Double-Lepton Polarization Asymmetries in B_s \rar \phi \ell^+ \ell^- Decay in the Fourth-Generation Standard Model

In this paper, we investigate the effects of the fourth generation of quarks on the double-lepton polarization asymmetries in the B_s \rar \phi \ell^+ \ell^- decay. It is shown that these asymmetries in B_s \rar \phi \ell^+ \ell^- decay compared with those of B \rar K \ell^+ \ell^- decay are more sensitive to the fourth-generation parameters. We conclude that an efficient way to establish the existence of the fourth generation of quarks could be the study of these asymmetries in the B_s \rar \phi \ell^+ \ell^- decay.Comment: 25 pages and 7 figure

Residual bitumen recovery from oil sand tailings with lime

All oil sands plants operating in Alberta, Canada use the Clark Hot Water Extraction process. This process causes production of mature fines tailings (MFT) at 30-35% solids content which remains in a fluid state for decades because of its very slow consolidation rate. Existing mature fines tailings inventory is approaching 10⁹ m³, remediation of which by thin layer deposition and centrifuging are being tested by oil industry. Residual bitumen in mature fine tailings can complicate remediation, as it can interfere with the performance of coagulants and polymers which hinders the dewatering process. To support oil industries mature fine tailings remediation effort, we have investigated a method that reduces residual bitumen content, facilitates dewatering of the mature fine tailings and improves process water chemistry, simultaneously, by using lime as a process aid between 750 to 1500 mg-CaO/kg-MFT dosages. Experimental observations suggest that the residual bitumen of the mature fine tailings could be recovered by flotation process with about 5-10 minutes retention time. This investigation shows that use of lime could enhance the performance of mature fine tailings remediation processes.Applied Science, Faculty ofMining Engineering, Keevil Institute ofUnreviewedOthe

Myeloid-derived suppressor cells and tumor: Current knowledge and future perspectives

The immunosuppressive features of tumor lesions participate not only as one of the major players inducing cancer progression but also a big challenge for effective immunotherapy. It has been found that immunosuppression associated with chronic inflammatory factors, such as growth factors, cytokines, and chemokines is generated by stroma and tumor cells. Chronic and exhaustive secretion of these mediators triggers the generation of myeloid-derived suppressor cells (MDSCs) demonstrating one of the key players engaged in tumor immunosuppression. In point of fact, direct cell-to-cell contact is a prerequisite for immunosuppressive functions of MDSCs. From the clinical perspective, the frequency of peripheral blood MDSCs is correlated with clinical stage and therapeutic response in various cancers. Furthermore, MDSCs are involved in chemoresistant settings. Altogether, it is a rational therapeutic approach to block the fierce cycle in which MDSCs are developed and infiltrated to favor cancer progression. In this review, we will summarize recent findings of MDSCs in tumor progression and discuss potential therapeutic strategies that could be evaluated in future clinical trials. © 2018 Wiley Periodicals, Inc

Systematic review and meta-analytic findings on the association between killer-cell immunoglobulin-like receptor genes and susceptibility to pulmonary tuberculosis

Several studies have evaluated the association between killer-cell immunoglobulin-like receptors (KIR) genes and susceptibility risk to tuberculosis (TB) infection. Nonetheless, their outcomes have not been conclusive and consistent. Here we implemented a systematic review and meta-analysis of KIR genes association to susceptibility risk of pulmonary TB (PTB) infection to attain a clear understanding of the involvement of these genes in susceptibility to PTB infection. A systematic search was conducted in the MEDLINE/PubMed and Scopus databases to find case-control studies published before November 2020. Pooled odds ratio (OR) and 95 confidence interval (95 CI) were calculated to determine the association between KIR genes and risk of PTB infection. After comprehensive searching and implementing the inclusion and exclusion criteria, 10 case-control studies were included in the meta-analysis. Four KIR genes were found to have significant positive association with PTB susceptibility risk of infection, including 2DL3 (OR = 1.454, 95 CI = 1.157�1.827; P = 0.001), 2DS1 (OR = 1.481, 95 CI = 1.334�1.837; P < 0.001), 2DS4 (OR = 1.782, 95 CI = 1.273�2.495; P = 0.001) and 3DL1 (OR = 1.726, 95 CI = 1.277�2.333; P < 0.001). However, the results showed that the remaining KIR genes (2DS2-4, 2DL1, 2, 4, 3DL1-2) and two pseudogenes (2DP1 and 3DP1) did not have significant associations with risk of PTB infection. This meta-analysis provides reliable evidence that the KIR genes 2DL3, 2DS1, 2DS4, and 3DL1 may be associated with an increased risk of PTB infection. © 2020 Informa UK Limited, trading as Taylor & Francis Group

Comparative assessment of innovative methods to improve solar chimney power plant efficiency

