bluuebunny/crossref_metadata_2025 huggingface dataset:
Cisplatin-, Doxorubicin-, and Docetaxel-Induced Cell Death Promoted by the Aqueous Extract of Solanum nigrum in Human Ovarian Carcinoma Cells
Authors: Wang Chia-Woei , Chen Chun-Liang , Wang Chien-Kai , Chang Yu-Jia , Jian Jiun-Yu , Lin Chi-Shian , Tai Cheng-Jeng , Tai Chen-Jei
Published: June 2015

Chemotherapy is a major clinical treatment for managing patients with advanced and recurrent ovarian cancer. However, the clinical performance of chemotherapy is limited, and adverse effects have been observed. Integrating chemotherapy with current chemotherapeutic drugs and novel antitumor ingredients might improve the clinical performance of current chemotherapy for ovarian cancer. The aqueous extract of Solanum nigrum leaves (AE-SN), a key ingredient in many traditional Chinese medicine formulae, has exhibited tumor suppression efficacy in numerous human cancer cells but not in ovarian cancer cells. In this study, tumor suppression efficacy was determined using the ES-2, SKOV-3, and OVCAR-3 human ovarian cancer cell lines. The half-maximal inhibitory concentrations of the AE-SN in ES-2 and SKOV-3 cells were 1.052 and 1.779 mg/mL, respectively. AE-SN treatment increased the accumulation of mammalian microtubule-associated protein 1 light chain 3 A/B, an autophagic cell marker, in all the tested cell lines; however, it activated the cleavage of caspase-3, an apoptotic marker, only in SKOV-3 cells. Furthermore, the AE-SN also promoted tumor suppression efficiency of cisplatin, doxorubicin, and docetaxel in the tested ovarian cancer cells. In addition, AE-SN-enhanced cell death was associated with AE-SN-induced caspase-3 cleavage in SKOV-3 cells. In conclusion, the AE-SN exhibited tumor suppression efficacy and improved the tumor suppression efficiency of cisplatin, doxorubicin, and docetaxel in human ovarian cancer cells. Therefore, the AE-SN is a candidate antitumor ingredient that can be used in developing future integrated chemotherapy for managing ovarian cancer.
Recent discoveries concerning the involvement of transcription factors from the Grainyhead-like family in cancer
Authors: Mlacki Michal , Kikulska Agnieszka , Krzywinska Ewa , Pawlak Magdalena , Wilanowski Tomasz
Published: June 2015

The Grainyhead-like (GRHL) family of transcription factors has three mammalian members, which are currently termed Grainyhead-like 1 (GRHL1), Grainyhead-like 2 (GRHL2), and Grainyhead-like 3 (GRHL3). These factors adopt a DNA-binding immunoglobulin fold homologous to the DNA-binding domain of key tumor suppressor p53. Their patterns of expression are tissue and developmentally specific. Earlier studies of the GRHL proteins focused on their functions in mammalian development. In recent years, these factors have been linked to many different types of cancer: squamous cell carcinoma of the skin, breast cancer, gastric cancer, hepatocellular carcinoma, colorectal cancer, clear cell renal cell carcinoma, neuroblastoma, prostate cancer, and cervical cancer. The roles of GRHL proteins in these various types of cancer are complex, and in some cases appear to be contradictory: they can serve to promote cancer development, or they may act as tumor suppressors, depending on the particular GRHL protein involved and on the cancer type. The reasons for obvious discrepancies in results from different studies remain unclear. At the molecular level, the GRHL transcription factors regulate the expression of genes whose products are involved in cellular proliferation, differentiation, adhesion, and polarity. We herein review the roles of GRHL proteins in cancer development, and we critically examine relevant molecular mechanisms, which were proposed by different authors. We also discuss the significance of recent discoveries implicating the involvement of GRHL transcription factors in cancer and highlight potential future applications of this knowledge in cancer treatment.
Direct Monte Carlo simulation of nanoscale mixed gas bearings
Authors: Myo Kyaw Sett , Zhou Weidong , Lee Kok Leong , Yu Shengkai , Hua Wei
Published: June 2015

The conception of sealed hard drives with helium gas mixture has been recently suggested over the current hard drives for achieving higher reliability and less position error. Therefore, it is important to understand the effects of different helium gas mixtures on the slider bearing characteristics in the head–disk interface. In this article, the helium/air and helium/argon gas mixtures are applied as the working fluids and their effects on the bearing characteristics are studied using the direct simulation Monte Carlo method. Based on direct simulation Monte Carlo simulations, the physical properties of these gas mixtures such as mean free path and dynamic viscosity are achieved and compared with those obtained from theoretical models. It is observed that both results are comparable. Using these gas mixture properties, the bearing pressure distributions are calculated under different fractions of helium with conventional molecular gas lubrication models. The outcomes reveal that the molecular gas lubrication results could have relatively good agreement with those of direct simulation Monte Carlo simulations, especially for pure air, helium, or argon gas cases. For gas mixtures, the bearing pressures predicted by molecular gas lubrication model are slightly larger than those from direct simulation Monte Carlo simulation.
Effects of cutting conditions on forces and force coefficients in plunge milling operations
Authors: Rafanelli Francesco , Campatelli Gianni , Scippa Antonio
Published: June 2015

