Effect of PCM fill ratio and heat sink orientation on the thermal management of transient power spikes in electronics

The goal of this paper is to investigate the usefulness of Phase Change Material based heat sinks in power surge operations. Experiments have been carried out on a PCM based heat sink for different fill ratios (0, 33, 66, and 99%) of the PCM and different orientations (0, 90, 180°) of the heat sink under constant and power surge heat loads. The heat sink with a fill ratio of 0% is considered as the baseline case for comparison. The heat sink with a fill ratio of 66% at 0° orientation recorded lower temperatures among all the fill ratios and orientations under both constant and power surge heat loads. Partial filling (66% fill ratio) of the PCM in the cavity is more effective than complete filling (99% fill ratio) in handling both constant and power surge heat loads.

Acclimatization studies for degradation of Acid Red 3BN dye and its treatment in moving bed biofilm reactor

In this study, acclimatization of microorganisms for the degradation of Acid Red 3BN dye bearing water (AR3BNDW) using activated sludge was performed in a cylindrical aerobic reactor. The initial value of chemical oxygen demand (COD), dye, and mixed liquor suspended solids (MLSS) of activated sludge were evaluated as 870.5, 80.6 and 1200 mg/L The experiments were performed at ambient temperature (25–35 °C) and the stabilization was achieved at 15 d. Maximum reduction of chemical oxygen demand (COD) and color were observed to be 94.2%, and 91% after 15 d of acclimatization. After completion of acclimatization process, degradation of dye was studied in moving bed biofilm reactor (MBBR). In the process, 38, 50, 68 and 76% color reduction were achieved with polymer carrier fill ratio (FR) of 40, 50, 60 and 70%, respectively in 24 h. For effluent flow rate of 180, 240, 300 and 360 mL/h, respectively, the dye reductions of 76, 60, 48 and 36% and COD reductions of 72, 58, 46 and 34% were achieved in 24 h

Discrete collective estimation in swarm robotics with distributed Bayesian belief sharing

Multi-option collective decision-making is a challenging task in the context of swarm intelligence. In this paper, we extend the problem of collective perception from simple binary decision-making of choosing the color in majority to estimating the most likely fill ratio from a series of discrete fill ratio hypotheses. We have applied direct comparison (DC) and direct modulation of voter-based decisions (DMVD) to this scenario to observe their performances in a discrete collective estimation problem. We have also compared their performances against an Individual Exploration baseline. Additionally, we propose a novel collective decision-making strategy called distributed Bayesian belief sharing (DBBS) and apply it to the above discrete collective estimation problem. In the experiments, we explore the performances of considered collective decision-making algorithms in various parameter settings to determine the trade-off among accuracy, speed, message transfer and reliability in the decision-making process. Our results show that both DC and DMVD outperform the Individual Exploration baseline, but both algorithms exhibit different trade-offs with respect to accuracy and decision speed. On the other hand, DBBS exceeds the performances of all other considered algorithms in all four metrics, at the cost of higher communication complexity.

Differences in femoral component subsidence rate after THA using an uncemented collarless femoral stem: full weight-bearing with an enhanced recovery rehabilitation versus partial weight-bearing

Background Femoral component subsidence is a known risk factor for early failure of total hip arthroplasty (THA) using cementless stems. The aim of the study was to compare an enhanced recovery concept with early full weight-bearing rehabilitation and partial weight-bearing on stem subsidence. In addition, the influence of patient-related and anatomical risk factors on subsidence shall be assessed. Methods One hundred and fourteen patients underwent primary cementless THA and were retrospectively analyzed. Sixty-three patients had an enhanced recovery rehabilitation with early full weight-bearing and 51 patients had rehabilitation with partial weight-bearing (20 kg) for 6 weeks. Postoperative subsidence was analyzed on standing pelvic anterior–posterior radiographs after 4 weeks and 1 year. Subsidence was measured in mm. Anatomical and prosthetic risk factors (stem size, canal flare index, canal fill ratio as well as BMI and demographic data) were correlated. Results Femoral stem subsidence rate was significantly higher for the group with an enhanced recovery concept compared to the group with partial weight-bearing at the first radiological follow up after 4 weeks [2.54 mm (SD ± 1.86) vs. 1.55 mm (SD ± 1.80)] and the second radiological follow up after 1 year [3.43 mm (SD ± 2.24) vs. 1.94 (SD ± 2.16)] (p < 0.001, respectively). Stem angulation > 3° had a significant influence on subsidence. Canal flare index and canal fill ratio showed no significant correlation with subsidence as well as BMI and age. Conclusion In the present study, cementless stem subsidence was significantly higher in the group with enhanced recovery rehabilitation compared to partial weight-bearing. Small absolute values and differences were demonstrated and therefore possibly below clinical relevance. Anatomical radiological parameters and anthropometric data did not appear to be risk factors for stem subsidence.

