Commercial Cleaning Research Articles

A Design Study on Commercial Cleaning Robots Based on Kano–QFD

In the post-pandemic era, public space safety has emerged as a central public concern. As global public health awareness rose, traditional manual cleaning methods were increasingly inadequate for large-scale and high-standard cleaning requirements. Therefore, the design of a commercial cleaning robot that combined cleaning efficiency, environmental performance, and sustainability was essential to meet evolving societal demands. This paper systematically gathered and analyzed commercial cleaning robot functional requirements through a comprehensive investigation. According to the Kano model, functional requirements were categorized by attributes and their importance was quantified. Subsequently, using the QFD model, the design requirements for commercial cleaning robots were determined, and their significance weights were established. This identified the key design requirements. The results of this study indicated that the integration of the Kano and QFD models provided a novel perspective for the design of functional integration in commercial cleaning robots. Furthermore, it provided a practical methodological framework for addressing similar issues in the future.

Evaluating DIY air cleaner variability and potential for post-construction emission of aromatic VOCs during wildfire events

While do-it-yourself (DIY) air cleaners such as the Corsi-Rosenthal Box (CR Box) are an increasingly popular choice for low-cost, accessible air cleaning during a wildfire event, construction and performance variability remains a concern. Using the same set of instructions, materials, and location of assembly, seven CR Boxes are constructed by individuals with no prior DIY air cleaner experience and clean air delivery rates (CADRs) are experimentally determined for each of the devices. Against a challenge aerosol consisting of fresh smoke generated via pine needle combustion, average number-based, PM2.5 CR Box CADRs range from 313–396 m3/h (relative standard deviation = 7.6 %). Over this modest range of observed variability, constructed units outperform many higher-cost commercial air cleaners. A review of the literature demonstrates that across studies, substantial CADR variability is observed (285–1448 m3/h); differences in materials (including filter type) used during air cleaner construction, challenge aerosols tested, and evaluation protocol are major contributors to variability. To evaluate the potential for exposure to aromatic volatile organic compounds (VOCs) from CR Box materials, we place three devices in a large chamber for 24–72 hours immediately following construction. Toluene and C8 aromatics (ethylbenzene and xylenes) are emitted at 2289 and 89 μg/h, respectively, with emission rates decreasing by 94 % and 82 % after 12 hours. Using experimentally determined PM2.5 CADRs and VOC emission rates, a hypothetical wildfire event impacting the bedroom of a home is modeled at four outdoor air exchange rates (AERs) to assess tradeoffs between building airtightness, particle removal effectiveness, and VOC off-gassing from a newly built CR Box. PM2.5 effectiveness ranges from 0.88 to 0.95, depending on AER (0.1–1 h−1). While modeled maximum VOC concentrations remain orders of magnitude below short-term permissible exposure limits at all AERs considered, modeled and observed VOC dynamics imply that an off-gassing period of ∼6–12 hours would avoid episodic emission of VOCs at rates that may cause accumulation in excess of the lower-limit of toluene odor threshold estimates.

Rapid oxidation of semiconductors at room temperature with a basic plasma cleaner

This paper shows how a simple modification of the electrodes in a basic commercial plasma cleaner allowed the oxidation of compound semiconductors (GaAs) and Si at room temperature. We explained the oxidation of the semiconductor surface by the participation of aluminum atoms evaporated from the electrode surface in the discharge, which resulting in additional ultraviolet (UV) radiation from the plasma. The UV radiation not only increases the decomposition of oxygen molecules adsorbed on the surface but also results in photoionization of GaAs with the formation of Ga and As ions at the oxide–GaAs interface. In addition to obtaining oxides on semiconductor surfaces, the modified device proved to be an effective tool for etching amorphous carbon films.

