Impact of primary and secondary air supply intensity in stove on emissions of size-segregated particulate matter and carbonaceous aerosols from apple tree wood burning

In order to assess emission factors (EF) more accurately from household biomass burning, a series of laboratory controlled apple tree wood burning tests were conducted to measure the EFs of size-segregated particulate matter (PM) and carbonaceous aerosols. The controlled burning experiments were conducted with designed primary air (PA) and secondary air (SA) supply intensity. An optimum value of 7 m(3).h(-1) was found for SA, resulting the highest modified combustion efficiency (92.4 +/- 2.5%) as well as the lowest EFs of PM2.5 (0.13 +/- 0.01 g.MJ(-1)), OC (0.04 +/- 0.03 g.MJ(-1)) and EC (0.03 +/- 0.01 g.MJ(-1)). SA values of 7 and 10 m(3).h(-1) resulted the lowest EFs for all the different PM sizes. In a test with PA of 6 m(3.)h(-1) and SA of 7 m(3).h(-1), very low EFs were observed for 0C1 (8.2%), 0C2 (11.2%) and especially OP (Pyrolyzed OC) (0%, not detected), indicating nearly complete combustion under this air supply condition. Besides SA, higher PA was proved to have positive effects on PM and carbonaceous fraction emission reduction. For example, with a fixed SA of 1.5 m(3).h(-1), EFs of PM2.5 decreased from 0.64 to 0.27 g.MJ(-1) when PA increased from 6 to 15 m(3).h(-1) (P < 0.05). Similar reductions were also observed in EFs of OC, EC and size segregated PM

THE INFLUENCE OF LOWER LIMB MUSCLE PRE-ACTIVATION ON KNEE JOINT DYNAMIC CONTROL DURING A SINGLE-LEG LANDING TASK IN BADMINTON

Purpose: Lower limb neuromuscular strategies impact knee biomechanics, crucial for ACL injury prevention. Yet, the link between them remains unclear. In our randomized trial with 34 badminton players, we examined lower limb muscle preactivity during single-leg landings. Findings revealed that increased rectus femoris preactivation correlated with heightened knee valgus angle. Moreover, higher lateral hamstring/quadriceps co-contraction ratios predicted increased knee extension moments. These outcomes suggest potential benefits in ACL injury prevention through reduced quadriceps pre-activation and optimal lateral hamstring/quadriceps co-contraction ratios. Understanding these relationships aids in developing targeted prevention strategies for anterior cruciate knee injuries

Terahertz master-oscillator power-amplifier quantum cascade laser with a grating coupler of extremely low reflectivity

A terahertz master-oscillation power-amplifier quantum cascade laser (THz-MOPA-QCL) is demonstrated where a grating coupler is employed to efficiently extract the THz radiation. By maximizing the group velocity and eliminating the scattering of THz wave in the grating coupler, the residue reflectivity is reduced down to the order of 10−3. A buried DFB grating and a tapered preamplifier are proposed to improve the seed power and to reduce the gain saturation, respectively. The THz-MOPA-QCL exhibits single-mode emission, a single-lobed beam with a narrow divergence angle of 18° × 16°, and a pulsed output power of 136 mW at 20 K, which is 36 times that of a second-order DFB laser from the same material

GENDER DIFFERENCES IN MUSCLE CONTRACTION AND CO-CONTRACTION ACTIVITIES DURING THE IMPACT PHASE OF SINGLE-LEG LANDING TASK IN BADMINTON

Our study aimed to explore ACL injury risk factors in females versus males during badminton single-leg landings. Sixteen players (8 male, 8 female) participated, with lower limb kinematics, ground reaction forces, and muscle activity measured using motion capture, force plates, and electromyography (EMG). Independent samples t-test analyzed gender differences in leg kinematics, mean normalized leg muscle activation (MVC%), and muscle co-contraction post-landing. Females, compared to males, exhibited higher rectus femoris, medial hamstring, and gastrocnemius muscle activity during the post-landing phase. Additionally, males had a higher co-contraction ratio in the medial and lateral gastrocnemius than females. Female badminton players\u27 neuromuscular control strategies may lack ACL protection, posing a potential risk for higher ACL injury incidence