Automated Dispensing Cabinet Optimization in a Level 2 Trauma Center

Introduction Opportunities have been identified regarding timely delivery of medications due to lack of ADC inventory related to stock outs or other variances in pharmacy workflow (i.e. compounding and distribution times). These opportunities for improvement impact patient care and result in both nursing and pharmacy staff frustration. Additionally, there are significant costs associated with unused medications stored in ADCs, taking up valuable real estate that would otherwise house more opportune inventory. This situation has created a need for more efficient management of the ADC inventory. Currently, research in the topic area is sparse. We hypothesize that the systematic management and oversight of ADC inventory will demonstrate a significant improvement in key performance indicators and provide insight to the current gaps in knowledge. Methods This study will be a continuous quality improvement project with a combination of retrospective data review and prospective optimization interventions of automated dispensing cabinets (Pyxis®). Interventions include review and adjustment of ADC par levels, removal of unused/stagnate medications, standardization of stock, and continual review of ADC inventory turns and associated optimization opportunities. The primary outcomes are the change in vend/fill ratio from baseline, change in medication stockout percentage from baseline. Results There was no significant difference in vend/fill ratio after the optimization phase compared with baseline [Difference 0.13 (11.56 ± 6.1 vs. 11.43 ± 5.41) respectively, (p=0.84)]. Medication stockout percentage was also found to be similar with baseline [Difference -0.05 (0.71% ± 0.12 vs. 0.76% ± 0.08) respectively, (p=0.37)]. For secondary outcomes, the change in blind stockout percentage from baseline was -0.04 [0.13 ± 0.02 vs. 0.17 ± 0.02, (p=0.004)] and the change in medications dispensed per day from baseline was 317 [2656 ± 143 vs. 2339 ± 200, (p=0.0002)]. Conclusion Optimization of automated dispensing cabinets yielded marginal improvements in vend/fill ratio and stockout percentage and significantly improved overall efficiency through an increase in the number of medications stocked in ADCs and number of medications dispensed per day from ADCs. Evaluation of more clinically significant performance indicators may better characterize the benefits from the optimization process.

Influence of femoral morphology and canal fill ratio on early radiological and clinical outcomes of uncemented total hip arthroplasty using a fully coated stem

Aims The diversity of femoral morphology renders femoral component sizing in total hip arthroplasty (THA) challenging. We aimed to determine whether femoral morphology and femoral component filling influence early clinical and radiological outcomes following THA using fully hydroxyapatite (HA)-coated femoral components. Methods We retrospectively reviewed records of 183 primary uncemented THAs. Femoral morphology, including Dorr classification, canal bone ratio (CBR), canal flare index (CFI), and canal-calcar ratio (CCR), were calculated on preoperative radiographs. The canal fill ratio (CFR) was calculated at different levels relative to the lesser trochanter (LT) using immediate postoperative radiographs: P1, 2 cm above LT; P2, at LT; P3, 2 cm below LT; and D1, 7 cm below LT. At two years, radiological femoral component osseointegration was evaluated using the Engh score, and hip function using the Postel Merle d’Aubigné (PMA) and Oxford Hip Score (OHS). Results CFR was moderately correlated with CCR at P1 (r = 0.44; p < 0.001), P2 (r = 0.53; p < 0.001), and CFI at P1 (r = − 0.56; p < 0.001). Absence of spot welds (n = 3, 2%) was associated with lower CCR (p = 0.049), greater CFI (p = 0.017), and lower CFR at P3 (p = 0.015). Migration (n = 9, 7%) was associated with lower CFR at P2 (p = 0.028) and P3 (p = 0.007). Varus malalignment (n = 7, 5%), predominantly in Dorr A femurs (p = 0.028), was associated with lower CFR at all levels (p < 0.05). Absence of spot welds was associated with lower PMA gait (p = 0.012) and migration with worse OHS (p = 0.032). Conclusion This study revealed that femurs with insufficient proximal filling tend to have less favourable radiological outcomes following uncemented THA using a fully HA-coated double-tapered femoral component. Cite this article: Bone Joint Res. 2020;9(4):182–191.