Multi-Stage Fast Charging Technique for Lithium Battery in Photovoltaic systems

In renewable energy resources such as photovoltaic (PV) systems, fast charging is an emerging case for the battery charger. In this paper, constant-current (CC) and constant-voltage (CV) charging scheme has been studied since it has the highest possible reliability for lithium based batteries. In this work a new charging technique to expedite charging time is proposed. This is a multi-stage technique which improves the threshold voltage detection during CC-stage. Thus the transition to CV-stage occurs accurately at the knee voltage. The novelty of the proposed technique is in the charging algorithm. An experiment was setup based on PIC18f4520 microcontroller. The performance of the proposed technique and the conventional CC-CV Li-ion battery charger has been compared. The result of the proposed technique shows that there is 20% improvement in charging time compared to the conventional CC-CV Li-ion battery charger. © 2022 IEEE

Performing total knee replacement in cases with various degrees of bone loss

The paper analyses main factors that effect treatment results of total knee arthroplasties in cases of bone defects, such as a size and types of bone defects, their connection with previous surgeries, existing classification with their benefits and weak points. Authors show various possibilities of surgical treatment of bone defects that can provide better stability for prosthetic devices. The importance of bone grafts is highlighted as their remodeling provides the base for implant stability in late period of outcome

Design and characteristics of the prophylactic intra-operative ventricular arrhythmia ablation in high-risk LVAD candidates (PIVATAL) trial

BACKGROUND: The use of a Left Ventricular Assist Device (LVAD) in patients with advanced heart failure refractory to optimal medical management has progressed steadily over the past two decades. Data have demonstrated reduced LVAD efficacy, worse clinical outcome, and higher mortality for patients who experience significant ventricular tachyarrhythmia (VTA). We hypothesize that a novel prophylactic intra-operative VTA ablation protocol at the time of LVAD implantation may reduce the recurrent VTA and adverse events postimplant. METHODS: We designed a prospective, multicenter, open-label, randomized-controlled clinical trial enrolling 100 patients who are LVAD candidates with a history of VTA in the previous 5 years. Enrolled patients will be randomized in a 1:1 fashion to intra-operative VTA ablation (n = 50) versus conventional medical management (n = 50) with LVAD implant. Arrhythmia outcomes data will be captured by an implantable cardioverter defibrillator (ICD) to monitor VTA events, with a uniform ICD programming protocol. Patients will be followed prospectively over a mean of 18 months (with a minimum of 9 months) after LVAD implantation to evaluate recurrent VTA, adverse events, and procedural outcomes. Secondary endpoints include right heart function/hemodynamics, healthcare utilization, and quality of life. CONCLUSION: The primary aim of this first-ever randomized trial is to assess the efficacy of intra-operative ablation during LVAD surgery in reducing VTA recurrence and improving clinical outcomes for patients with a history of VTA

HDAC4-regulated STAT1 activation mediates platinum resistance in ovarian cancer

Ovarian cancer frequently acquires resistance to platinum chemotherapy, representing a major challenge for improving patient survival. Recent work suggests resistant clones exist within a larger drug sensitive cell-population prior to chemotherapy, implying that resistance is selected for rather than generated by treatment. We sought to compare clinically-derived, intra-patient paired models of initial platinum response and subsequent resistant relapse to define molecular determinants of evolved resistance. Transcriptional analysis of a matched cell-line series from three patients with high-grade serous ovarian cancer before and after development of clinical platinum resistance (PEO1/PEO4/PEO6, PEA1/PEA2, PEO14/PEO23) identified 91 up- and 126 down-regulated genes common to acquired resistance. Significantly enhanced apoptotic response to platinum treatment in resistant cells was observed following knockdown of HDAC4, FOLR2, PIK3R1 or STAT1 (p<0.05). Interestingly, HDAC4 and STAT1 were found to physically interact. Acetyl-STAT1 was detected in platinum sensitive but not HDAC4 over-expressing platinum resistant cells from the same patient. In resistant cells, STAT1 phosphorylation/nuclear translocation was seen following platinum exposure, whereas silencing of HDAC4 increased acetyl-STAT1 levels, prevented platinum induced STAT1 activation and restored cisplatin sensitivity. Conversely, matched sensitive cells were refractory to STAT1 phosphorylation on platinum treatment. Analysis of 16 paired tumor biopsies taken before and after development of clinical platinum resistance showed significantly increased HDAC4 expression in resistant tumors (n=7/16[44%]; p=0.04). Therefore, clinical selection of HDAC4 overexpressing tumor cells upon exposure to chemotherapy promotes STAT1 deacetylation and cancer cell survival. Together, our findings identify HDAC4 as a novel, therapeutically tractable target to counter platinum resistance in ovarian cancer

