Status Of Pumps Research Articles

WaveNet based Autoencoder Model: Vibration Analysis on Centrifugal Pump for Degradation Estimation.

Centrifugal pumps are versatile and have been used in a wide range of applications such as agricultural services, wastewater services, and other industrial services. The mechanism behind the pump is converting rotational kinetic energy to induce flow or raise pressure of liquid. Boiler feedewater pump (BFP) is an important piece of equipment in a thermal power generation plant. Generally, the cost of the pump itself only account less than 20% of its life cost and about 30% - 35% of the life cost spend on pump operation and maintenance. Therefore, it is important to understand the degradation status of the pumping system for optimizing the operational procedures and maintenance schedule to reduce the cost. Traditionally, engineers evaluate the performance and/or find faults by observing the vibrational signal on the pump, specifically, looking at the power spectrum density of the vibrational signal measured on different locations of the pump. However, such vibration analysis requires substantial domain knowledge and experience to accommodate all the variables caused by various conditions like different models, sizes in different plants, units and facilities. Often Vibration Analyst have to bin the vibration signal according to a predetermined frequency bins and potentially removing useful markers about vibration health.
 This paper presents a novel way of conducting vibration analysis on pumps to determine the degradation trend, without requiring expert domain knowledge by extracting useful information using a WaveNet based autoencoder on the historical vibration data. WaveNet is known for processing raw audio data and building generative models. Unlike recurrent neural network (RNN), WaveNet is capable of handling much longer sequential data, which is very suitable for high frequency signals like sound and vibration signals. The autoencoder model extract essential information for reconstructing the input data. The embeddings from the autoencoders can represent the characteristics of the input data. Combining the two techniques, we were able to compress the vibration data 12x and extract the embeddings from raw vibration data and use them to estimate the degradation status of pumps. We pre-selected a collection of vibration data from pumps under “normal” condition. The degradation trend is estimated by computing the distance of the embeddings from “normal” data to new inputs. Such model provides additional information on pump condition vis-a-vis vibration data with no prior domain knowledge. This technique can assist decision making and reduce costs from improper operation and maintenance.

Blockage and cavitation detection in centrifugal pumps from dynamic pressure signal using deep learning algorithm

Centrifugal pumps play an important role in many industrial applications even in harsh environment for prolong duration. High efficiency with very low power consumption makes them very popular in industry. However, during their operation, they may fail due to some operationally developed faults, which may subsequently lead to the interruption in the continuous operation of pumps. Therefore, monitoring the health status of the centrifugal pumps is essential to prevent unwanted stoppage, which may further lead to the breakdown of the whole system. The main focus of this study is to propose a methodology to identify the presence and severity of blockages, and cavitation in the centrifugal pump using fluid pressure, which is very vital for fluid related faults. To simulate the blockage in the pump, the flow area of the suction pipe is restricted by dividing into six equal intervals (i.e., 0%, 16.7%, 33.3%, 50%, 66.6% and 83.33%) using a mechanical modulating valve. Due to blockage and cavitation, the main parameter which directly gets affected is the fluid dynamic pressure. Hence, in the present study, pressure signatures were captured at different blockage levels and at different running speeds with the help of a pressure transducer, which was mounted on the circumference of the centrifugal pump casing. Deep learning based binary data classification methodology is used to classify the data acquired from the pressure transducer. To get better performance of the data classifier, statistical features are extracted from time domain pressure signals. In order to identify the severity of the faults, binary classification of the data is performed at different blockage levels and running speeds. Finally, based on the results obtained from the classifier, existence of the faults (i.e., blockage and the cavitation), their severity levels are presented.

