Single Formulation Research Articles

Structure and equation of state of Bi2Sr2Can−1CunO2n+4+δ from x-ray diffraction to megabar pressures

Pressure is a unique tuning parameter for probing the properties of materials, and it has been particularly useful for studies of electronic materials such as high-temperature cuprate superconductors. Here we report the effects of quasihydrostatic compression produced by a neon pressure medium on the structures of bismuth-based high-Tc cuprate superconductors with the nominal composition Bi2Sr2Can−1CunO2n+4+δ (n=1,2,3) up to 155 GPa. The structures of all three compositions obtained by synchrotron x-ray diffraction can be described as pseudotetragonal over the entire pressure range studied. We show that previously reported pressure-induced distortions and structural changes arise from the large strains that can be induced in these layered materials by nonhydrostatic stresses. The pressure-volume equations of state (EOS) measured under these quasihydrostatic conditions cannot be fit to single phenomenological formulation over the pressure ranges studied, starting below 20 GPa. This intrinsic anomalous compression as well as the sensitivity of Bi2Sr2Can−1CunO2n+4+δ to deviatoric stresses provide explanations for the numerous inconsistencies in reported EOS parameters for these materials. We conclude that the anomalous compressional behavior of all three compositions is a manifestation of the changes in electronic properties that are also responsible for the remarkable nonmonotonic dependence of Tc with pressure, including the increase in Tc at the highest pressures studied so far for each. Transport and spectroscopic measurements up to megabar pressures are needed to fully characterize these cuprates and explore higher possible critical temperatures in these materials.1 MoreReceived 15 December 2022Accepted 5 May 2023DOI:https://doi.org/10.1103/PhysRevMaterials.7.064803©2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasEquations of stateHigh-pressure studiesPhysical SystemsCupratesTechniquesX-ray diffractionCondensed Matter, Materials & Applied Physics

Utilization of Chemometric Aided UV- Spectrophotometric Methods for Concurrent Assessment of Emtricitabine, Tenofovir Disoproxil Fumarate, Elvitegravir and Cobicistat in Tablet Formulation.

Emtricitabine (ETC), Tenofovir disoproxil fumarate (TNF), Elvitegravir (EVG), and Cobicistat (CBS) are antiviral drugs used to treat human immunodeficiency virus (HIV) infections. To develop chemometric-aided UV spectrophotometric methods for concurrent estimation of the aforementioned drugs used to treat HIV. This method can be used to reduce the modification of the calibration model by assessing the absorbance at various points in the zero-order spectra within the selected wavelength range. Additionally, it eliminates interfering signals and provides sufficient resolution in multi-component systems. Two Chemo-metric assisted UV-spectrophotometric methods, namely, partial least square (PLS) and principal component regression (PCR) models, were established for the concurrent assessment of EVG, CBS, TNF, and ETC in tablet formulations. The proposed methods were applied to decrease complexity of overlapped spectra and to achieve maximum sensitivity and the lowest error. These approaches were performed in accordance with ICH criteria and compared to the reported HPLC method. The proposed methods were used to assess EVG, CBS, TNF, and ETC in the range of 5-30 µg/mL, 5-30 µg/mL, 5-50 µg/mL and 5-50 µg/mL, respectively, with an excellent correlation coefficient (r ≥ 0.998). The accuracy and precision results were found to be within the acceptable limit. No statistical difference was observed between the proposed and reported studies. The chemometric aided UV-spectrophotometric approaches could be taken into consideration as an alternative of chromatographic procedures in the pharmaceutical industry for routine analysis and testing of readily accessible commercial formulations. Novel chemometric-UV assisted spectrophotometric techniques were developed for assessment of multicomponent antiviral combinations in single tablet formulations. The proposed methods were performed without using harmful solvents, tedious handling, or expensive instruments. The proposed methods were compared statistically with reported HPLC method. Assessment of the EVG, CBS, TNF, and ETC was performed without interference from excipients in their multicomponent formulations.

