Now showing items 19220-19239 of 49060

    • F(i)unding Your Way: A Managerial Compass for Social Organizations

      Jessica Aschari-Lincoln; Barbara Scheck (MDPI AG, 2022-01-01)
      Social organizations are faced with an increasing diversification of funders, financial sources, and financing instruments and a growing complexity of funding relationships. They still prioritize social impact over financial returns, but funding considerations significantly influence the way these organizations operate. Existing models to understand the sector do not include this essential component, thus limiting insights and decision-making premises on how to reach as many beneficiaries as possible. Based on previous quantitative and qualitative research, this article conceptualizes the organizational, programmatic, impact, and financing strategies of social organizations and their interrelatedness in a new framework. This could be perceived as a managerial compass illustrating the multiple dependencies social organizations are confronted with. The compass aims at reducing complexity, serving as a tool for social organizations for more effective financial management. The article closes with a call for more analysis on how social organizations manage their multiple bottom line.
    • FabLabs: The Road to Distributed and Sustainable Technological Training through Digital Manufacturing

      María-Elena García-Ruiz; Francisco-Javier Lena-Acebo (MDPI AG, 2022-03-01)
      The fast expansion of digital culture has fostered the creation of makerspaces such as fabrication laboratories (FabLabs) that, thanks to their flexibility and their use of open source tools, strengthen the sense of community and produce true transformations within those communities. Despite their relevance, few studies focus on the characterization of these environments. This paper presents the results of the FabLab Global Survey, aimed at understanding the characteristics of FabLabs through the visions of their managers, or “FabManagers”. The results show an enormous diversity of approaches within the FabLab movement that cannot be extrapolated to a single characteristic element, but that allow its global compression. Their properties reveal them as transforming elements that eliminate technological and cultural barriers, empowering user communities and optimizing learning processes regarding digital technology. FabLab activities allow not only economic and industrial development thanks to innovative projects, but also a digital technology approach for young students and the inclusion of minorities at risk, thus eliminating old cultural and social barriers.
    • Fabless Semiconductor Firms’ Financial Performance Determinant Factors: Product Platform Efficiency and Technological Capability

      Jun Hong Park; Sang Ho Kook; Hyeonu Im; Soomin Eum; Chulung Lee (MDPI AG, 2018-09-01)
      The semiconductor industry is experiencing a rapid change since new markets and new technologies have emerged to give insights to product innovation. The semiconductor industry is now specializing into the integrated device manufacturer (IDM), fabless, and foundry sectors. We investigated the determinant factors that affect the financial performance of firms in the fabless sector, which is the most technology-intensive and product-oriented sector among the three sectors. The correlation among technological capability, product platform, and financial performance is analyzed by structural equation modeling. The data includes 17,256 patents from 2005 to 2014 and financial data from 2012 to 2016 from 57 firms that run businesses in the fabless sector. Specifically, technological capability includes technological assets, technology breadth, and technology depth. New product development occurs by applying product platform efficiency. Financial performance includes growth and profitability. The results show that advancing product platform efficiency brings positive effects to financial performance. Also, increasing technological depth and technological assets not only improve product platform efficiency, but also bring positive effects to financial performance. In addition, technological depth affected growth positively, and technological breadth affected profitability positively. The results show the direction that new product development strategy needs to take.
    • Fabrication and Performance of Low-Fouling UF Membranes for the Treatment of Isolated Soy Protein Solutions

