Experimental study of a membrane-based dehumidification cooling system

Membrane-based liquid desiccant dehumidification has attracted increasing interests with elimination of solution droplets carryover problem. A membrane-based hybrid liquid desiccant dehumidification cooling system is developed in this study, which has the ability to remove latent load by a liquid desiccant dehumidification unit and simultaneously to handle sensible load by an evaporative cooling unit. The hybrid system mainly consists of a dehumidifier, a regenerator and an evaporative cooler, calcium chloride is used as liquid desiccant in the system. This paper presents a performance evaluation study of the hybrid system based on experimental data. Series of tests have been conducted to clarify the influences of operating variables and conditions (i.e. desiccant solution concentration ratio, regeneration temperature, inlet air condition, etc.) on the system performance. The experimental results indicate that the system is viable for dehumidification cooling purpose, with which the supply air is provided at temperature of 20.4°C for the inlet air condition at temperature of 34°C and relative humidity of 73%. At desiccant solution concentration ratio of 36%, the thermal COPth of 0.70 and electrical COPel of 2.62 are achieved respectively under steady operating condition

Experimental study of a membrane-based dehumidification cooling system

Membrane-based liquid desiccant dehumidification has attracted increasing interests with elimination of solution droplets carryover problem. A membrane-based hybrid liquid desiccant dehumidification cooling system is developed in this study, which has the ability to remove latent load by a liquid desiccant dehumidification unit and simultaneously to handle sensible load by an evaporative cooling unit. The hybrid system mainly consists of a dehumidifier, a regenerator and an evaporative cooler, calcium chloride is used as liquid desiccant in the system. This paper presents a performance evaluation study of the hybrid system based on experimental data. Series of tests have been conducted to clarify the influences of operating variables and conditions (i.e. desiccant solution concentration ratio, regeneration temperature, inlet air condition, etc.) on the system performance. The experimental results indicate that the system is viable for dehumidification cooling purpose, with which the supply air is provided at temperature of 20.4°C for the inlet air condition at temperature of 34°C and relative humidity of 73%. At desiccant solution concentration ratio of 36%, the thermal COPth of 0.70 and electrical COPel of 2.62 are achieved respectively under steady operating condition

Estimating the Φ(n) of Upper/Lower Bound in its RSA Cryptosystem

The RSA-768 (270 decimal digits) was factored by Kleinjung et al. on December 12 2009, and the RSA-704 (212 decimal digits) was factored by Bai et al. on July 2, 2012. And the RSA-200 (663 bits) was factored by Bahr et al. on May 9, 2005. Until right now, there is no body successful to break the RSA-210 (696 bits) currently. In this paper, we would discuss an estimation method to approach lower/upper bound of Φ(n) in the RSA parameters. Our contribution may help researchers lock the Φ(n) and the challenge RSA shortly

Expectation-Confirmation Model and IPA Continuance Behavior

With the emergence of Intelligent Personal Assistants (IPAs) such as Amazon Alexa, Google Home, and Apple Siri, etc., IPA arises as one of the fastest-growing artificial intelligence applications in recent years. Since the success of information technology (IT) depends on the continuance of its usage (Bhattacherjee, 2001), studies on IPA continuance behavior should also attract academic attention. IPA continuance refers to long-term or sustainable use of intelligent personal assistants, which make use of Natural Language User Interfaces (NLUI) to provide users with information about the weather, maps, schedules, calls, events, etc. (Kennington & Shukla, 2017). Prior studies in the IPA usability domain mainly focus on improving user interactions, understanding how people use IPAs, and explaining their uses (de Barcelos Silva et al., 2020). Previous literature related to IT continuance behavior captures satisfaction, attitude or habitual responses, and emotional attachment (Mamun et al., 2020), ignoring the usability of specific IT applications like IPAs, especially the interaction quality between humans and IPAs. Exploring IPA Continuance based on the expectation-confirmation theory (ECT) is the goal of this study. Oliver (1980)’s expectation-confirmation theory (ECT) is broadly used in consumer behavior studies to examine consumer satisfaction and post-purchase behaviors. Derived from ECT, Bhattacherjee (2001)’s expectation-confirmation model (ECM) investigates user continuance intention for a system, which is widely accepted by IS scholars Whether the API can accurately recognize natural human language and respond quickly may determine the user\u27s satisfaction with the API product. Therefore, we introduced the concept of API Interaction Quality, based on the ECM, to extend the original model, exploring the key factors affecting the continued use of IPA. The proposed model was empirically tested within the context of most popular IPAs, such as Amazon Alexa, Google Home and Apple Siri. we will collect empirical data from college students who are users of IPA, a class of conversational, where ages limit from 18 to 30. This research will contribute to both theory and practice in the IT area. It will enrich the theory of ECT and extend expectation-confirmation model in IS research. Tech giants who have developed their own IPAs like Apple, Microsoft, and Amazon may benefit from our research findings in the perspective of how to improve interaction quality between their IPA products and potential users