Modeling fatigue failure in soft tissue using a visco-hyperelastic model with discontinuous damage

Soft tissue is susceptible to injury from single high-magnitude static loads and from repetitive low-magnitude fatigue loads. While many constitutive formulations have been developed and validated to model static failure in soft tissue, a modeling framework is not well-established for fatigue failure. Here we determined the feasibility of using a visco-hyperelastic damage model with discontinuous damage (strain energy-based damage criterion) to simulate low- and high-cycle fatigue failure in soft fibrous tissue. Cyclic creep data from six uniaxial tensile fatigue experiments of human medial meniscus were used to calibrate the specimen-specific material parameters. The model was able to successfully simulate all three characteristic stages of cyclic creep, and predict the number of cycles until tissue rupture. Mathematically, damage propagated under constant cyclic stress due to time-dependent viscoelastic increases in tensile stretch that in turn increased strain energy. Our results implicate solid viscoelasticity as a fundamental regulator of fatigue failure in soft tissue, where tissue with slow stress relaxation times will be more resistant to fatigue injury. In a validation study, the visco-hyperelastic damage model was able to simulate characteristic stress-strain curves of pull to failure experiments (static failure) when using material parameters curve fit to the fatigue experiments. For the first time, we've shown that a visco-hyperelastic discontinuous damage framework can model cyclic creep and predict material rupture in soft tissue, and may enable the reliable simulation of both fatigue and static failure behavior from a single constitutive formulation.

Influence of extrudate to SPI-gel-binder ratios and transglutaminase crosslinking on texture of a plant-based salami analogue

A plant-based salami-type sausage analogue was manufactured with a glucono-δ-lactone- or transglutaminase+glucono- δ -lactone-induced soy protein isolate-gel as binder to hold together fat mimetic particles and extruded proteins with fibrous structure to resemble the structure of classical dry-fermented sausages. The objective was to study the influence of the binder content on the texture of this complex meat analogues. The sausage analogues were processed similarly to traditional sausages. Texture, sensory and composition were analyzed. The hardness of dry-fermented sausages was found to decrease with increasing binder content (e.g. at 45% dry matter from ∼ 110 N to ∼ 80 N), whereas the cohesiveness increased with increasing binder content (e.g. at 45% dry matter from ∼ 0.21 to ∼ 0.41). Results from sensory and texture analysis correlated well and showed that both a high firmness and cohesiveness could not be reached in a single formulation. Furthermore, the addition of transglutaminase slightly increased firmness and cohesiveness, however, drying of sausages had a significantly higher impact on increasing hardness. These results indicate that, at lower binder contents, the structure is dominated by the extrudate particles, leading to an increased firmness but a lack of cohesiveness, whereas higher binder contents increased the cohesiveness but decreased hardness.

Fading of Wideband Signals Due to Propagation Through Equatorial Plasma Bubbles and Diversity Mitigation Effects

Equatorial Plasma Bubbles (EPBs) and their ionospheric density irregularities exhibit structures with scale sizes that can vary from several hundred kilometers to tens of meters. These random irregularities degrade both the performance and the availability of space-based communication and navigation systems, in different ways. As examples of effects to be analyzed, wideband UHF (360 MHz – 380 MHz) transmissions received by Ascension Island (7.93°S, 14.25°W) monitors during an observational campaign in October 2016 displayed flat-fading and frequency-selective fading conditions. In this report, the ionospheric structures that are responsible for the harmful observed behavior (flat and frequency-selective fading) will initially be identified, through the application of a discrete version of the single phase-screen formulation to low-and high-resolution in-situ ion density data recorded by the Planar Langmuir Probe (PLP) onboard the Communications/ Navigation Outage Forecasting System (C/NOFS) satellite. Next, the resulting hypothesis will be confirmed, by the application of the continuous version of the same formulation to single-scale irregularities with different scale sizes. Finally, mitigation effects from space and frequency diversity on the observed behavior will be discussed, with basis on the application of the initial formulation to the high-resolution C/NOFS PLP data.

Extraction, phytochemical characterization and anti-cancer mechanism of Haritaki churna: An ayurvedic formulation.

