Approach For Synthesis Research Articles

Synthesis of dynamic modelling framework and optimal control strategy for virtually coupled train sets with guaranteed safety

Virtual coupling represents a novel railway operational mechanism, wherein several trains share state information and adjust their behaviours based on control objectives, which include safety (collision avoidance) assurance and stability (uniform velocity and constant spacing between trains) maintenance. However, the conflict between safety and stability requirements becomes more apparent, as the closer spacing between trains. Moreover, the hybrid nature of the train platoon operation, which involves both discrete events and continuous dynamics, also poses a significant barrier to the control strategy synthesis. This paper presents the Virtually Coupled Train Sets (VCTS) dynamic modelling framework and strategy synthesis approach to address these problems. A Hybrid Markov Decision Process (HMDP) is adopted for relative longitudinal dynamics modelling of trains, considering the influence of the uncertainty dynamic of trains ahead. A Stackelberg game-based strategy synthesis algorithm is applied for the safe guarantee by overcoming the uncertainty, and a Q-learning method is used for stability strategy selection from the safe strategy. The results showed a 17.95% expansion in the safe state space when compared to the general relative braking scheme (which assumes maximal acceleration during the delay horizon). In a four-train tracking operation scenario, compared with Q-learning without safe constraints, our approach gives similar stability performance; compared with Q-learning with general relative braking safe constraints, our approach not only assurance safety but has a better stability performance.

Biomimetic folding strategies for chemical synthesis of disulfide-bonded peptides and proteins.

Disulfide-bonded peptides and proteins, including hormones, toxins, growth factors, and others, are abundant in living organisms. These molecules play crucial physiological roles such as regulating cell and organism growth, development, and metabolism. They have also found widespread applications as drugs or tool molecules in biomedical and pharmaceutical research. However, the chemical synthesis of disulfide-bonded proteins is complicated by the challenges associated with their folding. This review focuses on the latest advancements in disulfide-bonded peptide and protein folding technologies. Particularly, it highlights biomimetic folding strategies that emulate the naturally occurring oxidative folding processes in nature. These strategies include chaperone-assisted folding, glycosylation-assisted folding, and organic-based oxidative folding methods. The review also anticipates future directions in folding technology. Such research offers innovative approaches for the chemical synthesis of complex proteins that are otherwise difficult-to-fold.

Total Synthesis of an Immunosuppressive C25 Macrocyclic Terpenoid Produced by Terpene Synthase (LcTPS2).

Macrocyclic natural products, particularly those with no functionalities except unsaturation, are recognized for their therapeutic potential but are notoriously challenging to synthesize. In this study, we report the first total synthesis of an unconventional 18-membered, C25 macrocyclic terpenoid, which has demonstrated substantial immunosuppressive activity. This synthesis was achieved through strategic modifications and innovative reaction engineering, utilizing α-terpineol and geraniol as starting materials, highlighting a novel approach in macrocyclic terpenoid synthesis.

Direct synthesis of nickel oxide nanoparticles from pregnant leach solution by using electrodeionization and Fenton processes in the presence of EDTA

This paper presents the results of a novel study on the direct synthesis of nickel oxide nanoparticles from a synthetic pregnant leach solution (PLS) as a middle stage product of hydrometallurgy process of nickel production. To increase the nickel proportion in the initial PLS, electrodeionization was utilized in the presence of EDTA to form an anionic complex ([Ni-EDTA]2−) with Ni2+ cations, allowing their separation from cobalt cations through the EDI process. Subsequently, the Fenton process was applied to synthesize nickel oxide nanoparticles from the complex containing solution. The proposed hybrid process was conducted in two different modes of one-stage and two-stage EDI process followed by the Fenton process. Different analysis methods including AAS, XRD, FE-SEM, and ICP were used for qualitative and quantitative evaluations. The analyses’ results revealed that by implementing one-stage EDI process followed by Fenton process resulted in producing nickel oxide nanoparticles with an average particle size of 45 nm and purity of about 98 %. Also, it was seen that about 81 % of initial nickel content of the initial PLS was recovered as nickel oxide nanoparticles. In the case of two-stage EDI process, 100 % pure nickel oxide nanoparticles with average size of 55 nm and recovery of 65 % was produced. The results showed that the innovative hybrid EDI/Fenton process can be considered as a promising approach for direct synthesis of high purity nickel oxide nanoparticles from PLS. However, it should be noted that there was a trade-off between purity of nickel oxide and nickel recovery from PLS.

