bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical modelling of the quenching process of 6061 aluminium alloy plates
Authors: Petre Marin , Efrem Raluca , Drăghici Nicuşor Constantin , Achim Alexandra Valerica
Published: December 2020

In recent decades, due to the increase in computing power, mathematical modelling has experienced a fulminant development in almost all areas. The aluminium industry is one of these areas. One of the main processes for improving the properties of certain aluminium alloys is the solution heat treatment and quenching process. The most common quenchant used for aluminium alloys is water. The main advantage of using a water quenchant is that water can provide the rapid quenching. By considering the temperature dependence of the thermo-physical properties, the non-linear thermo-mechanical direct coupled analysis of the quenching process for a 6061 aluminium alloy plate was achieved. The structural stress due to solid thermal eﬀects were studied by using ANSYS ﬁnite element software. The quenching rate, which determines the plate deformation after quenching, was estimated and validated on independent equipment for the research of aluminium alloy quenching process. The developed mathematical model serves as a tool by simulation of various scenarios that may occur in the industrial process.
Uniformly convergent numerical scheme for singularly perturbed parabolic delay differential equations
Authors: Woldaregay Mesﬁn Mekuria , Duressa Gemechis File
Published: December 2020

This paper deals with numerical treatment of singularly perturbed parabolic diﬀerential diﬀerence equations having small shifts on the spatial variable. The considered problem contain small perturbation parameter (ε) multiplied on the diﬀusion term of the equation. For small values of ε the solution of the problem exhibits a boundary layer on the left or right side of the spatial domain depending on the sign of the convective term. The terms involving the shifts are approximated using Taylor’s series approximation. The resulting singularly perturbed parabolic partial diﬀerential equation is solved using implicit Euler method in the temporal discretization with exponentially ﬁtted operator ﬁnite diﬀerence method in the spatial discretization. The uniform stability of the scheme investigated using comparison principle and discrete solution bound by constructing barrier function. Uniform convergence analysis has been carried out. The scheme gives second order convergence for the case ε >N−1and first order convergence for the case ε «N−1, whereNis number of mesh interval. Test examples and numerical results are considered for validating the theoretical analysis of the scheme.
On quaternionic product on some sets of hyperbolas
Authors: Crasmareanu Mircea , Popescu Marcela
Published: December 2020

The aim of this paper is to introduce some products, induced by the quaternionic product, on the set of equilateral hyperbolas. The study is a mix of elements from Euclidean and projective geometry. Some properties of these products are highlighted and are connected with some special numbers as roots or powers of the unit. Then we extend these products in a natural manner to oriented equilateral hyperbolas and to pairs of equilateral hyperbolas, using the algebra of octonions. Further, using an inversion, we extend these products to Bernoulli lemniscates and to Bernoulli q-lemniscates. Finally, using some isomorphisms, we extend these products to conics, and using an inversion, we extend these products to other curves. In order to highlight the importance of these studied products, the paper ends with some applications.
The study of a fourth-order differential equation: existence, uniqueness and a dynamical system approach
Authors: Danet Cristian Paul
Published: December 2020

This paper is concerned with the problem of existence and uniqueness of solutions for the semilinear fourth-order diﬀerential equation uiv – ku′′ + a(x)u+c(x) f (u) = 0. Existence and uniqueness is proved using variational methods and maximum principles. We also give a dynamical system approach to the equation. We study the bifurcation of the system and show that the behaviour of the stationary points S (α, 0, 0, 0) depend on the relation between the parameter k and β = f ′(α).
Painlevé integrability and multisoliton solutions of a generalized KdV system
Authors: Kumari Pinki , Gupta R.K. , Kumar Sachin
Published: December 2020

The integrability of a generalized KdV model, which has abundant physical applications in many ﬁelds, is investigated by employing Painlevé test. Eventually, we discover a new generalized P-type KdV model in sense of WTCKruskal method. Subsequently, Hereman’s simpliﬁed bilinear method is used to examine the integrability of the resulted model. As a result, multiple soliton solutions of newly discovered model are formally obtained.
Android Malware Detection Based on API Pairing
Authors: Guan Jun , Liu Huiying , Mao Baolei , Jiang Xu
Published: December 2020

Aiming at the problem that the permission-based detection is too coarse-grained, a malware detection method based on sensitive application program interface(API) pairing is proposed. The method decompiles the application to extract the sensitive APIs corresponding to the dangerous permissions, and uses the pairing of the sensitive APIs to construct the undirected graph of malicious applications and undirected graph of benign applications. According to the importance of sensitive APIs in malware and benign applications, different weights on the same edge in the different graphs are assigned to detect Android malicious applications. Experimental results show that the proposed method can effectively detect Android malicious applications and has practical significance.
In-Situ SEM Study on Deformation and Failure Mechanism of TC4 Titanium Alloy by Laser Additive Manufacturing
Authors: Zhang Shuangyin , Suo Tao , Li Yulong
Published: December 2020