      Esperanza M. Garcia-Castello; Antonio D. Rodriguez-Lopez; Sergio Barredo-Damas; Alicia Iborra-Clar; Jairo Pascual-Garrido; Maria Isabel Iborra-Clar (MDPI AG, 2021-12-01)
      Consumers are becoming more conscious about the need to include functional and nutritional foods in their diet. This has increased the demand for food extracts rich in proteins and peptides with physiological effects that are used within the food and pharmaceutical industries. Among these protein extracts, soy protein and its derivatives are highlighted. Isolated soy protein (ISP) presents a protein content of at least 90%. Wastewaters generated during the production process contain small proteins (8–50 kDa), and it would be desirable to find a recovery treatment for these compounds. Ultrafiltration membranes (UF) are used for the fractionation and concentration of protein solutions. By the appropriate selection of the membrane pore size, larger soy proteins are retained and concentrated while carbohydrates and minerals are mostly recovered in the permeate. The accumulation and concentration of macromolecules in the proximity of the membrane surface generates one of the most important limitations inherent to the membrane technologies. In this work, three UF membranes based on polyethersulfone (PES) were fabricated. In two of them, polyethylene glycol (PEG) was added in their formulation to be used as a fouling prevention. The membrane fouling was evaluated by the study of flux decline models based on Hermia’s mechanisms.
    • Fabrication of Au-Nanoparticle-Decorated Cu Mesh/Cu(OH)<sub>2</sub>@HKUST-1 Nanorod Arrays and Their Applications in Surface-Enhanced Raman Scattering

      Xiaoqiao Huang; Li Cai; Tingting Fan; Kexi Sun; Le Yao; Lijun Zhang; Zhongbo Li (MDPI AG, 2022-12-01)
      Here we report a simple fabrication method for large-scale hybrid surface-enhanced Raman scattering (SERS) active substrates composed of Au-nanoparticle-decorated three-dimensional (3D) Cu(OH)<sub>2</sub>@HKUST-1 (Cu<sub>3</sub>(btc)<sub>2</sub>, H<sub>3</sub>btc = 1,3,5-benzenetricarboxylic acid) nanorod arrays on a woven Cu mesh (Cu mesh/Cu(OH)<sub>2</sub>@HKUST-1@Au). Cu(OH)<sub>2</sub> nanorods were first obtained from a simple in situ chemical engraving Cu mesh and then utilized as self-sacrificing templates to achieve HKUST-1 nanocube-assembled nanorods; finally, Au nanoparticles (Au NPs) were sputtered onto the Cu(OH)<sub>2</sub>@HKUST-1 nanorods. Due to the large surface area, the three-dimensional Cu mesh/Cu(OH)<sub>2</sub>@HKUST-1 nanorods could load high-density Au NPs and capture target detection molecules, which is beneficial to the formation of a strong electromagnetic field coupling between Au NPs, and provides abundant “hot spots” for a sensitive and uniform SERS effect. Using the Cu mesh/Cu(OH)<sub>2</sub>@HKUST-1@Au nanorod arrays as the SERS substrate, 10<sup>−9</sup> M Rhodamine 6G and 10<sup>−8</sup> M 4-aminothiophenolcan were identified. To verify their practical application, the fabricated arrays were employed as SERS substrates for the detection of thiram, and 10<sup>−8</sup> M thiram could be recognized. The hybrid SERS substrates show potential applications in the field of environmental pollutant detection and this is of great significance to the sustainable development of the environment.
    • Fabrication of Bimetallic Oxides (MCo<sub>2</sub>O<sub>4</sub>: M=Cu, Mn) on Ordered Microchannel Electro-Conductive Plate for High-Performance Hybrid Supercapacitors

