Discontinuous Process Research Articles

Identifying priorities for future research on reducing and stopping psychiatric medication: results of a James Lind Alliance priority-setting partnership.

The objective of this study is to identify the top 10 research priorities on reducing and stopping psychiatric medication that reflect the perspectives and unmet needs of three key stakeholder groups (people with lived experience, family members/carers/supporters and healthcare professionals). A priority-setting partnership was conducted using the James Lind Alliance's seven-step process. This involved (1) creating an international Steering Group of key stakeholder representatives and (2) identifying potential partners; (3) gathering stakeholders' uncertainties about reducing and stopping psychiatric medication using an online survey and summarising the survey responses; (4) checking the summary questions against existing evidence and verifying uncertainties; (5) shortlisting the questions using a second online survey; (6) determining the top 10 research questions through a prioritisation workshop; and (7) disseminating the results. A total of 3635 questions were collected in the initial survey from 884 respondents of which 32 questions were verified as uncertainties. These questions were then ranked in a second online survey by 526 respondents and the findings discussed in a final prioritisation workshop by 30 participants to produce the final top 10 list of research questions. These questions cover a range of areas including the most effective ways of safely reducing/stopping psychiatric medication and providing support to individuals undergoing the discontinuation process, as well as the best ways to educate healthcare professionals on this topic. The top 10 list of research priorities was produced through extensive engagement with key stakeholders and highlights important uncertainties and gaps in the existing evidence base that need to be addressed by future research.

Development of a GC-FID method for the analysis of fatty acids in palm olein to study the formation of C18:1 trans during deep discontinuous frying processes in El Salvador food industry.

An analytical method for the derivatization of fatty acids to methyl esters using basic catalysis with special emphasis on the identification of the different C18:1 trans isomers was developed and validated, showing excellent accuracy, precision and linearity. This method was employed to evaluate the degradation of palm olein during the deep discontinuous frying process of potatoes and bananas over 60 hours at different temperatures, simulating most habitual food processing methods used in El Salvador. It was observed that untreated oils already showed low levels of trans fatty acids (around 0.085%) although these products were marketed as if they did not contain any trans fats. As expected, the concentration of trans fatty acids in the oil increased throughout the deep-frying process, while contents in mono- and polyunsaturated fatty acids decreased. This degradation of the oil varied depending on the temperature and the amount of water of the product being cooked.

Fatigue Crack Growth Monitoring and Investigation on G20Mn5QT Cast Steel and Welds via Acoustic Emission

The fatigue crack growth properties of G20Mn5QT cast steel and corresponding butt welds, using compact tension specimens, were monitored and investigated via acoustic emission (AE) techniques. Fatigue crack growth is a combination of cyclic plastic deformations before the crack tip, tensile crack fractures, and shear crack fractures. The cyclic plastic deformations release the maximum amount of energy, which accounts for half of the total energy, and the second-largest number of AE signals, which are of the continuous-wave type. The tensile crack fractures release the second-largest amount of energy and the largest number of AE signals, which are of the burst-wave type. The shear crack fractures release the least amount of energy and the lowest number of AE signals, which are similar to the burst type, albeit with a relatively longer rise time and duration. Crack tip advancement can be regarded as a discontinuous process. The critical area before the crack tip brittlely ruptures when the fatigue damage caused by cyclic plastic deformations reaches critical status. The ruptures produce a large number of tensile crack fractures and rare shear crack fractures. Through fractography observation, the shear crack fractures occur probabilistically around defects caused by casting or welding, which lead to stress and strain in the local complex.

Hydro-mechanical modeling of cohesive crack propagation of concrete lining in high internal pressure tunnels

High pressure tunnels with concrete lining have been extensively utilized in project practice. However, due to the characteristic of concrete being susceptible to cracking under tension, the lining inevitably develops cracks under high internal water pressure, posing a serious threat to the operation of tunnels. This study aims at developing a hydro-mechanical numerical model of cohesive crack propagation of concrete lining in high internal pressure tunnels. In this regard, the determination of cohesive element parameters is elucidated, the contact simulation within the software ABAQUS is improved to accurately characterize the interface between lining and surrounding rock, and the numerical calculation process in ABAQUS is realized using indirect coupled method. The simulation results align well with the physical model test and engineering monitoring data, demonstrating that the proposed method can accurately simulate the hydraulic interactions of high pressure tunnel. Additionally, a comparison with calculation models employing tie constraints to simulate the lining-surrounding rock interface is conducted. Finally, comparison with traditional continuum method reveals that while both methods exhibit consistent overall trends. It is recommended to choose the proposed method when describing the discontinuous propagation process of cracks, which cannot be simulated by the continuum analysis method.