Haritaki churna (HC), a single herb ayurvedic formulations is known to be prescribed for various gastro-intestinal disorders in Ayurveda. Haritaki churna aqueous extract (HCAE) has anti-cancer activity against different types of cancer cells with an IC50 in the range of 50-97 μg/ml. Bioavailability of Haritaki Churna is very high in digestive track and treatment of colorectal cancer cells HCT-116, DLD1, HT-29 with HCAE reduces its cellular viability with anti-cancer IC50 70μg/ml. HCAE consumption is safe for human as it didn't affect the cellular viability of primary human PBMCs or non-cancerogenic HEK-293 cells. Haritaki churna was found to be stable in biological gastric fluids and bioactive agents are not losing their anti-cancer activity under such harsh conditions. The HPLC Chromatogram of HCAE is giving 13 major peaks and 11 minor peaks. Exploiting LC-MS, IR and NMR spectroscopic techniques, a total of 13 compounds were identified from HCAE namely Shikimic acid, Chebulic acid, gallic acid, 5-hydroxymethylfurfural, Protocatechuic acid, 4-O-galloyl-shikimic Acid, 5-O-galloyl-shikimic Acid, Methylgallate, corilagin, 1, 2, 6, Tri-O-galloyl β-D-glucose, chebulagic acid, chebulinic acid, and Ellagic acid. Reconstitution and subtraction of phytochemicals from the mixture indicate that Ellagic acid significantly contribute into anti-cancer effect of HCAE. Cancer cells treated with ellagic acid from HCAE were incapable of completing their cell-cycle and halted the cell-cycle at DNA synthesis S-Phase, as demonstrated by decreased cyclin A2 expression levels with increasing ellagic acid concentration. Halting of cells at S-phase causes induction of apoptosis in cancer cells. Cancer cells exhibiting DNA fragmentation, changes in expression of several apoptotic proteins such as Bcl2, cytochrome-c and formation of cleaved products of caspase 3 and PARP-1 suggests ellagic acid induces cell death via mitochondrial pathway of apoptosis.

Development of Efficient Analytical method for the multicomponent analysis of Pravastatin Sodium and Nebivolol Hydrochloride in Bulk Drug by RP-HPLC

Cardiovascular diseases are managed through multi drug regimens. For better patient compliance and cost effectiveness, desired therapeutic efficacy is achieved through combination of more than two drugs in single dosage form. Nebivolol Hydrochloride is β1 receptor blocker and Pravastatin sodium exhibits its pharmacological action through inhibition of cholesterol synthesis. Both drugs are therapeutically compatible and can be administered in single dose formulation. A review of the literature found that there was no effective strategy for the selected drug combination. As a result, an attempt was made to establish a simple, efficient, sensitive, specific, and rapid method for simultaneously estimating Pravastatin sodium and Nebivolol hydrochloride in bulk drugs using RP-HPLC.Column C-18 (Shim-pack) 250 x 4.6 mm, particle size 5 m, mobile phase acetonitrile and water in the ratio 20:80 at 257 nm were found to be the optimal chromatographic conditions. Pravastatin sodium and Nebivolol hydrochloride had retention times of 2.092 and 3.623 minutes, respectively, with average percentage recovery of 99.38% and 99.54%, respectively.The proposed technique was found to be in accordance with the guidelines of the International Conference on Harmonization (ICH).

The use of analgesics for intentional self-poisoning: Trends in U.S. poison center data