Comparative analysis of commercial cleaning and disinfection formulations and protocols for effective eradication of biofilms formed by a Pseudomonas fluorescens strain isolated from a poultry meat plant

Pseudomonas spp. is the main genus of spoilage bacteria for meat stored under aerobic chilling conditions. Given their ability to adapt to various environmental conditions and to form biofilms, they are common among residential microbiota in the food industry. Biofilms are complex, structured microbial communities encased in a self-produced exopolysaccharide matrix. Resident biofilm bacteria show increased resistance against disinfectants and dynamic or hostile environments, and are therefore a persistent source of food contamination. Hence, there is a need to design and implement control strategies that are effective against biofilms in the food industry. In this study, we tested a series of commercial cleaning and disinfection agents applied by immersion or aerosolization against robust biofilms of a Pseudomonas fluorescens strain isolated from a poultry meat plant by comparing the sessile cell counts before and after the procedure. The single application of a) an alkaline or an enzymatic detergent, b) a disinfectant based on peracetic acid and hydrogen peroxide, or c) a detergent-disinfectant based on tertiary alkylamines or sodium hypochlorite, failed to completely eradicate the biofilm. However, two-step cleaning and disinfection procedures involving the application of a detergent (either alkaline or enzymatic at 50 °C) followed by the application of the disinfectant based on peracetic acid and hydrogen peroxide at the manufacturer's recommended concentrations did result in the complete eradication (p ≤ 0.05) of the robust biofilm. In addition, cleaning and disinfection procedures applied by aerosolization showed a notable efficacy (p ≤ 0.05) against surface-dried cells and sessile cells of P. fluorescens. Therefore, this approach could be regarded as a potentially viable alternative to commonly applied immersion techniques.

Growth and physiological responses of submerged macrophytes to linear alkylbenzene sulfonate (LAS)

The potential toxic effects of linear alkylbenzene sulfonate (LAS), widely used in commercial detergents and cleaners, on submerged macrophytes remain unclear. We conducted a two-week exposure experiment to investigate LAS toxicity on five submerged macrophytes (four native and one exotic), focusing on their growth and physiological responses. The results showed that lower concentrations of LAS (< 5 mg/L) slightly stimulated the growth of submerged macrophytes, while higher doses inhibited it. Increasing LAS concentration resulted in decreased chlorophyll content, increased MDA content and POD activity, and initially increased SOD and CAT activities before declining. Moreover, Elodea nuttallii required a higher effective concentration for growth compared to native macrophytes. These findings suggest that different species of submerged macrophytes exhibited specific responses to LAS, with high doses (exceeding 5 ∼ 10 mg/L) inhibited plant growth and physiology. However, LAS may promote the dominance of surfactant-tolerant exotic submerged macrophytes in polluted aquatic environments.

Polycyclic Aromatic Hydrocarbons (PAHs) in Wildfire Smoke Accumulate on Indoor Materials and Create Postsmoke Event Exposure Pathways.

Wildfire smoke contains PAHs that, after infiltrating indoors, accumulate on indoor materials through particle deposition and partitioning from air. We report the magnitude and persistence of select surface associated PAHs on three common indoor materials: glass, cotton, and mechanical air filter media. Materials were loaded with PAHs through both spiking with standards and exposure to a wildfire smoke proxy. Loaded materials were aged indoors over ∼4 months to determine PAH persistence. For materials spiked with standards, total PAH decay rates were 0.010 ± 0.002, 0.025 ± 0.005, and 0.051 ± 0.009 day-1, for mechanical air filter media, glass, and cotton, respectively. PAH decay on smoke-exposed samples is consistent with that predicated by decay constants from spiked materials. Decay curves of smoke loaded samples show that PAH surface concentrations are elevated above background for ∼40 days after the smoke clears. Cleaning processes efficiently remove PAHs, with reductions of 71% and 62% after cleaning smoke-exposed glass with ethanol and a commercial cleaner, respectively. Laundering smoke-exposed cotton in a washing machine and heated drying removed 48% of PAHs. An exposure assessment indicates that both inhalation and dermal PAH exposure pathways may be relevant following wildfire smoke events.

