Concentration Limit Research Articles

Real-Time Control of the Air Volume in Ventilation Facilities by Limiting CO$_{2}$ Concentration With Cluster Algorithms

Ventilation improves indoor air quality and reduces airborne infections. It is particularly important at present because of the COVID-19 pandemic. Commercially available ventilation facilities can only be instantly turned on/off or at a set time with adjustable air volumes (high, middle, and low). However, maintaining the indoor carbon dioxide concentration while reducing the energy consumption of these facilities is challenging. Hence, this study developed clustering algorithms to determine the carbon dioxide concentration limit thus enabling real-time air volume adjustment. These limit values were set using the existing energy recovery ventilation (ERV) controller. In the experiment, dual estimation was adopted, and the constructing building energy models from data were sampled at a low rate to compare that the ventilation facilities are only turned on/off. In addition, switching control is closely related to fuzzy control; that is, fuzzy control can be considered a smooth version of switching control. The experimental results indicated that the limits of 600 and 700 ppm were suitable to effectively control the real-time air volume based on the ERV operation. An ERV-based carbon dioxide concentration limit reduced the energy consumption of ventilation facilities by 11% implications of this study.

B and N substitutional co-doping in 7AGNRs

On-surface synthesis of graphene nanoribbons enables engineering their electronic and magnetic properties, which sensitively depend on their precise bonding structure, morphology and chemical composition. Here, we investigate nitrogen and boron co-doping in order to better understand the effects of simultaneous chemical substitution in sites along the backbone of 7AGNRs. In a comparative analysis with the pristine system, the origin of the impurity bands that nitro-borylated systems exhibit was addressed. In addition to this, we studied the appearance of an electric dipolar moment, the charge transfer mechanism behind it and its dependence on the distance between BN centres. The high defect concentration limit and the dilute limit were investigated, along with various doping schemes with four substitutional doping sites and the possible emergence of magnetism in these systems.

Determination of the Boundaries of Region of Metastable ω-Phase in Titanium and Zirconium Alloys

Abstract—The concentration boundary of the formation of the ω-phase in binary titanium alloys with d-metals of 4−11 groups of 4−6 periods were studied by X-ray diffraction analysis. It is established that the ω-phase is formed in all the alloys studied, with the exception of Ti−Zr alloys. It is shown that the minimum concentration limit of the formation of the ω-phase is determined by the position of the curve of the end of the martensitic β → \(\alpha {\kern 1pt} '\)(\(\alpha {\kern 1pt} ''\)) transformation (Mf). For most of the studied titanium alloys, concentrations were determined at which the Ms and Mf points correspond to a temperature of 20°C. The conditions for the formation of the ω-phase in titanium alloys were compared with the conditions for its formation in zirconium alloys.

Detonation decomposition of hydrocarbons to produce hydrogen

Detonation decomposition of methane, ethane, propane, butane, propylene and ethylene in their mixtures with oxygen was conducted in a pulsed gas detonation device (PGDD) with a goal of obtaining gaseous hydrogen, H2. Chemical reactions occurring behind the detonation front were elaborated for mixtures differing in the oxygen content. The upper concentration limits of detonation corresponding to minimal oxygen contents (maximal fuel contents), at which detonation is still possible, were determined. It was shown that, in order to maximize the hydrogen yield, 15% of acetylene, C2H2, should be added to methane. The productivity of a PGDD device with a barrel of a diameter of 26 mm and a length of 2 m is 3.60, 3.67, 4.25, 4.39, 4.61 and 5.76 kg h−1 of hydrogen when processing methane, ethylene, ethane, propylene, propane and butane, respectively. Upon detonation of mixtures based on ethylene, propylene and butane, along with hydrogen, nanoscale detonation carbon (NDC) is generated at a rate of 6.9, 6.5 and 5.2 kg h−1, respectively. NDC can be used as an additive to metals and polymers to modify their properties. The obtained results are discussed together with data on the production of hydrogen and NDC by detonation decomposition of acetylene previously obtained by the authors.

Limits of Concentration of Separate Disputes within the Framework of Insolvency Cases

Limits of Concentration of Separate Disputes within the Framework of Insolvency Cases

Coupling capillary electrophoresis with mass spectrometry for the analysis of oxidized phospholipids in human high-density lipoproteins.

The oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (ox-PAPC) products in human high-density lipoproteins (HDLs) were investigated by low-flow capillary electrophoresis-mass spectrometry (low-flow CE-MS). To accelerate the optimization, native PAPC (n-PAPC) standard was first analyzed by a commercial CE instrument with a photodiode array detector. The optimal separation buffer contained 60% (v/v) acetonitrile, 40% (v/v) methanol, 20mM ammonium acetate, 0.5% (v/v) formic acid, and 0.1% (v/v) water. The selected separation voltage and capillary temperature were 20kV and 23°C. The optimal CE separation buffer was then used for the low-flow CE-MS analysis. The selected MS conditions contained heated capillary temperature (250°C), capillary voltage (10V), and injection time (1 s). No sheath gas was used for MS. The linear range for n-PAPC was 2.5-100.0µg/mL. The coefficient of determination (R2 ) was 0.9918. The concentration limit of detection was 1.52µg/mL, and the concentration limit of quantitation was 4.60µg/mL. The optimal low-flow CE-MS method showed good repeatability and sensitivity. The ox-PAPC products in human HDLs were determined based on the in vitro ox-PAPC products of n-PAPC standard. Twenty-one ox-PAPC products have been analyzed in human HDLs. Uremic patients showed significantly higher levels of 15 ox-PAPC products than healthy subjects.

Heterostructured organic/MoS2 nanowall with synergistic SERS enhancement enabling direct and sensitive detection of contaminants

In recent years, the π-conjugated organic molecular system has attracted considerable attention for its surface-enhanced Raman scattering (SERS) properties. However, the practical application of π-conjugated organic materials as SERS substrates is limited due to the inefficient dissociation of excitons, weak enhancement, and poor reproducibility. Herein, we proposed a novel nanowall SERS heterocomposite based on 3D D(C7CO)-BTBT nanowalls and 2D few-layer MoS2 flakes. A significant SERS activity of the D(C7CO)-BTBT/MoS2 nanowall heterocomposite can be achieved by the charge transfer (CT) resonance enabled by the π-conjugated interactions between D(C7CO)-BTBT and MoS2 and the electromagnetic field spatial distribution induced by the D(C7CO)-BTBT nanowalls. The concentration limit of detection (LOD) of the methylene blue (MB) molecules absorbed on the heterostructured D(C7CO)-BTBT/MoS2 nanowall substrate is as low as 8.2 × 10−11 M, which is excellent among the reported organic-based substrates. A practical SERS detection for the 100 nm polystyrene (PS) nanoparticles on the D(C7CO)-BTBT/MoS2 substrates can be down to 4.5 × 105 ng/L, which is exceptional for the real-time monitoring of emerging contaminants based on SERS technology. This research not only provides a new SERS enhancement strategy for organic-based materials, but also may be helpful in exploring a potential candidate for SERS detection of emerging contaminants.

Breathalyzer Test & Its Importance in Aviation Industry

The Indian aviation industry has witnessed significant growth in recent years, making safety and regulatory compliance paramount. To maintain the highest standards of safety, the Directorate General of Civil Aviation (DGCA) has implemented rigorous measures, including breathalyser testing for pilots and crew members. This abstract explores the significance of breathalyser testing in the Indian aviation sector, focusing on its role in enhancing safety and ensuring compliance with international aviation standards. Breathalyser testing has become a crucial component of the DGCA's safety protocols, aiming to prevent pilots and crew from operating aircraft under the influence of alcohol. This paper examines the key elements of the DGCA's alcohol testing regulations, including permissible blood alcohol concentration (BAC) limits, testing procedures, prohibition periods, and penalties for violations. The strict adherence to these regulations is essential to guarantee the safety of air travel and to maintain public trust in the industry. The abstract also delves into the impact of breathalyser testing on pilot behaviour and the overall safety culture within the Indian aviation sector. By acting as a strong deterrent against alcohol consumption before or during duty, these tests contribute to a safer and more responsible aviation workforce. Furthermore, this abstract discusses the role of breathalyser testing in aligning the Indian aviation industry with international standards, particularly those set by the International Civil Aviation Organization (ICAO). The adoption of stringent testing procedures demonstrates India's commitment to upholding global aviation safety norms. Finally, this paper highlights the importance of continuous monitoring and improvement of breathalyser testing programs, including pilot education and rehabilitation efforts for those facing alcohol-related issues. Such initiatives not only enhance safety but also promote a culture of responsibility and accountability within the industry. In conclusion, breathalyser testing has emerged as a pivotal tool for enhancing safety and compliance in the Indian aviation industry. It not only aligns with international standards but also plays a vital role in fostering a culture of safety and responsibility among aviation personnel. As the industry continues to expand, the strict enforcement of alcohol testing regulations remains essential to safeguarding the integrity of Indian aviation and ensuring the well-being of passengers and crew.

