Self-sustaining Manner Research Articles

Navigating the Challenges in Setting Up a Sustainable Open-Heart Surgery Unit in a Resource-Constrained Environment in Northern Nigeria: Model and Strategies.

Cardiac surgery requiring cardiopulmonary bypass had been unavailable in Northern Nigeria and the federal capital territory of Nigeria regularly. Several attempts in the past at setting up this service in a self-sustaining manner in Northern Nigeria had failed. This paper is a contrasting response to an earlier publication that emphasized the less-than-desirable role played by international cardiac surgery missions in the evolution of a sustainable open-heart surgery program in Nigeria. The cardiothoracic unit of Federal Medical Centre, Abuja, was established on March 1, 2021, but could not conduct safe open-heart surgery. The model and strategies employed in commencing open-heart surgeries, including the choice of personnel training within the country and focused collaboration with foreign missions, are discussed. We also report the first seven patients to undergo cardiac surgery under cardiopulmonary bypass in our government-run hospital as well as the transition from foreign missions to local team operations. Seven patients were operated on within the first six months of setting up with high levels of skill transfer and local team participation, culminating in one of the operations entirely carried out by the local team of personnel. All outcomes were good at an average of one-year follow-up. In resource-constrained government-run hospitals, a functional, safe cardiac surgery unit can be set up by implementing well-planned strategies to mitigate encountered peculiar challenges. Furthermore, with properly harnessed foreign missions, a prior-trained local team of personnel can achieve independence and become a self-sustaining cardiac surgery unit within the shortest possible time.

Study on prey preference of two indigenous larvivorous fish Trichogaster fasciata and Puntius sophore

The most effective way to control mosquito populations is through biological control methods, among them, fishes are the top contenders as natural agents to manage mosquito larvae. Fishes not only consume mosquito larvae efficiently but also readily adapt to new environmental conditions, reproduce rapidly and effectively control mosquito breeding in a self-sustaining manner. In present study two easily available indigenous fishes Trichogaster fasciata and Puntius sophore were considered to evaluate the feeding preference and the effect of alternative prey on larval feeding efficacy. For food preference test, mosquito larvae, mosquito pupae, chironomid larvae, daphnia and artificial fish food were considered. The live foods were gathered from the possible water lodging areas and artificial foods from aquarium shops. Experiments were conducted by providing equal number of different food items - mosquito larvae, mosquito pupae, chironomid larvae, daphnia and artificial fish food in the same container. Both the fish prefer maximum consumption of live and wriggly food than artificial stationery food. All length sizes of Puntius sophore consumed a maximum number of chironomid larvae, while Trichogaster fasciata prefer to consume mosquito larvae as the top choice. In both fish, as increasing length size, consumption rate of food increases significantly. Tested prey consumption data of both fishes were statistically represented by Mean±SD and significance differences of means was analysed by ANOVA. The food preferences of both fish directly depend on their feeding habits.

Movement of genetically modified insects for research purposes.

Insects play a crucial role in research. Many laboratories are developing technologies to control insect vectors or agricultural pests by using genetic modifications that either reduce insect reproduction or increase refractoriness to disease transmission. Those tools include gene-drive elements that may spread such genetic traits in a selfsustaining and cost-effective manner. Since international research collaborations are nowadays routine, movement of genetically modified insects between laboratories under different regulatory jurisdictions is very common. This article describes the requirements and guidelines for transportation of genetically modified insects for research. The author draws upon the experience gained by an Italian laboratory, in its role as a research centre involved in shipments of wild and modified mosquitoes, within an international research consortium developing sustainable tools for malaria control.

Air-breathing rotating detonation fueled by liquid kerosene in cavity-based annular combustor