Strategic Placement of Portable Air Cleaners for Enhanced Aerosol Control in Dental Treatment Rooms: A Computational Fluid Dynamics (CFD) Analysis

Background. Adequate ventilation is imperative for controlling respiratory transmission, particularly in the context of the COVID-19 pandemic. The commercial portable air cleaners have emerged as practical solutions to reduce contaminated aerosols in dental treatment rooms. This study employs computational fluid dynamics (CFD) to assess their impact on airflow dynamics. Methods. Dental treatment room models were constructed using SolidWorks software, encompassing two distinct air conditioner grille orientations (straightening and 45-degree downward directions) and five different positions for the portable air cleaner (two located at the rear left/right of the dental unit and three at the foot end of the dental unit—center, left, and right corners). The study examined alterations in airflow direction and residual aerosol concentrations using ANSYS Fluent software. Results. The incorporation of portable air cleaners in dental treatment rooms significantly reduced aerosol levels across all model configurations. Notably, the placement of the portable air cleaner emerged as a critical factor influencing airflow patterns. In models with straightening and 45-degree downward air conditioner grille orientations, optimal positioning was near the operating field and at the foot end of the dental chair, respectively. Conclusion. This investigation highlights the pivotal role of strategic portable air cleaner placement in dental treatment rooms for effective aerosol removal. Placing the air cleaner near the operating field or at the foot end of the dental chair not only improved airflow patterns but also enhanced aerosol removal efficiency, ultimately promoting superior air quality within dental treatment environments.

Potential of Citronella Oil and Gum Rosin as Antimicrobial Agents in Floor Cleaner Liquid Against Salmonella thypi

Some floor cleaner products on the market contain antimicrobial agents that are harmful to humans and the environment, such as benzalkonium chloride. Therefore, searching for a new antimicrobial agent that is relatively safe is a significant challenge. In this study, we investigated the best formula for making floor cleaner using citronella oil and gum rosin as antimicrobial agents. Its antimicrobial activity against Salmonella thypi was investigated and compared with that of a commercial floor cleaner containing benzalkonium chloride. Five concentrations and ratios of citronella oil and gum rosin were investigated. The quality of floor cleaner in terms of pH range and the stability of the emulsion in hard water was assessed according to SNI 06-1842-1995. The results showed that all formulas met the pH range required by SNI, except for formulas containing citronella oil alone. The emulsion in hard water was stable for all formulas. The antimicrobial activity increased with increasing concentrations of antimicrobial agents. Citronella oil exhibited higher antimicrobial activity than gum rosin. Benzalkonium chloride showed higher microbial activity than gum rosin but lower than citronella oil. The combination of citronella oil and gum rosin showed higher microbial activity by 1.1–2.4 times than formulas containing benzalkonium chloride. The optimum floor cleaner formula (a concentration of citronella oil and gum rosin of 2% with a ratio of 1:1) has an inhibition zone diameter of 22.2 mm.

Enhancing the efficacy of peracetic acid against Listeria monocytogenes and Listeria innocua on fresh apples using commercial acidic and alkaline cleaners

Peracetic acid (PAA) is a commonly used antimicrobial in brush-bed spray bar interventions during apple packing. Prior to sanitizer application on the brush-bed, specific fruit cleaners, such as Acidex Duo (AD), EpiClean (EC), Nature's Shield 220-ACL (NS 220), or Nature's Shield 330-ALK (NS 330), are used to remove of soil, debris, and natural wax from the surfaces of apples. This study evaluated the effectiveness of commonly used cleaners in the apple industry to improve the antimicrobial efficacy of PAA against Listeria monocytogenes on apple surfaces during brush-bed spray bar interventions. Granny Smith apples, 48 h post-inoculation, underwent submersion treatment with different cleaners, as well as PAA alone or in combination with the cleaners. A 30-sec treatment of 5.0% AD, 4.2% EC, 10.0% NS 220, and 10.0% NS 330 resulted in 0.65, 0.50, 0.68, and 0.51 log10 CFU/apple reduction of L. monocytogenes on apples, respectively. Incorporating AD, NS 220, and EC significantly enhanced the antimicrobial efficacy of an 80 ppm PAA intervention. The enhancing effects were not impacted whether the cleaner was applied consecutively with PAA (sequentially) or in combination with PAA (simultaneously), nor were they impacted by a post-treatment water rinse. A 30–120 s wash of 80 ppm PAA with AD, EC, and NS 220 at their suggested concentration resulted in 2.46–2.55, 1.87–2.03, and 2.34–2.48 log10 CFU/apple reduction of L. monocytogenes, respectively, compared to 1.39–1.64 log10 CFU/apple in PAA treatment alone. The inclusion of AD or NS 220 in 80 ppm PAA solution resulted in a reduction of 1.51–1.63 log10 CFU/apple of Listeria after 30–60 s brush-bed spray wash. This enhancement in efficacy was significant compared to the treatment with 80 ppm PAA alone, which resulted in a reduction of 0.94–1.03 log10 CFU/apple. This study demonstrated that using certain commercially available cleaners along with PAA can enhance the effectiveness of PAA in reducing L. monocytogenes on fresh apples.