Health Burden and Driving Force Changes Due to Exposure to PM2.5 and O3 from 2014 to 2060 in a Typical Industrial Province, China

While air quality in China has improved significantly in recent years, the population is becoming increasingly vulnerable to air pollution due to the aging population. In this study, we assessed premature deaths attributable to long- and short-term exposures to PM2.5 and O3, as well as their driving forces in Shandong from 2014 to 2060 based on county-level near-real-time air pollutant concentration datasets and projected concentrations of PM2.5 and O3. We found that the concentrations of PM2.5 and O3 in most districts and counties from Shandong are still higher than the corresponding concentration limit of Grade II. Premature mortality caused by long- and short-term exposures to PM2.5 decreased by 13,045 and 8092 in 2020 compared with those in 2014, respectively. Furthermore, premature mortality attributable to short-term exposure to O3 was 36.08% higher than that due to short-term exposure to PM2.5 in 2020. The results of the driving force analysis indicate that the health benefits brought about by the improvement in air quality have been offset by the changes in population age structure. In the future, the increase in O3 concentration and population aging are the top two driving forces having adverse effects on the health burden. This study provides support for controlling the health risks of PM2.5 and O3 pollution, especially for the development of dual-pollutant concentration targets and synergistic control strategies.

Combination Chemotherapy Optimization with Discrete Dosing.

Chemotherapy drug administration is a complex problem that often requires expensive clinical trials to evaluate potential regimens; one way to alleviate this burden and better inform future trials is to build reliable models for drug administration. This paper presents a mixed-integer program for combination chemotherapy (utilization of multiple drugs) optimization that incorporates various important operational constraints and, besides dose and concentration limits, controls treatment toxicity based on its effect on the count of white blood cells. To address the uncertainty of tumor heterogeneity, we also propose chance constraints that guarantee reaching an operable tumor size with a high probability in a neoadjuvant setting. We present analytical results pertinent to the accuracy of the model in representing biological processes of chemotherapy and establish its potential for clinical applications through a numerical study of breast cancer.

Two-Dimensional Amorphous Titanium Dioxide/Silver (TiO2/Ag) Nanosheets as a Surface-Enhanced Raman Spectroscopy Substrate for Highly Sensitive Detection.

For the purpose of investigating the chemical enhancement of amorphous semiconductors as well as increasing the sensitivity of the surface-enhanced Raman spectroscopy (SERS) substrate, titanium dioxide (TiO2) precursors were calcined at different temperatures to generate crystallized TiO2 (c-TiO2) and amorphous TiO2 (a-TiO2) nanosheets, respectively. Afterward, a two-dimensional (2D) a-TiO2/Ag nanosheet SERS substrate was successfully fabricated using electrostatic interaction between a-TiO2 and Ag nanoparticles. In order to demonstrate a greater SERS sensitivity on a-TiO2/Ag compared to either c-TiO2 or Ag nanoparticles alone, the SERS probe molecules rhodamine 6G (R6G) and malachite green (MG) were utilized. Based on the results of SERS detections for probe molecules and contaminants, it demonstrates that a-TiO2/Ag nanosheets produce highly sensitive and repeatable Raman signals. The detectable concentration limits for R6G and MG were found to be 10-11 M and 10-10 M, respectively. And it has been determined that the system exhibits an enhancement factor (EF) of up to 1 × 108. The limit of detection for 4-mercaptobenzoic acid and alizarin red can both reach 1 × 10-8. Furthermore, a finite-difference time-domain simulation is performed in order to evaluate the magnetic field strength generated by Ag nanoparticles. As a result of the simulation, it is evident that the actual EF is smaller than the calculated one, leading support to the view that a-TiO2 nanosheets have a beneficial effect on the chemical enhancement of SERS.