The in-situ tensile test of the field emission scanning electron microscope was used to study the deformation mechanism of the TC4 titanium alloy manufactured by laser additive manufacturing along the L direction (grain growth direction) and T direction (perpendicular to the grain growth direction). The test results show that during the tensile process, as deposited specimen mainly cracks along the interfaces of α and β which is 45 ° to the tensile direction. With the increase of load, the cracking increases. The surface of the sample fluctuates until breaks. There is no obvious change in the prior β grain boundary in L direction. The microcracks along grain boundaries were observed in T direction, which is consistent with the result that the plasticity in the T direction is less than that in L direction. After heat treatment, due to the increase of α lath width compared with the as-deposition, slip bands were observed in α phase. However, a large number of slip bands appear on the equiaxed α phase of the forged specimen.
A Time Series Prediction Approach Based on Hybrid Tuning for Database Performance Indicator in AIOps
Authors: Wang Xiaoling , Zhang Xiaofang , Li Ning , Han Chengfeng , Yuan Zhuping , Gao Huanyu
Published: December 2020

One of the most important applications of the intelligent operation and maintenance of a cloud database is its trend prediction of key performance indicators (KPI), such as disk use, memory use, etc. We propose a method named AutoPA4DB (Auto Prophet and ARIMA for Database) to predict the trend of the KPIs of the cloud database based on the Prophet model and the ARIMA model. Our AutoPA4DB method includes data preprocessing, model building, parameter tuning and optimization. We employ the weighted MAPE coverage to measure its accuracy and use 6 industrial datasets including 10 KPIs to compare the AutoPA4DB method with other three time-series trend prediction algorithms. The experimental results show that our AutoPA4DB method performs best in predicting monotonic variation data, e.g.disk use trend prediction. But it is unstable in predicting oscillatory variation data; for example, it is acceptable in memory use trend prediction but has poor accuracy in predicting the number of database connection trends.
Bevacizumab in Aggressive Pituitary Adenomas – Experience with 3 Patients
Authors: Osterhage Katharina , Rotermund Roman , Droste Michael , Dierlamm Judith , Saeger Wolfgang , Petersenn Stephan , Aberle Jens , Flitsch Jörg
Published: December 2020

Objective To investigate bevacizumab as alternative treatment of aggressive pituitary adenomas after exhaustion of standard therapies.

Design and Methods Retrospectively, 3 patients undergoing microscopic transsphenoidal surgery of aggressive pituitary adenomas from 2008 till 2018 that were treated with bevacizumab were identified. Development of disease and treatment were evaluated.

Results Two patients suffered from ACTH-secreting adenomas, one from a non-functioning adenoma. All patients underwent multiple surgical, chemo- and radiotherapeutical approaches including temozolomide, showing favorable results in one patient. Deterioration of clinical condition in all patients led to an individual, palliative attempt of bevacizumab. Patients 1 and 2 showed a decrease of ACTH after first administrations, but therapy had to be ended shortly after due to a further deterioration of their condition. Patient 3 showed a stabilization of the disease for 18 months. Patients died 8, 15 and 7 years after initial diagnosis, respectively, and 2, 4, and 24 months after initiation of bevacizumab therapy, respectively.

Conclusion The demonstrated results suggest a considerable effect of bevacizumab in aggressive pituitary adenomas. The advanced stage of disease in all three patients, the overall short period of administration and just one patient showing a clinical benefit do not allow a general statement on the effectiveness. At the current stage of clinical experience, an approach with bevacizumab can be considered as an individual palliative attempt of treatment, when standard treatments are exhausted. Our results underline the need for further studies to evaluate this drug as potential player in therapy resistant aggressive pituitary tumors.
Roboterassistierte Hemihepatektomie rechts bei hepatozellulärem Karzinom bei nicht alkoholischer Steatohepatitis – Video der chirurgischen Technik
Authors: Fichtner-Feigl Stefan
Published: December 2020