This study experimentally demonstrates the practicality of air-breathing/ramjet rotating detonation engines fueled by liquid kerosene and air. Experiments are performed, via a direct-connect scheme, in an annular combustor with a specific air-heater for generating supersonic air with a total temperature of 860 K, which approximates the Mach-4 flight condition at an altitude of 20 km. To address the difficulty in stabilizing the liquid-kerosene-air fueled rotating detonations, an optimized cavity that mimics the functionality of a scramjet is adopted in the rotating detonation combustor. The results indicate that, while maintaining the mass flow rate of the supersonic air at approximately 1000 g/s, the kerosene-air detonations can be successfully obtained in a self-sustaining manner with the equivalence ratio located within a wide range of 0.77–1.47. To the best of the authors' knowledge, these are the first experimentally obtained liquid-kerosene-air rotating detonations operating in the air-breathing mode. The average propagation velocities of the rotating detonation waves are experimentally measured to be approximately 60% of the corresponding theoretical Chapman–Jouguet velocity. Such significant velocity deficits, typically reported for liquid-fueled detonations, are indicative of considerable non-ideal effects experienced by the rotating detonation. Additionally, both the maximum average propagation velocity and largest statistically averaged pressure peak are obtained when the equivalence ratio approaches 1.10. Moreover, owing to the high-speed air inflow and the characteristic distance required for the evaporation and mixing of liquid kerosene, the detonation wave is located significantly downstream of the cavity, rather than typically being attached directly or close to the combustor inlet. The findings of this study provide insights into rotating detonations fueled by liquid kerosene, as well as demonstrate the high potential of their application to air-breathing propulsion.

Micronutrients May Be a Unique Weapon Against the Neurotoxic Triad of Excitotoxicity, Oxidative Stress and Neuroinflammation: A Perspective.

Excitotoxicity has been implicated in many neurological disorders and is a leading cause of oxidative stress and neuroinflammation in the nervous system. Most of the research to date has focused on each of these conditions individually; however, excitotoxicity, oxidative stress, and neuroinflammation have the ability to influence one another in a self-sustaining manner, thus functioning as a “neurotoxic triad.” This perspective article re-introduces the concept of the neurotoxic triad and reviews how specific dietary micronutrients have been shown to protect against not only oxidative stress, but also excitotoxicity and neuroinflammation. Future dietary interventions for neurological disorders could focus on the effects on all three aspects of the neurotoxic triad.

Characteristics of tofu whey degradation during self-sustaining batch anaerobic process for methane production

Tofu whey is produced during protein coagulation and tofu pressing in tofu processing. It is highly potential for use as a substrate in biogas production. As a protein-rich substrate, tofu whey potentially provides nitrogen, the main nutrient required by anaerobic microorganisms; and Volatile Fatty Acids (VFA) neutralization effect by ammonia generation. In tropical climates, relatively stable warm temperatures can be maintained throughout the year and create a mesophilic condition. Therefore, biogas production from tofu whey can potentially be conducted in a self-sustaining manner, without any physicochemical addition or intervention, including chemical addition and temperature control, during the process. This research studied characteristics of tofu whey degradation to observe its VFA neutralization effect and methane production in the laboratory self-sustaining batch anaerobic process. The VFA neutralization effect was investigated by comparing the digestion performance of tofu whey as a substrate to glucose as the positive control substrate. This study also evaluated the distribution of individual VFA and gas products. Self-sustaining methane production from tofu whey ran well without any indication of process failure. Tofu whey provided a VFA neutralization effect and could maintain pH levels between 6.8 and 8.4 during the process. The modified Gompert model predicted the experimental data well. This technology offers environmental and economic benefits. It potentially provides energy-saving and greenhouse gas (GHG) emission reduction based on the LPG substitution to biogas.

Circadian rhythms: influence on physiology, pharmacology, and therapeutic interventions.

Circadian rhythms are ubiquitous phenomena that recur daily in a self-sustaining, entrainable, and oscillatory manner, and orchestrate a wide range of molecular, physiological, and behavioral processes. Circadian clocks are comprised of a hierarchical network of central and peripheral clocks that generate, sustain, and synchronize the circadian rhythms. The functioning of the peripheral clock is regulated by signals from autonomic innervation (from the central clock), endocrine networks, feeding, and other external cues. The critical role played by circadian rhythms in maintaining both systemic and tissue-level homeostasis is well established, and disruption of the rhythm has direct consequence for human health, disorders, and diseases. Circadian oscillations in both pharmacokinetics and pharmacodynamic processes are known to affect efficacy and toxicity of several therapeutic agents. A variety of modeling approaches ranging from empirical to more complex systems modeling approaches have been applied to characterize circadian biology and its influence on drug actions, optimize time of dosing, and identify opportunities for pharmacological modulation of the clock mechanisms and their downstream effects. In this review, we summarize current understanding of circadian rhythms and its influence on physiology, pharmacology, and therapeutic interventions, and discuss the role of chronopharmacometrics in gaining new insights into circadian rhythms and its applications in chronopharmacology.