Study on revision of standard limits for nitrogen dioxide in "Standards for indoor air quality（GB/T 18883-2022）" in China

Nitrogen dioxide (NO2) is an important indoor air pollutant, with both outdoor and indoor sources contributing to indoor NO2 exposure levels. Considering the association of high NO2 exposure with adverse health effects, the Standards for indoor air quality (GB/T 18883-2022) have been revised to further restrict indoor NO2 limit values. The 1-h average concentration limit value for NO2 has been reduced from 0.24 mg/m3 to 200 μg/m3.This study analyzed the technical contents related to the determination of the limits of indoor NO2 in Standards for Indoor Air Quality (GB/T 18883-2022), including source, exposure level, health effects, and the process and evidence basis for determining the limit value. It also proposed prospects for the direction for the implementation of the indoor NO2 standard.

Vision Zero and Impaired Driving: Near and Longer-Term Opportunities for Preventing Death and Injuries

Vision Zero involves the use of a systems approach to eliminate fatal and serious injuries from motor vehicle crashes by accommodating basic human limitations that lead to crashes through fundamental behavioral expectations, together with sound vehicle and road design.Alcohol-related crashes account for a significant proportion of motor vehicle crash death and injury and can be addressed in a safe road transport system. We look at near-term policy and program interventions that are known to motivate drivers to make safe drinking and driving decisions, and possibilities for using technology over the longer term to address risks resulting from driver impairment that is either inadvertent or willful high-risk behavior.From the Vision Zero perspective,”normal driving” refers to a situation where traffic and road users are operating as desired and planned. A driver in this normal driving envelope operates at a safe speed, wears a seat belt, focuses on the driving task, and is not impaired. A safe system accommodates human errors, mistakes, and misjudgments in the normal driving envelope. However, it may not be capable of compensating for deliberate violations and rule-breaking.A critical role of behavioral programs and policies is to motivate safe decisions by drivers and other road users and keep them in the normal driving envelope where they can be protected from unintentional errors by a safe system. While much progress has been made in developing and implementing impaired driving policies and programs, much potential remains in the their ability to motivate drivers to meet the fundamental expectations required in a safe system. Examples of behavioral programs and policies that have strong evidence of effectiveness but are underutilized in the U.S. include conducting periodic sobriety checkpoints, lowering the blood alcohol concentration limit for driving, and mandating the use of ignition interlock devices. While the specific interventions may differ, it is likely that the same situation of incomplete implementation of behavioral programs and policies - and consequent unrealized value to a comprehensive safe system - applies to many other nations.To reach the goal of zero deaths, a comprehensive Vision Zero program needs to address the problem of deliberate risk-taking, which can include driver impairment from alcohol or other causes and extend to dangerous and reckless driving. Advanced safety technologies offer a range of opportunities for this purpose. Cars available today and in the future will have a plethora of sensors that monitor circumstances inside and around the car. These systems can identify whether a driver is in their safe driving envelope and respond with interventions that are appropriate for the severity and nature of the risk. Interventions could range from those that are not perceivable to the driver, such as putting driver assist systems into active mode, to stronger steps such as limiting or preventing vehicle operation.Zero fatalities or serious injuries in motor vehicle crashes is possible with a systems approach that accommodates human errors and mistakes that occur with the normal driving envelope and incorporates effective responses to deliberate risk-taking outside of this envelope.

Dissolution of Silicon from Soilless Substrates and Additives

Silicon (Si) is a beneficial element that is usually ample in mineral soil solution, but it is minimally bioavailable from soilless substrates. Several Si additives are commercially available, but the rate of dissolution of Si is not well-characterized. The ideal additive would steadily release bioavailable Si over the crop lifecycle. We report the long-term (120 days) dissolution of Si from soilless substrates and substrate additives. Studies involving gently agitated containers with deionized water indicated that perlite, sphagnum peat, vermiculite, and coconut coir released less than 0.03 mmol Si per liter of substrate per day. Rice hulls and wollastonite (CaSiO3) had 7- to 130-times faster rates of dissolution in this system; therefore, they were further studied in peat-based media. Dissolution of Si from the addition of 1 g wollastonite per liter of peat peaked at day 10 at 2.1 mmol Si per liter of media per leaching event (15% by volume); then, it gradually decreased over 120 days. The peak dissolution of Si amended with 12% rice hulls was similar, but it gradually increased over time. The concentrations of nine heavy metals in plant tissue were compared with untreated control plants to determine wollastonite and steel slag. The concentration of some elements statistically increased, but all concentrations were well below the legal concentration limits of these elements for human consumption in the United States. These results indicate that both wollastonite and rice hulls steadily release Si for up to 4 months; therefore, they are good sources of Si for container-grown crops in soilless media.

