Investigation of Some Physical Properties of the Nanosized ZnO Prepared by the Coprecipitation Method

Zinc oxide (ZnO) nanoparticles have been fabricated via the coprecipitation method, where their structural, magnetic, thermal and optical properties have been investigated. The structural characteristics have been inspected through the X-ray diffraction patterns, particle size distribution, transmission electron microscopy, BET analysis, and Fourier transform Infrared spectroscopy, which confirm the nanostructure of the ZnO particles. The BET analysis confirms the mesoporous nature of the ZnO nanoparticles. The magnetic properties have been investigated by the vibrating sample magnetometer. The hysteresis (M-H) loop ensures the paramagnetic behavior of the ZnO nanoparticles. The measured thermal conductivity of the ZnO is about 0.2901 W/mK. The very low thermal conductivity value for the ZnO nanoparticles makes it an attractive contender for thermoelectric power applications. UV-vis Diffuse reflectance spectroscopy has been exploited to study the optical properties. The nano ZnO direct and indirect band gap energy determined using Tauc’s relation are 3.29 and 3.09 eV, respectively. The optical properties, high porosity, and specific surface area of the prepared nanosized ZnO particles make it a promising candidate for photocatalytic application

Investigation of Some Physical Properties of the Nanosized ZnO Prepared by the Coprecipitation Method

Zinc oxide (ZnO) nanoparticles have been fabricated via the coprecipitation method, where their structural, magnetic, thermal and optical properties have been investigated. The structural characteristics have been inspected through the X-ray diffraction patterns, particle size distribution, transmission electron microscopy, BET analysis, and Fourier transform Infrared spectroscopy, which confirm the nanostructure of the ZnO particles. The BET analysis confirms the mesoporous nature of the ZnO nanoparticles. The magnetic properties have been investigated by the vibrating sample magnetometer. The hysteresis (M-H) loop ensures the paramagnetic behavior of the ZnO nanoparticles. The measured thermal conductivity of the ZnO is about 0.2901 W/mK. The very low thermal conductivity value for the ZnO nanoparticles makes it an attractive contender for thermoelectric power applications. UV-vis Diffuse reflectance spectroscopy has been exploited to study the optical properties. The nano ZnO direct and indirect band gap energy determined using Tauc’s relation are 3.29 and 3.09 eV, respectively. The optical properties, high porosity, and specific surface area of the prepared nanosized ZnO particles make it a promising candidate for photocatalytic application

A Modified Hopfield Neural Network Algorithm (MHNNA) Using ALOS Image for Water Quality Mapping

Decreasing water pollution is a big problem in coastal waters. Coastal health of ecosystems can be affected by high concentrations of suspended sediment. In this work, a Modified Hopfield Neural Network Algorithm (MHNNA) was used with remote sensing imagery to classify the total suspended solids (TSS) concentrations in the waters of coastal Langkawi Island, Malaysia. The adopted remote sensing image is the Advanced Land Observation Satellite (ALOS) image acquired on 18 January 2010. Our modification allows the Hopfield neural network to convert and classify color satellite images. The samples were collected from the study area simultaneously with the acquiring of satellite imagery. The sample locations were determined using a handheld global positioning system (GPS). The TSS concentration measurements were conducted in a lab and used for validation (real data), classification, and accuracy assessments. Mapping was achieved by using the MHNNA to classify the concentrations according to their reflectance values in band 1, band 2, and band 3. The TSS map was color-coded for visual interpretation. The efficiency of the proposed algorithm was investigated by dividing the validation data into two groups. The first group was used as source samples for supervisor classification via the MHNNA. The second group was used to test the MHNNA efficiency. After mapping, the locations of the second group in the produced classes were detected. Next, the correlation coefficient (R) and root mean square error (RMSE) were calculated between the two groups, according to their corresponding locations in the classes. The MHNNA exhibited a higher R (0.977) and lower RMSE (2.887). In addition, we test the MHNNA with noise, where it proves its accuracy with noisy images over a range of noise levels. All results have been compared with a minimum distance classifier (Min-Dis). Therefore, TSS mapping of polluted water in the coastal Langkawi Island, Malaysia can be performed using the adopted MHNNA with remote sensing techniques (as based on ALOS images)