      Mai Li; Zheyi Meng; Ruichao Feng; Kailan Zhu; Fengfeng Zhao; Chunrui Wang; Jiale Wang; Lianwei Wang; Paul K. Chu (MDPI AG, 2021-09-01)
      AB<sub>2</sub>O<sub>4</sub>-type binary-transition metal oxides (BTMOs) of CuCo<sub>2</sub>O<sub>4</sub> and MnCo<sub>2</sub>O<sub>4</sub> were successfully prepared on ordered macroporous electrode plates (OMEP) for supercapacitors. Under the current density of 5 mA cm<sup>−2</sup>, the CuCo<sub>2</sub>O<sub>4</sub>/OMEP electrode achieved a specific capacitance of 1199 F g<sup>−1</sup>. The asymmetric supercapacitor device prepared using CuCo<sub>2</sub>O<sub>4</sub>/OMEP as the positive electrode and carbon-based materials as the negative electrode (CuCo<sub>2</sub>O<sub>4</sub>/OMEP//AC) achieved the power density of 14.58 kW kg<sup>−1</sup> under the energy density of 11.7 Wh kg<sup>−1</sup>. After 10,000 GCD cycles, the loss capacitance of CuCo<sub>2</sub>O<sub>4</sub>/OMEP//AC is only 7.5% (the retention is 92.5%). The MnCo<sub>2</sub>O<sub>4</sub>/OMEP electrode shows the specific and area capacitance of 843 F g<sup>−1</sup> and 5.39 F cm<sup>−2</sup> at 5 mA cm<sup>−2</sup>. The MnCo<sub>2</sub>O<sub>4</sub>/OMEP-based supercapacitor device (MnCo<sub>2</sub>O<sub>4</sub>/OMEP//AC) has a power density of 8.33 kW kg<sup>−1</sup> under the energy density of 11.6 Wh kg<sup>−1</sup> and the cycle stability was 90.2% after 10,000 cycles. The excellent power density and cycle stability prove that the prepared hybrid supercapacitor fabricated under silicon process has a good prospect as the power buffer device for solar cells.
    • Fabrication of Biochar Materials from Biowaste Coffee Grounds and Assessment of Its Adsorbent Efficiency for Remediation of Water-Soluble Pharmaceuticals

      Vuyokazi Zungu; Lungile Hadebe; Philani Mpungose; Izzeldin Hamza; James Amaku; Bhekumuzi Gumbi (MDPI AG, 2022-03-01)
      Biowaste coffee grounds have been recognized as an effective and relatively low-cost adsorbent to complement conventional treatment techniques for removing emerging contaminants (ECs) from the waste stream through modification to useful biochar. The purpose of this study was to make biochar from biowaste coffee grounds through the pyrolysis process and investigate its potential capacity for the removal of pharmaceuticals from water. The biochar was prepared by pyrolysis process under argon gas conditions, and its adsorption capacity for pharmaceuticals was evaluated. The as-prepared biochar shows a surface area of 232 m<sup>2</sup> g<sup>−1</sup>. The adsorption of salicylic acid, diclofenac, and caffeine onto the biochar show adsorption capacities of 40.47 mg g<sup>−1</sup>, 38.52 mg g<sup>−1</sup>, and 75.46 mg g<sup>−1</sup>, respectively. The morphology, functional groups, crystallinity, and specific surface area were determined by SEM, FTIR, XRD, and BET techniques, respectively. Kinetic results reveal that the experimental data fit the pseudo-second-order model and the Temkin isotherm model. In conclusion, these results illustrate the potential of biochar produced from biowaste coffee grounds could play an important role in environmental pollution mitigation by enhancing removal of pharmaceuticals from conventional wastewater treatment effluent, thereby minimizing their potential risks in the environment.
    • Fabrication of Black Silicon via Metal-Assisted Chemical Etching—A Review