Swashplateless-elevon Actuation for a Dual-rotor Tail-sitter VTOL UAV

In this paper, we propose a novel swashplateless-elevon actuation (SEA) for dual-rotor tail-sitter vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs). In contrast to the conventional elevon actuation (CEA) which controls both pitch and yaw using elevons, the SEA adopts swashplateless mechanisms to generate an extra moment through motor speed modulation to control pitch and uses elevons solely for controlling yaw, without requiring additional actuators. This decoupled control strategy mitigates the saturation of elevons' deflection needed for large pitch and yaw control actions, thus improving the UAV's control performance on trajectory tracking and disturbance rejection performance in the presence of large external disturbances. Furthermore, the SEA overcomes the actuation degradation issues experienced by the CEA when the UAV is in close proximity to the ground, leading to a smoother and more stable take-off process. We validate and compare the performances of the SEA and the CEA in various real-world flight conditions, including take-off, trajectory tracking, and hover flight and position steps under external disturbance. Experimental results demonstrate that the SEA has better performances than the CEA. Moreover, we verify the SEA's feasibility in the attitude transition process and fixed-wing-mode flight of the VTOL UAV. The results indicate that the SEA can accurately control pitch in the presence of high-speed incoming airflow and maintain a stable attitude during fixed-wing mode flight. Video of all experiments can be found in youtube.com/watch?v=Sx9Rk4Zf7sQComment: 8 pages, 13 figure

Making 2‐D Materials Mechanochemically by Twin‐Screw Extrusion:Continuous Exfoliation of Graphite to Multi‐Layered Graphene

Mechanochemistry has developed rapidly in recent years for efficient chemicals and materials synthesis. Twin screw extrusion (TSE) is a particularly promising technique in this regard because of its continuous and scalable nature. A key aspect of TSE is that it provides high shear and mixing. Because of the high shear, it potentially also offers a way to delaminate 2‐D materials. Indeed, the synthesis of 2‐D materials in a scalable and continuous manor remains a challenge in their industrialization. Here, as a proof‐of‐principle, the automated, continuous mechanochemical exfoliation of graphite to give multi‐layer graphene (MLG, ≈6 layers) by TSE is demonstrated. To achieve this, a solid‐and‐liquid‐assisted extrusion (SLAE) process is developed in which organic additives such as pyrene are rendered liquid due to the high temperatures used, to assist with the exfoliation, and simultaneously solid sodium chloride is used as a grinding aid. This gave MLG in high yield (25 wt%) with a short residence time (8 min) and notably with negligible evidence for structural deterioration (defects or oxidation)

Engineering electrode wettability to enhance mass transfer in hydrogen evolution reaction