Origami Microfluidic Microbial Fuel Cell for Powering Iot Node with Iot Cloud Platform

Microbial fuel cells (MFCs) are bio-electrochemical devices that produce electrical current from the electrochemically active bacteria (EABs). These bacteria generate the electrons from the degraded organic matter and harness renewable and pollution-free energy in a self-sustaining manner. Due to its user-friendly architecture, neutral pH, simple operating conditions and amenability to integrate with the on-chip technology, MFCs are the economical and convenient alternative to conventional power sources. Since the first development of MFC, an ample amount of studies have been reported especially to harness new bacteria types, inoculation protocols, and cell and bioelectrode fabrication methodologies. As a result, several MFCs have been successfully developed as a biosensor and power hub by utilizing various fluid resources, such as domestic and industrial wastewater, urine, and soiled water from sewage. However, in order to be commercially viable, the device architecture and size of the MFCs become the essential parameter for power generation, which decides the potential application. In this context, several micro-scale MFC architectures have been proposed. Among these, the paper-based microfluidic fuel cell technology has drawn remarkable attention due to its inexpensive and inherent fluid flow capillary action properties. In addition, wide array (series/parallel) configurations have been incorporated to further enhance the power output.With these MFCs, a extensive range of applications, such as powering LEDs, digital thermometer, wireless, sensors, radio nodes etc., have been successfully demonstrated. With this flexibility and unique features, paper-based MFCs have the ability to monitor the on-field parameter (temperature, humidity, hazardous gas etc.) using the Internet of Things (IoT) cloud network. Currently, The Internet of Things (IoT) technology is the most popular technology in the field of wireless data transmission with IoT cloud. It connects various devices and their protocols over internet infrastructure which can be monitored, analyzed, and controlled remotely over the internet. It has an immense application in the field of healthcare, agriculture, automotive, and remote sensing sectors.In this study, as a proof of concept, the Shewanella putrefaciens powered stacked origami MFCs have been demonstrated to drive an ultra-low-power (ULP) IoT node to measure the on-field ambient temperature and transmit corresponding data to a mobile phone. The IoT node requires 2.5–3.3 volt for proper operation, therefore a DC-DC booster was used just after the fuel cell to step-up the low voltage. This step-up voltage was further stored in the supercapacitor to supply power to the IoT node in case of a high current requirement. Finally, after powering the IoT node, it sends the temperature data over low-power Bluetooth low energy (BLE) that can be observed by any smartphone supporting Bluetooth 4.0 and nRF connect android app. The detailed stepwise integrated block diagram from MFC to a mobile phone has been displayed in Figure 1. The proposed approach offers autonomous environmental monitoring using paper-based MFC as a viable substitute for conventional power sources. Figure 1: Block diagram of complete setup MFCs powering IoT node which communicates to smartphone and IoT cloud servers Figure 1

The Performativity of Literature Reviewing: Constituting the Corporate Social Responsibility Literature Through Re-presentation and Intervention

Although numerous books and articles provide toolkit approaches to explain how to conduct literature reviews, these prescriptions regard literature reviewing as the production of representations of academic fields. Such representationalism is rarely questioned. Building on insights from social studies of science, we conceptualize literature reviewing as a performative endeavor that co-constitutes the literature it is supposed to “neutrally” describe, through a dual movement of re-presenting—constructing an account different from the literature, and intervening—adding to and potentially shaping this literature. We discuss four problems inherent to this movement of performativity— description, explicitness, provocation, and simulacrum—and then explore them through a systematic review of 48 reviews of the literature on corporate social responsibility (CSR) for the period 1975 to 2019. We provide evidence for the performative role of literature reviewing in the CSR field through both re-presenting and intervening. We find that reviews performed the CSR literature and, accordingly, the field’s boundaries, categories, and priorities in a self-sustaining manner. By reflexively subjecting our own systematic review to the four performative problems we discuss, we also derive implications of performative analysis for the practice of literature reviewing.