Abstract Utilizing Solar Chimney Power Plants (SCPPs) for manufacturing clean and environment-friendly energy has drawn a lot of attention in recent years and has (over the passing decades) become one of the most promising solutions in the solar energy field. Low efficiency, construction difficulties and other required improvements have encouraged researchers to work on this system. Many researchers put their efforts into proposing an optimized configuration for the main components, whereas others have proposed innovative ideas and add-on accessories to improve solar chimney power plants from an efficiency or construction viewpoint. This paper provides a comprehensive review of the past few decades and includes analyses of the theoretical, experimental and numerical studies conducted focused on optimizing the main characters of the system, such as the chimney, collector and Power Conversion Unit (PCU) together with other recently suggested innovative ideas and alternative technologies to improve solar chimney power plants efficiency. Concurrently, other researchers focused on hybrid solar chimney power plants to produce the desired by-product such as distilled water and so make SCPPs more practical

Design of the organic Rankine cycle for high-efficiency diesel engines in marine applications

Abstract Over the past few years, fuel prices have increased dramatically, and emissions regulations have become stricter in maritime applications. In order to take these factors into consideration, improvements in fuel consumption have become a mandatory factor and a main task of research and development departments in this area. Internal combustion engines (ICEs) can exploit only about 15–40% of chemical energy to produce work effectively, while most of the fuel energy is wasted through exhaust gases and coolant. Although there is a significant amount of wasted energy in thermal processes, the quality of that energy is low owing to its low temperature and provides limited potential for power generation consequently. Waste heat recovery (WHR) systems take advantage of the available waste heat for producing power by utilizing heat energy lost to the surroundings at no additional fuel costs. Among all available waste heat sources in the engine, exhaust gas is the most potent candidate for WHR due to its high level of exergy. Regarding WHR technologies, the well-known Rankine cycles are considered the most promising candidate for improving ICE thermal efficiency. This study is carried out for a six-cylinder marine diesel engine model operating with a WHR organic Rankine cycle (ORC) model that utilizes engine exhaust energy as input. Using expander inlet conditions in the ORC model, preliminary turbine design characteristics are calculated. For this mean-line model, a MATLAB code has been developed. In off-design expander analysis, performance maps are created for different speed and pressure ratios. Results are produced by integrating the polynomial correlations between all of these parameters into the ORC model. ORC efficiency varies in design and off-design conditions which are due to changes in expander input conditions and, consequently, net power output. In this study, ORC efficiency varies from a minimum of 6% to a maximum of 12.7%. ORC efficiency performance is also affected by certain variables such as the coolant flow rate, heat exchanger’s performance etc. It is calculated that with the increase of coolant flow rate, ORC efficiency increases due to the higher turbine work output that is made possible, and the condensing pressure decreases. It is calculated that ORC can improve engine Brake Specific Fuel Consumption (BSFC) from a minimum of 2.9% to a maximum of 5.1%, corresponding to different engine operating points. Thus, decreasing overall fuel consumption shows a positive effect on engine performance. It can also increase engine power output by up to 5.42% if so required for applications where this may be deemed necessary and where an appropriate mechanical connection is made between the engine shaft and the expander shaft. The ORC analysis uses a bespoke expander design methodology and couples it to an ORC design architecture method to provide an important methodology for high-efficiency marine diesel engine systems that can extend well beyond the marine sector and into the broader ORC WHR field and are applicable to many industries (as detailed in the Introduction section of this paper)

Validity of continuous metabolic syndrome score for predicting metabolic syndrome; a systematic review and meta-analysis

Background: Nowadays, use of continuous metabolic syndrome (cMetS) score has been suggested to improve recognition of metabolic syndrome (MetS). The aim of this study was to evaluate the validity of cMetS scores for predicting MetS. Methods: We searched the electronic databases included MEDLINE/PubMed, Embase, ISI Web of Science, and Scopus from 1 January 1980 to 30 September 2020. Observational studies on participants with different cMetS scores were included in this meta-analysis. The sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR) and diagnostic odds ratio (DOR) with 95 CI were calculated. Results: Ten studies involving a total of 25,073 participants were included. All studies had cross-sectional design. The pooled sensitivity and specificity of cMetS scores for predicting MetS were 0.90 (95 CI: 0.83 to 0.95) and 0.86 (95 CI: 0.83 to 0.89), respectively. Moreover, cMetS scores had the pooled LR+ of 6.5 (95 CI: 5.0 to 8.6), and a pooled (LR-) of 0.11 (95 CI: 0.063 to 0.21). The pooled DOR of cMetS scores to predict MetS were 57 (95 CI: 26 to 127). Conclusions: The high sensitivity and specificity of cMetS scores indicates that it has a high accuracy to predict the risk of MetS. Furthermore, the cMetS scores has a good ability to rule out healthy people. Study registration: This study was registered as PROSPERO CRD42020157273. © 2021, Springer Nature Switzerland AG