Acoustic Attenuation Performance Analysis and Optimisation of Expansion Chamber Coupled Micro-perforated Cylindrical Panel Using Response Surface Method

This paper describes boundary element method (BEM), experimental and optimization studies conducted to understand the potential of expansion tube coupled micro-perforated cylindrical panel (MPCP) to enhance the acoustic attenuation for in-duct noise control issues. Due to complex structure of the MPCP and for the correct prediction of acoustic attenuation, BEM is adopted on the basis of PLM Simcenter 3D software to compute the sound transmission loss (TL). As the MPCP is cylindrical in-shape with numbers of sub-milimeter holes, additive manufacturing based 3D printing was utilized for the model prototyping to reduce current design limitation and enabled fast fabrication. The TL measurement based two-load method is adopted for modal validation. Subsequently, a parametric studies of the MPCP concerning the perforation hole diameter, perforation ratio and depth of air space are carried out to investigate the acoustical performance. Optimization via response surface method (RSM) is used as it allows evaluating the effects of multiple parameters as required in this study. The model validation result shows that the error between the BEM and and measured values is relatively small and show a good agreement. The R-square value is 0.89. The finding from parametric study shows that a widen peak attenuation can be achieve by reducing the perforation hole diameter and one way to increase the transmission loss amplitude is by increasing the air cavity depth. Finally, the optimized MPCP model was adopted to the commercial vacuum cleaner for the verification. The sound pressure level (SPL) of the vacuum cleaner is significantly attenuated within the objective frequency of 1.7 kHz and its A-weighted SPL is reduced by 1.8 dB.

Formulation and Evaluation of Herbal Floor Cleaner

Abstract: Microorganisms, the friend and foe of human being are omnipresent in and around us. Innumerable pathogenic and nonpathogenic microorganisms remain present on the floor surface with which we are in direct physical contact. These organisms include Salmonella, Rhinovirus, Herpes, Trichophyton, Giardia, E. coli, Micrococcus species etc. Most of the microbes are nonpathogenic when present in less quantity, but as their concentration increases, they are able to cause various diseases like Stomach upsets, diarrhea, Cold, Cold sores etc. To restrict the growth of such microbes in the surroundings including floors, various commercially available floor cleaners such as Phenylsare used. Present study is an attempt to isolate and identify the floor micro flora from home and laboratory and to observe the efficacy of different floor cleaners. According to Indian Medical Association phenyl, identified as the most effective disinfectant against the floor micro flora, and therefore they are considered as standards to analyze effectiveness of other commercial surface cleaners. Our study suggested that can inhibit the growth of common floor micro flora as effectively.

