Hydrodynamic Torque Converters for Oil & Gas Compression and Pumping Applications: Basic Principles, Performance Characteristics and Applications

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Hydrodynamic Torque Converters For Oil & Gas Compression and Pumping Applications : Basic Principles, Performance Characteristics And Applications

TutorialHerrmann Foettinger as an alternative to a regular speed changing gear for shipboard propulsion. At that time, mechanical reduction gears for such high power applications were not available. The core idea of hydrodynamic torque converters and fluid couplings is to provide wear free power transmission using a hydraulic closed pump and turbine cycle. In the following decades, hydrodynamic torque converters experienced significant improvements driven by the automotive industry, and their use spread into various applications. Today, torque converters are commonly used in cars, busses, locomotives, construction equipment, and gas compression as a means of (i) smooth power transmission, (ii) to provide torque amplification during startup conditions, and (iii) to act as a damper for driver and driven equipment torsional disturbances and shock loads. In the oil and gas industry, torque converters are often used as integrated components in drive transmissions for electric motor driven compressors or pumps trains. They provide step-less speed variation along with progressive torque increase towards low speed. For example, torque converters and hydraulic couplings can be used to drive a variable speed centrifugal compressor using a fixed speed electric motor without the need for a variable frequency drive. In recent years, torque converters in combination with planetary gearboxes have been successfully demonstrated as a viable technology for variable speed electric motor driven centrifugal compressor applications. Torque converters are also used as soft starters between generators and gas or steam turbines. The unique power transmission features of the torque converter make it an option for equipment that requires start-up torque assistance and speed control. Modern torque converters up to 65,000 kW have been designed and are widely in operation

Antifibrotic effects of tocotrienols on human Tenon's fibroblasts

Purpose: To compare the antifibrotic effect of vitamin E isoforms α-, γ-, and δ-tocotrienol on human Tenon's fibroblasts (hTf) to the antimetabolite mitomycin C. Methods: Antifibrotic effects of α- (40, 60, 80, 100, and 120μM), γ- (10, 20, 30, and 40μM) and δ-tocotrienol (10, 20, 30, and 40μM) on hTf cultures were evaluated by performing proliferation, migration and collagen synthesis assays. Whereas for vitamin E the exposure time was set to 7days to mimic subconjunctival application, cultures were exposed only 5 min to mitomycin C 100μg/ml to mimic intraoperative administration. Cell morphology (phase contrast microscopy) as an assessment for cytotoxicity and cell density by measuring DNA content in a fluorometric assay to determine proliferation inhibition was performed on day 0, 4, and 7. Migration ability and collagen synthesis of fibroblasts were measured. Results: All tested tocotrienol isoforms were able to significantly inhibit hTf proliferation in a dose-dependent manner (maximal inhibitory effect without relevant morphological changes at day 4 for α-tocotrienol 80μM with 36.7% and at day 7 for α-tocotrienol 80μM with 42.6% compared to control). Degenerative cell changes were observed in cultures with concentrations above 80μM for α- and above 30μM for γ- and δ-tocotrienol. The highest collagen synthesis inhibition has been found with 80 µM α-tocotrienol (62.4%) and no significant inhibition for mitomycin C (2.5%). Migration ability was significantly reduced in cultures exposed to 80 µM α- and 30 µM γ-tocotrienol (inhibition of 82.2% and 79.5%, respectively, compared to control) and also after mitomycin C treatment (60.0%). Complete growth inhibition without significant degenerative cell changes could only be achieved with mitomycin C. Conclusion: In vitro, all tested tocotrienol isoforms were able to inhibit proliferation, migration and collagen synthesis of human Tenon's fibroblasts and therefore may have the potential as an anti-scarring agent in filtrating glaucoma surger