Generador de Agua mediante el uso de Celdas Peltier y Energía Solar

At present, the drought periods are longer due to global warming, which has generated scarcity and water rationing, these conditions become the main problem in remote villages to urban areas and with little infrastructure. Mexico, with 653 aquifers throughout its territory, 106 are overexploited due to agricultural, mining, industrial and urban activities, which projects to the country a possible depletion and contamination of its vital liquid. For this reason, in order to contribute to a solution to the problem of water scarcity, by applying a control system to the technology used by the Peltier cells, a moderate flow of water is generated, since it condenses the particles of water suspended in the air. In this way, an array of Peltier cells will be implemented to obtain as much water as possible under environmental factors, such as humidity and temperature. In addition, when dealing with areas where the climate is arid, it is intended to use alternative sources of energy, of autonomous photovoltaic type, to take advantage of solar radiation and feed the control system in a self-sustaining manner.

Combustion Synthesis of FeAl-based Composites from Thermitic and Intermetallic Reactions

Combustion syntheses involving intermetallic and thermitic reactions were conducted to fabricate FeAl–TiB2–Al2O3 composites. Two combustion systems consisting of Fe, Al, Ti, Fe2O3 and B2O3 were studied for formation of xFeAl–yTiB2–Al2O3 composites with x = 1.5–3.5 and y = 0.5–0.8. In the reaction series, thermitic reduction of Fe2O3 and B2O3 by Al thermally activated the reaction between Fe and Al. As a result, the combustion wave of the synthesis reaction was sufficiently exothermic to propagate in a self-sustaining manner. With an increase in TiB2 and FeAl of the composites, the decrease of reaction exothermicity resulted in a decline of the combustion wave velocity and reaction temperature. The activation energy Ea = 88.92 kJ/mol was deduced for the synergetic combustion reaction. Based on XRD analysis, a thorough phase conversion was achieved and composites composed of FeAl, TiB2, and Al2O3 with different contents were obtained. The SEM micrograph showed the FeAl-based composite with a dense and connecting morphology.

Rapid mechanochemical synthesis of nanostructured mohite Cu2SnS3 (CTS)

Rapid solvent-free mechanochemical synthesis of CTS nanocrystals from elemental precursors is reported herein. The process is completed in 15 min, proceeding through immediate formation of CuS in a self-sustaining manner and its subsequent reaction with Sn and residual sulfur. The reaction progress was monitored by pressure and temperature changes in the milling vessel, X-ray diffraction, Soxhlet analysis, grain size analysis and electric resistivity measurements. The relationship between the consumption of metallic precursors, grain size and electrical resistivity is provided. The final product was nanocrystalline with crystallite size below 10 nm, as confirmed by both X-ray diffraction and transmission electron microscopy. The nanocrystals are agglomerated into micrometer-sized grains. It exhibits poor porous properties with the specific surface area value of 2.5 m2/g. The X-ray photoelectron spectroscopy has shown that the surface is significantly oxidized, due to milling in air. The optical properties of the prepared CTS nanocrystals are interesting for photovoltaic applications.

Canadian micro-credit programs: an investigation of model differences

The formation of new social institutions is changing the landscape of the current economy. Social entrepreneurs develop innovative models to help marginalized communities, all in a self-sustaining manner. Such innovative models can be seen in institutions engaging in micro-credit activity, which offer access to financial services to the poor, who are generally excluded from the traditional banking system. This study investigates five institutions offering micro-credit across Canada. Particular attention is paid to the models they employ to help their clientele in Canada and also the repayment rates they report. The study concludes with the three key policy prescriptions.

Fabrication of WSi2–Al2O3 and W5Si3–Al2O3 composites by combustion synthesis involving thermite reduction

Formation of WSi2–Al2O3 and W5Si3–Al2O3 composites was studied by thermite-based combustion synthesis. The addition of two thermite combinations composed of WO3+2Al and 0.6WO3+0.6SiO2+2Al into the W-Si reaction systems facilitated the combustion wave propagating in a self-sustaining manner and contributed to the in situ formation of tungsten silicides along with Al2O3. Experimental results showed that the former thermite mixture is more exothermic than the latter, and a decrease in the combustion temperature and flame-front velocity with increasing silicide phase formed in the composite. Depending on the reaction stoichiometry, the combustion wave velocity varied from 9.5 to 3.7mm/s and temperature from 1650 to 1280°C. A complete phase conversion and a broad range of the molar ratio of WSi2/Al2O3 from 0.8 to 4.0 were achieved for the production of the WSi2–Al2O3 composites. Due to the lower formation exothermicity, the W5Si3–Al2O3 composites were produced with a narrower range of W5Si3/Al2O3 from 0.4 to 2.0, beyond which combustion failed to proceed. Moreover, there exist WSi2 and unreacted W in the as-synthesized W5Si3–Al2O3 composites.