반도체 공정용 진공펌프의 보증 데이터 분석을 위한 신뢰성 대시보드 개발

Purpose: This paper presents a reliability dashboard incorporating big data visualization technology to realize the warranty data analysis of vacuum pumps for semiconductor processes.BRMethods: A reliability dashboard was developed in accordance with 1) KPI definition, 2) business process and data understanding, 3) data extraction, loading and transformation, 4) reliability analysis, and 5) dashboard implementation. MS Excel, MS Access, Weibull++, and MS Power BI were used for the data collection, data integration and analysis, statistical analysis of reliability data, and calculation processing and data visualization for the status analysis, respectively.BRResult: The developed reliability dashboard was used to indentify the failure status and reliability analysis aspects of vacuum pumps for semiconductor processes. BRConclusion: The reliability dashboard can help monitor the quality level experienced by customers and provide the basis for the root cause analyses for failures occurring in the field.

A Distributed Optimization Method for Energy Saving of Parallel-Connected Pumps in HVAC Systems

Motivated by the importance and challenges of the energy saving problem of parallel-connected pumps in heating, ventilation, and air-conditioning (HVAC) systems, we propose a distributed optimal control algorithm for on-off status and flow rate set points of parallel-connected pumps in HVAC systems. The proposed algorithm consists of two parts: First, in order to process the network information, we apply the breadth first search algorithm to construct a tree for exchanging messages. Second, all nodes coordinate with each other and randomly sample the speed ratios. To our best knowledge, the algorithm proposed in this paper is the first effort to address the challenges of existing studies at the same time. The algorithm solves the pump optimization problem in a distributed manner, achieves the minimum pump energy consumption and has the convergence guarantee. Even if some of the pumps break down, the whole system can still be working and have great flexibility. Simulation experiments on six parallel-connected pumps are provided for different working cases to demonstrate the effectiveness of the proposed algorithm and compare with the other four methods. The results show that our algorithm strictly satisfies the demand constraints and presents good energy saving potential, the convergence guarantee, and flexibility. The maximum energy saving can be up to 29.92%.

Leakage Control and Energy Consumption Optimization in the Water Distribution Network Based on Joint Scheduling of Pumps and Valves

Apart from water quality, leakage control and energy consumption management are the most concerning challenges for water treatment plants (WTPs). The joint scheduling of pumps and pressure reducing valves (PRVs) in the water distribution network can reduce excessive pressure and distribute pressure more evenly, which achieves comprehensive reduction of leakages and energy consumption. Taking into account the main shortcomings of the commonly used methods, such as scheduling pumps or PRVs separately, or optimizing PRV settings when their position is given, etc., this paper has taken the PRV (position and setting) and the working status of variable speed pumps (VSPs) as decision variables and the cost savings contributed by leakage reduction and energy consumption savings as the objective function, which maximized the economic benefits brought by PRV and/or VSP scheduling. A genetic algorithm (GA) was used to optimize the solution under multiple working conditions. The performance of three control strategies (PRV-only scheduling, VSP-only scheduling, and joint scheduling of PRVs and VSPs) are compared to each other based on a small network. Joint scheduling has achieved the best economic benefits in reducing the gross cost (contributed by leakage and energy consumption) of the three control strategies, which results in a leakage reduction of 33.4%, an energy consumption reduction of 25.4%, and a total cost reduction of 33.1%, when compared to the original network, and saving about 1148 m 3 water (7% of the original consumption) and 722 kWh electric energy (25.4% of the original consumption) per day.

Improving Intelligence and Efficiency of Salt Lake Production by Applying a Decision Support System Based on IOT for Brine Pump Management

At present, due to their geographical distribution, environmental conditions and traditional monitoring technologies, the manual inspection of brine pumps in Qinghai Saline Lake can not be effectively carried out in real time, so the pumps have a high failure rate. This has seriously affected the chemical production of this saline lake. The paper designed a remote real-time monitoring terminal and a decision support system based on LoRa technology, GPRS (General Packet Radio Services) remote communication technology and remote-control technology. The system integrated the liquid-level sensing model and the decision support model for brine pump management. The system monitored and analyzed the voltage, current, and liquid-level parameters in real time to determine the operating status or failure of the brine pump. The ID3 (Iterative Dichotomiser 3) method was used to establish the correlation models between the dynamic monitoring information and the brine pump failure, which is the core of the decision support model. The remote controller was implemented to display and control the running status of the brine pumps when the maintenance personnel received the warning information. PHP (Hypertext Preprocessor) language and a MySQL database were implemented to realize the data display, management and decision support system.