Seit der Einführung der roboterassistierten Chirurgie können immer kompliziertere Operationen in dieser Technik durchgeführt werden. Auch in der hepatobiliären Chirurgie gewinnt die roboterassistierte Operation zunehmend an Bedeutung. Artikulierte und skalierte Bewegungen in einem 3-dimensionalen Operationsfeld ermöglichen eine präzise Präparation, notwendig für Majorresektionen an der Leber. Dieses Video demonstriert die Machbarkeit und Präzision der vollständig roboterassistierten Technik in der Durchführung einer Hemihepatektomie rechts bei einem hepatozellulären Karzinom (HCC) der Segmente V – VIII bei nicht alkoholischer Steatohepatitis (NASH). Der Patient ist bei Operation 72 Jahre und begleiterkrankt mit einem ausgeprägten metabolischen Syndrom.
Psychedelics and Psychotherapy
Authors: Nayak Sandeep , Johnson Matthew W.
Published: December 2020

Psychedelics have shown great promise in modern clinical trials for treating various psychiatric conditions. As a transdiagnostic treatment that exerts its effects through subjective experiences that leave enduring effects, it is akin to psychotherapy. To date, there has been insufficient discussion of how psychedelic therapy is similar to and different from conventional psychotherapy. In this article, we review the shared features of effective conventional psychotherapies and situate therapeutic psychedelic effects within those. We then discuss how psychedelic drug effects might amplify conventional psychotherapeutic processes—particularly via effects on meaning and relationship—as well as features that make psychedelic treatment unique. Taking into account shared features of conventional psychotherapies and unique psychedelic drug effects, we create a framework for understanding why psychedelics are likely to be effective with very diverse types of psychotherapies. We also review the formal psychotherapies that have been adjunctively included in modern psychedelic trials and extend the understanding of psychedelics as psychotherapy towards implications for clinical ethics and trial design. We aim to provide some common conceptual vocabulary that can be used to frame therapeutic psychedelic effects beyond the confines of any one specific modality.
Dental Office Prevention of Coronavirus Infection
Authors: D’Amico Cesare , Bocchieri Salvatore , Stefano Rosa De , Gorassini Francesca , Surace Giovanni , Amoroso Giulia , Scoglio Cristina , Mastroieni Roberta , Gambino Dario , Amantia Emanuele Mario , Marino Stefania , Stumpo Chiara , Fiorillo Luca
Published: December 2020

Coronavirus disease is now spreading in different countries of the world. The alarmism created through the media also creates confusion in people about virus spreading. The health care environments among which the dental practice could be places of spread of the virus, especially places where patients with systemic pathology could be exposed to this. The purpose of this article is to clarify coronavirus disease 2019 and its management in the dental practice. Only by following the normal guidelines on disinfection and sterilization of environments and operators, with some additional rules on the management of patients in the waiting room, it is possible to limit this risk. Limiting the risk of spreading the virus is one of the keys to its eradication.
Thoracic Vertebral Canal Stenosis Associated with Vertebral Arch Anomalies in Small Brachycephalic Screw-Tail Dog Breeds
Authors: Conte Alessandro , Bernardini Marco , De Decker Steven , Ricco Cristoforo , Behr Sebastien , Sanchez-Masian Daniel , Cherubini Guinio B. , De Risio Luisa , Gutierrez-Quintana Rodrigo
Published: December 2020

Objective The aim of this study was to describe clinical and imaging features of thoracic vertebral canal stenosis secondary to the hypertrophy of the vertebral lamina and articular processes in screw-tail brachycephalic dog breeds, to evaluate the prevalence of the malformation in a large group of screw-tail dog breeds and to determine if degree of stenosis is associated with presence of neurological signs.

Study Design This is a retrospective multicentric study.

Materials and Methods Clinical records of 185 screw-tail brachycephalic dogs (French Bulldogs, English Bulldogs, Boston Terriers) and Pugs were reviewed. Ten dogs with neurological deficits secondary to thoracic vertebral canal stenosis diagnosed on magnetic resonance imaging were identified (Group 1). Neurologically normal dogs (n = 175) of the same breeds underwent computed tomographic imaging of the thoracic vertebral column for other medical reasons (Group 2). Cross-sectional measurements were used to calculate a stenotic ratio.

Results Group 1 consisted of three French Bulldogs, six English Bulldogs and one Pug. Eight were males. Most dogs presented with progressive non-painful pelvic limbs ataxia and paresis. Twenty stenotic sites were identified with the most common being T4–T5. Three of ten dogs were treated surgically and all had a good long-term outcome. In Group 2, 33 of 175 dogs had one or more stenotic sites with the most common being T2–T3. The degree of the stenosis was significantly higher in Group 1 (p = 0.019). A stenotic ratio of 0.56 had sensitivity and specificity of 67% to differentiate between dogs with and without neurological signs.

