Targeting optimal power consumption: Optimizing operational parameters for orchard furrowing and fertilizing machine.

In response to the problem of excessive power consumption during the furrowing operation of orchard furrowing fertilizer machines, an optimization experiment of furrowing operation parameters for orchard furrowing fertilizer machine was conducted based on discrete element simulations. This research focused on the impact of furrowing device operation parameters on furrowing power consumption under full machine operating conditions. Firstly, a kinematics analysis of the soil granules during cutting was done. The mathematical model of soil granules through three movement processes of rising, detachment, and falling was established to determine the main factors affecting the power consumption of furrowing. Secondly, in assessing the furrowing power consumption, the stability coefficient of the furrowing depth, and the percentage of soil cover, alongside the key parameters of furrowing depth, forward propulsion velocity, and furrowing blade rotation speed, a comprehensive quadratic orthogonal rotation regression experiment was meticulously conducted. It was established that test metrics and test parameters regress. Finally, the test parameters were comprehensively optimized after analyzing each factor's impact on the test metrics. The orchard furrowing fertilizer machine's optimal operating parameters were determined, and the verification test was performed. According to the field test findings, the forward propulsion velocity was 785 m/h, and the furrowing blade rotation speed was 190 r/min when the furrowing depth was 275 mm. At this point, the furrowing power consumption was 2.39 kW, the soil cover percentage was 69.06%, and the furrowing depth stability coefficient was 95.08%. These results were in line with the requirements of orchard furrowing operation. The findings of the study can be utilized as a guide for structural changes to orchard furrowing equipment and the management of furrowing operation parameters.

Cognitive Appraisal, Dispositional Coping, and Posttraumatic Growth among Patient-Caregiver Dyads Undergoing Hemodialysis.

The present study aims to investigate the mediating effect of dispositional coping on the relationship between cognitive appraisal (which includes areas of threat, challenge, harm/loss, and benign/irrelevant appraisals) and posttraumatic growth (PTG) among patient-caregiver dyads undergoing hemodialysis. In total, 237 dyads of patients undergoing hemodialysis and their family caregivers were recruited from a tertiary hospital in Tianjin, China. Dyadic data were analyzed using the Actor-Partner Interdependence Mediation Model (APIMeM). The final APIMeM model examining dyadic effects of challenge appraisal and dispositional coping on PTG demonstrated an excellent model fit. The challenge appraisal of family caregivers was directly associated with the PTG of patients undergoing hemodialysis. Dispositional coping mediated the pathways between challenge appraisal and PTG for both patients undergoing hemodialysis and family caregivers. By exploring the cognitive appraisal and dispositional coping of patient-caregiver dyads undergoing hemodialysis may help both partners foster PTG.

Finite element analysis and optimization of tractor gearbox body under various kinds of working conditions.

As the main component of the tractor gearbox, the box has the functions of shifting operation and carrying the cab, it also carries part of the framework function. If the strength, stiffness, or vibration characteristics of the box do not meet the allowable requirements, large vibration and noise may occur, and even there is the possibility of fracture in some limiting conditions. To solve this problem, according to the structural parameters of a gearbox, the three-dimensional model of the box was established by using the three-dimensional modeling software Creo. According to the dangerous degree of the transmission load when the tractor is working normally, three vehicle working conditions are selected: a round of suspension conditions, farm tool lifting conditions, and emergency turning conditions. In addition, according to the transmission ratio of each gear meshing inside the gearbox, two gear conditions are selected: gear condition one and reverse gear condition one. The forces of the box under these extreme conditions are analyzed. The static analysis and modal analysis of the tractor gearbox are carried out by using the Static Structural module of ANSYS Workbanch. The deformation, equivalent stress distribution, and modal vibration frequency of the gearbox are tested. The topology optimization method is used to improve structural defects and reduce box quality. The results show that the weight of the optimized box reduces by 8.44%, the deformation decreased by 15.89%, and the equivalent stress decreased by 18.34%. The strength and stiffness of the box are improved, the quality is lightweight, the waste of resources is reduced, and the heat dissipation performance and fracture resistance of the box are enhanced.

The fluorescence and resonance Rayleigh scattering spectral study and analytical application of cerium (IV) and cefoperazone system.

In weak acidic medium of pH3.5-5.6, Ce(IV) can be reduced by cefoperazone (CPZ) to be Ce(III), which further combined with CPZ to form complex Ce(OH)3CPZ. This complex not only has higher fluorescence than Ce(III), but also results in significant increase of resonance Rayleigh scattering (RRS), second order scattering (SOS) and frequency doubling scattering (FDS). The wavelengths of maximum fluorescence exciting and emission are located at 356 nm/349 nm, while the maximum wavelengths of RRS, SOS and FDS are at 312 nm, 550 nm and 390 nm, respectively. The intensity of fluorescence and scattering are all linear with the concentration of CPZ in certain conditions. The detection limit of most sensitive RRS method for CPZ is 2.1 ng mL(-1). The optimum conditions for detecting CPZ using RRS method are investigated. The effect of co-existing substances shows that the method has excellent selectivity, especially since other cephalosporins don't have similar reactions. Therefore, it can be achieved to determine CPZ in cephalosporins selectively. The paper also focuses on the reaction mechanism, the consistent and contracture of the resultant. The reasons for enhanced intensity are presumed in the meantime.