Rapid decalcification of articular cartilage and subchondral bone using an ultrasonic cleaner with EDTA

Articular cartilage and subchondral bones were used to be the samples for studying effects of drugs in the joint degenerative diseases such as osteoarthritis. Because of the deposition of mineral salts, articular cartilage and subchondral bones require decalcification process to soften the tissues. EDTA is a chelating agent that is commonly used to remove mineral salts, but this step is time-consuming and can take as long as 45 days. Commercial ultrasonic cleaner and microwave oven were reported to reduce the decalcification timing. The aim of this study is to determine and compare the decalcification of human articular cartilage and subchondral bone using EDTA together with ultrasonic cleaner or microwave oven. Hundred pieces of articular cartilage and subchondral bones obtained from osteoarthritis patients undergone total-knee-replacement were divided into 10 groups according to decalcification method (ultrasonic cleaner or microwave) and timing (2, 4, 6, 8, and 10 h). In each group, all cartilage and subchondral bone pieces were decalcified and sectioned, and subsequently stained with haematoxylin and eosin, Von Kossa, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, or caspase-3 immunohistochemistry. The optimal timing of decalcification of articular cartilage and subchondral bones using EDTA together with ultrasonic cleaner was at 8 and 10 h, while the timing using EDTA together with microwave oven was more than 10 h. Clear TUNEL and caspase-3 signals were obtained from samples decalcified using EDTA together with ultrasonic cleaner for 8 h. In summary, to our knowledge, this is the first study that compared EDTA decalcification between ultrasonic cleaner and microwave oven. Here, we report a new methodology for decalcification for articular cartilage and subchondral bones that reduces decalcification time from weeks to hours and is suitable for further pathological analyses.

Anti-fungal efficacy of Miswak Extract (Salvadora Persica) and commercial cleaner against Candida albicans on heat cured polymethylmethacrylate denture base.

The aim of the study was to compare the antifungal efficacy between commercial cleaner (Corega) and Miswak extract (Salvadora persica) against Candida albicans on heat cured Polymethyl methacrylate (PMMA) acrylic denture base resin. Forty-eight samples of heat cured PMMA acrylic denture base resin were fabircated in the study. The sterile acrylic resin specimens were immersed in standardized cell suspension of Candida albicans and incubated for 60 min at 370°C for cell adhesion and 2 h at 370°C for biofilm formation. After 24 h biofilm was evaluated by cell viability (CFUs) on SDA and cell counting of Candida albicans under light microscope at 400× magnification. The fungicidal effect of commercial cleaner and Miswak extract on Candida albicans biofilm was then evaluated by colony-forming units on SDA and cell counting under light microscope at 400× magnification. Screening test agar disk-diffusion assay showed mean inhibitory zone of 3 mm for commercial cleaner as compared to Miswak extract, which showed mean inhibitory zone of 2 and 1 mm for different concentrations. Broth microdilution method showed 31 mg/ml MIC and 62.5 mg/ml Minimal Fungicidal Concentration (MFC) values for commercial cleaner as compared to Miswak extract that showed 125 mg/ml MIC and 250 mg/ml MFC values against Candida albicans. A significant difference (p < 0.05) was observed between pre and post treatment of both commercial cleaner and Miswak extract, for CFUs and cell count for Candida albicans. Commercial denture cleaner (Corega) showed better antifungal (C albicans) activity than Miswak extract (Salvadora persica) on heat cured PMMA acrylic denture base resin.

Evaluation of hypochlorous acid as an ear flush in dogs with chronic otitis externa.

Chronic otitis externa (OE) in dogs frequently requires anaesthetised ear flushing. To evaluate hypochlorous acid as an ear flushing and antimicrobial agent in dogs with chronic OE. Twenty dogs with chronic OE caused by the same organisms bilaterally. One ear was flushed under anaesthesia with hypochlorous acid, the other with saline solution. Subsequently, the ear flushed with hypochlorous acid was cleaned with the same solution twice daily for 2 weeks, the other ear with a commercial ear cleaner. An ear medication containing miconazole, polymyxin B and prednisolone was used once daily in both ears. Clinical scores were determined before the flush. Ear cytological results were obtained, a hearing test was conducted before and after the ear flush, and a culture was taken directly after flushing. Ears were evaluated after 2 weeks of therapy. Yeast was present in the ears of 11, cocci in one and a mixed infection in eight dogs. Five ears were negative on culture after flushing with hypochlorous acid, one after the saline flush. Clinical and cytological scores decreased significantly with both solutions after 2 weeks of treatment. There was no difference between treatments in any of the scores at any time point between treatments and in the results of the hearing test before and after the flushing procedure. Adverse effects were not seen. Hypochlorous acid is a suitable cleaning solution for canine OE.