The modeling of milling forces is a crucial issue to understand milling processes. In the literature, many force models and experiments to identify force coefficients are found. The objective of this article is to develop a new approach, based on the traditional average force method, able to measure and compute the cutting coefficients for end mills used in plunging operations. This model has been used to evaluate the effect of the radial engagement on the cutting coefficients themselves, proposing a new strategy to update these values for different cutting parameters. This dependency of the cutting coefficient is particularly important for the determination of the stability lobe diagrams, used to predict the chatter conditions. In this article, the method to assess the cutting coefficients, the results of the experimental tests, and the effect of condition-dependent cutting coefficients on process stability are presented.
All that wheezes is not asthma: A cautionary case study of shortness of breath in pregnancy
Authors: Varnier Nicla A , Chwah Sarah , Miller Trent , Pettit Franziska , Brown Mark , Rees David , Henry Amanda
Published: June 2015

Background

Shortness of breath is a common physiological pregnancy presentation, secondary to both hormonal and mechanical effects. Its pathological causes are common (asthma exacerbation or infection); new-onset cardiac pathology is rarely considered.

Case

JC, a 39-year old G4P2T1, presented at 34 weeks’ gestation with shortness of breath unrelieved by salbutamol. History included asthma, poly-drug abuse and smoking. Initial presentation was consistent with asthma exacerbation and she was treated as such. There was deterioration of symptoms and on re-examination raised jugular venous pressure was noted with bibasal lung crepitations and cardiac systolic murmur. Echocardiogram showed severe cardiomyopathy (left ventricular ejection fraction 20%). JC was commenced on diuretics, digoxin and fluid restricted. Labour was induced at 35 weeks’ gestation, with birth of a healthy female infant (BW 2475 g) by elective assisted vaginal delivery. Cardiac function improved in subsequent weeks, confirming peripartum cardiomyopathy.

Conclusion

Peripartum cardiomyopathy affects 1 in 2500–4000 live births. Over 90% of women regain normal cardiac function postpartum with optimal medical management. Peripartum cardiomyopathy presents a diagnostic conundrum as its primary symptoms mimic not only those of normal pregnancy but also a number of other, more common conditions. It is important to consider cardiac causes of shortness of breath initially, and vital to revisit an initial non-cardiac shortness of breath diagnosis if there is no sustained improvement with treatment. In this case, asthma history and initial wheeze on examination impeded correct diagnosis; however, the situation was re-evaluated and correct diagnosis made when the patient’s shortness of breath deteriorated. Subsequent multidisciplinary management and birth in an appropriate setting facilitated the best outcome for both mother and baby.
Small Big Data: Using multiple data-sets to explore unfolding social and economic change
Authors: Gray Emily , Jennings Will , Farrall Stephen , Hay Colin
Published: June 2015

Bold approaches to data collection and large-scale quantitative advances have long been a preoccupation for social science researchers. In this commentary we further debate over the use of large-scale survey data and official statistics with ‘Big Data’ methodologists, and emphasise the ability of these resources to incorporate the essential social and cultural heredity that is intrinsic to the human sciences. In doing so, we introduce a series of new data-sets that integrate approximately 30 years of survey data on victimisation, fear of crime and disorder and social attitudes with indicators of socio-economic conditions and policy outcomes in Britain. The data-sets that we outline below do not conform to typical conceptions of ‘Big Data’. But, we would contend, they are ‘big’ in terms of the volume, variety and complexity of data which has been collated (and to which additional data can be linked) and ‘big’ also in that they allow us to explore key questions pertaining to how social and economic policy change at the national level alters the attitudes and experiences of citizens. Importantly, they are also ‘small’ in the sense that the task of rendering the data usable, linking it and decoding it, required both manual processing and tacit knowledge of the context of the data and intentions of its creators.
Using contracted assets to undertake non-contracted services as a way to improve cost efficiency under negotiated or tendered bus contracts
Authors: Hensher David A
Published: June 2015

Public transit (bus) operators in many jurisdictions throughout the world currently deliver regular public transport services under a negotiated contract, typically between five and ten years, with renegotiation commonly assumed. In the last 20 years, however, there has been a move to competitively tendered service supply or a dialogue as a pre-phase to considering competitive tendering. Despite the growing interest in competitive tendering in the belief (almost ideological in many situations) that it will deliver value for taxpayers’ money in contrast to negotiated contracts, accumulating evidence suggests that negotiated performance-based contracts associated with a well-designed and effective actionable benchmarking programme with high quality incumbent service providers, can provide as good if not better value for money to government and society. Much of the evidence is now well documented in the literature; however there is one feature of the contracting environment that has not been given sufficient consideration, namely the complementary role that non-contracted services such as charter activity can play in improving the cost efficiency of contracted services. This paper investigates this phenomenon in the context of Sydney (Australia) bus service provision, aligned to the literature on output-based incentives, and shows that operators who participate in greater non-contracted services, while also delivering contracted services, have higher cost efficiency (in terms of cost per contracted in-service kilometres). While this can be explained in part by the quality of such operators, who are often more entrepreneurial and better managers, the evidence suggests that if operators can be encouraged (or allowed) to use contract assets to gain supplementary revenue (without incurring the same unit rate of costs per kilometre), then the negotiated (or tendered) prices are likely to be lower than they would otherwise be. Making this opportunity explicit is equivalent to adding an element of increased incentive compatibility.
Diagnostic accuracy of three different MRI protocols in patients with inflammatory bowel disease
Authors: Jesuratnam-Nielsen Kayalvily , Løgager Vibeke Berg , Munkholm Pia , Thomsen Henrik S
Published: June 2015

Background

Magnetic resonance imaging (MRI) is used for workup and control of inflammatory bowel disease (IBD); however, disagreement remains as to how the MRI should be performed.