Factors related to fatigue in Chinese patients with end-stage renal disease receiving maintenance hemodialysis: a multi-center cross-sectional study.

BACKGROUD: Fatigue is considered as a common symptom in patients with end-stage renal disease (ESRD) and can significantly decrease patients' quality of life. This study aimed to assess fatigue in hemodialysis patients and to investigate risk factors of fatigue in Chinese patients receiving maintenance hemodialysis (MHD) in China. METHODS: Eligible patients completed questionnaires including demographic information, a Chinese version of the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue), the Family APGAR Index (APGAR), the medical outcomes study health status-Social Functioning subscale (SF-36,SocF), and the Pittsburgh sleep quality index (PSQI). Laboratory parameters were abstracted by medical records review. The multiple linear regression model was used to relate parameters with the FACIT-Fatigue score. RESULTS: A total of 345 MHD patients (216 men and 129 women, age 55.6 ± 12.8) were recruited in this study. The score of FACIT-Fatigue was 39 (Interquartile Range, 31-44). Fatigue was correlated with PSQI scores (p < 0.001), SocF scores (p < 0.001), comorbidity (p = 0.006), exercise time <1 hour per day (p = 0.003), adequacy of dialysis (Kt/V) < 1.2 (p = 0.016), APGAR scores (p = 0.014), and high Scr (p = 0.043). CONCLUSIONS: Fatigue is related to sleep disturbance, social and family functioning, taking physical exercise time, comorbidity condition, Kt/V and serum creatinine level in Chinese MHD patients. Future studies and interventions should focus on developing strategies and improving the quality of life in patients by addressing these significant contributing factors.

Study on the resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectra of the interactions of palladium(II)-ceftriaxone chelate with anionic surfactants and their analytical applications.

In pH 1.8-2.9 Britton-Robinson (BR) buffer medium, ceftriaxone (CTRX) can react with palladium(II) (Pd(II)) to form 1:2 cationic chelate, which can further react with anionic surfactants (AS) such as sodium lauryl sulfonate (SLS), sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) to form 1:3 ion-association complexes. As a result, the resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced greatly. The maximum RRS, SOS and FDS wavelengths of three ion-association complexes were located at 335 nm, 560 nm and 390 nm, respectively. The increments of scattering intensity (DeltaI) were directly proportional to the concentrations of CTRX in certain ranges. The detection limits (3sigma) of CTRX for SLS, SDBS and SDS systems were 1.8 ng ml(-1), 2.3 ng ml(-1) and 2.3 ng ml(-1) (RRS method), 4.9 ng ml(-1), 7.4 ng ml(-1) and 4.7 ng ml(-1) (SOS method) and 6.8 ng ml(-1), 7.3 ng ml(-1) and 9.1 ng ml(-1) (FDS method), separately. The sensitivity of RRS method was higher than those of SOS and FDS methods. The optimum conditions of RRS method and the influence factors were investigated, and the composition of ion-association complexes and the reaction mechanism were discussed also. The effects of foreign substances were tested and it showed that the method has a good selectivity. Based on the ion-association reaction, the sensitive, simple and rapid methods for the determination of CTRX have been developed.

Study on the resonance Rayleigh scattering spectra of the interactions of palladium (II)-cephalosporins chelates with 4,5-dibromofluorescein and their analytical applications.

In pH 2.8-3.8 BR buffer medium, the third generation cephalosporin antibiotics (TGCs) such as ceftazidime (CZD), ceftriaxone (CTRX), cefoperazone (CPZ), and cefotaxime (CFTM) react with palladium(II) (Pd(II)) to form 1:2 yellowish-brown cationic chelates, which further react with 4,5-dibromofluorescein (DBF) to form 1:3 brown ion-association complexes. As a result, not only the spectra of absorption and fluorescence are changed, but also the resonance Rayleigh scattering (RRS) is enhanced greatly and the new RRS spectra are observed. The four TGCs products have similar spectral characteristics and their maximum RRS wavelengths are all located at 291 nm. The quantitative determination ranges and the detection limits of the four TGCs are 0.0065-1.0 microg mL(-1) and 2.0 ng mL(-1) for CZD, 0.0070-1.1 microg mL(-1) and 2.2 ng mL(-1) for CTRX, 0.0090-1.6 microg mL(-1) and 2.7 ng mL(-1) for CPZ, and 0.014-2.2 microg mL(-1) and 4.2 ng mL(-1) for CFTM, respectively. The optimum conditions of the reactions and the effects of foreign substances are investigated, and the composition of ion-association complexes is discussed also. Based on the ion-association reaction, a highly sensitive, simple and rapid method has been proposed to the determination of TGCs.