Corporal Punishment, Social Norms, and Norm Cascades: Examining Cross-National Laws and Trends in Homes Across the Globe

For centuries, parents across the globe have utilized corporal punishment against children in the name of discipline. This Article is the first legal article to examine cross-national trends in child corporal punishment laws and to propose ideas for reducing its practice using the social norms approach. By examining 192 countries over a 46-year period, we shed light on emerging patterns. Additionally, by delving into countries’ self-reports regarding their compliance with the United Nations Convention on the Rights of the Child (CRC) treaty, we observe other unique patterns globally. Notably, during the course of our empirical research and data collection (2017–2019), significant moves to decrease the prevalence of child corporal punishment have emerged, such as the 2019 legislation in Japan seeking to outlaw the practice of child corporal punishment in Japanese homes, and the 2018 American Association for Pediatricians Statement asserting its first public admonishment of physical discipline against children in the home. In our analysis, we utilize the country of Sweden—the first country worldwide to ban outright corporal punishment in the home—as our first case study to delve into the concept of norm cascades. We then showcase the country of Ethiopia—a country making great strides in changing societal norms about corporal punishment through public dissemination of literature and norm campaigns—as our second case study to examine concepts of re-norming. In conclusion, we demonstrate how social norms theories may be utilized to decrease the use and societal acceptance of child corporal punishment in the home

Trustworthy IoT: An evidence collection approach based on smart contracts

Today, Internet of Things (IoT) implements an ecosystem where a panoply of interconnected devices collect data from physical environments and supply them to processing services, on top of which cloud-based applications are built and provided to mobile end users. The undebatable advantages of smart IoT systems clash with the need of a secure and trustworthy environment. In this paper, we propose a service-based methodology based on blockchain and smart contracts for trustworthy evidence collection at the basis of a trustworthy IoT assurance evaluation. The methodology balances the provided level of trustworthiness and its performance, and is experimentally evaluated using Hyperledger fabric blockchain

Investigation of Some Physical Properties of the Nanosized ZnO Prepared by the Coprecipitation Method

Zinc oxide (ZnO) nanoparticles have been fabricated via the coprecipitation method, where their structural, magnetic, thermal and optical properties have been investigated. The structural characteristics have been inspected through the X-ray diffraction patterns, particle size distribution, transmission electron microscopy, BET analysis, and Fourier transform Infrared spectroscopy, which confirm the nanostructure of the ZnO particles. The BET analysis confirms the mesoporous nature of the ZnO nanoparticles. The magnetic properties have been investigated by the vibrating sample magnetometer. The hysteresis (M-H) loop ensures the paramagnetic behavior of the ZnO nanoparticles. The measured thermal conductivity of the ZnO is about 0.2901 W/mK. The very low thermal conductivity value for the ZnO nanoparticles makes it an attractive contender for thermoelectric power applications. UV-vis Diffuse reflectance spectroscopy has been exploited to study the optical properties. The nano ZnO direct and indirect band gap energy determined using Tauc’s relation are 3.29 and 3.09 eV, respectively. The optical properties, high porosity, and specific surface area of the prepared nanosized ZnO particles make it a promising candidate for photocatalytic application

Use of human perivascular stem cells for bone regeneration

Human perivascular stem cells (PSCs) can be isolated in sufficient numbers from multiple tissues for purposes of skeletal tissue engineering(1-3). PSCs are a FACS-sorted population of 'pericytes' (CD146+CD34-CD45-) and 'adventitial cells' (CD146-CD34+CD45-), each of which we have previously reported to have properties of mesenchymal stem cells. PSCs, like MSCs, are able to undergo osteogenic differentiation, as well as secrete pro-osteogenic cytokines(1,2). In the present protocol, we demonstrate the osteogenicity of PSCs in several animal models including a muscle pouch implantation in SCID (severe combined immunodeficient) mice, a SCID mouse calvarial defect and a femoral segmental defect (FSD) in athymic rats. The thigh muscle pouch model is used to assess ectopic bone formation. Calvarial defects are centered on the parietal bone and are standardly 4 mm in diameter (critically sized)(8). FSDs are bicortical and are stabilized with a polyethylene bar and K-wires(4). The FSD described is also a critical size defect, which does not significantly heal on its own(4). In contrast, if stem cells or growth factors are added to the defect site, significant bone regeneration can be appreciated. The overall goal of PSC xenografting is to demonstrate the osteogenic capability of this cell type in both ectopic and orthotopic bone regeneration models