Purpose

To compare prospectively the diagnostic accuracy of MRI with neither oral nor intravenous contrast medium (plain MRI), magnetic resonance follow-through (MRFT) and MR enteroclysis (MRE) using MRE as the reference standard in patients with inflammatory bowel disease.

Material and Methods

Plain MRI and MRE were carried out in addition to MRFT. All patients underwent both plain MR and MRFT on the same day and MRE within seven days. For the evaluation, the bowel was divided into nine segments. One radiologist, blinded to clinical findings, evaluated bowel wall thickness, diffusion weighted imaging (DWI), mural hyperenhancement, and other inflammatory changes in each bowel segment.

Results

Twenty patients (6 men, 14 women; median age, 43.5 years; age range, 26–76 years) underwent all three examinations; 10 with Crohn’s disease (CD), three with ulcerative colitis (UC), and seven with IBD unclassified (IBD-U). Sensitivity, specificity, and accuracy were in the range of 0–75%, 81–96%, and 75–95% for wall thickening, and 0–37%, 59–89%, and 50–86% for DWI in plain MRI, respectively. Sensitivity, specificity, and accuracy were in the range of 0–50%, 96–100%, and 90–100% for wall thickening, 0–50%, 84–97%, and 82–95% for DWI, and 0–71%, 94–100%, and 85–100% for mural hyperenhancement in MRFT, respectively.

Conclusion

The use of oral and intravenous contrast agent improves detection of bowel lesions resulting in MRFT remaining the superior choice over plain MRI for diagnostic workup in patients with IBD.
The Transgender Military Experience
Authors: Dietert Michelle , Dentice Dianne
Published: June 2015

Although there have been studies that focus on the experiences of the gay and lesbian population serving in the United States military, few have focused on the experience of active duty transgender service members. Transgender individuals transgress the binary conception of gender by deviating from societal gender norms associated with assigned sex at birth. The Department of Defense has set policies and standards that reflect a binary conception of gender, with a focus on conformity. We argue that able-bodied gender variant service personnel are just as capable of serving their country as anyone else. Because of the repercussions associated with active duty transgender military personnel, our sample is small and involves nine clandestine service members and two international service members who wanted to share their stories from a different perspective. Snowball sampling was aimed at finding current active duty and reserve transgender service members. Using a combination of telephone interviews and questionnaires, data were collected from active duty transgender service personnel throughout the United States and two from international militaries that allow transgender people to serve. Data collection focused on the overall experiences of the participants along with questions regarding workplace discrimination, suggestions for policy changes, and their views about the overturn of Don’t Ask, Don’t Tell. Our findings add to a growing source of information about the transgender military experience in the U.S. armed forces and the importance of overturning discriminatory workplace policies that negatively impact transgender service members.
Initial treatment of CLL: integrating biology and functional status
Authors: Jain Nitin , O’Brien Susan
Published: June 2015

A better understanding of the biology of chronic lymphocytic leukemia (CLL) has led to significant advances in therapeutic strategies for patients with CLL. Chemoimmunotherapy (CIT) has been the standard first-line therapy for CLL. Age and comorbidities can help decide which patients may benefit from a CIT approach. FCR (fludarabine, cyclophosphamide, and rituximab) is the current standard treatment option for younger patients with CLL. For older patients and for patients with renal dysfunction, bendamustine and rituximab may be a better option. For older patients with comorbidities who may not be able to tolerate intensive CIT, the combination treatment of chlorambucil and obinutuzumab or ofatumumab is an option. For patients with del(17p), ibrutinib is the treatment of choice. Several ongoing phase 3 clinical trials with novel therapies will further refine the frontline therapy of CLL.
Mapping the interaction between factor VIII and von Willebrand factor by electron microscopy and mass spectrometry
Authors: Chiu Po-Lin , Bou-Assaf George M. , Chhabra Ekta Seth , Chambers Melissa G. , Peters Robert T. , Kulman John D. , Walz Thomas
Published: June 2015

Key Points

Electron microscopy and hydrogen-deuterium exchange establish the C1 domain as the major binding site for the VWF D′D3 domain on FVIII. Additional sites implicated in the FVIII-VWF interaction are located within the a3 acidic peptide and the A3 and C2 domains of FVIII.
Visualization of an N-terminal fragment of von Willebrand factor in complex with factor VIII
Authors: Yee Andrew , Oleskie Austin N. , Dosey Anne M. , Kretz Colin A. , Gildersleeve Robert D. , Dutta Somnath , Su Min , Ginsburg David , Skiniotis Georgios
Published: June 2015

Key Points

The VWF D′ domains are flexibly tethered entities projecting outside antiparallel dimers of the VWF D3 domain. Extensive interactions between the VWF D′ domain and primarily the FVIII C1 domain mediate VWF-FVIII association.
RETRACTED ARTICLE: The traditional Tibetan medicine Yukyung Karne exhibits a potent anti-metastatic activity by inhibiting the epithelial to mesenchymal transition and cell migration
Authors: Choedon Tenzin , Mathan Ganeshan , Kumar Vijay
Published: June 2015

Background

In Traditional Tibetan medicine, Yukyung Karne has been used for the treatment of ovarian cancer. Though Yukyung Karne has been reported to be clinically effective, the molecular mechanism of its anti-metstatic action remains elusive.