Motion priority optimization framework towards automated and teleoperated robot cooperation in industrial recovery scenarios

In this study, we introduce an optimization framework to enhance the efficiency of motion priority design in scenarios involving automated and teleoperated robots within an industrial recovery context. The increasing utilization of industrial robots at manufacturing sites has been instrumental in reducing human workload. Nevertheless, achieving effective human–robot collaboration/cooperation (HRC) remains a challenge, especially when human workers and robots share a workspace for collaborative tasks. For instance, when an industrial robot encounters a failure, such as dropping an assembling part, it triggers the suspension of the corresponding factory cell for safe recovery. Given the limited capacity of pre-programmed robots to rectify such failures, human intervention becomes imperative, requiring entry into the robot workspace to address the dropped object while the robot system is halted. This discontinuous manufacturing process results in productivity loss. Robotic teleoperation has emerged as a promising technology enabling human workers to undertake high-risk tasks remotely and safely. Our study advocates for the incorporation of robotic teleoperation in the recovery process during manufacturing failure scenarios, which is referred to as “Cooperative Tele-Recovery”. Our proposed approach involves formulating priority rules designed to facilitate collision avoidance between manufacturing and recovery robots. This, in turn, ensures a continuous manufacturing process with minimal production loss within a configurable risk limitation. We present a comprehensive motion priority optimization framework composed of an HRC simulator and a cooperative multi-robot controller to identify optimal parameters for the priority function. The framework dynamically adjusts the allocation of motion priorities for manufacturing and recovery robots while adhering to predefined risk limitations. Through quantitative and qualitative assessments, we validate the novelty of our concept and demonstrate its feasibility.

Frost crystal growth behavior on a hydrophilic surface over a wide range of cold surface temperature

The initial frosting phenomenon is a discontinuous phase nucleation process, the cold surface temperature and properties have a decisive influence on this phenomenon, especially in the initial frosting stage. With the development of aerospace and energy transportation technology, frost formation at low temperatures (-100 °C∼-30 °C) and ultra-low temperatures (-273 °C∼-100 °C) has gradually attracted the attention of researchers. In this paper, the initial frosting phenomena on hydrophilic surfaces with a contact angle of 10° (CA= 10°) and ordinary (CA= 95°) surfaces are studied experimentally in a wide range of cold surface temperatures (-190 °C∼-30 °C). Four modes are confirmed: cold surface condensation frosting, cold surface sublimation frosting, air boundary layer condensation frosting and air boundary layer sublimation frosting. It is also found that the four frosting modes do not appear in turn with the decrease of the cold surface temperature, but two or more frosting modes appear at the same time. And the surface contact angle has an important influence on the frosting mode. The initial frost crystal morphology mainly depends on the cold surface temperature and the corresponding frosting mode. Four different forms of frost crystals are observed: hexagonal prism (feather), branch (pine needle), cluster (shrub) and floc (grape), in which the cluster frost crystal is more sensitive to the surface contact angle and can appear in different temperature ranges due to different contact angles. Based on the statistics of the size, quantity, and distribution of the initial frost crystals, it is found that -70 °C is a major turning point for frost formation from the cold surface sublimation frosting to the air boundary layer sublimation frosting, and an important change has taken place near this point. Furthermore, it affects the shape and size distribution of frost crystals. These findings are of great significance for the study and understanding of frost crystal growth mechanism in the initial stage of frost formation at low and ultra-low temperatures.

The person behind the therapist: a recall study on significant events that contribute to therapists' personal and professional development.