Smoldering Combustion (STAR) for the Treatment of Contaminated Soils: Examining Limitations and Defining Success

Smoldering combustion, commercially available as the Self-sustaining Treatment for Active Remediation (STAR) technology, is an innovative technique that has shown promise for the remediation of contaminant source zones. Smoldering combustion is an exothermic reaction (net energy producing) converting carbon compounds and an oxidant (e.g., oxygen in air) to carbon dioxide, water, and energy. Thus, following ignition, the smoldering combustion reaction can continue in a self-sustaining manner (i.e., no external energy or added fuel input following ignition) as the heat generated by the reacting contaminants is used to preheat and initiate combustion of contaminants in adjacent areas, propagating a combustion front through the contaminated zone provided a sufficient flux of air is supplied. The STAR technology has applicability across a wide-range of hydrocarbons in a variety of hydrogeologic settings; however, there are limitations to its use. Impacted soils must be permeable enough to allow a sufficient flux of air to the combustion front and there exists a minimum required concentration of contaminants such that the soils contain sufficient fuel for the reaction to proceed in a self-sustaining manner. Further limitations, as well as lessons learned and methods to mitigate these limitations, are presented through a series of case studies. In summary, the successful implementation of STAR will result in >99 percent reduction in contaminant concentrations in treated areas, limited residual contaminant mass, reduced groundwater contaminant mass flux which can be addressed through monitored natural attenuation; and an enhanced site exit strategy, reduced lifecycle costs, and reduced risk. ©2016 Wiley Periodicals, Inc.

Design and packaging of a highly integrated microreactor system for high-temperature on-board hydrogen production

The development of miniaturized reactors that can operate at high temperatures independently is always of great interest for many applications, especially in the area of portable hydrogen production. Here we present such microreactor systems, made of glass, with integrated heating and fluidic features based on thick-film technology. Key considerations on design, fabrication and packaging of our systems to achieve a high-temperature operation (>500°C), a thermal decoupling over 400°C for the device in the use of standard electrical/fluidic connections, as well as a simple catalyst installation method, are described. Demonstration of these “plug-and-play” microreaction systems is shown with producing hydrogen on-board from catalytic partial oxidation of propane at about 550°C (achieving 85% conversion of propane and 46.8% of hydrogen yield). The energy efficiency in comparison of the power consumption of electrical heating with the estimated energy produced from reformates shows a negative balance in the system under 30sccm feed of fuel/air mixture, indicating that a sufficient feed rate of fuel/air mixture is required for the system to achieve optimal energy balance. At an adequate level of the feed rate, the CPOX carried in our systems can even reach a thermally self-sustaining manner without needs of the electrical heating, which have been illustrated in our application development in micro-fabricated microreactors and micro-scale solid oxide fuel cells.

Saving mothers and newborns in communities: strengthening community midwives to provide high quality essential newborn and maternal care in Baluchistan, Pakistan in a financially sustainable manner

BackgroundTo address it's persistently high maternal mortality rate of 276/100,000 live births, the government of Pakistan created a new cadre of community based midwives (CMW). One expectation is that CMWs will improve access to maternal health services for underserved women. Recent research shows the CMWs have largely failed to establish midwifery practices, because CMW's lack of skills, both clinical and entrepreneurial and funds necessary to develop their practice infrastructure and logistics. Communities also lack trust in their competence to conduct safe births. To address these issues, the Saving Mothers and Newborn (SMNC) intervention will implement three key elements to support the CMWs to establish their private practices: (1) upgrade CMW clinical skills (2) provide business-skills training and small loans (3) generate demand for CMW services using cellular phone SMS technology and existing women’s support groups.Methods/DesignThis 3-year project aims to investigate whether CMWs enrolled in this initiative are providing the essential maternal and newborn health care to women and children living in districts of Quetta, and Gwadar in a financially self-sustaining manner. Specifically the research will use quasi-experimental impact assessment to document whether the SMNC initiative is having an impact on CMW services uptake, financial analysis to assess if the initiative enabled CMWs to develop financially self-sustainable practices and observation methods to assess the quality of care the CMWs are providing.DiscussionA key element of the SMNC initiative - the provision of business skills training and loans to establish private practices - is an innovative initiative in Pakistan and little is known about its effectiveness. This research will provide emperic evidence of the effectiveness of the intervention as well as contribute to the body of evidence around potential solutions to improve sustainable coverage of high impact Maternal, Neonatal and Child Health interventions in vulnerable populations living in remote rural areas.