Fe0-MAP Prepared Glycosurfaces for Selective Cell Capture: From Adherent to Suspended Cells.

The specific capture of live cells is crucial for various biomedical applications. Existing methods often are limited by complex production processes. This study introduces Fe0-mediated monomer-adaptation polymerization (Fe0-MAP), a convenient and rapid synthesis approach for selective cell capture using surface-engineered glycopolymer brushes. This method utilizes surface-initiated zerovalent iron-mediated reversible-deactivation radical polymerization (Fe0-SI-RDRP), offering advantages like simplicity, biocompatibility and oxygen-tolerance due to the use of iron sheet as catalysts. We successfully employed Fe0-MAP to selective capture both adherent (HeLa, L929) and suspended cells (Ramos, U937) in mammalian cell cultures. Combining excellent biocompatibility, specific and reusable cell capture capabilities, and applicability to suspended cells, Fe0-MAP establishes itself as a promising strategy for selective cell capture, holding significant potential for diverse biomedical applications.

Sampled-Data H∞ Dynamic Output-Feedback Control for NCSs With Successive Packet Losses and Stochastic Sampling.

The problem of sampled-data H∞ dynamic output-feedback control for networked control systems with successive packet losses (SPLs) and stochastic sampling is investigated in this article. The aim of using sampled-data control techniques is to alleviate network congestion. SPLs that occur in the sensor-to-controller (S-C) and controller-to-actuator (C-A) channels are modeled using a packet loss model. Additionally, it is assumed that stochastic sampling follows a Bernoulli distribution. A model is established to capture the stochastic characteristics of both the SPL model and stochastic sampling. This model is crucial as it allows us to determine the probability distribution of the sampling interval between successive update instants, which is essential for stability analysis. An exponential mean-square stability condition for the constructed equivalent discrete-time stochastic system, which also guarantees the prescribed H∞ performance, is established by incorporating probability theory. The desired controller is designed using a step-by-step synthesis approach, which may offer lower design conservatism compared to some existing methods. Finally, our designed approach using a networked F-404 engine system model is validated and its merits relative to existing results are discussed. The proposed method is finally validated by employing a networked model of the F-404 engine system. Furthermore, the advantages of our method are presented in comparison to previous results.

Projection of Electric Ships as Sustainable Transportation in the Capital City of Indonesia “Nusantara”

Abstract Nusantara is Indonesia’s new capital or knows as Ibu Kota Nusantara (IKN) for implementing the sustainable city concept. Waters separate the area around IKN with a total area of 68,188 ha. Therefore, people living in IKN, namely in Penajam and its surroundings, have become accustomed to using water transportation to travel between regions. Ship transportation that the community has often used has also been developed with electric ships to support sustainable cities and zero emissions at IKN. However, in implementing electric ships, problems arise, namely how to project the development of electric ship technology based on policy documents and development planning in the Nusantara Capital City. The objective to be achieved is to see the planning and policy document for developing environmentally friendly water transportation using electric power. The method used in this study is qualitative, with a synthesis approach. Data collection was carried out by document study from policies and regulations. The data was then analyzed descriptively to obtain important information about the problem. For the result, the projection of the of electric ships in IKN must be carefully planned so that it can be realized to support Sustainable City and zero emission in IKN later.

Greener Approach to Cost‐Effective Electrochemical L‐cysteine Sensing Using Polyaniline‐Modified Carbon Paste Electrodes

AbstractIn this study, we present a facile approach for the green synthesis of polyaniline (PANI) through electrochemical polymerization on a graphitic paste electrode, thus enhancing its use in electrochemical sensing applications. The morphology of the synthesized PANI was observed using scanning electron microscopy (SEM), the crystallinity of the material was studied using XRD, and further functional groups were characterized by FT‐IR and UV spectroscopy. PANI, coated on the surface of a graphitic paste ‐modified electrode (P‐GPME) by controlled electrolysis, demonstrated notable electrocatalytic activity toward L‐cysteine (L‐cyst). The redox behavior of L‐cyst at the P‐GPME surface was investigated using cyclic voltammetry. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 2.4 × 10−6 and 1.21 × 10−5 mol L−1, respectively. These results highlight the potential of P‐GPME for selective and sensitive detection of L‐cyst. Furthermore, the designed electrode was effectively employed for the determination of L‐cyst in urine samples.