This study explores the interconnexion between personal and professional development in therapist growth. This research examines a self-integrated perspective on training, by looking at the equal importance of nurturing personal development alongside professional skills cultivation. The study uses the concept of Significant Events (SE) which was originally developed to understand client change processes and applies the concept to investigate the development of the person-of-the-therapist. SE is events that are experienced in the therapy process and that are experienced by the client as being helpful or hindering for therapeutic change. Similar to the process of therapy, professional development is not a linear process of acquiring skills and knowledge but a discontinuous process that is driven by SE. The goal is to explore transformative moments in therapists' development. 281 participants completed an online questionnaire, evaluating: i) ) personal events (physical and mental health, interpersonal relationships, exploring the world, losses and deaths), ii) professional events (training, clinical experiences, relationship with colleagues, challenges due to work position), and iii) hybrid events where personal and professional aspects intertwine (personal therapy and societal context inducing insecurity). Findings suggest a more integrated self in personal and professional development. The study contributes to ongoing discussions on professional development, revealing the interplay between personal and professional spheres of therapists.

Elementary Observations: Building Blocks of Physical Information Gain.

In this paper, we are concerned with the process of experimental information gain. Building on previous work, we show that this is a discontinuous process in which the initiating quantum-mechanical matter-instrument interactions are being turned into macroscopically observable events (EOs). In the course of time, such EOs evolve into spatio-temporal patterns of EOs, which allow conceivable alternatives of physical explanation to be distinguished. Focusing on the specific case of photon detection, we show that during their lifetimes, EOs proceed through the four phases of initiation, detection, erasure and reset. Once generated, the observational value of EOs can be measured in units of the Planck quantum of physical action h=4.136×10-15eVs. Once terminated, each unit of entropy of size kB=8.617×10-5eV/K, which had been created in the instrument during the observational phase, needs to be removed from the instrument to ready it for a new round of photon detection. This withdrawal of entropy takes place at an energetic cost of at least two units of the Landauer minimum energy bound of ELa=ln⁡2kBTD for each unit of entropy of size kB.

Green adsorption of quinoline as basic N-compounds from liquid fuel using mesoporous and Fe-functionalized walnut shell-activated carbon

Removing nitrogenous compounds from liquid fuels is essential, and adsorption de-nitrogenation is a new process for this goal. This work has the purpose of investigating quinoline adsorption using Iron functionalized Activated carbon (IFAC) mesoporous nanocomposite. The mesoporous nanocomposite was synthesized in a one-step process by chemical activation of the walnut shell using Iron chloride as the activation and modification agent. The IFAC mesoporous nanocomposite was utilized to remove quinoline from isooctane as the liquid fuel via a discontinuous (batch) process by examining the effect of initial concentration, contact time, and temperature. The effect of contact time on the adsorption ability of IFAC for quinoline was well described by the pseudo-second-order model. The Langmuir model described the equilibrium manner of the process well, and the adsorbent could retain 344.82 mg/g of quinoline (37.37 mg N/g). The thermodynamic parameters show the endothermic (ΔH°= +30.070 kJ/mol) and spontaneity of the adsorption process. The regeneration experiments indicated that functionalized AC’s adsorption ability for quinoline adsorption decreased by 23% after five cycles. The obtained data indicate that the functionalization of activated carbon surface with iron particles leads to improving its adsorption ability toward N-containing compounds from liquid fuels.

The discontinuous mesh processing for electromagnetic scattering analysis of conducting objects by PO method

In electromagnetic (EM) simulations, conventional triangular patches are implemented to discretize the surfaces of conducting objects. The EM scattering of the conducting objects is presented based on the Rao-Wilton-Glisson basis function and continuity of the surface current across the boundary with different mesh sizes. The radar cross section (RCS) is acquired for conducting objects using physical optics (PO). The numerical results are compared with those from a commercial software (FEKO), which indicated the accuracy and effectiveness of the method in this study.

Continuous Rapid Fabrication of Ceramic Fiber Sponge Aerogels with High Thermomechanical Properties via a Green and Low-Cost Electrospinning Technique.

Ceramic aerogel is an appealing fireproof and heat-insulation material, but synchronously improving its mechanical and thermal properties is a challenge. Moreover, the expensive discontinuous processing techniques inhibit the large-scale fabrication of ceramic aerogels. Here, we propose a water-based electrospinning method, based on the hydrolysis and condensation reactions of ceramic precursor salts themselves, for the continuous and rapid (0.025 m3/min) fabrication of ceramic fiber sponge aerogels with dual micronano fiber networks, which show synchronous enhanced fireproof, thermal insulation, and resilience performance. The elastic ceramic micro/nano fiber sponge aerogels contain robust silica-based microfibers as a firm skeleton and alumina-based nanofibers as elastic thermal insulation filler. The sponges have a high porosity of >99.8%, a low mass density (6.21 mg/cm3), a small thermal conductivity (0.022 W/m·K), and a large compression strength (21.15 kPa at 80% strain). The ceramic fiber sponges can effectively prevent the propagation of thermal runaway when a lithium battery experiences catastrophic thermal shock (>1000 °C) in the power battery packs. The proposed strategy is feasible for low-cost and rapid synthesizing ceramic aerogels toward effective battery thermal management.