Designing brazing filler metal for heat-resistant nickel alloys of new generation marine gas turbines

The object of research is the processes of the formation of brazed joints and the stressed state. The subject of research is structure, chemical composition, long-term high-temperature strength at a temperature of 900 °C, speed of high-temperature salt corrosion. Existing brazing filler metals have a high-temperature performance of 40–50 % of the performance of the SM93-VI and SM96-VI alloys. Despite this, brazing is the main technique of joining modern heat-resistant cast alloys. Therefore, the development of new brazing filler metals that ensure the formation of joints with increased long-term high-temperature strength is relevant. Ship gas turbine blades operate at a temperature of 900 °C. The purpose of the development of the new SBM-4 brazing filler metal is to achieve long-term high-temperature strength of brazed joints at a temperature of 900 °C at the level of 85–90 % of the strength of heat-resistant alloys SM93-VI and SM96-VI. A two-stage method was used in the development of SBM-4 brazing filler metal. At the first stage, the chemical composition of the brazing filler metal base was determined, taking into account the peculiarities of operating conditions of the blades of marine gas turbine engines and the achievements of materials science of heat-resistant alloys. At the second stage, the depressant and its necessary content were selected. Computer software was used to determine the distribution between the γ- and γ'-phases, taking into account the participation of each element in both dispersion and solid-solution strengthening. Rational limits of concentrations of alloying elements were determined. The criterion was the minimum susceptibility of brazing filler metal to the formation of brittle phases, taking into account the influence of chromium, rhenium, and tantalum concentrations on resistance to high-temperature salt corrosion and high-temperature performance. The long-term strength of SM93-VI and CM96-VI alloys brazed with SBM-4 brazing filler metal is 89–91 % of the strength of the base metal. Technologies of brazing and correction of casting defects have been introduced into production.

Environmental health risk analysis of nitrogen dioxide (NO2) exposure in children around sugar factory X, Nganjuk Regency

Nitrogen dioxide (NO2) gas in the air surrounding residential areas near Sugar Factory X presents a noteworthy health hazard, particularly for children. The objective of this study is to identify the sources of NO2 pollution and perform an Environmental Health Risk Analysis (EHRA) on children's exposure. This study is a quantitative, descriptive-analytical research using secondary data from ambient air quality tests in residential areas surrounding Sugar Factory X in 2022. The data were obtained from relevant agencies. The data were analyzed using EHRA method. The analysis identified the boiler chimney emissions of Sugar Factory X as the primary source of NO2 gas in that area. The overall risk characterization indicated that NO2 concentrations of 0.0514 mg/m3, 0.0528 mg/m3, and 0.0541 mg/m3 were unsafe for children weighing 15 kg and 20 kg, based on a 24-hour daily inhalation time and an exposure frequency of 350 days/year. The effects of exposure were projected over a period of 6 years. Children weighing 15 kg are at a higher risk than children weighing 20 kg. The NO2 concentration limit for a 15 kg child was 0.0261 mg/m3, while for a 20 kg child, it was 0.0348 mg/m3. Sugar factory X is the only source of NO2 pollution in the adjacent residential areas, which poses a threat to children living in these nearby areas, especially those weighing 15 kg. Sugar Factory X is expected to undertake several measures, including replacing the boiler chimneys, conducting regular equipment maintenance, and establishing green belts.

Recovery of Phosphorus and Metals from the Ash of Sewage Sludge, Municipal Solid Waste, or Wood Biomass: A Review and Proposals for Further Use

This review provides an overview of methods to extract valuable resources from the ash fractions of sewage sludge, municipal solid waste, and wood biomass combustion. The resources addressed here include critical raw materials, such as phosphorus, base and precious metals, and rare earth elements for which it is increasingly important to tap into secondary sources in addition to the mining of primary raw materials. The extraction technologies prioritized in this review are based on recycled acids or excess renewable energy to achieve an optimum environmental profile for the extracted resources and provide benefits in the form of local industrial symbioses. The extraction methods cover all scarce and valuable chemical elements contained in the ashes above certain concentration limits. Another important part of this review is defining potential applications for the mineral residues remaining after extraction. Therefore, the aim of this review is to combine the knowledge of resource extraction technology from ashes with possible applications of mineral residues in construction and related sectors to fully close material cycle loops.