Microstructural evolution and 1500 °C oxidation resistance of Mo(Al,Si)2 fabricated via an innovative two-step SHS-SPS technique

An innovative two-step approach of self-propagating high-temperature synthesis (SHS) and spark plasma sintering (SPS) was developed to rapidly fabricate MoSi2 and Mo(Al,Si)2 ceramics for high-temperature anti-oxidation applications. The SHS process predominantly promoted the synthesis of high-purity and high-yield MoSi2 and Mo(Si,Al)2 phases in the alloyed powders. Subsequently, dense and crack-free MoSi2 and Mo(Al,Si)2 ceramics were produced using SPS. 1500 °C oxidation tests of the ceramics (100 h) revealed the formation of a protective SiO2 oxide layer on the surface of MoSi2 ceramics, while an Al-Si-O composite glassy oxide layer formed on Mo(Si,Al)2 ceramics., which exhibited better thermal stability and lower oxygen permeability compared to the single SiO2 oxide layer. However, an excessive Al content (>0.05 at.%) compromised the oxidation resistance due to the emergence of a Si-depleted Mo5(Si,Al)3 layer with inferior oxidation resistance, which was caused by the high-temperature diffusion of Si. Therefore, via this novel two-step SHS-SPS technique compact and crack-free Mo(Si,Al)2 ceramics can be rapidly synthesized at high temperatures. When trace amount of Al was added (0.05 at.%), Mo(Si0.95,Al0.05)2 showed optimum high-temperature oxidation resistance.

Investigation on melt growth (Mg, Co, Ni, Cu, Zn)O oxide ceramics prepared by laser directed energy deposition

High-entropy oxides (HEOs) have attracted extensive research interest due to their unique structural features, customizable elemental compositions, and tunable functional properties. Nevertheless, the complexity, low efficiency, and high cost of the existing HEO synthesis methods place limitations on them. In this study, Laser directed energy deposition (LDED) was employed to synthesize (Mg, Co, Ni, Cu, Zn)O oxides. Additionally, the novelty of applying the LDED process to multicationic systems was emphasized. The comparison between specimens fabricated from mixed powder via LDED(MP) and those fabricated from pre-sintered powder via LDED(SP) encompasses macroscopic morphology, microstructure, and performance. The results showed that SP significantly enhanced the density from 86.44% to 96.70% compared to MP. The macro-segregation of Cu and Cu2O in the phase composition was observed in MP and SP. High-temperature pre-sintering promoted the solid solution formation of Co and Ni during LDED, leading to more severe micro-segregation of Co and Ni. When employed as anodes in lithium-ion batteries, MP and SP have outstanding long-term cycle stability, according to electrochemical performance studies. At a current density of 100 mAg-1, these specimens maintained a capacity retention rate of 100% even after 200 cycles. The initial discharge capacities of MP and SP were respectively 477.73 mAh g-1 and 373.86 mAh g-1. This study is expected to present a novel approach for the rapid synthesis of (Mg, Co, Ni, Cu, Zn)O oxide ceramics.

Enabling Sustainable Ammonia Synthesis: From Nitrogen Activation Strategies to Emerging Materials.

Ammonia (NH3) is one of the most important precursors of various chemicals and fertilizers. Given that ammonia synthesis via the traditional Haber-Bosch process requires high temperatures and pressures, it is critical to explore effective strategies and catalysts for ammonia synthesis under mild reaction conditions. Although electrocatalysis and photocatalysis can convert N2 to NH3 under mild conditions, their efficiencies and production scales are still far from the requirements for industrialization. Thermal catalysis has been proven to be the most direct and effective approach for ammonia synthesis. Over the past few decades, significant efforts have been made to develop novel catalysts capable of nitrogen fixation and ammonia generation via thermal catalytic processes. In parallel with catalyst exploration, new strategies such as self-electron donation, hydride fixation, hydridic hydrogen reduction, and anionic vacancy promotion have also been explored to moderate the operating conditions and improve the catalytic efficiency of ammonia synthesis. In this review, the emergence of new materials and strategies for promoting N2 activation and NH3 formation during thermal catalysis is briefly summarized. Moreover, challenges and prospects are proposed for the future development of thermal catalytic ammonia synthesis.