      Mohammad Yasir Arafat; Mohammad Aminul Islam; Ahmad Wafi Bin Mahmood; Fairuz Abdullah; Mohammad Nur-E-Alam; Tiong Sieh Kiong; Nowshad Amin (MDPI AG, 2021-09-01)
      The metal-assisted chemical etching (MACE) technique is commonly employed for texturing the wafer surfaces when fabricating black silicon (BSi) solar cells and is considered to be a potential technique to improve the efficiency of traditional Si-based solar cells. This article aims to review the MACE technique along with its mechanism for Ag-, Cu- and Ni-assisted etching. Primarily, several essential aspects of the fabrication of BSi are discussed, including chemical reaction, etching direction, mass transfer, and the overall etching process of the MACE method. Thereafter, three metal catalysts (Ag, Cu, and Ni) are critically analyzed to identify their roles in producing cost-effective and sustainable BSi solar cells with higher quality and efficiency. The conducted study revealed that Ag-etched BSi wafers are more suitable for the growth of higher quality and efficiency Si solar cells compared to Cu- and Ni-etched BSi wafers. However, both Cu and Ni seem to be more cost-effective and more appropriate for the mass production of BSi solar cells than Ag-etched wafers. Meanwhile, the Ni-assisted chemical etching process takes a longer time than Cu but the Ni-etched BSi solar cells possess enhanced light absorption capacity and lower activity in terms of the dissolution and oxidation process than Cu-etched BSi solar cells.
    • Fabrication of Catalytic Converter with Different Materials and Comparison with Existing Materials in Addition to Analysis of Turbine Installed at the Exhaust of 4 Stroke SI Engine

      Roman Kalvin; Juntakan Taweekun; Kittinan Maliwan; Hafiz Muhammad Ali (MDPI AG, 2021-09-01)
      Harmful pollutants (CO, NO, and unburnt hydrocarbons) coming out from the exhaust manifold of an engine must be converted into harmless gases by using catalytic converter. This field has seen vast research for increasing the conversion efficiency of pollutants by using different cheap metals. Nowadays, catalysts used in catalytic converter are noble metals, and they are also critical in the sense that they are not abundant on Earth. Platinum, palladium and rhodium are very expensive; hence, low-cost cars are not installed with catalytic converter, especially in third world countries. This research has been carried out to assess the catalytic activity of catalysts made from the salt/metal precursors, cerium sulphate tetra hydrate, manganese sulphate mono hydrate and copper sulphate penta hydrate that are not expensive and also less affected by the poison. Test sample catalysts were prepared through a coprecipitation method having different molar concentrations, and then tested for the conversion efficiency by applying the catalysts on ceramic plates by using flue gas analyzer. On the basis of the results, final catalysts were prepared and applied on a monolithic ceramic plate and then tested with regard to the resulting conversion rate of pollutants as compared to already installed catalytic converter. Moreover, turbine was installed in the exhaust passage to generate the power that would be utilized to run the electrical accessories of the engine. SOLIDWORKS were used for 3D CAD modeling and the flow analysis of turbine with radial inlet-axial outlet. In addition, ANSYS was used for stress-strain analysis.
    • Fabrication of Mg-Doped Sargassum Biochar for Phosphate and Ammonium Recovery

      Ye-Eun Lee; Yoonah Jeong; Dong-Chul Shin; Kwang-Ho Ahn; Jin-Hong Jung; I-Tae Kim (MDPI AG, 2021-11-01)
      Biochars prepared from macro-algae have a lower C/N ratio compared to lignocellulosic biochar, which is advantageous for direct nutrition. In particular, <i>Sargassum</i>, a marine macro-algae, has a high Mg content; hence, it can be expected to adsorb P and N simultaneously. In this study, <i>Sargassum horneri</i> biochar (SB), pyrolyzed at 400, 500, and 600 °C, was doped with innate Mg through water leaching, and nutrient recovery from the wastewater-mimicking solution was confirmed. The biochar pyrolyzed at 600 °C showed maximum Mg adsorption during water leaching, and the efficiency of K and Na removal was also high, at 92.7% and 91.9%, respectively. The addition of MgCl<sub>2</sub> during pyrolysis and high ion exchange did not show distinct advantages for surface modification and nutrient adsorption. X-ray photoelectron spectroscopy analysis confirmed the participation of biochar in the surface adsorption of Mg and PO<sub>4</sub> recovery. The PO<sub>4</sub> sorption capacity of biochar reached >120 mg·g<sup>−1</sup>, while the sorption capacity for NH<sub>4</sub> was low, at 22.8–28.2 mg·g<sup>−1</sup>, suggesting that Mg-surface-doped SB presented excellent phosphorus recovery. Hence, upgrading an adsorbent as a wastewater-treatment material and soil ameliorant that recovers nutrients using innate Mg from <i>Sargassum</i> is possible through appropriate surface modification.
    • Fabrication of Poly (Acrylonitrile-Co-Methyl Methacrylate) Nanofibers Containing Boron via Electrospinning Method: A Study on Size Distribution, Thermal, Crystalline, and Mechanical Strength Properties