Methods

The cytotoxic property of Yukyung Karne was evaluated by crystal violet staining while its ability to induce ceramide production was analyzed by sphingomyelinase assay. The anti-metastatic property was investigated using adhesion, invasion, migration and colony formation assays. The effect of Yukyung Karne on the expression of extracellular matrix components, and epithelial and mesenchymal markers were evaluated by confocal microscopy and western blotting.

Results

Yukyung Karne exhibited a strong anti-metastatic property by significantly reducing the invasion, migration and colony formation ability of ovarian cancer cells. Besides it inhibited the levels of biomarkers involved in epithelial to mesenchymal transition such as down-regulation of vimentin and N-cadherin and up-regulation of epithelial E-cadherin. Yukyung Karne also induced the neutral sphingomyelinase II (nSMNaseII) enzyme activity that is known to hydrolyze sphingomyelins into pro-apoptotic intracellular molecule ceramide.

Conclusions

The study provides some compelling evidences supporting the anti-metastatic potential of Yukyung Karne which strongly suggests its possible usage as a promising alternative medicine. Thus, Yukyung Karne may be used as an anticancer and anti-metastatic agent along with other conventional anticancer therapeutics to increase their efficacy.
Rapid response systems: a systematic review and meta-analysis
Authors: Maharaj Ritesh , Raffaele Ivan , Wendon Julia
Published: June 2015

Introduction

Although rapid response system teams have been widely adopted by many health systems, their effectiveness in reducing hospital mortality is uncertain. We conducted a meta-analysis to examine the impact of rapid response teams on hospital mortality and cardiopulmonary arrest.

Method

We conducted a systematic review of studies published from January 1, 1990, through 31 December 2013, using PubMed, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and the Cochrane Library. We included studies that reported data on the primary outcomes of ICU and in-hospital mortality or cardiopulmonary arrests.

Results

Twenty-nine eligible studies were identified. The studies were analysed in groups based on adult and paediatric trials that were further sub-grouped on methodological design. There were 5 studies that were considered either cluster randomized control trial, controlled before after or interrupted time series. The remaining studies were before and after studies without a contemporaneous control. The implementation of RRS has been associated with an overall reduction in hospital mortality in both the adult (RR 0.87, 95 % CI 0.81–0.95, p<0.001) and paediatric (RR=0.82 95 % CI 0.76–0.89) in-patient population. There was substantial heterogeneity in both populations. The rapid response system team was also associated with a reduction in cardiopulmonary arrests in adults (RR 0.65, 95 % CI 0.61–0.70, p<0.001) and paediatric (RR=0.64 95 % CI 0.55–0.74) patients.

Conclusion

Rapid response systems were associated with a reduction in hospital mortality and cardiopulmonary arrest. Meta-regression did not identify the presence of a physician in the rapid response system to be significantly associated with a mortality reduction.
MicroRNA profiling of the pubertal mouse mammary gland identifies miR-184 as a candidate breast tumour suppressor gene
Authors: Phua Yu Wei , Nguyen Akira , Roden Daniel L. , Elsworth Benjamin , Deng Niantao , Nikolic Iva , Yang Jessica , Mcfarland Andrea , Russell Roslin , Kaplan Warren , Cowley Mark J. , Nair Radhika , Zotenko Elena , O’Toole Sandra , Tan Shi-xiong , James David E. , Clark Susan J. , Kouros-Mehr Hosein , Swarbrick Alexander
Published: June 2015

Introduction

The study of mammalian development has offered many insights into the molecular aetiology of cancer. We previously used analysis of mammary morphogenesis to discover a critical role for GATA-3 in mammary developmental and carcinogenesis. In recent years an important role for microRNAs (miRNAs) in a myriad of cellular processes in development and in oncogenesis has emerged.

Methods

microRNA profiling was conducted on stromal and epithelial cellular subsets microdissected from the pubertal mouse mammary gland. miR-184 was reactivated by transient or stable overexpression in breast cancer cell lines and examined using a series of in vitro (proliferation, tumour-sphere and protein synthesis) assays. Orthotopic xenografts of breast cancer cells were used to assess the effect of miR-184 on tumourigenesis as well as distant metastasis. Interactions between miR-184 and its putative targets were assessed by quantitative PCR, microarray, bioinformatics and 3′ untranslated region Luciferase reporter assay. The methylation status of primary patient samples was determined by MBD-Cap sequencing. Lastly, the clinical prognostic significance of miR-184 putative targets was assessed using publicly available datasets.