Design and testing of wall cabinet frames constructed with round mortise-and-tenon joints

WOS: 000245218700004This study investigated the design, construction, testing, and performance characteristics of wall cabinets constructed with round mortise-and-tenon joints that are suitable for use in classrooms, school libraries, and homes. Four wall cabinets, utilizing round mortise-and-tenon joints, were constructed to evaluate their performance. Tests indicated that the attachment of thin plywood panels to the frames increased overall cabinet stiffness by 62 and 70 percent for red oak and yellow-poplar wall cabinets, respectively. Also, wood species was found to affect creep deflection. Overall, this study clearly demonstrated that wall cabinets constructed with round mortise-and-tenon joints were able to withstand normal service loads without loss of structural integrity or function

Design and testing of bookcase frames constructed with round mortise and tenon joints

WOS: 000184799200011Previous work has shown that by using round mortise and tenon joints, durable maintenance-free school chairs and desks can be produced from largely waste local woody materials by cottage industries in remote regions of the world. Results of this previous work would suggest that by using this same method of construction, well-designed, durable, functional bookcases also could be produced from locally available small-diameter tree species and thin plywood or other thin panel materials. A number of panel and frame bookcases utilizing round mortise and tenon joints were constructed to evaluate their performance. Tests conducted on the resulting bookcase frames and shelves indicated that shelves constructed of thin plywood supported by small front and back shelf rails with ends joined to the corner posts with round mortise and tenon joints easily met critical shelf deflection criteria. The excellent deflection characteristics of the shelves were credited to the high degree of end fixity of the shelf rails that was obtained through the use of snug fitting round mortise and tenon joints

Effects of Fe-TiB2 addition as binder phase on the liquid phase sintering behaviour of tungsten carbide cermets

The sintering behaviour of tungsten carbide compacts with a eutectic Fe-TiB2 mixture was studied. In order to have a clear view of the mechanisms that occur during liquid phase sintering, the hardness, transverse rupture strength, toughness, and densification values were measured and the micrographs were examined for WC-Fe-TiB2 cermets with varying compositions, sintering times and sintering temperatures. The findings were then with the propeerties known for WC-Fe and WC-Co cermets

Design and testing of bookcase frames constructed with round mortise and tenon joints

Previous work has shown that by using round mortise and tenon joints, durable maintenance-free school chairs and desks can be produced from largely waste local woody materials by cottage industries in remote regions of the world. Results of this previous work would suggest that by using this same method of construction, well-designed, durable, functional bookcases also could be produced from locally available small-diameter tree species and thin plywood or other thin panel materials. A number of panel and frame bookcases utilizing round mortise and tenon joints were constructed to evaluate their performance. Tests conducted on the resulting bookcase frames and shelves indicated that shelves constructed of thin plywood supported by small front and back shelf rails with ends joined to the corner posts with round mortise and tenon joints easily met critical shelf deflection criteria. The excellent deflection characteristics of the shelves were credited to the high degree of end fixity of the shelf rails that was obtained through the use of snug fitting round mortise and tenon joints

Tertiary volcanism of the Galatia province, north-west central Anatolia, Turkey

Large volumes of trachyandesitic-dacitic lava flows and pyroclastics of Miocene age are associated with small volumes of alkali basalt lava flows in the Galatia volcanic province, northwest Central Anatolia, Turkey. The volcanism postdates continental collision, occurring in a transtensional tectonic setting associated with movement along the North Anatolian Fault zone. Major and trace element (including REE) and Sr-Nd isotope data and K-Ar ages for representative samples of mafic-intermediate volcanic rocks have been obtained from a series of localities within the province. The K-Ar age data indicate that alkali basalts were erupted during two distinct time periods in the Early Miocene (17-19 Ma) and Late Miocene (< 10 Ma). The two groups of basalts are inferred to have been derived from different mantle sources, based on their Sr-Nd isotope and geochemical characteristics. The Late Miocene basalts were derived from a more depleted mantle source than the Early Miocene basalts, which were generated by partial melting of an incompatible element enriched, subduction-modified, mantle source. The depleted source component is inferred to reside within the asthenosphere and has some affinities with the source of HIMU oceanic island basalts. On the basis of a comprehensive major and trace element and Nd-Sr isotope dataset for the intermediate-acid volcanics and the alkali basalts, it is possible to demonstrate a cogenetic relationship between the alkali basalts and the intermediate volcanics of Early Miocene age, involving fractional crystallisation and assimilation of a heterogeneous upper crustal component. (C) 1997 Elsevier Science B.V