      Meisam Sadeghi; Zahra Moghimifar; P. Senthil Kumar; Hamedreza Javadian; Majid Farsadrooh (MDPI AG, 2021-04-01)
      Electrospun polymeric nanofibers have attracted great attention in filtration systems and protective clothes. One of them is polyacrylonitrile (PAN) nanofibers, which are a suitable choice for the fabrication of protective clothes in the defense industry, due to their good fiber formation and easy optimization with chemical reagents. They do not possess adequate properties for protection against chemical, biological, and radiological agents. In this research, poly (acrylonitrile-co-methyl methacrylate) (PANMM) nanofibers and PANMM nanofibers containing <sup>10</sup>B were fabricated via the electrospinning method. The study of the morphology of nanofibers, using scanning electron microscopy (SEM), revealed that smooth and knotted fibers with an average diameter of 259 ± 64 nm were obtained, using 12% (<i>w</i>/<i>v</i>) of PANMM in the solution as the optimal concentration for the electrospinning process. This sample was doped with boron (10%, 30%, and 50% (<i>w</i>/<i>w</i>)) to fabricate the samples of PANMM + boric acid (BA) nanofibers. The results demonstrated an increasing trend in the diameter of the nanofibers with an increase in BA up to 50%. At this concentration, smooth fibers were formed with lower knots. Furthermore, the presence of B-O and O-H groups was observed using Fourier transform infrared (FTIR) spectroscopy. To study the tensile properties, the nanofibrous web was tested, and the results showed that introducing <sup>10</sup>B to PANMM nanofiber structures reduced the strength of the nanofibers. Thermal gravimetric analysis (TGA) showed that BA-modified PANMM nanofibers had lower thermal degradability, as compared with pure PANMM.
    • Fabrication of the Ordered Mesoporous nZVI/Zr-Ce-SBA-15 Composites Used for Crystal Violet Removal and Their Optimization Using RSM and ANN–PSO