Constructing perfluorinated UiO-67 for enrichment of polycyclic aromatic hydrocarbons in seawater and seabed sediments

To investigate the ocean contamination caused by polycyclic aromatic hydrocarbons (PAHs), UiO-67/perfluorooctanoic acid (UiO-67/PFOA) was synthesized through solvent-assisted ligand incorporation method. The UiO-67/PFOA was then served as an adsorbent in headspace solid-phase microextraction (HS-SPME) technology for collecting and concentrating trace PAHs. The addition of the PFOA improved the hydrophobicity and stability of the UiO-67/PFOA coating, and the C-F functional group in UiO-67/PFOA could form the pseudo hydrogen bonding with the C-H on the benzene ring of PAHs, which endowed the UiO-67/PFOA with 1.60-4.63 times enrichment performance for PAHs than UiO-67. Under optimal conditions, the wide linear ranges of PAHs (0.01-20 ng·mL−1) with good coefficients of determination (R2 ≥ 0.9950) and low limits of detection (LODs, 0.003-0.008 ng·mL−1) were obtained. The recoveries of five PAHs from spiked seawater and seabed sediment by the developed method ranged from 81.14% to 116.0% with satisfactory results. This work provided a good adsorbent for the enrichment of trace PAHs in complicated environments and a new approach for the subsequent synthesis of adsorbents with good enrichment performance.

A classical peptide coupling approach for the total synthesis of simnotrelvir#

A classical peptide coupling approach for the total synthesis of simnotrelvir#

A Facile and Greener Approach for Synthesis of Lignin Capped-Silver Nanoparticles (LS-AgNPs) and Assessment of their Antibacterial and Antioxidant Properties

Silver nanoparticles have garnered significant attention in research due to their numerous advantageous qualities, such as antimicrobial, antioxidant, and anticancer activities. Several methods have been employed previously to produce these nanoparticles, but green synthesis has gained prominence due to its lack of harmful by-products. In this study, stable and biocompatible lignin-capped silver nanoparticles (LS-AgNPs) have been synthesized using a green approach that utilized nontoxic sodium lignosulfonate as both the reducing and capping agents. Various process parameters, such as pH, temperature, time, and raw material concentration have been optimized to simplify, accelerate and mould the synthesis activity easy and eco-friendly. The morphology and dimensions of the prepared lignin-capped silver nanoparticles (LS-AgNPs) have been characterized using UV–Vis spectroscopy, particle size analyser, X-ray diffraction analysis, Fourier transform infrared spectroscopy and Transmission Electron Microscopy. The produced nanoparticles have an average diameter of 24 nm and a FCC crystalline structure that is capped with lignin components. MBC of LS-AgNPs has been found 4 and 6 ppm against S. aureus and E. coli bacteria, respectively. The IC50 value for antioxidant property has been found 34.37 μg/mL. In summary, the prepared LS-AgNPs have exhibited a synergistic effect resulting from the combination of lignosulfonate and silver particles. The synergistic effect not only enhances antimicrobial activity and antioxidant property remarkably, this approach enables the utilization of biobased silver nanoparticles for various applications with its requirement of minimal quantity to have much lowered toxicity compared to pure silver nanoparticles.

Plant-synthesis of co-doped tin dioxide nanocomposite with magnetic activity and its photocatalytic performance assessment on dyes and pesticides

The hydrothermal method was used to introduce different amounts of Praseodymium ion (Pr3+) (1, 3, 5, 7, 9, and 11 at.%) and Yttrium ion (Y3+) (1, 3, 5, 7, 9, and 11 at.%) into existing SnO2 nanoparticles. A novel nanocomposite was created by combining Fe3O4 and SnO2:Pr3+,Y3+ nanoparticles, resulting in a material with magnetic properties, i.e., Fe3O4/SnO2:Pr3+,Y3+, named FPYS. Subsequently, the hydrothermal synthesis approach was utilized to produce nanocomposites of FPYS in the presence of plant extract. The photodecomposition efficiency of as-synthesized nanocomposite was studied with some selected dyes and pesticides under 50W LED light. The present study focused on experimentally optimising the key parameters like the initial concentration, photocatalyst quantity, photocatalyst reuse, and pH level. By employing the Langmuir-Hinshelwood model, we successfully calculated the rate at which RhB, MB, 2,4-DCP, and MB undergo photocatalytic degradation under optimal conditions (pH = 7, pollutant concentration = 8 ppm, volume of pollutants = 20 mL, and photocatalyst amount = 3 mg). The model showed that MB, RhB, 2,4-DCP, and TCAA have k values of 0.061, 0.062, 0.051, and 0.036 min−1, respectively. The breakdown rate for MB dye was 81% and for RhB dye was 78% with nanocomposite made in the presence of 2 mL of Parkia speciosa extract, which was subjected to LED radiation for 150 min at pH 7. The degradation rates of 2,4-DCP and TCAA differed, i.e., the former was degraded by 68% and the latter by 52%. Pr3+ and Y3+ ions co-doped with SnO2 enhanced the photocatalytic degradation of dyes and pesticides.