A Deep Learning‐Based Data Assimilation Approach to Characterizing Coastal Aquifers Amid Non‐Linearity and Non‐Gaussianity Challenges

AbstractSeawater intrusion (SI) poses a substantial threat to water security in coastal regions, where numerical models play a pivotal role in supporting groundwater management and protection. However, the inherent heterogeneity of coastal aquifers introduces significant uncertainties into SI predictions, potentially diminishing their effectiveness in management decisions. Data assimilation (DA) offers a solution by integrating various types of observational data with the model to characterize heterogeneous coastal aquifers. Traditional DA techniques, like ensemble smoother using the Kalman formula (ESK) and Markov chain Monte Carlo, face challenges when confronted with the non‐linearity, non‐Gaussianity, and high‐dimensionality issues commonly encountered in aquifer characterization. In this study, we introduce a novel DA approach rooted in deep learning (DL), referred to as ESDL, aimed at effectively characterizing coastal aquifers with varying levels of heterogeneity. We systematically investigate a range of factors that impact the performance of ESDL, including the number and types of observations, the degree of aquifer heterogeneity, the structure and training options of the DL models. Our findings reveal that ESDL excels in characterizing heterogeneous aquifers under non‐linear and non‐Gaussian conditions. Comparison between ESDL and ESK under different experimentation settings underscores the robustness of ESDL. Conversely, in certain scenarios, ESK displays noticeable biases in the characterization results, especially when measurement data from non‐linear and discontinuous processes are used. To optimize the efficacy of ESDL, attention must be given to the design of the DL model and the selection of observational data, which are crucial to ensure the universal applicability of this DA method.

Serpentinization as a Tape Recorder of (Dis)Continuous Mantle Exhumation along the Alpine Tethys Ocean-Continent-Transition

Abstract Serpentinization has been widely documented and investigated at mid-ocean ridges (MOR) and subduction zones. In contrast, at magma-poor rifted margins serpentinization has received much less attention, despite its importance in controlling rheology and mass fluxes during breakup and establishing of a steady-state MOR. In this study, we present new petrological and geochemical data on subcontinental exhumed serpentinized peridotites from the spectacularly exposed Platta, Tasna and Totalp nappes in the Eastern Central Alps in SE Switzerland, belonging to the Alpine Tethys Ocean Continent Transition (OCT). The results testify of a complex history of fluid–rock interactions recorded by several serpentinization events starting with lizardite mesh and bastite textures (S1), subsequently followed by a succession of serpentine-filling veins with distinct textures and serpentine polysomes that include spherical polyhedral serpentine (S2); chrysotile ± polygonal ± lizardite banded veins (S3); lamellar antigorite veins and patches (S4) and chrysotile crack-seal (S5). The serpentinization sequence differs at proximal (i.e. continentwards) and distal (i.e. oceanwards) domains of the OCT. At proximal domains of the OCT (Upper Platta, Tasna) serpentinites record the complete serpentinization sequence (S1 to S5), whereas at distal domains (Lower Platta) serpentinization is restricted to pseudomorphic mesh and bastite (S1) and chrysotile crack-seal (S5). We attribute this discrepancy to contrasted mechanisms of mantle exhumation along the OCT. While at proximal domains mantle is unroofed along continuous and single large offset detachment faults allowing for the formation of all serpentine generations, mantle exhumation at distal domains is a more discontinuous process, controlled by sequential out-of-sequence detachment and flip-flop faults preventing the full development of all serpentine generations. In this frame, the nature and order of formation of the serpentine polysomes are directly controlled by the conditions of serpentinization (i.e. temperature, mantle composition and fluid/rock ratio). We propose that this new conceptual model can be extrapolated to serpentinization at slow to ultra-slow MORs, where close similarities in the serpentinization sequences have been recently reported.