In the U.S., intentional self-poisonings with analgesics that are available without a prescription increased from 2000 to 2018. Given concerns regarding mental health outcomes during the COVID-19 pandemic, we examined and compared trends in pediatric and adult intentional self-poisoning with acetaminophen, aspirin, ibuprofen, and naproxen from 2016 to 2021 using the National Poison Data System (NPDS) to see if these trends have continued. We extracted annual case counts of all suspected suicide attempts from intentional poisoning, and of suspected suicide attempts resulting in major effects or death, from the NPDS for non-prescription single ingredient adult formulation acetaminophen, non-prescription single ingredient adult formulation aspirin, single ingredient formulation ibuprofen, and single ingredient formulation naproxen. We enumerated the cases by year, age, and gender.Most cases of intentional self-poisoning within the review period involved acetaminophen and ibuprofen and the 13–19-year-olds constituted the highest proportion of intentional self-poisoning cases across age groups for all four analgesics. Cases involving females predominated cases involving males by 3:1 or greater. The 13–19-year-old age group also represented the largest proportion of cases that resulted in major clinical effects or deaths. An increasing trend in suicide poisoning cases with acetaminophen and ibuprofen was observed in the 6-19-years age group and this trend appeared to exacerbate from 2020 to 2021 corresponding with the start of the COVID-19 pandemic period.

DNA based neoepitope vaccination induces tumor control in syngeneic mouse models

Recent findings have positioned tumor mutation-derived neoepitopes as attractive targets for cancer immunotherapy. Cancer vaccines that deliver neoepitopes via various vaccine formulations have demonstrated promising preliminary results in patients and animal models. In the presented work, we assessed the ability of plasmid DNA to confer neoepitope immunogenicity and anti-tumor effect in two murine syngeneic cancer models. We demonstrated that neoepitope DNA vaccination led to anti-tumor immunity in the CT26 and B16F10 tumor models, with the long-lasting presence of neoepitope-specific T-cell responses in blood, spleen, and tumors after immunization. We further observed that engagement of both the CD4+ and CD8+ T cell compartments was essential to hamper tumor growth. Additionally, combination therapy with immune checkpoint inhibition provided an additive effect, superior to either monotherapy. DNA vaccination offers a versatile platform that allows the encoding of multiple neoepitopes in a single formulation and is thus a feasible strategy for personalized immunotherapy via neoepitope vaccination.

Modeling and simulation of single droplet drying in an acoustic levitator

We present a mathematical model for the full drying process of a single protein formulation droplet taking into account the convective impact arising from its levitation by a standing ultrasound wave. Using the finite element method allows us to compute the evaporation rate directly from the fully resolved heat and mass transfer within and around the levitated droplet. We apply our model to simulate the drying kinetics of pure water and aqueous phosphoglycerate kinase (PGK) droplets under various levitation and drying conditions. Empirical data from the literature are used to validate and discuss our numerical results. The acoustic streaming turns out to accelerate not only the first but also the second drying stage. Moreover, the dehydration of the protein molecules is found to be primarily responsible for their enzymatic inactivation throughout the drying process.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 33.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 33.

US Army Aviation air movement operations assignment, utilization and routing

PurposeThe purpose of this study was to create an air movement operations planning model to rapidly generate air mission request (AMR) assignment and routing courses of action (COA) in order to minimize unsupported AMRs, aircraft utilization and routing cost.Design/methodology/approachIn this paper, the US Army Aviation air movement operations planning problem is modeled as a mixed integer linear program (MILP) as an extension of the dial-a-ride problem (DARP). The paper also introduces a heuristic as an extension of a single-vehicle DARP demand insertion algorithm to generate feasible solutions in a tactically useful time period.FindingsThe MILP model generates optimal solutions for small problems (low numbers of AMRs and small helicopter fleets). The heuristic generates near-optimal feasible solutions for problems of various sizes (up to 100 AMRs and 10 helicopter team fleet size) in near real time.Research limitations/implicationsDue to the inability of the MILP to produce optimal solutions for mid- and large-sized problems, this research is limited in commenting on the heuristic solution quality beyond the numerical experimentation. Additionally, the authors make several simplifying assumptions to generalize the average performance and capabilities of aircraft throughout a flight.Originality/valueThis research is the first to solve the US Army Aviation air movement operations planning problem via a single formulation that incorporates multiple refuel nodes, minimization of unsupported demand by priority level, demand time windows, aircraft team utilization penalties, aircraft team time windows and maximum duration and passenger ride time limits.

A combined approach of DNA metabarcoding collectively enhances the detection efficiency of medicinal plants in single and polyherbal formulations.