Evaluation of the performance of elastomeric pumps in practice: are we under-delivering on chemotherapy treatments?

Background and aims: Elastomeric pumps are widely used to facilitate ambulatory chemotherapy, and studies have shown that they are safe and well received by patients. Despite these advantages, their end of infusion time can fluctuate significantly. The aim of this research was to observe the performance of these pumps in real practice and to evaluate patients’ satisfaction.Methods: This was a two-phase study conducted at three cancer units over 6 months. Phase-1 was an observational study recording the status of pumps at the scheduled disconnection time and noting remaining volume of infusion. Phase-2 was a survey of patients and their perception/satisfaction. Ethical approval was granted.Results: A total of 92 cases were observed covering 50 cases disconnected at hospital and 42 disconnected at home. The infusion in 40% of hospital disconnection cases was slow, with patients arriving at hospital with unfinished pumps; 58% of these had an estimated remaining volume which exceeded 10 mL with 35% exceeded 20 mL. In 73% of these cases, and regardless of the remaining volume, the patient was disconnected and the pump was discarded.Conclusions: The performance of pumps varied, which affected nurse workload and patients’ waiting-times. A smart system is an option to monitor the performance of pumps and to predict their accuracy.

Automatizacija postrojenja za skladištenje i pretakanje metanola u pogonu za proizvodnju biodizela

Opisan je sistem za akviziciju podataka, nadzor i upravljanje postrojenjem za skladištenje i pre-takanje metil alkohola, koji se koristi kao reaktant u tehnološkom procesu (proizvodnja biodizela u sklopu Fabrike FAM Kruševac). Upravljanje i nadzor se vrše pomoću PLC i SCADA sistema. Pregled i zadavanje karakterističnih parametara i veličina vrši se preko kreiranih ekrana na touch panelu i PC računaru na kome se izvršava arhiviranje podataka. Pod nadzorom SCADA su: diskretni i kontinualni nivoi rezervoara za skladištenje metanola, statusi pumpi za pretakanje, temperature metanola u rezervoarima i cevovodu, pritisak u cevovodu i maseni protok metanola. Omogućeno je arhiviranje podataka i generisanje izveštaja.

Technological status of reactor coolant pumps in generation III+ pressurized nuclear reactors

Abstract KSB has been developing and producing pumps for thermal power plants for nearly 90 years. Consequently, KSB also started to develop and manufacture pumps for all kinds of nuclear power plants from the very beginning of the civil use of nuclear energy. This is especially true for reactor coolant pumps for pressurized water reactors. For the generation of advanced evolutionary reactors (Generation III+ reactors), KSB developed an advanced shaft seal system which is also able to fulfill the requirements of station blackout conditions. The tests in the KSB test rigs, which were successfully completed in December 2015, proved the full functionality of the new design. For generation III+ passive plant reactors KSB developed a new reactor coolant pump type called RUV, which is based on the experience of classic reactor coolant pumps and reactor internal pumps. It is a very compact, hermetically sealed vertical pump-motor unit with a wet winding motor. A full scale prototype successfully passed the 1st stage qualification test program in October 2015.

Feasibility of solar pump for sustainable irrigation in Bangladesh

A base-line survey was conducted in 2010 at different locations of Bangladesh to know the present status of solar pumps. The respondents were solar pump users, suppliers and service providers. There were about 150 solar pumps in Bangladesh, among them 65 % were used for supplying drinking water to the poor people of the locality and about 35 % solar pumps were used for irrigation purposes. The size of solar pumps varied from 300 to 1,190 Wp and discharge capacity varied from 2,000 to 800,000 L/day. Panel cost was the major cost (45 %) in solar pump followed by the costs of installation (18 %), motor (16 %), pump (10 %), and pipes and fittings (4 %). Life cycle cost of diesel engine-operated pump was lower up to 5 years. After 5 years, the life cycle cost of solar pump became lower than that of diesel engine-operated pump. Benefit cost ratio, net present value and internal rate of return of solar pump were found higher than diesel-operated pump. Therefore, solar pump is profitable and investment on solar pump is more risk free than diesel engine-operated pump. Diesel engine-operated irrigation pump emits carbon dioxide and pollutes environment, but solar pump is an environment-friendly irrigation technology.