Results

A large number of microRNA were restricted in their expression to specific tissue subsets. MicroRNA-184 (miR-184) was exclusively expressed in epithelial cells and markedly upregulated during differentiation of the proliferative, invasive cells of the pubertal terminal end bud (TEB) into ductal epithelial cells in vivo. miR-184 expression was silenced in mouse tumour models compared to non-transformed epithelium and in a majority of breast cancer cell line models. Ectopic reactivation of miR-184 inhibited the proliferation and self-renewal of triple negative breast cancer (TNBC) cell lines in vitro and delayed primary tumour formation and reduced metastatic burden in vivo. Gene expression studies uncovered multi-factorial regulation of genes in the AKT/mTORC1 pathway by miR-184. In clinical breast cancer tissues, expression of miR-184 is lost in primary TNBCs while the miR-184 promoter is methylated in a subset of lymph node metastases from TNBC patients.

Conclusions

These studies elucidate a new layer of regulation in the PI3K/AKT/mTOR pathway with relevance to mammary development and tumour progression and identify miR-184 as a putative breast tumour suppressor.
Testing a conditional cash transfer program in the U.S.: the effects of the family rewards program in New York City
Authors: Miller Cynthia , Riccio James , Verma Nandita , Nuñez Stephen , Dechausay Nadine , Yang Edith
Published: June 2015

Family Rewards represents the first test of a Conditional Cash Transfer (CCT) program in the U.S., offering families incentives for children’s education, family preventive health care and parents’ work and training. Using a randomized controlled trial, we find that the program led to substantial reductions in poverty and hardship during the 3 years in which the rewards were offered. The program also led to some effects in each of the three areas of education, health and work, although the effects were fairly modest or limited to certain subgroups.

JEL classification: I1, I2, I3, J1.
Stk40 represses adipogenesis through translational control of CCAAT/enhancer-binding proteins
Authors: Yu Hongyao , He Ke , Wang Lina , Hu Jing , Gu Junjie , Zhou Chenlin , Lu Rui , Jin Ying
Published: June 2015

A better understanding of molecular regulation in adipogenesis may help develop efficient strategies to cope with obesity-related diseases. Here, we report CCAAT/enhancer binding protein (C/EBP) β and δ, two critical pro-adipogenic transcription factors, are controlled at a translational level by serine/threonine kinase 40 (Stk40). Genetic knockout (KO) or knockdown (KD) of Stk40 leads to increased protein levels of C/EBP proteins and adipocyte differentiation in mouse embryonic fibroblasts (MEFs), fetal liver stromal cells, and mesenchymal stem cells (MSCs). In contrast, overexpression of Stk40 abolishes the enhanced C/EBP protein translation and adipogenesis observed in Stk40-KO/KD cells. Functionally, knockdown of C/EBPβ eliminates the enhanced adipogenic differentiation in Stk40-KO/KD cells substantially. Mechanistically, deletion of Stk40 enhances phosphorylation of eIF4E-binding protein 1, leading to increased eIF4E-dependent translation of C/EBPβ and C/EBPδ. Knockdown of eIF4E in MSCs decreases translation of C/EBP proteins. Moreover, Stk40-KO fetal livers display an increased adipogenic program and aberrant lipid/steroid metabolism. Collectively, our study uncovers a new repressor of C/EBP protein translation as well as adipogenesis and provides new insights into the molecular mechanism underpinning the adipogenic program.
Development of Flotation-assisted Homogeneous Liquid–Liquid Microextraction to Determine Organochlorine Pesticides in Soil by GC-MS
Authors: Sarkhosh Maryam , Niazi Ali
Published: June 2015

This work describes optimal flotation-assisted homogeneous liquid–liquid microextraction with a special homemade extraction cell that was designed to collect the low-density extraction solvent without centrifugation for the extraction of heptachlor, aldrin, trans-chlordane, cis-chlordane, and op-DDD in soil samples. The extraction solvent was transferred to GC-MS for analysis in the selected ion-monitoring mode. To obtain the optimum conditions for extraction, a rotatable face-centered central composite design consisting of three factors at three levels was used. Under optimum conditions, the method performance was studied in term of the linear dynamic range (LDR from 0–500 µg kg−1 soil), linearity (R2 > 0.9989), and precision (in the range of 0.036–0.062).
Geology and Hydrocarbon Accumulation of the Large Ultra-Deep Rewapu Oilfield in Tarim Basin, China
Authors: Zhu Guangyou , Liu Xingwang , Zheng Duoming , Zhu Yongfeng , Su Jin , Wang Kai
Published: June 2015