Empirical research has refined traditional herbal medicinal systems. The traditional market is expanding globally, but inadequate regulatory guidelines, taxonomic knowledge, and resources are causing herbal product adulteration. With the widespread adoption of barcoding and next-generation sequencing, metabarcoding is emerging as a potential tool for detecting labeled and unlabeled plant species in herbal products. This study validated newly designed rbcL and ITS2 metabarcode primers for metabarcoding using in-house mock controls of medicinal plant gDNA pools and biomass pools. The applicability of the multi-barcode sequencing approach was evaluated on 17 single drugs and 15 polyherbal formulations procured from the Indian market. The rbcL metabarcode demonstrated 86.7% and 71.7% detection efficiencies in gDNA plant pools and biomass mock controls, respectively, while the ITS2 metabarcode demonstrated 82.2% and 69.4%. In the gDNA plant pool and biomass pool mock controls, the cumulative detection efficiency increased by 100% and 90%, respectively. A 79% cumulative detection efficiency of both metabarcodes was observed in single drugs, while 76.3% was observed in polyherbal formulations. An average fidelity of 83.6% was observed for targeted plant species present within mock controls and in herbal formulations. In the present study, we achieved increasing cumulative detection efficiency by combining the high universality of the rbcL locus with the high-resolution power of the ITS2 locus in medicinal plants, which shows applicability of multilocus strategies in metabarcoding as a potential tool for the Pharmacovigilance of labeled and unlabeled plant species in herbal formulations.

Anticancer Evaluation of Methoxy Poly(Ethylene Glycol)-b-Poly(Caprolactone) Polymeric Micelles Encapsulating Fenbendazole and Rapamycin in Ovarian Cancer.

We aimed to inhibit ovarian cancer (OC) development by interfering with microtubule polymerization and inhibiting mTOR signaling. To achieve this, previously developed micelles containing fenbendazole and rapamycin were applied. Herein, we prepared micelles for drug delivery using fenbendazole and rapamycin at a 1:2 molar ratio and methoxy poly(ethylene glycol)-b-poly(caprolactone)(mPEG-b-PCL) via freeze-drying. We revealed their long-term storage capacity of up to 120 days. Furthermore, a cytotoxicity test was performed on the OC cell line HeyA8, and an orthotopic model was established for evaluating in vivo antitumor efficacy. Fenbendazole/rapamycin-loaded mPEG-b-PCL micelle (M-FR) had an average particle size of 37.2 ± 1.10 nm, a zeta potential of -0.07 ± 0.09 mV, and a polydispersity index of 0.20 ± 0.02. Additionally, the average encapsulation efficiency of fenbendazole was 75.7 ± 4.61% and that of rapamycin was 98.0 ± 1.97%. In the clonogenic assay, M-FR was 6.9 times more effective than that free fenbendazole/rapamycin. The in vitro drug release profile showed slower release in the combination formulation than in the single formulation. There was no toxicity, and tumor growth was suppressed substantially by our formulation compared with that seen with the control. The findings of our study lay a foundation for using fenbendazole and rapamycin for OC treatment.

Partially coherent broadband 3D optical transfer functions with arbitrary temporal and angular power spectra.

Optical diffraction tomography is a powerful technique to produce 3D volumetric images of biological samples using contrast produced by variations in the index of refraction in an unlabeled specimen. While this is typically performed with coherent illumination from a variety of angles, interest has grown in partially coherent methods due to the simplicity of the illumination and the computation-free axial sectioning provided by the coherence window of the source. However, such methods rely on the symmetry or discretization of a source to facilitate quantitative analysis and are unable to efficiently handle arbitrary illumination that may vary asymmetrically in angle and continuously in the spectrum, such as diffusely scattered or thermal sources. A general broadband theory may expand the scope of illumination methods available for quantitative analysis, as partially coherent sources are commonly available and may benefit from the effects of spatial and temporal incoherence. In this work, we investigate partially coherent tomographic phase microscopy from arbitrary sources regardless of angular distribution and spectrum by unifying the effects of spatial and temporal coherence into a single formulation. This approach further yields a method for efficient computation of the overall systems' optical transfer function, which scales with O(n 3), down from O(mn 4) for existing convolutional methods, where n 3 is the number of spatial voxels in 3D space and m is the number of discrete wavelengths in the illumination spectrum. This work has important implications for enabling partially coherent 3D quantitative phase microscopy and refractive index tomography in virtually any transmission or epi-illumination microscope.