Condition monitoring of PARR-1 rotating machines by vibration analysis technique

Vibration analysis is a key tool for preventive maintenance involving the trending and analysis of machinery performance parameters to detect and identify developing problems before failure and extensive damage can occur. A lab-based experimental setup has been established for obtaining fault-free and fault condition data. After this analysis, primary and secondary motor and pump vibration data of the Pakistan Research Reactor-1 were obtained and analyzed. Vibration signatures were acquired in horizontal, vertical, and axial directions. The 48 vibration signatures have been analyzed to assess the operational status of motors and pumps. The vibration spectrum has been recorded for a 2000 Hz frequency span with a 3200 lines resolution. The data collected should be helpful in future Pakistan Research Reactor-1 condition monitoring.

An Communication and Battery Performance Evaluation of the Demand Response and Battery Storage Coordination System Potential for Providing Microgrid Tie-Line Smoothing Services

In this paper, an communication and battery performance evaluation is discussed for a demand response and battery storage coordination algorithm, which provides a new way of microgrid tie-line smoothing service. A battery storage system and a total number of 1000 heat pumps are modeled to demonstrate the algorithm. A temperature priority list (TPL) model is used to describe the behavior of the heat pumps. Besides, a control strategy via a two-way communication networks is implemented to smooth the tie-line fluctuations. Then considering in a no ideal communication environment, the impacts of the unexpected changes of the on/off status of the heat pumps on the simulation results are studied. Meanwhile, the impacts of different numbers of batteries and batteries with different charging rates are also referred. The results show that coordinating the heat pumps and batteries can significantly smooth the fluctuations brought by the integration of the renewable resources such as the wind and solar power. The switching status changes of the heat pumps, the numbers and charging rate of the batteries also have great influence on the proposed smoothing performance.

Moderate Exercise Training Induces ROS-Related Adaptations to Skeletal Muscles

Aim of the present work was the evaluation of the effects of moderate exercise training on 2 skeletal muscles differing in fibre-type composition, Tibialis Anterior (TA) and Soleus (SOL). Fibre adaptations, including their metabolic shift and mechanisms underlying proliferation and differentiation, oxidative stress markers, antioxidant and cytoprotective molecules, activity of Ca2+-handling molecules were examined. 6 male 2-month-old rats trained on a treadmill for 1 h/day, 3 days/week, for 14 weeks, reaching 30 m/min at the end of training. 6 age-matched sedentary rats served as controls. Rats were sacrificed 24 h after the last training session. Muscle regulatory factors increased in both muscles, activating satellite cell proliferation, which led to moderate hypertrophy in SOL and to moderate hyperplasia in TA, where the upregulation of desmin and TNFR2 expression suggests that myotube formation by proliferating myoblasts is somehow delayed. Changes leading to a more oxidative metabolism together with the upregulation of a number of antioxidant enzymes occurred in TA. HSP70i protein was upregulated in both SOL and TA, while oxidative stress markers increased in SOL alone. The status of ionic channels and pumps was preserved. We suggest that the increase in ROS, known to be associated with exercise, underlies most observed results.

Optimal Water Distribution Network Design Accounting for Valve Shutdowns

AbstractThe hydraulic system functioning is determined by the boundary conditions (e.g., network topology, pipe resistances/diameters, tank levels, status of control devices, and status of pumps). Shutdown of isolation valves to detach a portion of the hydraulic network for planned or unplanned works generates abnormal working conditions because of the induced topological modification of the network, which may reduce the hydraulic capacity of the water system with respect to the portions still connected. Thus, a challenge for network design is to optimize diameters versus system management under abnormal working conditions, i.e., accounting for the isolation valve system. To this purpose, a methodology for optimal system design accounting for valve shutdowns is herein presented. Because the optimization asks for the evaluation of network configurations that can be generated by the isolation valve system, a strategy to reduce the computational burden is required. In fact, the analysis of a large number of ...