Properties and characteristics of foam denture cleaners as denture adhesive removers.

The need for denture adhesives is increasing worldwide, but few denture-care products target denture adhesive users. Foam denture cleaners have been recently marketed to assist brush denture cleaning, but there is a lack of objective evaluation. In this study, we compared the detergency of denture adhesives using six commercial foam-denture cleaners. For removing the adhesives, most of the tested cleaners were effective in immersion experiments, and three cleaners were more effective in the denture cleaning experiment compared to control water. However, only one could effectively remove the slime that is derived from the adhesive and detergency of artificial dirt. The surface roughnesses of the denture base and the relining material revealed that prolonged immersion in some cleaners could be affected. The results suggest that different commercial foam denture cleaners have different detergency levels, and that some cleaners may affect the properties of denture materials upon long-term use.

Impact of Do-It-Yourself and Commercial Air Cleaner Usage on Health and Residential PM2.5

Background and aim: Wildfire smoke can threaten health, necessitating creating cleaner indoor air spaces. Commercially available portable air cleaners (PACs) mitigate smoke impacts indoors but can be expensive or inaccessible. Lower-cost Do-It-Yourself (DIY) PACs (furnace filter attached to box fan) offer an affordable alternative. However, evidence of their effectiveness in real-world settings is limited. This pilot study aimed to 1) evaluate the effect of DIY/commercial PAC usage on indoor PM2.5 and health outcomes during wildfire season among tribal community members in Hoopa, California and 2) assess barriers and facilitators to use of either intervention. Methods: During four one-to-two-week phases (baseline; DIY PAC usage &amp;#x2265;8 hours/day; commercial PAC usage &amp;#x2265;8 hours/day; and air sensor with visual display with optional PAC use), we monitored indoor and outdoor PM2.5 at participants’ homes. We conducted phase-specific phone surveys about participants’ health, behaviors, and perceptions. We analyzed indoor PM2.5 and health outcomes associated with PAC usage using mixed effects multivariate linear regression and tabulated behavioral responses. Results: DIY and commercial PAC usage was significantly associated with reduced infiltrated PM2.5 (n=6). High usage (&amp;#x2265;30% of phase) of either PAC was significantly associated with improved health (measured as a composite score), relative to low usage (&amp;#x3c;10% of phase) (n=10). Noise was the primary barrier to DIY PAC use, while quiet operation and small size of commercial PACs facilitated use. Nonetheless, eight of nine participants who preferred commercial PACs said they would use DIY PACs if the air were very smoky. Conclusions: DIY and commercial PACs were associated with improved indoor PM2.5 and health, but the loudness of DIY PACs hindered use. State, local, and tribal organizations should consider these conclusions in tailoring messaging and allocating resources in preparation for wildfire seasons. Disclaimer: Does not reflect EPA views or policy. Keywords: Indigenous, wildfire smoke, indoor air quality

Ultrathin MnO2-Coated FeOOH Catalyst for Indoor Formaldehyde Oxidation at Ambient Temperature: New Insight into Surface Reactive Oxygen Species and In-Field Testing in an Air Cleaner.

Herein, we tailored a series of ultrathin MnO2 nanolayers coated on the surface of commercial goethite (α-FeOOH) by a facile in situ chemical precipitation method. α-FeOOH inhibited the MnO2 crystal growth via the incorporation of K+ ions between MnO2 and α-FeOOH interfaces during the synthesis process. The hybrid design of MnO2 with an ultrathin nanolayer structure could reduce the electron transfer resistance and bring abundant oxygen vacancies, accelerating the activation of molecular O2 to generate more oxygen-free radical species and favoring the thermodynamic HCHO oxidation. The ROS quenching in gas/aqueous systems and DRIFTS results demonstrated that •O2- was responsible for HCHO oxidization, which assisted the preliminary intermediate dioxymethylene dehydrogenation into formate species. The 25%MnO2@FeOOH(25wt% of MnO2) catalyst was subsequently loaded into the filter substrates of a commercial air cleaner and tested in an indoor room with actual application conditions. As a result, the composite filter could eliminate different initial concentrations of HCHO (150-450 ppb) to the WHO guideline value (≈81 ppb) within 60 min. Furthermore, the 25%MnO2@FeOOH sample was also effective against the representative bacteria and mold in indoor air. This study provides new insight into the role of the chemisorbed ROS for HCHO oxidation at ambient temperature.