Self-sustaining reactions as a tool to study mechanochemical activation.

Ever since Faraday reported on the reduction of AgCl with Zn and Sn the "dry way", the study of Mechanically induced Self-propagating Reactions (MSRs) has been an important area within mechanochemistry. An interesting phenomenon is the mutual suppression of ignition in some mixed metal-chalcogen systems, such as in (1 - x)(Sn + Se) + x(Zn + Se) powders. Here both the Sn + Se and Zn + Se mixtures react in a self-sustaining manner after some activation time, but when they are combined, the reaction is gradual in the middle of the concentration scale. Mechanically induced metal-chalcogen combination reactions were studied by Chakurov et al. in the 1980s, using a low-energy vibratory mill. Similar measurements were carried out in our laboratory using the more energetic SPEX 8000 shaker mill. The results show qualitative similarities, but the details are different. It is suggested that the loss of MSR in mixed systems is the consequence of the very different properties of the binary systems, so that either one of the components (Zn) or a product formed gradually without ignition (e.g. SnSe) can act as an inert component relative to the rest of the system. Several examples are presented and the effect of the milling conditions is discussed. Finding new systems with similar behaviour and detailed studies of the activated state are needed to understand MSR in these systems.

High pressure synthesis of magnesium aluminate composites with MoSi2 and Mo5Si3 in a self-sustaining manner

Magnesium aluminate/MoSi2 and magnesium aluminate/Mo5Si3 composites were successfully prepared by combustion synthesis with a special emphasis on the thermodynamic of the reactions involved in the process. The process involves loading of a very weak exothermic formation reaction of MgAl2O4 onto a highly exothermic formation reaction of MoSi2 and Mo5Si3. The starting material was a blend of MoO3, SiO2, Al and MgO. The effect of Al grain size (−5 to −71μm), MoO3 stoichiometric value (0.7–1.25x), MgO additions (15–25wt%) and working pressure (50bar) on the synthesis process were investigated. Microstructure of the combustion products was inspected by SEM. It was found that using −5μm grain size Al was necessary for reaction completion. Higher stoichiometric value of MoO3 was found to be necessary to compensate for its volatilization from the reaction media. Addition of MgO as diluents reduced combustion temperature but unexpectedly it reacted with some amounts of SiO2 and formed Mg2SiO2 phase and Mo5Si3 instead of MoSi2. However, increasing the reaction pressure was found to be the most effective factor to suppress the MoO3 volatilization. Thermodynamic study of the process revealed the production of entire phases in molten states whereas the adiabatic temperatures of the formation reaction of MgAl2O4/MoSi2 and MgAl2O4/Mo5Si3 composites were 2408 and 3210K, respectively.

Multisite models to determine the distribution of kink sites adjacent to low-energy edges

Kink sites play a critical role in crystal growth. The incorporation of a growth unit into a kink site (1) maintains the free energy of the edge constant and (2) creates another site with the same properties. These properties allow growth through successive incorporation events to proceed in a self-sustaining manner such that the equilibrium spacing between kinks is maintained on average. Traditionally the distributions of kink sites have been determined using a single-site model whereby the probabilities of encountering a kink site adjacent to an edge and encountering a disturbance along an edge are assumed equivalent. In this paper, we develop multisite models that determine the probabilities of encountering kink sites; with the requirement that they obey both properties necessary for growth through successive self-sustaining incorporation events. The probabilities determined using the multisite models diverge significantly from the single-site model for edges with intermolecular interactions ≲6k(b)T between successive molecules. The implications of these findings for the development of predictive crystal shape models and experimental analysis are discussed.