Experimental study on rotating detonation wave discontinuous propagation process of high-temperature ethylene-rich gas

The combination of air turbine rocket (ATR) and rotating detonation engine (RDE) is a promising form of combined power, and it is of great significance to study the propagation characteristics of rotating detonation waves (RDW) using rich combustion gas as fuel. Owing to the complex composition of the rich combustion gas, RDWs are prone to unstable propagation. In this study, the discontinuous propagation state of quenching and re-initiation of an ethylene-rich gas RDW was experimentally investigated. It was found that the back pressure of RDWs blocked the air injection process and influenced the mixing effect and filling height of the propellant, resulting in decoupling of the RDW. An increase in the gas temperature would shorten the formation time of the RDW and avoid its discontinuous propagation state. The re-initiation process was similar to the auto-initiation process which the combustible mixture generated an RDW through a deflagration-to-detonation process (DDT). The designed experiment verified this analysis. Increasing the air injection pressure and gas temperature can improve the propagation stability of the RDW and reduce the frequency of the quenching and re-initiation process.

Pharmacists' views on discontinuing long-term use of antidepressants and supporting patients during the discontinuation process: a qualitative study.

Long-term antidepressant (AD) use, much longer than recommended by guidelines, may cause harms and generate unnecessary costs. Community pharmacists have frequent contact with AD users and advise them on appropriate and safe medication use. GPs recognised pharmacists as potential sources of additional support for the AD discontinuation process, but there is a lack of knowledge about pharmacists' views. To explore pharmacists' perspectives on discontinuing long-term use of ADs and supporting patients during the discontinuation process and their barriers and facilitators. Qualitative study in Belgian pharmacists. The authors conducted 14 semi-structured face-to-face interviews. Interviews were analysed thematically. The first theme 'Antidepressants at the pharmacy: a persistent taboo' described the challenges pharmacists encounter in initiating discussions with patients about their ADs and mental health, and the persistent taboo around ADs at pharmacies. Second, pharmacists were concerned about the risks associated with AD discontinuation but recognise that harm from continuing ADs may outweigh concerns. Third, although pharmacists can be a starting point for discontinuation, they hesitate to do this and question if this is their role. They prefer that GPs have this responsibility. Deprescribing long-term ADs is a challenging concept for pharmacists, especially when there is no patient request. The taboo around ADs and the fear of relapse of symptoms in a stable patient are important barriers for pharmacists when considering discontinuation. Pharmacist education and confidence-building is essential to involve the pharmacist in the discontinuation process. Findings also highlight a strong need for multidisciplinary collaboration and agreements with GPs to reduce unnecessary antidepressant treatment.

Performance benchmark of different cell clones in discontinuous and continuous bioprocesses reveals critical impact of cellular diameter

Therapeutic proteins such as monoclonal antibodies are usually manufactured either in continuous processes such as steady-state perfusion or in discontinuous processes like fed-batch (FB). Thereby, both process formats have fundamentally different requirements for the utilized cell factories. This poses a problem as common cell line development programs are designed to select cell clones to perform well in FB cultivation. The aim of this study was to identify critical and easy to access cell line attributes for each process format and with that for the transfer of clones from fed-batch to perfusion. As a result, increased cell-volume specific productivity could be identified as beneficial within the FB not only impacting performance but as well diminishing media utilization and host-cell-proteins level. Within the perfusion, a stable cell diameter was identified as major beneficial characteristic, positively influencing cell viability, metabolite and glycan profile, as well as equipment utilization. Consistent with this, our data suggest that the inclusion of cell volume in the screening parameters is important for clone selection for both process formats and can lead to improved process design and robust cell line process transfer. Overall, this work gives valuable new insights in cell behaviour across discontinuous and continuous process formats to improve clone cell selection for both process strategies and streamline the process transfer from discontinuous towards continuous.