Evaluation of the efficacy and safety of hyaluronic acid and supplemented with amino acids, and glutathione or colin, for the prevention and treatment of wrinkles on the face, neck, décolleté and hands.

Hyaluronic acid has been used for a long time as a biorevitalizer to treat skin aging both in single formulation and in association with other compounds such as amino acids or vitamins. The purpose of this study was to evaluate the efficacy and safety of class III medical devices SKIN B, SKIN R, SKIN OX, SKIN COLIN, for the treatment of wrinkles on the face, neck, décolleté and hands. These medical devices are all based on hyaluronic acid and supplemented with amino acids (SKIN B and SKIN R) and glutathione (SKIN OX) or colin (SKIN COLIN). This gives broader possibilities to the aesthetic surgeon for personalization and pharmacological diversification based on the patient's deficits to treat. A total of 60 subjects affected by skin damage such as rhytidids, dehydration, reduced sebum production and skin hypoxia were enrolled. The patients were treated with a session of mesotherapy every 7 days for 30 days, followed by other 2 sessions every 15 days for 30 days and the follow-up on day 90. The primary efficacy endpoint was evaluated by means of a 0-10 visual analog scale at day 60; the secondary efficacy endpoint was evaluated by means of a 0-10 visual analog scale at day 90. All patients completed the 3-month follow-up. Treatment with SKIN B, SKIN OX, SKIN COLIN and SKIN R medical devices for the prevention and treatment of wrinkles on the face, neck, décolleté and hands were associated with favorable and positive results. A clear reduction of wrinkles has been clinically observed with improvement in the texture, brightness, and turgor of the skin. No adverse events were reported. The medical devices SKIN B, SKIN SKIN OX, SKIN COLIN produce an aesthetic improvement in patients affected by skin defects, when administered by mesotherapy technique. This study confirms the safety and efficacy of the medical devices based on hyaluronic acid supplemented with amino acids and glutathione or colin.

A REVIEW ON TABLET USAGE AND ITS ACCEPTABILITY IN PEDIATRIC POPULATION

Due to variety of pediatric population and barriers of modern technologies it looks that a single formulation strategy will now not be suited for all pediatric patients. The determination of a suitable formulation strategy for a targeted population crew wants to be cautiously considered for every individual product. When managing patients who can't swallow solid oral dosage forms, switching to choice liquid components or different route is greater suitable. To limit unnecessary drugs manipulation it is fundamental for prescribers to think about age appropriateness, type of formulation (in relation to ease of administration), swallowing issues and patient capability to swallow. Palatability needs to be considered carefully by pharmaceutical companies when designing new formulations and also by prescribers in order to optimize effective prescribing, adherence, therapeutic results and lowering wastage with cost savings. . Majority of drugs prescribed for children have not been competently examined in pediatric population. Future formulation work needs to be carried out to strengthen pediatric based formulations. Formulations accepted by children need to be accessible in suitable unit doses covering child dosing ranges and it should be able to tapered accordingly. Monolithic solid dosage form was discovered to be an alternative choice in case of unavailable liquid dosage form. It is very necessary therefore that all requests to crush, split, or opening of capsules have to be discussed with clinical pharmacist prior to beginning administration of the crushed products.