      Gang Xiang; Shengxing Long; Anzhi Dang (MDPI AG, 2022-05-01)
      Crystal violet (CV), a triphenylmethane dye, is widely used in the textile, printing, paper, leather, and cosmetics industries. However, due to its higher chemical stability and lower biodegradability, CV has teratogenic and carcinogenic toxic effects on animals and humans. Therefore, the objective of the present study was to investigate whether or not the as-prepared nZVI supported on an ordered mesoporous Zr-Ce-SBA-15 composite (nZVI/Zr-Ce-SBA-15) had more potential for CV removal from simulated wastewater in comparison with Zr-Ce-SBA-15. Meanwhile, the parameters of CV adsorption onto nZVI/Zr-Ce-SBA-15 composites were optimized by a response surface methodology (RSM) and an artificial neural network combined with particle swarm optimization (ANN–PSO). According to XRD, FTIR, SEM, and TEM, N2 adsorption, and thermogravimetric analyses, nZVI was supported successfully on Zr-Ce-SBA-15 composites, becoming an ordered mesoporous material. The results of RSM indicated that the order of the effects of the four parameters on CV removal was, successively, initial pH, contact time, temperature, and initial CV concentration. ANN–PSO was more suitable, in comparison to RSM, to optimize the experimental parameters for CV removal from simulated wastewater using ordered mesoporous nZVI/Zr-Ce-SBA-15 composites. The optimized removal rate of CV was 93.87% under an initial pH of 3.00, a contact time of 20.00 min, an initial CV concentration of 261.00 mg/L, and a temperature of 45. Pseudo-second-order kinetics can better describe the behavior of CV adsorption onto nZVI/Zr-Ce-SBA-15 composites. The process of CV adsorption onto Zr-Ce-SBA-15 composites was followed by the Langmuir model, and its maximum adsorption capacity was 105 mg/g in 213 K. It was indirectly confirmed that the maximum adsorption capacity of nZVI/Zr-Ce-SBA-15 exceeded this value because the removal efficiency of CV using nZVI/Zr-Ce-SBA-15 was obviously higher than that of using Zr-Ce-SBA-15. The thermodynamics results indicated that CV adsorption onto nZVI/Zr-Ce-SBA-15 was a spontaneous, endothermic, and entropy-driven process. The dissolution of Fe ions and light/dark experiments confirmed nZVI/Zr-Ce-SBA-15 was simultaneously of adsorption and catalysis in the process of CV removal. The effect of removal CV was still maintained in the first four experiments (removal rate > 78%), and our suggestion is that nZVI/Zr-Ce-SBA-15 is a potential adsorbent for CV remediation from wastewater compared to Zr-Ce-SBA-15 and other adsorbents.
    • Fabricators and End-Users of Single-Pot Biomass Stoves: Conceptualizing, Hypothesis and Performance Metrics for Developing Energy Sustainability Framework

      George Yaw Obeng; Ebenezer Mensah; Richard Opoku (MDPI AG, 2021-06-01)
      In this study, interviewer-based questionnaires of 67 variables were administered to local fabricators and end-users of single-pot biomass stoves (SPBS) in Ghana. Additionally, two randomly selected traditional and improved SPBS were lab-tested using standard performance metrics. From the study, the relationship between fabricators and end-users was conceptualized based on selected indicators and assumptions. The study results indicated that the primary design resources for fabrication were patterns and templates, and that major challenges to fabrication were lack of training in design principles, standards and safety, poor emission efficiency and financial sustainability. Whereas end-users of improved SPBS were less affected by heat and smoke, end-users of traditional SPBS were mostly affected. From hypothesis test, because the calculated χ2<sub>cal</sub> = 24.05, and is greater than the tabulated χ2<sub>crit</sub> = 3.841, it is concluded that there is a relationship between heat, smoke effect and gender, and that female end-users of traditional SPBS were particularly affected during cooking. The traditional SPBS emitted more CO<sub>2</sub> and CO than improved SPBS. Comparatively, 38% more end-users of traditional SPBS observed charcoal ash residue in the cooking area than improved SPBS users. Four basic practices of managing ashes from SPBS are developed. Finally, a fabricator and end-user framework are developed for energy sustainability and quality improvement.
    • Face-to-Face Communication as A Tool to Support Second-Hand Fashion Sales: A Field Experiment at Fashion Week in Berlin

      Nicole Stein; Stefan Spinler; Helga Vanthournout (MDPI AG, 2020-02-01)
      We conducted a random allocation experiment at fashion week in Berlin in 2017, testing how face-to-face (f2f) communication affects sales of a fashion start-up focusing on second-hand. The experiment revealed that 11% of guests of an f2f event afterwards turned paying customers with an average basket size 11.8% higher than the overall sales event average. We add insights to research on entrepreneurial practice as well as on offline operations in the context of circular consumption in fashion, exposing the leveraging effect of f2f communication for customer acquisition and revenue of start-ups in the field of sustainable fashion.
    • Facebook Data as Part of Cultural Heritage Investments Toolbox: Pilot Analysis of Users Interests and Preferences Concerning Adaptive Reuse