Ultra-low jitter clock distribution for the trigger electronics of the New Small Wheel for the ATLAS experiment

The Large Hadron Collider (LHC) at CERN plans to have a series of upgrades to increase its instantaneous luminosity to 7.5 × 1034 cm−2 s−1. The increased luminosity drastically impacts the ATLAS trigger and readout data rates. The inner-most station of the ATLAS muon spectrometer, the so-called Small Wheels is being replaced with a New Small Wheel (NSW) system, consisting of Micromegas and small-strip Thin Gap Chambers (sTGC) detectors. The on-detector radiation levels required radiation tolerant electronics. The lower radiation levels on the rim of the NSW allowed utilizing commercial electronic chips, such as Field Programmable Gate Arrays (FPGAs), in the trigger chain of the sTGC detectors. Those FPGAs require an ultra-low jitter clock for the proper operation of their Gigabit transceivers (4.8 Gb/s serial links). The initial design was based on a clock provided by a radiation tolerant ASIC designed at CERN, but due to its intrinsic jitter and consequent marginal error rate on the transmission lines, a different approach had to be chosen. An additional clock source based on commercial jitter cleaners, fanout chips and optical transmitters driving dedicated fibers was built. The new scheme provides 64 low-jitter clocks (32 main and 32 redundant) from the radiation-protected area (USA15) to the trigger electronics over 60 m of OM3 fiber.

Alumina beads decorated copper-based coordination polymer particle filter for commercial indoor air cleaner

This paper provided an insight into the dual functionalities of air filter for the removal of multiple volatile organic compounds (VOCs) and Escherichia coli (E. coli) pathogen pollutants. In this regard, a cost-effective and eco-friendly method was developed to grow copper coordination polymer particles (Cu-CPP) onto porous alumina (Al2O3) support, resulting in the formation of Cu-CPP /Al2O3 composite beads. The use of coordination polymer particles can allow more control of the physical and chemical properties of the adsorptive materials at a molecular level through rational selection of metal nodes and organic ligands. Notably, excellent toluene adsorption capacities (256.97 mg g−1) and breakthrough behaviors were observed in Cu-CPP/Al2O3 beads. For the first time, the Cu-CPP/Al2O3 beads air filter was successfully scaled up and installed on a commercial air cleaner with 1 m3 test chamber for various VOCs adsorption. The Cu-CPP/Al2O3 beads air filter exhibited removal efficiency for formaldehyde (99.5%), toluene (99.5%), acetic acid (100%) and ammonia (100%), which are superior to conventional activated carbon. The E. coli was chosen as a model for testing the inactivation performance. The Cu-CPP/Al2O3 beads showed an efficiency of 97.02%, which was substantially higher than that of activated carbon (43.78%) after 120 min of exposure. This research paves the way for the development of multifunctional air filters based on copper coordination polymer particles, which would be excellent for commercial indoor air cleaner applications.

In the service of…

In the service of … recalls ground maintenance, a live art performance enacted at the 2013 Plenitude and Emptiness Symposium, Edinburgh, Scotland. This essay takes the form of a series of letters written to the commercial cleaner who was responsible for maintaining the space on an everyday basis. Invoking an empathy-inducing method to build a relational affinity with the cleaner and her labour, the letters perform a next iteration of caring for the interior space on her behalf, specifically, sweeping the gallery and presentation room over the three-day event. Documented in a video, this durational gesture raised greater awareness of the invisible yet material labour so key to the university’s delivery of learning services and to the ongoing life of the building. It amplified the low-tech spatio-political and material agency of the broom and dirt’s long social history in relation to a woman’s everyday work on the interior’s surfaces of a public architecture.