The development of local ambient air quality standards: A case study of Hainan Province, China

The ambient air quality standard (AAQS) is a vital policy instrument for protecting the environment and human health. Hainan Province is at the forefront of China's efforts to protect its ecological environment, with an official goal to achieve world-leading air quality by 2035. However, neither the national AAQS nor the World Health Organization guideline offers sufficient guidance for improving air quality in Hainan because Hainan has well met the former while the latter is excessively stringent. Consequently, the establishment of Hainan's local AAQS becomes imperative. Nonetheless, research regarding the development of local AAQS is scarce, especially in comparatively more polluted countries such as China. The relatively high background values and significant interannual fluctuations in air pollutant concentrations in Hainan present challenges in the development of local AAQS. Our research proposes a world-class local AAQS of Hainan Province by reviewing the AAQS in major countries or regions worldwide, analyzing the influence of different statistical forms, and carefully evaluating the attainability of the standard. In the proposed AAQS, the annual mean concentration limit for PM2.5, the annual 95th percentile of daily maximum 8-h mean (MDA8) concentration limit for O3, and the peak season concentration limit for O3 are set at 10, 120, and 85 μg/m3, respectively. Our study indicates that, with effective control policies, Hainan is projected to achieve compliance with the new standard by 2035. The implementation of the local AAQS is estimated to avoid 1,526 (1,253–1,789) and 259 (132–501) premature deaths attributable to long-term exposure to PM2.5 and O3 in Hainan in 2035, respectively.

Charge-Density-Wave Order And Electronic Phase Transitions in a Dilute D-Band Semiconductor.

As one of the most fundamental physical phenomena, charge density wave (CDW) order predominantly occurs in metallic systems such as quasi-one-dimensional (quasi-1D) metals, doped cuprates, and transition metal dichalcogenides, where it is well understood in terms of Fermi surface nesting and electron-phonon coupling mechanisms. On the other hand, CDW phenomena in semiconducting systems, particularly at the low carrier concentration limit, are less common and feature intricate characteristics, which often necessitate the exploration of novel mechanisms, such as electron-hole coupling or Mott physics, to explain. In this study, we combined electrical transport, synchrotron X-ray diffraction and density-functional theory (DFT) calculations to investigate CDW order and a series of hysteretic phase transitions in a dilute d-band semiconductor, BaTiS3 . Our experimental and theoretical findings suggest that the observed CDW order and phase transitions in BaTiS3 may be attributed to both electron-phonon coupling and non-negligible electron-electron interactions in the system. Our work highlights BaTiS3 as a unique platform to explore CDW physics and novel electronic phases in the dilute filling limit and could open new opportunities for developing novel electronic devices. This article is protected by copyright. All rights reserved.

Determining suitable surfactant concentration ranges to avoid protein unfolding in pharmaceutical formulations using UV analysis

Protein stability is fundamental to maintain pharmaceutical efficacy in the nascent field of biologics. One particular property that is essential for therapeutic effect is retention of the folded 3-dimensional conformation, i.e. once unfolding has occurred the biologic is often rendered inactive. In this work we propose a modified form of a recently published UV spectroscopic method that identifies protein unfolding. In this study we determine concentration limits to avoid protein unfolding of two model surfactants, namely polysorbate 20 and polysorbate 80, by correlating surfactant concentration with percentage ‘unfolded’ for three model proteins. For each scenario two distinct regions were observed, firstly surfactant concentrations at which no unfolding had occurred, followed by a second region whereby unfolding steadily increased with surfactant concentration. In general for the combinations analysed in this study, this second region began to appear around ten times below the critical micellar concentration of each surfactant, regardless of the protein or polysorbate chosen. It is therefore proposed that this adapted method could be used by researchers in the early stages of formulation development as a convenient and simple screening tool to confirm the ‘onset of unfolding’ concentration for protein-surfactant formulations, thus helping to optimise surfactant concentration selection in pharmaceutical formulations to maintain the benefits of surfactants yet avoid inadvertent unfolding.