Clean energies for sustainable development for built environment

The move towards a de-carbonised world, driven partly by climate science and partly by the businessopportunities it offers, will need the promotion of environmentally friendly alternatives, if an acceptablestabilisation level of atmospheric carbon dioxide is to be achieved. This requires the harnessing and use of natural resources that produce no air pollution or greenhouse gases and provides comfortable coexistence of human, livestock, and plants. This article presents a comprehensive review of energy sources, and the development of sustainable technologies to explore these energy sources. It also includes potential renewable energy technologies, efficient energy systems, energy savings techniques and other mitigation measures necessary to reduce climate changes. The article concludes with the technical status of the ground source heat pumps (GSHP) technologies. Key words: Climate, energy, natural resources, carbon dioxide, technologies.

Statins Increase Antileukemic Potency of Imatinib Through the Inhibition of MDR/ABCB1 and BCRP/ABCG2 Drug Transporters Activity

Abstract 2742The treatment of chronic myeloid leukemia (CML) was revolutionized by the introduction of tyrosine kinase inhibitors (TKIs) to the clinical practice. However, there is still a significant group of patients who due to drug resistance do not fully benefit from the therapy. Among various reasons of drug resistance, the changes of intracellular concentration of TKIs caused by the activity of drug transporters may have profound effect on clinical activity of the drug. Intracellular concentration of imatinib is a result of: drug influx into the cell and drug efflux out of the cell. The latter is mediated by ATP-binding casette (ABC) transporters - MDR/ABCB1 and BCRP/ABCG2. According to the recent knowledge modulation of membrane cholesterol level may change the activity of ABC transporters by changing their conformation. Hence we decided to evaluate potential effect of statins, widely used hypocholesterolemic drugs, on antileukemic activity of imatinib in cell lines transformed with BCR/ABL oncoprotein and primary human CML CD34+ cells.In a set of experiments involving cytotoxic assays (i.e. clonogenic assay, XTT, trypan blue exclusion assay) we revealed that lovastatin, a member of statin family, is able to enhance imatinib cytotoxicity both in established cell lines (32Dcl3 BCR/ABL+, K562) as well as in primary CML CD34+ cells obtained from patients in various stages of the disease, including those clinically resistant to imatinib with no detectable ABL kinase domain mutations. In the same time, lovastatin alone and in combination with imatinib did not influence BCR/ABL negative cells (32Dcl3 wild type, HL-60, CD34+ cells obtained from healthy blood donors). As measured using specific, fluorescent-labeled substrates for ABC transporters (rhodamine-123 and Bodipy-FL-prazosin respectively), lovastatin significantly inhibits MDR/ABCB1- and BCRP/ABCG2-mediated efflux capacity. Similar effects were observed for other statins. The addition of cholesterol to the samples previously incubated with lovastatin completely reversed inhibitory activity of statins. To confirm these results we examined direct changes of intracellular concentration of imatinib itself using radiolabeled 14C-imatinib. In these settings, statins caused 2–3-fold increase in intracellular imatinib concentration in murine and human cell lines (32Dcl3 BCR/ABL+, K562) and also in primary CML CD34+ cells including clones resistant to imatinib (Figure 1). Statins did not influence initial concentration of imatinib what may suggest that their effects on imatinib concentration are not mediated by changes in OCT-1 activity. In addition, statins did not influence expression of MDR/ABCB1 and BCRP/ABCG2 drug transporters measured using qPCR nor ABC proteins levels measured using Wester blotting. Combination of imatinib and lovastatin induced cell cycle arrest and increased percentage of apoptotic leukemic cells measured using flow cytometric analysis after propidium iodide staining. Lovastatin also reduced imatinib-induced phosphorylation of the adaptor protein CrkL.In summary, we show that statins are able to increase therapeutic efficacy of imatinib through the inhibition of drug efflux mediated by MDR/ABCB1 and BCRP/ABCG2 transporters. Our results suggest that statin-mediated depletion of cholesterol in the cell may change conformational status of the efflux pumps, including MDR/ABCB1 and BCRP/ABCG2 pumps involved in the transport of imatinib, and in that way modulate intracellular concentration of the drug. The addition of statins may become attractive treatment modality for the selected group of patients in chronic phase and blast crisis. [Display omitted] CML-CP, CML-BP–CD34+ cells obtained from CML patient in chronic phase or blast crisis respectively; *p<0,05 Disclosures:No relevant conflicts of interest to declare.