      Magdalena Roszczyńska-Kurasińska; Anna Domaradzka; Bartosz Ślosarski; Agata Żbikowska (MDPI AG, 2021-02-01)
      The growing popularity of social media data brings questions about its accuracy and usefulness for a wide array of cultural heritage projects, often lacking data sources crucial for better planning and implementation. In this paper, we are studying the opportunities offered by the freely available Facebook Ads Manager data on target group sizes in different locations. We conducted a small experiment and a pilot survey to verify if Facebook data concerning its users’ interests is accurate and could be used to facilitate the implementation of projects in the field of adaptive reuse. Despite all discovered limitations of this approach, we point out how Facebook data, along with other social media outlets, can be used to extract some strategic information and add to the socio-cultural assessment toolbox. As such, this type of data could be of use to local leaders planning activities and investments around cultural heritage sites. We also posit that such data can facilitate benefit transfer between cities through better understanding of local preferences and values-orientations.
    • Facemask Global Challenges: The Case of Effective Synthesis, Utilization, and Environmental Sustainability

      Kamyar Shirvanimoghaddam; Bożena Czech; Ram Yadav; Cemile Gokce; Laura Fusco; Lucia Gemma Delogu; Açelya Yilmazer; Graham Brodie; Amani Al-Othman; Adil K. Al-Tamimi (MDPI AG, 2022-01-01)
      Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a rapidly spreading pandemic and is severely threatening public health globally. The human-to-human transmission route of SARS-CoV-2 is now well established. The reported clinical observations and symptoms of this infection in humans appear in the range between being asymptomatic and severe pneumonia. The virus can be transmitted through aerosols and droplets that are released into the air by a carrier, especially when the person coughs, sneezes, or talks forcefully in a closed environment. As the disease progresses, the use and handling of contaminated personal protective equipment and facemasks have become major issues with significant environmental risks. Therefore, providing an effective method for treating used/contaminated facemasks is crucial. In this paper, we review the environmental challenges and risks associated with the surge in facemask production. We also discuss facemasks and their materials as sources of microplastics and how disposal procedures can potentially lead to the contamination of water resources. We herein review the potential of developing nanomaterial-based antiviral and self-cleaning facemasks. This review discusses these challenges and concludes that the use of sustainable and alternative facemask materials is a promising and viable solution. In this context, it has become essential to address the emerging challenges by developing a new class of facemasks that are effective against the virus, while being biodegradable and sustainable. This paper represents the potentials of natural and/or biodegradable polymers for manufacturing facemasks, such as wood-based polymers, chitosan, and other biodegradable synthetic polymers for achieving sustainability goals during and after pandemics.
    • Faces of Marginal Housing in Romania

      Gheorghe-Gavrilă Hognogi; Ana-Maria Pop; Alexandra-Camelia Marian-Potra (MDPI AG, 2021-04-01)
      Marginal settlements may be defined as inhabited areas characterized by a series of negative features, typicallyethnic segregation, social discrimination, poor living conditions and conflicts, with impact on their dwellers and neighboring communities. In Romania, informal settlements were legislated in 2019; it subsequently became mandatory for the local authorities to spatially delimit them and formulate measures to improve living conditions. However, there are still numerous issues to be solved, from the lack of basic services (health, education) to the persistent poor living conditions or serious environmental problems. The Roma communities selected for our study are no exception. They are located on the outskirts of some cities or in their historical centers (Cluj-Napoca, Sibiu, Timișoara, Baia Mare). Through content analysis, based on print and electronic media from the last 10 years (<i>n</i> = 150 news items), different aspects of marginal housing were illustrated. The results of the study revealed some particular aspects, namely: some of the Roma communities are relocated whilst some others are subject to environmental conflicts; funding addressing the quality of life of Roma ethnics seems to deepen the phenomenon of segregation among communities, most of the measures being limited to the creation of housing facilities.
    • Facial Recognition System for People with and without Face Mask in Times of the COVID-19 Pandemic