“Novel chemo-enzymatic synthesis, structural elucidation and first antiprotozoal activity profiling of the atropoisomeric dimers of trans-8-Hydroxycalamenene”

Leishmaniasis and malaria are two debilitating protozoan diseases affecting millions globally, particularly in tropical and subtropical regions. Current therapeutic options face significant challenges due to emerging drug-resistant strains, necessitating the discovery of novel antiprotozoal agents. This study explores, for the first time, the antiprotozoal potential of calamenenes and their dimers, naturally occurring sesquiterpenes found in essential oils, through a novel chemo-enzymatic synthesis approach. Using the laccase from Trametes versicolor, atropoisomeric dimers of (−)- and (+)-8-trans-hydroxycalamenene were synthesized from commercially available (−)- and (+)-menthol. Structural elucidation was achieved via 2D-NMR spectroscopy, electronic circular dichroism, and DFT calculations. In vitro profiling against Leishmania spp and drug-resistant Plasmodium falciparum revealed that calamenene dimers exhibited significantly higher antiprotozoal activity compared to their monomeric counterparts, highlighting the potential of dimeric terpenoids as promising antiprotozoal agents. This work lays the foundation for developing novel antimalarial drugs based on calamenene scaffolds, encouraging further interactome studies to optimize their pharmacological properties.

Ultralong K0.5Mn0.75PS3 Nanowires Tailored by K-Ion Scissors for Extraordinary Sodium-Ion Storage.

1Dlayered nanowires (NWs) are expected to be excellent electrode materials due to their efficient electron/ion transport and strain/stress relaxation. However, it is a great challenge to synthesize layered NWs by a top-down synthetic route. Herein, ultralong 1D layered K0.5Mn0.75PS3 NWs (length: >100µm; diameter: ≈300nm) are synthesized for the first time using "K-ion chemical scissors", whose excellent sodium storage performance originates from the bifunctional structural unit, ingeniously combining the alloying energy storage functional unit (P-P dimer) with the quasi-intercalated functional unit ([MnS3]4- framework). Stress-driven K-ion scissors achieve the rapid transformation of MnPS3 bulk to K0.5Mn0.75PS3 NWs with directed tailoring. Compared to MnPS3, the NWs exhibit enlarged interlayer spacing (9.32 Å), enhanced electronic conductivity (8.17×10-5 S m-1 vs 4.47×10-10 S m-1), and high ionic conductivity (2.14 mS cm-1). As expected, the NWs demonstrate high capacity (709 mAh g-1 at 0.5 A g-1) and excellent cycling performance (≈100% capacity retention after 2500 cycles at 10 A g-1), ranking among metal thiophosphates. A quasi-topological intercalation mechanism of the NWs is revealed through further characterizations. This work expands the top-down synthesis approach and offers innovative insights for the cost-effective and large-scale fabrication of NWs with outstanding electrochemical performance.

Simultaneous structure and surface engineering of metal-organic framework derived LiNi0.5-xFe2xMn1.5-xO4 cathode material for improving high voltage performance of lithium-ion batteries