Over the past five years, oil and gas exploration to marine facies carbonate rock in China took on a fast-growing tendency, and a lot of large-scale oil and gas fields were discovered in succession. Particularly in the north of Tarim Basin, the large-scale Rewapu oil field was recently discovered in the Ordovician carbonate rock layer system with buried depth of 7,000 meters, manifesting that a significant potential of exploration exists in Tarim Basin's deep layer and ultra deep layer of Tarim basin. The results indicate that reservoirs of Rewapu oilfield are low porosity and low permeability layers karst reservoirs, reservoir temperature is around at 160 °C with oil, and the crude oil comes from the upper Ordovician source rock of the Manjaer depression. The hydrocarbon accumulation time is in the Late Permian, and since the Triassic sedimentation, the reservoir is in the continuous process of burying. It belongs to the old oil and gas system. Due to low geothermal gradient and late quick deep burial, oil reservoir has yet to be cracked, so well-preserved old oil reservoir can be discovered at the depth of 7000 m. The Ordovician carbonate reservoir in Rewapu was a fracture-cavity oil reservoir, and the oil and gas distribution and enrichment are controlled not by the local structure, but by the distribution and the development degree of Ordovician carbonate reservoir. The reservoirs of Rewapu block are mainly distributed in the Ordovician Yijianfang formation and at the top Yingshan formation, and the reservoir development degree was controlled by the karstification, the degree of fracture development and the sedimentation facies, concentrating into belts in plane and not controlling by the depth vertically. The overlying strata are limestone of Tumuxiuke formation and marls and limestone of Sangtamu formation in the upper Ordovician. Rewapu oil reservoir features stratified oil and mainly contains normal oil with low viscosity and high wax. Research results show that Ordovician reservoirs in Rewapu block have relatively large depth of burial, but they are still favorable in quality and sit along the path for the oil and gas's northward migration. Therefore, this block has immense resources potential and boasts good exploration and development outlook. In this paper, we study Rewapu block oil reservoir's geological features and hydrocarbon accumulation mechanism, which is of important significance for directing the exploration to oil and gas at the deep layer and ultra deep layer of Tarim Basin.
Effect of Fracture Design Parameters on the Well Performance in a Hydraulically Fractured Shale Gas Reservoir
Authors: Jang Hochang , Lee Jeonghwan
Published: June 2015

This study investigates the impact of fracture design parameters from the results of sensitivity analysis in a shale gas reservoir. When a shale gas reservoir is hydraulically fractured, the fracture network systems are formed comprising primary and secondary fractures. In the case of low permeability reservoir, especially, the more complex fracture network systems is, the more the productivity is improved. In this study, a sensitivity analysis was carried out to evaluate the impact of fracture design parameters on the well performance in a hydraulically fractured shale gas reservoir using simulation model. The productivity is improved when the secondary fracture conductivity increases or spacing decreases with various conditions of reservoir. It is shown that the determination of whether to increase or decrease secondary fracture growth is required to improve the productivity of shale gas reservoir. Based on the results, a guideline for hydraulic fracturing is proposed.
Mean Temperature Effect on a Thermoacoustic System Stability and Non-Normality
Authors: Li Xinyan , Zhao Dan
Published: June 2015

The stability and non-normality of an open-ended thermoacoustic system with three different mean temperature configurations are considered. An acoustically-compact heat source is confined and modeled by using a modified form of King's Law. Coupling the heat release model with a Galerkin series expansion of the acoustic waves enables the time evolution of flow disturbances to be calculated, thus providing a platform on which to gain insights on the thermoacoustic system stability and non-normality behaviors. The three mean temperature configurations are a). the mean temperature in pre- and after-heater regions is assumed to be same, i.e. T̄2 / T̄1 = 1. b). the mean temperature in the after-heater region is undergoing a sudden jump, i.e. T̄2 / T̄1 > 1. c). the mean temperature in pre and after-heater regions is undergoing linear variation with axial location, i.e. T̄ = T0 + ax. First the mechanism of combustion oscillations in the modeled thermoacoustic system with the third mean temperature configuration is verified. Then the mean temperature effects on the thermoacoustic eigenfrequency and eigenmode are investigated. Compared with the experimental measurements, the predicted eigenfrequencies with the third configuration agree better with the experimental measured ones. Furthermore, the differences in the mean temperature configurations result in a variation in combustion modes. Last the mean temperature effects on the transient growth of acoustical energy are studied. The transient energy growth analysis of acoustic disturbances is performed by linearizing the heat source model and recasting it into the classical time-lag N – τ formulation. Comparison is then made between the predicted transient growths from the thermoacoustic systems with different mean temperature configurations. It is shown that the mean temperature distribution plays an important role on determining the thermoacoustic system stability. It is also found that different mean temperature configuration leads to different maximum transient growth rate.
Adsorption—Desorption Processes on Mesoscopic Pores Connected to Microscopic Pores of Complex Geometry Using the Ising Model
Authors: Altamirano M.A. Balderas , Cordero S. , Román G. , Goicochea A. Gama
Published: June 2015

In this work, nitrogen adsorption and desorption onto solid surfaces were studied using computer simulations of the three-dimensional Ising model, for systems with complex porous structures at the mesoscopic and microscopic levels. A hysteresis cycle between the adsorption and desorption processes appears and it was found that its characteristics are dependent on the geometry of the pore and on the strength of the surface–fluid interaction. We also obtained an average adsorption isotherm, which represents a combination of differently shaped pores, and shows robust jumps at certain values of the chemical potential as a consequence of the shape of the pores. A comparison of the results of this study with experimental data is also made. In addition, we report the filling of microscopic pores connected with mesopores. It is argued that these predictions are useful for researchers working on the enhanced recovery of oil and for the design of new nanomaterials, among others.
Magnetic Molecularly Imprinted Polymer Beads Obtained by Suspension Polymerization for the Adsorption of 2,4,6-Trichlorophenol from an Aqueous Solution in a Fixed-Bed Column
Authors: Yu Ping , Sun Qilong , Tan Zhenjiang , Meng Minjia , Pan Jianming , Yan Yongsheng , Li Chunxiang
Published: June 2015

