacy of vaccines against tick infestations on cattle

Articles in International JournalsCattle ticks are responsible for great economic losses in cattle farming worldwide, and their main control method, chemicals, has been showing problems, whether resulting from the development of resistant strains of ticks or environmental contamination. Research studies directed toward developing vaccines against ticks are emerging. One way to evaluate those vaccines is to calculate the percentage of efficacy. The aim of this study was to analyze scientific publications archived in PubMed that used this method of assessment and discuss the main factors that may affect its calculation. Thus, 25 articles addressing this subject were selected. The percentage of efficacy was usually calculated in one of two ways, with one considering the reduced fertility of eggs and the other not. The latter method may underestimate the vaccine efficacy, and the most complete formula for calculating the efficacy reflects how much the vaccine actually affects the infestation. In our view, the use of the complete formula for calculating the percentage of efficacy is broader and more representative of the vaccine effect on the tick population.RESUMO - Carrapatos de bovinos são responsáveis por grandes perdas econômicas para a pecuária bovina mundial e seu principal método de controle, o químico, vem apresentando problemas, seja pelo desenvolvimento de amostras de carrapatos resistentes ou pela contaminação ambiental. Na tentativa de diminuir a utilização dos acaricidas, surgem pesquisas direcionadas ao desenvolvimento de vacinas contra carrapatos. Uma maneira de avaliar essas vacinas é pelo cálculo de percentagem de eficácia. O objetivo deste trabalho foi analisar as publicações científicas indexadas no PubMed que utilizaram este método de avaliação e discutir os principais fatores que podem interferir no seu cálculo. Dessa maneira, selecionaram-se 25 artigos que tratavam desse assunto. A percentagem de eficácia apareceu sendo calculada de duas formas, uma considerando a redução da fertilidade dos ovos e a outra não. Essa última pode subestimar a eficiência da vacina, e a fórmula de cálculo da eficácia mais completa representa o quanto da infestação a vacina realmente reduziu. Em nosso entendimento, a utilização da fórmula completa para o cálculo da percentagem de eficácia é mais abrangente e representativa do efeito da vacina na população de carrapatos

Resolving the Role of Actoymyosin Contractility in Cell Microrheology

Einstein's original description of Brownian motion established a direct relationship between thermally-excited random forces and the transport properties of a submicron particle in a viscous liquid. Recent work based on reconstituted actin filament networks suggests that nonthermal forces driven by the motor protein myosin II can induce large non-equilibrium fluctuations that dominate the motion of particles in cytoskeletal networks. Here, using high-resolution particle tracking, we find that thermal forces, not myosin-induced fluctuating forces, drive the motion of submicron particles embedded in the cytoskeleton of living cells. These results resolve the roles of myosin II and contractile actomyosin structures in the motion of nanoparticles lodged in the cytoplasm, reveal the biphasic mechanical architecture of adherent cells—stiff contractile stress fibers interdigitating in a network at the cell cortex and a soft actin meshwork in the body of the cell, validate the method of particle tracking-microrheology, and reconcile seemingly disparate atomic force microscopy (AFM) and particle-tracking microrheology measurements of living cells

Innovation, technology and user experience in museums: insights from scientific literature

Museums play an important role in preserving the heritage and cultural legacy of humanity, however, one of their main weaknesses in regards the user is their static nature. At present, and in the face of the development of diverse technologies and the ease of access to information, museums have upgraded their implementation of technologies aimed at improving the user experience, trying more and more to access younger audiences with a sensitivity and natural capacity for the management of new technologies. This work identifies trends in the use of technological tools by museums worldwide and the effect of these on the user or visitor experience through a review of scientific literature. To complete the work, we performed a search of the publications in the Scopus® referencing database, and downloaded, processed, and visualized the data using the VOSviewer® tool. The main trends identified in this context of analysis are related to the role of museums with the development and improvement of the user experience; orientation to young audiences and innovation driven by the user through Interactive Systems, digital games, QR Codes, apps, augmented reality, virtual reality and gamification, among others. The objective of the implementation of new technologies in the context of museums is to satisfy the needs of contemporary communication, for all types of content and aimed at an increasingly digital audience, in order to ensure positive interaction and feedback from ideas with social and cultural changes