In hydrogen evolution reaction, inefficient mass transfer caused by bubble adhesion on electrode, bubble dispersion in electrolyte and slow H2 diffusion, has greatly impeded the reaction process. Existing techniques can only resolve bubble adhesion or bubble dispersion problems. Strategy that simultaneously solve bubble adhesion, bubble dispersion and poor hydrogen diffusion problems is rarely reported. Recently, an article reported a new electrode with special wettability design, which can efficiently promote bubble transfer and dissolved H2 diffusion. This design can simultaneously solve above mentioned three mass transfer issues and improve electrode efficiency. We summarize the remaining challenges of this work and outlook potential approaches to promote mass transfer in gas-evolution reactions

Efficacy of Chinese herbal medicine on nasal itching in children with allergic rhinitis: a systematic review and meta-analysis

Background: Allergic rhinitis is prevalent among children and can cause nasal itching, fatigue, and even hinder growth and development. The main discomfort symptom of allergic rhinitis is nasal itching. Clinical reports suggest that Chinese herbal medicine (CHM) is effective in allergy rhinitis treatment. Therefore, we evaluate the clinical efficacy of Chinese herbal medicine in treating nasal itching caused by allergic rhinitis in children.Methods: Nine databases, including PubMed, Embase, The Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wan Fang Data, CQVIP, Chinese Biological Medicine, and ClinicalTrials.gov, were systematically searched from their inception until March 2023. Randomized controlled trials (RCTs) comparing the efficacy of Chinese herbal medicine, either alone or in combination with Western medicine, to Western medicine treatment or placebo intervention for treating allergic rhinitis in children were eligible for inclusion. The effectiveness of Chinese herbal medicines for nasal itching was mainly evaluated. The Risk of Bias tool 2.0 assessed the risk of bias. Statistical analysis using RevMan 5.3 and Stata/SE 12. The quality of evidence was evaluated by GRADEpro 3.6. Risk ratios (RR) with corresponding 95% confidence intervals (CI) were utilized to evaluate and present dichotomous data, while mean difference (MD) and standardized mean difference (SMD) were employed for continuous data. A fixed-effects model was applied in cases where the data exhibited homogeneity (p > 0.1, I2 < 50%), whereas a random-effects model was utilized for heterogeneous data. Statistical significance was determined by a p-value <0.05. This study was conducted by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and its review protocol was registered on the International Platform for Registered Systematic Reviews and Meta-Analysis Programs (INPLASY202340076).Results: The review incorporated 23 studies. The meta-analysis indicated that herbal medicine was significantly related to the reduction of nasal itching (MD = −0.59, 95%CI: −0.94–0.24) and the increase of interleukin 10 level (SMD = 1.47, 95% CI: 0.90–2.05). Compared to Western medicine, the combining herbs and Western medicine showed better efficacy in relieving nasal itching, inhibiting immunoglobulin E, interleukin 4 and 33, enhancing interleukin 10, improving therapeutic efficiency, and reducing recurrent. Oral herbal medicine was more effective in treating nasal itching (MD = −0.45, 95% CI: −0.62–0.29). Combining oral and external herbal medicines was more efficient in treating nasal itching (MD = −0.44, 95% CI: −0.54–0.33), inhibiting immunoglobulin E, interleukin 4 (SMD = −0.87, 95% CI: −1.24–0.50) and 33 (SMD = −1.16, 95% CI: −1.54–0.77), and improving therapeutic efficiency. External herbal medicine did not show differences compared to Western medicines. Regarding safety, herbal medicine alone exhibited fewer adverse events than Western medicine; combining herbal and Western medicine showed no significant variation in adverse event incidence.Conclusion: Chinese herbal medicine (CHM) holds great potential in alleviating symptoms, modulating immune factors levels, and reducing relapse in pediatric rhinitis. Meanwhile, CHM is relatively safe. However, the efficacy and safety of CHM in treating pediatric rhinitis still need to be confirmed due to the inclusion of studies with low methodological quality, small sample sizes, and potential heterogeneity. More high-quality research is necessary to provide reliable evidence for the clinical application of CHM.Systematic Review Registration: INPLASY.com, identifier INPLASY20234007