Ensemble-approaches for clustering health status of oil sand pumps

Centrifugal slurry pumps are widely used in the oil sand industry, mining, ore processing, waste treatment, cement production, and other industries to move mixtures of solids and liquids. Wear of slurry pump components, caused by abrasive and erosive solid particles, is one of the main causes of reduction in the efficiency and useful life of these pumps. This leads to unscheduled outages that cost companies millions of dollars each year. Traditional maintenance strategies can be applied, but they provide insufficient warning of impending failures. On the other hand, condition monitoring and on-line assessment of the wear status of wetted components in slurry pumps are expected to improve maintenance management and generate significant cost savings for pump operators. In this context, the objective of the present work is to develop and compare two unsupervised clustering ensemble methods, i.e., fuzzy C-means and hierarchical trees, for the assessment and measurement of the wear status of slurry pumps when available data is extremely limited. The idea is to combine predictions of multiple classifiers to reduce the variance of the results so that they are less dependent on the specifics of a single classifier. This will also reduce the variance of the bias, because a combination of multiple classifiers may learn a more expressive concept class than a single classifier.

Potentiation of the Antileukemic Effects of Imatinib through the Modulation of BCRP/ABCG2 Activity.

AbstractAbstract 3400Resistance to tyrosine kinase inhibitors (TKI) constitutes a growing problem in chronic myeloid leukemia (CML) therapy. Variations of intracellular concentration of TKIs, dependable on the activity of drug transporters, are among major mechanisms responsible for the development of resistance. Intracellular imatinib concentration depends on the balance of active transport of the drug into the cell, mediated mainly by OCT-1 transporter, and drug efflux out of the cell, mediated by transmembrane pumps belonging to ABC transporters family. While there are reports that imatinib is a substrate for ABCG2 efflux pump, other studies show that it rather acts as an inhibitor of this drug transporter. According to the latest reports both views may be true – in low concentration imatinib seems to be a substrate of ABCG2 pump while in high concentrations it can inhibit activity of the pump. Drugs able to modulate membrane-bound proteins conformation, including drug transporters, may influence intracellular concentration of imatinib. Statins, inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, widely used in the treatment of hypercholesterolemia, can modulate activity of ABC transporters. Therefore, we evaluated the potential influence of statins on the antileukemic activity of imatinib in cell lines transformed with BCR/ABL oncoprotein and primary human CML CD34+ cells. Lovastatin, a member of statin family, not only exerted antileukemic activity alone, but also significantly enhanced cytotoxicity of imatinib in BCR/ABL-positive murine 32Dcl3 cells and in human K562 cells as compared to 32Dcl3 wild-type counterparts and HL-60 cells respectively, which was measured in cytotoxic assays (i.e. trypan blue, XTT) and clonogenic tests. Similar effects were observed for other statins (incl. atorvastatin, simvastatin and mevastatin). Potentiation of antileukemic activity of imatinib by lovastatin was also observed for primary CML CD34+ cells from patients in different stages of the disease. In contrast, this antileukemic effect was not observed in peripheral blood leukocytes from healthy blood donors. Moreover, in comparison to monotherapy the co-treatment induced cell cycle arrest and increased percentage of apoptotic leukemic cells measured using flow cytometric analysis after propidium iodide staining. Lovastatin also increased imatinib-induced reduction of the phosphorylated form of the adaptor protein CrkL, which serves as a marker for efficient BCR/ABL kinase inhibition in both stable cell lines and primary CML CD34+ cells. Additionally, co-treatment with statin and imatinib has modified cell cycle/apoptosis controlling proteins profile. Cytometric analysis of intracellular concentration of ABCG2 substrate (fluorescent dye BODIPY-prazosin), revealed that lovastatin significantly decreased ABCG2 mediated efflux capacity in BCR/ABL-positive cells. The effect was completely reversed by the addition of cholesterol to the sample previously incubated with lovastatin. These results suggest that statin-mediated depletion of cholesterol may influence conformational status of the efflux pumps and hence can modulate their activity. Such phenomenon was observed both for stable cell lines and primary CD34+ CML cells including cells from patients clinically resistant to imatinib with no detectable ABL kinase domain mutations. To confirm the results of indirect experiments with BODIPY-prazosin we examined whether statins modulate intracellular level of imatinib itself, employing radiolabeled 14C-imatinib. Pretreatment of K562 cells with lovastatin resulted in significant increase in intracellular labeled drug concentration (at least 2-fold). This effect was due to diminished efflux of the drug, since we did not observe changes in initial influx of imatinib between statin-treated and control cells. This suggests that statins may exert significant effect on activity of ABCG2, but not Oct1 transporter.Our results indicate that statins can positively influence the therapeutic potency of imatinib and modification of drug efflux may be a major mechanism responsible for such effect. We conclude that addition of statins to the treatment regimen may become an effective treatment modality capable of potentiating the antileukemic effectiveness of tyrosine kinase inhibitors. Disclosures:No relevant conflicts of interest to declare.