Genetic and functional characterization of disease associations explains comorbidity

Understanding relationships between diseases, such as comorbidities, has important socio-economic implications, ranging from clinical study design to health care planning. Most studies characterize disease comorbidity using shared genetic origins, ignoring pathway-based commonalities between diseases. In this study, we define the disease pathways using an interactome-based extension of known disease-genes and introduce several measures of functional overlap. The analysis reveals 206 significant links among 94 diseases, giving rise to a highly clustered disease association network. We observe that around 95% of the links in the disease network, though not identified by genetic overlap, are discovered by functional overlap. This disease network portraits rheumatoid arthritis, asthma, atherosclerosis, pulmonary diseases and Crohn's disease as hubs and thus pointing to common inflammatory processes underlying disease pathophysiology. We identify several described associations such as the inverse comorbidity relationship between Alzheimer's disease and neoplasms. Furthermore, we investigate the disruptions in protein interactions by mapping mutations onto the domains involved in the interaction, suggesting hypotheses on the causal link between diseases. Finally, we provide several proof-of-principle examples in which we model the effect of the mutation and the change of the association strength, which could explain the observed comorbidity between diseases caused by the same genetic alterations

Effects of guide vane thickness on pressure pulsation of mixed-flow pump in pumped-storage power station

The pressure pulsation is one of the key factors affecting instability operation and vibration of large mixed-flow pump units in pumped-storage power station. The unsteady flow field in a mixed-flow pump with different guide vane thicknesses was numerically simulated based on the standard k-ε turbulence model, the SIMPLE algorithm and the sliding mesh technique. By setting pressure measurement points, the pressure pulsation characteristics in the impeller inlet, outlet and the middle of guide vane were discussed and the influence of the guide vanes’ thickness on pressure pulsation was analyzed. The results show that the type of numerical simulation grid, turbulence model can accurately predict the internal flow characteristics of the mixed-flow pump. The dominant frequency of pressure pulsation was approximate to the impeller blade passing frequency. The thickness of the guide vane have less influence on pressure pulsation in the inlet of impeller, and have more influence on pressure pulsation in the middle of guide vane. Compared with the thinning guide vanes, the pressure pulsation amplitude of the thicken guide vane increase 7.8 %. Therefore, appropriately reducing the thickness of guide vane is beneficial to the stability of the internal flow of guide vane

Rapid Maxillary Anterior Teeth Retraction En Masse by Bone Compression: A Canine Model

The present study sought to establish an animal model to study the feasibility and safety of rapid retraction of maxillary anterior teeth en masse aided by alveolar surgery in order to reduce orthodontic treatment time.Extraction of the maxillary canine and alveolar surgery were performed on twelve adult beagle dogs. After that, the custom-made tooth-borne distraction devices were placed on beagles' teeth. Nine of the dogs were applied compression at 0.5 mm/d for 12 days continuously. The other three received no force as the control group. The animals were killed in 1, 14, and 28 days after the end of the application of compression.The tissue responses were assessed by craniometric measurement as well as histological examination. Gross alterations were evident in the experimental group, characterized by anterior teeth crossbite. The average total movements of incisors within 12 days were 4.63±0.10 mm and the average anchorage losses were 1.25±0.12 mm. Considerable root resorption extending into the dentine could be observed 1 and 14 days after the compression. But after consolidation of 28 days, there were regenerated cementum on the dentine. There was no apparent change in the control group. No obvious tooth loosening, gingival necrosis, pulp degeneration, or other adverse complications appeared in any of the dogs.This is the first experimental study for testing the technique of rapid anterior teeth retraction en masse aided by modified alveolar surgery. Despite a preliminary animal model study, the current findings pave the way for the potential clinical application that can accelerate orthodontic tooth movement without many adverse complications.It may become a novel method to shorten the clinical orthodontic treatment time in the future