This study presents a novel material synthesis approach utilizing a terephthalic acid-based metal-organic framework as a precursor and employing an ethanol-assisted hydrothermal treatment to produce high-performance Fe-doped LiNi0.5Mn1.5O4 (LNMO) cathode material. This strategy yields a well-crystallized spinel structure with uniformly distributed transition metal ions. Additionally, the appropriate quantity of Fe dopant can achieve the desired Mn3+/Mn4+ ratio, level of structural disordering, and crystal phase purity for Fe-doped LNMO. The synthesis process also aids in forming an amorphous Li2CO3 surface layer, approximately 1 nm thick, which protects the active material from excessive reaction with electrolyte. The typical Fe-doped LNMO cathode (S-05) exhibits superior performance compared to a commercialized LNMO counterpart. It delivers an initial discharge capacity of 135 mAh g-1 at 1 C with exceptional cycling stability over 500 cycles (capacity retention of 90%) under high voltage (5.0 V vs. Li+/Li). Furthermore, its rate capability significantly improves, with a capacity retention of 85% (5 C/0.2 C). This enhanced performance aligns with evidence of activated Ni2+/Ni3+/Ni4+ redox reactions and suppressed cathode electrolyte interphase resistance, leading to promoted Li+ diffusion. Moreover, it is found the cathode helps alleviate electrolyte degradation at high voltages by inhibiting the formation of singlet oxygen in the electrolyte.

Solution-focused approaches for treating self-injurious thoughts and behaviours: a scoping review

Abstract Background Self-injurious thoughts and behaviours are a major global public health concern, not least because they are one of suicide’s strongest predictors. Solution-focused approaches are a psychotherapeutic approach currently being used to treat individuals with self-injurious thoughts and behaviours but there is little published evidence of their use. We conducted a scoping review to provide a comprehensive overview of how solution-focused approaches are being used to treat self-injurious thoughts and behaviours. Methods Publications describing a solution-focused approach being delivered to any individuals experiencing any form of self-injurious thought and/or behaviour were eligible for inclusion. Five databases were searched (EMBASE, PubMed, Web of Knowledge, PsycINFO, and Google Scholar) from inception to August 2024. Search terms contained keywords relating to both solution-focused and self-injurious thoughts and/or behaviours. Data were analysed using relevant steps from a narrative synthesis approach to summarise the participants, concepts, context and outcomes described in the included publications. Results Twenty-four publications were included in the review. Publications demonstrated a global reach although the majority were published in the UK and USA. Five publications formally assessed and reported outcomes; two randomised controlled trials, one experimental pilot study, one case study, and one single group study. Only the Beck Depression Inventory was collected in more than one study (n = 4), with a range of other psychopathology and wellbeing-related measures. Three studies reported qualitative data, finding positive perceptions of the approaches by patients and clinicians. Fifty-one unique components were identified within solution-focused approaches. Often specific adaptations were described, or components were introduced, that specifically addressed suicide or self-harm. For example, identifying and working on goals related to reducing or stopping self-harm, or scaling questions that assess how suicidal someone currently feels on a 0 to 10 scale. Conclusions This review demonstrates the application of solution-focused approaches for treating individuals with self-injurious thoughts and behaviours. The findings provide a comprehensive overview of how these approaches are delivered. The lack of outcome data and empirical studies highlights a need for more formalised evidence.

Technological Change and Techno-Social Systems: Re-Examining Sustainable Development and Digitalisation in Africa

This article argues that understanding currently dominant technological change models in low-and-middle income countries is important to addressing challenges to sustainable development with enhanced knowledge and effective policies. Combining such understanding with using systems thinking, as a theoretical framework, helps in illuminating techno-social systems and their overlaps with economic and human development systems, therefore highlighting possible leverage points for interventions to usher technological change towards sustainable development objectives. The proposed conceptual synthesis between technological change models and systems thinking is then critically applied to case studies related to digitalisation in Africa, where challenges to sustainability are amplified by continuous pressure for technological advancement, making local capabilities a central issue. The case studies examine how continental digitalisation indicators are ahead of industrialisation and human development indicators, with similar issues in digitalising agri-food ecosystems. We show that, while Africa is currently increasing in digitalisation, correlations between digitalisation and sustainable development are not as direct, or necessarily positive, as initially assumed. Similar trends are seen in digitalisation and agri-food ecosystems, where farm-raised data is monetised off-farm, thus removing opportunities for farmers to realise return on their knowledge investment. Examining the cases, using the proposed synthesis approach, reveals that digitalisation can contribute to development indicators when coupled with enhancing employment in productive sectors and that the prevailing order of ‘technology-push, demand-pull’ models suggests more investment in technological improvement. The article contributes to theory by illuminating overlaps between two theoretical/conceptual areas and to praxis by informing alternative policy directions.