Highly effective magnetic molecularly imprinted polymer (MMIP) beads for adsorption of 2,4,6-trichlorophenol (2,4,6-TCP) were synthesized by suspension polymerization. The effect of various parameters such as bed depths (0.6, 1.1 and 1.7 cm), flow rate (1, 2 and 3 ml minute−1), influent 2,4,6-TCP concentrations (50, 100 and 200 mg l−1), influent solution pH (4, 6 and 8) and temperature (288, 298 and 308 K) was investigated. The breakthrough time increased with the increase of the bed depth, but decreased with an increase of the initial concentration, flow rate and temperature. The Adams–Bohart and Thomas models were applied to the adsorption process under experimental conditions to predict the breakthrough curves for process design. The Thomas model was in good agreement with the experimental data. Compared with magnetic non-imprinted polymers, MMIPs exhibited an excellent selectivity towards 2,4,6-TCP.
Sensitivity and Correlation Analysis of Double-Layer Cylindrical Reticulated Shell considering Several Performance Functions
Authors: Hui-Jun LI , Xue FENG , Zhen-Xing CHENG , Ming-Fu LI , Guang-De LI
Published: June 2015

Reliability, sensitivity between random variables and response, and correlation between responses of double-layer cylindrical reticulated shells with three different span-to-rise ratios are deeply investigated, furthermore the effects of different kinds of random variables and different positions of random variables on reliability and sensitivity between random variable and response are also investigated in details. Cross-sectional area, yielding strength and modulus of elasticity of members and external vertical load are defined as one or more random variables respectively according to their layouts in the reticulated shells, and their effects on sensitivity are substantially carried out. Subsequently, two cases in all are taken into account based on the different classification of random variables. Three performance functions, e.g., the maximal deflection, the total plastic strain energy, the number of yielding members, are taken into consideration for two cases, and correlations among the above performance functions are investigated.
Repowering a Windfarm — A Techno-Economic Approach
Authors: Prabu T , Kottayil Sasi. K.
Published: June 2015

Repowering one of the old Indian wind farms located at a potential wind site is discussed. Various options of repowering have been suggested and compared based on annual energy production and levelised cost of generation. Economic performance indices of repowering in the current wind power policy scenario have been evaluated and the feasibility is discussed. The study infers that partial repowering could be economically more attractive than total repowering, whereas total repowering of old wind farms located at potential sites would be essential to meet renewable energy targets of a nation like India.
Failure Prognostic Schemes and Database Design of a Software Tool for Efficient Management of Wind Turbine Maintenance
Authors: Sinha Yashwant , Steel John A
Published: June 2015

Wind Turbines require numerous and varied types of maintenance activities throughout their lifespan, the frequency of which increases with years in operation. At present the proportion of maintenance cost to the total cost for wind turbines is significant particularly for offshore wind turbines (OWT) where this ratio is ∼35%. If this ratio is to be reduced in-spite of adverse operating conditions, pre-mature component failures and absence of reliability database for wind turbine components, there is a need to design unconventional maintenance scheme preferably by including novel failure prediction methodologies. Several researchers have advocated the use of Artificial Neural Networks (ANN), Bayesian Network Theory (BNT) and other statistical methods to predict failure so as to plan efficient maintenance of wind turbines, however novelty and randomness of failures, nature and number of parameters involved in statistical calculations and absence of required amount of fundamental work required for such advanced analysis have continued to maintain the high cost of maintenance. This work builds upon the benefits of condition monitoring to design methods to predict generic failures in wind turbine components and exhibits how such prediction methods can assist in cutting the maintenance cost of wind turbines. This study proposes using a dedicated tool to assist with failure prediction and planning and execution of wind turbine maintenance. The design and development of such an all-inclusive tool will assist in performing administrative works, inventory control, financial calculations and service management apart from failure prediction in wind turbine components. Its database will contain reference to standard management practices, regulatory provisions, staff details and their skillsets, service call register, troubleshooting manuals, installation guide, service history, details of customers and clients etc. that would cater to multiple avenues of wind turbine maintenance. In order to build such a software package, a robust design of its database is crucial. This work lists prerequisites for choosing a physical database and identifies the benefits of relational database software in controlling large amounts of data of various formats that are stored in such physical databases. Such a database would be an invaluable resource for reliability studies, an area of interest for both academic researchers and the industry that are identifying avenues to economise wind turbine operations.
A Comparison of PI vs LPV Controllers for a Doubly-Fed Induction Generator in a Microgrid
Authors: Vo T. , Ravishankar J. , Nurdin H. I. , Fletcher J.
Published: June 2015