Improvement and Application of Hale’s Dynamic Time Warping Algorithm

Due to the different generation and propagation mechanisms of P- and S-waves, there may be significant differences in the seismic data collected by the two, which poses a great obstacle to the time domain matching of P- and S-waves in multiwave exploration. Furthermore, the quality and accuracy of the matching effect will directly affect the subsequent multiwave joint inversion and interpretation effect. Therefore, the study of P and S-wave-matching methods plays a crucial role in seismic exploration. In 2013, Hale improved the classical Dynamic Time Warping (DTW) algorithm applied to solve the problem of speech recognition, and obtained the DTW algorithm suitable for solving the matching of P-waves and S-waves. The seismic wave-matching results generated by this algorithm are horizontal discontinuous (different trajectories) and need further processing. This study analyses the algorithm based on simulations of seismic waves using Ricker wavelets. In response to existing problems, this paper proposes strategies to improve the DTW algorithm. The algorithm in this study significantly improved the continuity of the registration results of the actual seismic wave data in the horizontal direction (different traces).

A novel strategy to enhance the interfacial bonding quality of CoCrFeMnNi high-entropy alloy joints produced by vacuum hot-compression bonding

The strain history of strain rate transient changes was introduced into the vacuum hot-compression bonding (VHCB) process of CoCrFeMnNi high-entropy alloy, which rapidly improved the interfacial bonding quality of the joint. The results of interfacial microstructure characterization indicated that the high-density dislocations generated in the interfacial region during the initial high strain rate stage not only promoted the nucleation of the interfacial recrystallized grains but also induced the transformation of the sub-boundaries and the interfacial grain boundaries (IGBs) to the high mobility twin boundaries (TBs). The accelerated discontinuous dynamic recrystallization process, the growth of TB-type continuous dynamic recrystallization grains, and the interfacial TB migration during the transient VHCB dramatically enhance the IGB migration level of the joints. This study provides an effective strategy for the interfacial regulation of high-quality VHCB joints.

Barriers, facilitators and needs to deprescribe benzodiazepines and other sedatives in older adults: a mixed methods study of primary care provider perspectives

BackgroundBenzodiazepines and other sedative hypnotic drugs (BSHs) are frequently prescribed for sleep problems, but cause substantial adverse effects, particularly in older adults. Improving knowledge on barriers, facilitators and needs of primary care providers (PCPs) to BSH deprescribing could help reduce BSH use and thus negative effects.MethodsWe conducted a mixed methods study (February-May 2023) including a survey, semi-structured interviews and focus groups with PCPs in Switzerland. We assessed barriers, facilitators and needs of PCPs to BSH deprescribing. Quantitative data were analyzed descriptively, qualitative data deductively and inductively using the Theoretical Domain Framework (TDF). Quantitative and qualitative data were integrated using meta-interferences.ResultsThe survey was completed by 126 PCPs (53% female) and 16 PCPs participated to a focus group or individual interview. The main barriers to BSH deprescribing included patient and PCP lack of knowledge on BSH effects and side effects, lack of PCP education on treatment of sleep problems and BSH deprescribing, patient lack of motivation, PCP lack of time, limited access to cognitive behavioral therapy for insomnia and absence of public dialogue on BSHs. Facilitators included informing on side effects to motivate patients to discontinue BSHs and start of deprescribing during a hospitalization. Main PCP needs were practical recommendations for pharmacological and non-pharmacological treatment of sleep problems and deprescribing schemes. Patient brochures were wished by 69% of PCPs. PCPs suggested the brochures to contain explanations about risks and benefits of BSHs, sleep hygiene and sleep physiology, alternative treatments, discontinuation process and tapering schemes.ConclusionThe barriers and facilitators as well as PCP needs and opinions on patient material we identified can be used to develop PCP training and material on BSH deprescribing, which could help reduce the inappropriate use of BSHs for sleep problems.

Distributions for Compositionally Differentiating Parametric Discontinuities

Computations in physical simulation, computer graphics, and probabilistic inference often require the differentiation of discontinuous processes due to contact, occlusion, and changes at a point in time. Popular differentiable programming languages, such as PyTorch and JAX, ignore discontinuities during differentiation. This is incorrect for parametric discontinuities —conditionals containing at least one real-valued parameter and at least one variable of integration. We introduce Potto, the first differentiable first-order programming language to soundly differentiate parametric discontinuities. We present a denotational semantics for programs and program derivatives and show the two accord. We describe the implementation of Potto, which enables separate compilation of programs. Our prototype implementation overcomes previous compile-time bottlenecks achieving an 88.1x and 441.2x speed up in compile time and a 2.5x and 7.9x speed up in runtime, respectively, on two increasingly large image stylization benchmarks. We showcase Potto by implementing a prototype differentiable renderer with separately compiled shaders.