The developmental dynamics of terrorist organizations

We identify robust statistical patterns in the frequency and severity of violent attacks by terrorist organizations as they grow and age. Using group-level static and dynamic analyses of terrorist events worldwide from 1968-2008 and a simulation model of organizational dynamics, we show that the production of violent events tends to accelerate with increasing size and experience. This coupling of frequency, experience and size arises from a fundamental positive feedback loop in which attacks lead to growth which leads to increased production of new attacks. In contrast, event severity is independent of both size and experience. Thus larger, more experienced organizations are more deadly because they attack more frequently, not because their attacks are more deadly, and large events are equally likely to come from large and small organizations. These results hold across political ideologies and time, suggesting that the frequency and severity of terrorism may be constrained by fundamental processes.Comment: 28 pages, 8 figures, 4 tables, supplementary materia

Human Perivascular Stem Cells Show Enhanced Osteogenesis and Vasculogenesis with Nel-Like Molecule I Protein

An ideal mesenchymal stem cell (MSC) source for bone tissue engineering has yet to be identified. Such an MSC population would be easily harvested in abundance, with minimal morbidity and with high purity. Our laboratories have identified perivascular stem cells (PSCs) as a candidate cell source. PSCs are readily isolatable through fluorescent-activated cell sorting from adipose tissue and have been previously shown to be indistinguishable from MSCs in the phenotype and differentiation potential. PSCs consist of two distinct cell populations: (1) pericytes (CD146+, CD34−, and CD45−), which surround capillaries and microvessels, and (2) adventitial cells (CD146−, CD34+, and CD45−), found within the tunica adventitia of large arteries and veins. We previously demonstrated the osteogenic potential of pericytes by examining pericytes derived from the human fetal pancreas, and illustrated their in vivo trophic and angiogenic effects. In the present study, we used an intramuscular ectopic bone model to develop the translational potential of our original findings using PSCs (as a combination of pericytes and adventitial cells) from human white adipose tissue. We evaluated human PSC (hPSC)-mediated bone formation and vascularization in vivo. We also examined the effects of hPSCs when combined with the novel craniosynostosis-associated protein, Nel-like molecule I (NELL-1). Implants consisting of the demineralized bone matrix putty combined with NELL-1 (3 μg/μL), hPSC (2.5×10(5) cells), or hPSC+NELL-1, were inserted in the bicep femoris of SCID mice. Bone growth was evaluated using microcomputed tomography, histology, and immunohistochemistry over 4 weeks. Results demonstrated the osteogenic potential of hPSCs and the additive effect of hPSC+NELL-1 on bone formation and vasculogenesis. Comparable osteogenesis was observed with NELL-1 as compared to the more commonly used bone morphogenetic protein-2. Next, hPSCs induced greater implant vascularization than the unsorted stromal vascular fraction from patient-matched samples. Finally, we observed an additive effect on implant vascularization with hPSC+NELL-1 by histomorphometry and immunohistochemistry, accompanied by in vitro elaboration of vasculogenic growth factors. These findings hold significant implications for the cell/protein combination therapy hPSC+NELL-1 in the development of strategies for vascularized bone regeneration

The internal brakes on violent escalation:a typology

Most groups do less violence than they are capable of. Yet while there is now an extensive literature on the escalation of or radicalisation towards violence, particularly by ‘extremist’ groups or actors, and while processes of de-escalation or de-radicalisation have also received significant attention, processes of non- or limited escalation have largely gone below the analytical radar. This article contributes to current efforts to address this limitation in our understanding of the dynamics of political aggression by developing a descriptive typology of the ‘internal brakes’ on violent escalation: the mechanisms through which members of the groups themselves contribute to establish and maintain limits upon their own violence. We identify five underlying logics on which the internal brakes operate: strategic, moral, ego maintenance, outgroup definition, and organisational. The typology is developed and tested using three very different case studies: the transnational and UK jihadi scene from 2005 to 2016; the British extreme right during the 1990s, and the animal liberation movement in the UK from the mid-1970s until the early 2000s