Morphogenic regulator EFG1 affects the drug susceptibilities of pathogenic Candida albicans

This study shows that the morphogenic regulator EFG1 level affects the drug susceptibilities of Candida albicans when grown on solid growth media. The Deltaefg1 mutant showed sensitivity particularly to those drugs that target ergosterol or its metabolism. Efg1p disruption showed a gene-dosage effect on drug susceptibilities and resulted in enhanced susceptibility to drugs in the homozygous mutant as compared with the wild type, heterozygous and revertant strains. The enhanced sensitivity to drugs was independent of the status of ATP-binding cassette and MFS multidrug efflux pumps of C. albicans. The Deltaefg1 mutant displayed increased membrane fluidity that coincided with the downregulation of ERG11 and upregulation of OLE1 and ERG3, leading to enhanced passive diffusion of drugs. Interestingly, Deltaefg1 mutant cells displayed enhanced levels of endogenous ROS levels. Notably, the higher levels of ROS in the Deltaefg1 mutant could be reversed by the addition of antioxidants. However, the restoration of ROS levels did not reverse the drug sensitivities of the Deltaefg1 mutant. Taken together, we, for the first time, establish a new role to EFG1 in affecting the drug susceptibilities of C. albicans cells, independent of ROS and known drug efflux mechanisms.

Current status of ground-source heat pumps in China

As a renewable energy technology, the ground-source heat pump (GSHP) technologies have increasingly attracted world-wide attention due to their advantages of energy efficiency and environmental friendliness. This paper presents Chinese research and application on GSHP followed by descriptions of patents. The policies related to GSHP are also introduced and analyzed. With the support of Chinese government, several new heat transfer models and two new GSHP systems (named pumping and recharging well (PRW) and integrated soil cold storage and ground-source heat pump (ISCS&GSHP) system) have been developed by Chinese researchers. The applications of GSHP systems have been growing rapidly since the beginning of the 21st century with financial incentives and supportive government policies. However, there are still several challenges for the application of GSHP systems in large scale. This paper raises relevant suggestions for overcoming the existing and potential obstacles. In addition, the developing and applying prospects of GSHP systems in China are also discussed.