      Jonathan S. Talahua; Jorge Buele; P. Calvopiña; José Varela-Aldás (MDPI AG, 2021-06-01)
      In the face of the COVID-19 pandemic, the World Health Organization (WHO) declared the use of a face mask as a mandatory biosafety measure. This has caused problems in current facial recognition systems, motivating the development of this research. This manuscript describes the development of a system for recognizing people, even when they are using a face mask, from photographs. A classification model based on the MobileNetV2 architecture and the OpenCv’s face detector is used. Thus, using these stages, it can be identified where the face is and it can be determined whether or not it is wearing a face mask. The FaceNet model is used as a feature extractor and a feedforward multilayer perceptron to perform facial recognition. For training the facial recognition models, a set of observations made up of 13,359 images is generated; 52.9% images with a face mask and 47.1% images without a face mask. The experimental results show that there is an accuracy of 99.65% in determining whether a person is wearing a mask or not. An accuracy of 99.52% is achieved in the facial recognition of 10 people with masks, while for facial recognition without masks, an accuracy of 99.96% is obtained.
    • Facile Bioinspired Preparation of Fluorinase@Fluoridated Hydroxyapatite Nanoflowers for the Biosynthesis of 5′-Fluorodeoxy Adenosine

      Ningning Li; Bingjing Hu; Anming Wang; Huimin Li; Youcheng Yin; Tianyu Mao; Tian Xie (MDPI AG, 2020-01-01)
      To develop an environmentally friendly biocatalyst for the efficient synthesis of organofluorine compounds, we prepared the enzyme@fluoridated hydroxyapatite nanoflowers (FHAp-NFs) using fluorinase expressed in <i>Escherichia coli</i> Rosetta (DE3) as the biomineralization framework. The obtained fluorinase@FHAp-NFs were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and FT-IR spectrum and used in the enzymatic synthesis of 5′-fluorodeoxy adenosin with S-adenosyl-L-methionine and fluoride as substrate. At an optimum pH of 7.5, fluorinase confined in the hybrid nanoflowers presents an approximately 2-fold higher synthetic activity than free fluorinase. Additionally, after heating at 30 °C for 8 h, the FHAp-NFs retained approximately 80.0% of the initial activity. However, free enzyme could remain only 48.2% of its initial activity. The results indicate that the fluoride and hybrid nanoflowers efficiently enhance the catalytic activity and thermal stability of fluorinase in the synthesis of 5′-fluorodeoxy adenosine, which gives a green method for producing the fluorinated organic compounds.
    • Facilitating Aligned Co-Decisions for More Sustainable Food Value Chains

      Gaëlle Petit; Gwenola Yannou-Le Bris; Claudia Eckert; Yan Liu (MDPI AG, 2021-06-01)
      The transition of existing food value chains towards greater sustainability is a societal imperative and a potential competitive factor. To succeed, some actors in the chains define new practices to establish common sustainability goals. To date, there is little evidence that the visions and values of the various actors in the chains have been leading to common solutions. This work explores the impact of collaboration on the value chain actors’ ability to jointly decide strategies for redesigning their activities. It reports on an empirical approach, which elicits the values and priorities of different stakeholders. The case takes place in the context of a value chain of the production/processing/sale of pork products. This value chain involves two French production-processing and redistribution cooperatives. Stakeholders were questioned about their prioritization of sustainability issues and these weights were applied to evaluate 12 animal feed solutions that vary in terms of the composition and geographical origin of rations, and the means and locations of their production. The results show that despite several years of cooperation, the objectives of the upstream and downstream actors remain different. The objectives of the upstream actors are driven by the economic difficulties of production and those of the downstream actors by the multiplicity of consumer demands and cost control objectives. In a reversal of the current practice marked by the economic difficulties of the actors upstream of the chain, an integrated culture could be led by bottom-up approaches to create a shared vision. Public policy would be then essential in regulating the sharing of value among actors; and in promoting chain models that help the required investments.