State-space controllers have been central to modern control theory and are often preferred over classical controllers such as PI and lag-lead controllers. This is because they offer flexibility in design, such as being able to simultaneously incorporate performance and robustness requirements, and have a solid mathematical foundation. Recently, doubly-fed induction generators (DFIGs) for wind turbines have been modeled as linear parameter varying (LPV) systems, a special class of time-varying linear state-space systems, for which LPV state-space controllers can be designed. The LPV controllers have been introduced for DFIG mainly because of their novelty and that they can offer the typical advantages that come with state-space controllers. However, no comparison has yet been made regarding the control performance of LPV controllers versus more traditional PI controllers for DFIGs. In this paper, LPV controllers have been designed using linear matrix inequality (LMI) techniques and their performance is compared to PI controllers via simulation studies on a DFIG in a microgrid. Our study shows that if a mathematical model represents the DFIG accurately, then both controllers can be tuned to give comparable performance.
Comparing Wind Development Policies in Europe, Asia and America
Authors: Regueiro-Ferreira R. , García X Doldán
Published: June 2015

In recent years, the wind industry has undergone considerable development worldwide, thanks mainly to state support for renewable energy embodied in various standards and initiatives. However, the situation differs significantly among the main world producers of electricity from wind power, and in some, we can find incomplete energy policies and regulatory frameworks, which have led to very different economic and social outcomes. In this paper, we present a comparative study of wind policies (based on a multidisciplinary approach) in the leading countries of Europe, Asia and America, in order to establish a comprehensive framework for the sector's future.
Regulation Strategy of China's Petrol Market: Empirical Evidence from Beijing
Authors: Ma Zhengwei , Xu Rui , Chen Chi , Wu Teng
Published: June 2015

Traffic congestion is now an intractable problem in China, causing serious air pollution and oil shortages. This problem must be solved; otherwise it will restrict China's economic development. This paper demonstrated the impact of petrol prices on the congestion index based on the statistical analysis with the SPSS 19.0. The results indicate that the two factors were negatively related, even allowing for the time lag of consumers' purchase decisions. In other words, the traffic problem can be solved to a certain degree by petrol price rises. Before making this suggestion of raising petrol prices, the authors attempted to discover the potential effect on the Chinese macro economy because of the predominant role of petrol price in China's secondary industry. They simulated the possible scenario with the derivative of a Computable General Equilibrium (CGE) model MCHUGE from the prospects of long-term, short-term and secondary industry. After the simulation, it was concluded that the increase in petrol price will not have crucial impact on the macro economy but will optimize the structure of secondary industry. According to the previous implications, a new pricing scheme (step tariff on petrol) is suggested which is quite suited to the Chinese market.
The Effect of Plantation Site Conditions on Adaptive Capability and Growth Performance of Taurus Cedar (Cedrus Libani A. Rich.) Seedlings
Authors: Atik Atilla , Aslan Fürüzan
Published: June 2015

The present study was conducted to determine the effect of site conditions on the adaptation capability and growth performance of cedar seedlings ( Cedrus libani) planted on a tree plantation on the South coast of Karakaya Dam Watershed in Malatya province, Eastern Turkey. In total, 93 experimental areas were chosen systematically at the end of second vegetation period, and various parameters were measured in these areas. A factor analysis was carried out to determine the most critical factors influencing the percent of seedling survival, height and root collar diameter. These parameters were found to be most affected by Organic Substance Rate, Inorganic Substance Rate (I), Soil Texture Type, Lime (CaCO3) Content, Elevation, and Inorganic Substance Rate (II).
Sound Absorption of Materials Obtained from the Shredding of Worn Tyres
Authors: Iannace Gino
Published: June 2015

The current legislation forbids depositing tyres in landfill at the end of their useful life (European Directive 1999/31 on the landfill of waste). Thus a problem for the reuse of these waste materials arises. One possible use of worn tyres is in the field of applied acoustics. After being shredded, in appropriate particle sizes, it can be possible to reutilise tyres as sound absorbing material. The purpose of this paper is to provide a theoretical model for predicting the sound absorption coefficient of granular materials resulting from the shredding of worn tyres. Starting from the knowledge of the physical properties (such as resistivity, porosity and the structure factor) measured for each range of particle size, by the application of a theoretical model it is possible to obtain the coefficient of absorption of the tested material. Measurements of the absorption coefficient were made using a tube of Kundt, with the use of FFT techniques. Given the dimensions of the tube, the measurements of the absorption coefficient were valid in the range from 200 Hz to 2.0 kHz. Then the theoretical developments were compared with the experimental ones in function of the frequency.
Nonlinear Interstory Drift Contours for Idealized Forward Directivity Pulses Using “Modified Fish-Bone” Models
Authors: Khaloo A.R. , Khosravi H. , Jamnani H. Hamidi
Published: June 2015

Four 5-, 10-, 20- and 30-story moment frames, representing low-, mid-, and two high-rise structures, were subjected to a great number of idealized directivity pulses. The amplitudes and periods of pulses vary from 0.02 g to 1.0 g and 0.5 to 12 sec, respectively. Over 1400 nonlinear dynamic analyses of low- to high-rise moment frames were performed which were feasible through using modified fish-bone model. The distribution of interstory drift along the height was studied and two applied contours were proposed: (i) the maximum interstory drift contour, and (ii) the critical story contour. These contours were demonstrated versus the ratio of natural period of the structure to the pulse period and the response modification coefficient (R-factor). Hence, the contours could provide the possibility of investigating the measure of damage, its location and also the conditions leading to collapse based on these parameters. These investigations justify the vulnerability of flexible buildings versus long-period directivity pulses. They also show that some near-fault directivity pulses could impose serious damage to low-rise buildings.