Antifibrotic effects of tocotrienols on human Tenon's fibroblasts

Antifibrotic effects of α- (40, 60, 80, 100, and 120 μM), γ- (10, 20, 30, and 40 μM) and δ-tocotrienol (10, 20, 30, and 40 μM) on hTf cultures were evaluated by performing proliferation, migration and collagen synthesis assays. Whereas for vitamin E the exposure time was set to 7 days to mimic subconjunctival application, cultures were exposed only 5 min to mitomycin C 100 μg/ml to mimic intraoperative administration. Cell morphology (phase contrast microscopy) as an assessment for cytotoxicity and cell density by measuring DNA content in a fluorometric assay to determine proliferation inhibition was performed on day 0, 4, and 7. Migration ability and collagen synthesis of fibroblasts were measured. Results All tested tocotrienol isoforms were able to significantly inhibit hTf proliferation in a dose-dependent manner (maximal inhibitory effect without relevant morphological changes at day 4 for α-tocotrienol 80 μM with 36.7% and at day 7 for α-tocotrienol 80 μM with 42.6% compared to control). Degenerative cell changes were observed in cultures with concentrations above 80 μM for α- and above 30 μM for γ- and δ-tocotrienol. The highest collagen synthesis inhibition has been found with 80 µM α-tocotrienol (62.4%) and no significant inhibition for mitomycin C (2.5%). Migration ability was significantly reduced in cultures exposed to 80 µM α- and 30 µM γ-tocotrienol (inhibition of 82.2% and 79.5%, respectively, compared to control) and also after mitomycin C treatment (60.0%). Complete growth inhibition without significant degenerative cell changes could only be achieved with mitomycin C. Conclusion In vitro, all tested tocotrienol isoforms were able to inhibit proliferation, migration and collagen synthesis of human Tenon’s fibroblasts and therefore may have the potential as an anti-scarring agent in filtrating glaucoma surge

Dietary tocopherol supplementation after trabeculectomy and phacotrabeculectomy: double-blind randomized placebo-controlled trial

The vitamin E compound alpha-tocopherol inhibits fibroblast growth in vitro. To evaluate its potential benefit in preventing failure of glaucoma filtration surgery, we prospectively investigated the outcome of filtering surgery with postoperative dietary alpha-tocopherol supplementation

Mutational landscape of intestinal crypt cells after long-term in vivo exposure to high fat diet

Abstract Obesity is a modifiable risk factor in cancer development, especially for gastrointestinal cancer. While the etiology of colorectal cancer is well characterized by the adenoma-carcinoma sequence, it remains unclear how obesity influences colorectal cancer development. Dietary components of a high fat diet along with obesity have been shown to modulate the cancer risk by perturbing the homeostasis of intestinal stem cells, yet how adiposity impacts the development of genomic instability has not been studied. Mutational signatures are a powerful way to understand how a complex biological response impacts genomic stability. We utilized a mouse model of diet-induced obesity to study the mutational landscape of intestinal crypt cells after a 48-week exposure to an experimental high fat diet in vivo. By clonally enriching single crypt derived cells in organoid culture and obtaining whole genome sequences, we analyzed and compared the mutational landscape of intestinal epithelial cells from normal diet and high fat diet mice. Single nucleotide substitution signatures and indel signatures present in our cohort are found equally active in both diet groups and reflect biological processes of normal aging, cellular replication, and oxidative stress induced during organoid culturing. Thus, we demonstrate that in the absence of activating mutations or chemical exposure, high fat diet alone is not sufficient to increase genomic instability

Trastuzumab Emtansine (T-DM1) in Patients with Previously Treated HER2-Overexpressing Metastatic Non-Small Cell Lung Cancer: Efficacy, Safety, and Biomarkers

PURPOSE HER2-targeted therapy is not standard of care for HER2-positive non-small cell lung cancer (NSCLC). This phase II study investigated efficacy and safety of the HER2-targeted antibody-drug conjugate trastuzumab emtansine (T-DM1) in patients with previously treated advanced HER2-overexpressing NSCLC. PATIENTS AND METHODS Eligible patients had HER2-overexpressing NSCLC (centrally tested IHC) and received previous platinum-based chemotherapy and targeted therapy in the case of mutation or gene rearrangement. Patients were divided into cohorts based on HER2 IHC (2+, 3+). All patients received T-DM1 3.6 mg/kg intravenously every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was investigator-determined overall response rate (ORR) using RECIST v1.1. RESULTS Forty-nine patients received T-DM1 (29 IHC 2+, 20 IHC 3+). No treatment responses were observed in the IHC 2+ cohort. Four partial responses were observed in the IHC 3+ cohort (ORR, 20%; 95% confidence interval, 5.7%-43.7%). Clinical benefit rates were 7% and 30% in the IHC 2+ and 3+ cohorts, respectively. Response duration for the responders was 2.9, 7.3, 8.3, and 10.8 months. Median progression-free survival and overall survival were similar between cohorts. Three of 4 responders had gene amplification. No new safety signals were observed. CONCLUSIONS T-DM1 showed a signal of activity in patients with HER2-overexpressing (IHC 3+) advanced NSCLC. Additional investigation into HER2 pathway alterations is needed to refine the target population for T-DM1 in NSCLC; however, HER2 IHC as a single parameter was an insufficient predictive biomarker