Pharmaceutical Micropellets: A Multi-particulate Drug Delivery System

Abstract: The major target of Pharmaceutical Sciences is to design a successful and suitable dosage forms for effective therapy, considering individual patient needs and compliance. Development of new technology or development of new dosage form using the existing technology is growing in importance and attracting increased interest, as they are specifically effective at a comparably low dose. Pellets falling in the size range of 1-1000μm are of great interest in the pharmaceutical industry for a variety of reasons which are not only offer flexibility in dosage form design and development, but are also utilized to improve the safety and efficacy of bioactive agents. The most important factor responsible for the proliferation of pelletized products is the popularity of controlled release technology in the delivery of drugs. Moreover, controlled release pellets are less susceptible to dose dumping than the reservoir-type single unit formulations. In case of oral products these pellets solve difficult taste-masking problems, disperse freely in the gastro intestinal tract, invariably maximize drug absorption, reduce peak plasma fluctuations and minimize potential side effects without appreciably lowering drug bioavailability, and also reduce variations in gastric emptying rate and overall transit time, thus, intra and inter subject variability of plasma profiles, which are common with single unit regimens, are minimized.

Thermal management of storage unit reporting unsteady physical behavior of NEPCM

Researchers always like to find way for improving the performance of system integrated with PCM. In this paper, the container was combined with fins and PCM was mixed with nanoparticles to obtain quicker discharging process. Two significant variables related to second technique are fraction of additives ([Formula: see text] and their shapes ([Formula: see text]. To involve these factors in equations, single phase formulation was applied. Low magnitude of velocity of liquid material in freezing leads to simplification of equations of this transient procedure. Galerkin method which was applied for this modeling has good accommodation with previous publication. As [Formula: see text] soars, the solidification time declines from 4802.97s to 4244.61s and 3738.37s when blade shape particles were applied. This means that adding additive can enhance the rate of process about 22.16%. Moreover, augmenting the shape factor to higher level causes time to drop about 5.7%.

Integration of consumer preferences into dynamic life cycle assessment for the sharing economy: methodology and case study for shared mobility

PurposeThe rising of the sharing economy (SE) has lowered the barrier of purchase price to accessing many different products, thus changing the consumer decision paradigm. This paper addresses the challenge of assessing the life cycle impacts of SE systems in the context of this new consumer decision-making process. The paper proposes a methodological framework to integrate consumer preferences into the Dynamic Life Cycle Assessment (dynamic-LCA) of SE systems.MethodsIn the proposed consumer preference integrated dynamic-LCA (C-DLCA) methodological framework, system dynamics (SD) is used to combine consumer preference and the principal method, dynamic-LCA, which follows the ISO 14040 LCA framework. Choice-based conjoint analysis (CBCA) is chosen as the stated preference tool to measure consumer preference based on SE alternatives, attributes and attribute levels. CBCA integrates discrete choice experiments (DCE) and conjoint analysis features. Random utility theory is selected to interpret the CBCA results by employing multinomial logistics as the estimation procedure to derive the utilities. Derived utilities are connected in iterative modelling in the SD and LCA. Dynamic-LCA results are determined based on dynamic process inventory and DCE outcomes and then interpreted aligned with the SD policy scenarios.Results and discussionThe C-DLCA framework is applied to assess the GHG changes of the transition to car-based shared mobility in roundtrips to work in the USA. Carpooling and ridesourcing are selected as the shared mobility alternatives based on different occupancy behaviours. Powertrain system and body style are employed as the fleet technology attributes and the latter as an endogenous variable. Dynamic-LCA results are generated considering the high battery electrical vehicle (BEV) adoption as the policy scenario, and results are measured against a service-based functional unit, passenger-kilometre. The model outcomes show a significant reduction in aggregated personal mobility-related dynamic-GHG emissions by transitioning to car-based shared mobility. In contrast to the use phase GHG emissions, the production phase emissions show an increase. The results highlight the importance of integrating consumer preference and temporality in the SE environmental assessments.ConclusionsThe proposed C-DLCA framework is the first approach to combine consumer preferences, SD and LCA in a single formulation. The structured and practical integration of conjoint analysis, SD and LCA methods added some standardisation to the dynamic-LCAs of the SE systems, and the applicability is demonstrated. The C-DLCA framework is a fundamental structure to connect consumer preferences and temporal effects in LCAs that is expandable based on research scope.