Conclusion Cranial thoracic vertebral canal stenosis is observed predominantly in young male Bulldogs, but not all stenoses are clinically relevant.
Handling of Cadavers in a Mortuary amidst COVID-19 Pandemic
Authors: Gupta Rimpi , Goyal Deepak , Budhiraja Virendra , Swami Shveta , Bansal Swati , Gaur Neha
Published: December 2020

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) has been declared as a pandemic by the World Health Organization (WHO). This new disease is a challenge for the managers of health care facilities and mortuaries. It has impacted the practice of whole medical community. Though there is literature available on route of transmission of virus and time span for which virus is active on surfaces but there is no data available on how long the virus lives in and is active on the surface of a dead body. Thus, the health care professionals who handle cadavers and their specimens should use professional judgment to determine if a decedent had signs and symptoms compatible with COVID-19 during life and if autopsy is mandatory. Ministry of Health and Family Welfare and Centre for Disease Control & Prevention (CDC) have issued guidelines on dead body management and collection of postmortem specimens which should be observed in mortuary area and laboratories to limit the spread of disease among health care workers.
A neuronal wiring platform through microridges for rationally engineered neural circuits
Authors: Wu Yu , Wang Meijian , Wang Yong , Yang Huiran , Qi Hao , Seicol Benjamin J. , Xie Ruili , Guo Liang
Published: December 2020

Precisely engineered neuronal circuits are promising for both fundamental research and clinical applications. However, randomly plating thousands of cells during neural network fabrication remains a major technical obstacle, which often results in a loss of tracking in neurons' identities. In this work, we demonstrated an accurate and unique neural wiring technique, mimicking neurons' natural affinity to microfibers. SU-8 microridges, imitating lie-down microfibers, were photolithographically patterned and then selectively coated with poly-l-lysine. We accurately plated Aplysia californica neurons onto designated locations. Plated neurons were immobilized by circular microfences. Furthermore, neurites regrew effectively along the microridges in vitro and reached adjacent neurons without undesirable crosstalks. Functional chemical synapses also formed between accurately wired neurons, enabling two-way transmission of electrical signals. Finally, we fabricated microridges on a microelectrode array. Neuronal spikes, stimulation-evoked synaptic activity, and putative synaptic adaption between connected neurons were observed. This biomimetic platform is simple to fabricate and effective with neurite pathfinding. Therefore, it can serve as a powerful tool for fabricating neuronal circuits with rational design, organized cellular communications, and fast prototyping.
Terahertz optical machine learning for object recognition
Authors: Limbacher B. , Schoenhuber S. , Wenclawiak M. , Kainz M. A. , Andrews A. M. , Strasser G. , Darmo J. , Unterrainer K.
Published: December 2020

We demonstrate an optical machine learning method in the terahertz domain, which allows the recognition of objects within a single measurement. As many materials are transparent in the terahertz spectral region, objects hidden within such materials can be identified. In contrast to typical object recognition methods, our method only requires a single pixel detector instead of a focal plane array. The core of the calculation is performed by a quantum cascade laser generated terahertz beam, which is spatially modulated at a near-infrared encoded silicon wafer. We show that this method is robust against displacements of the objects and noise. Additionally, the method is flexible and, due to the optically performed recognition task, inherently fast.
Fabrication-tolerant and CMOS-compatible polarization splitter and rotator based on a compact bent-tapered directional coupler
Authors: Zafar Humaira , Pereira Mauro Fernandes , Kennedy Kenneth L. , Anjum Dalaver Hussain
Published: December 2020

In this paper, we demonstrate a broadband, low-loss, compact, and fabrication-tolerant polarization splitter and rotator (PSR) on a silicon-on-insulator platform. The PSR is based on an asymmetric directional coupler (ADC), which is covered with SiO2 from the top to make it compatible with the standard metal back end of line (BEOL) process. Conventional ADC-based PSRs suffer from stringent fabrication requirements and relatively low bandwidth, while the proposed bent-tapered design is highly insensitive to the fabrication errors (＞70 nm tolerance on the coupling gap) with an enlarged bandwidth and a compact footprint of 53 µm × 7 µm. It yields a polarization conversion loss less than 0.7 dB, a transverse electric (TE) insertion loss better than 0.3 dB, an ultra-low crosstalk with the TE extinction better than 30 dB, and the transverse magnetic extinction better than 25 dB, over a 200 nm wavelength range (1.5 µm–1.7 µm), in both ports. At the 1.55 µm wavelength, the calculated ultra-low polarization conversion loss and TE insertion loss are 0.27 dB and 0.08 dB, respectively.
Mixture productivity of sesame (Sesamum indicum L.) intercropped with sunflower (Helianthus annuus L.) in the humid tropics: effects of sunflower introduction date and organic fertiliser
Authors: Somefun Olabisi T. , Olowe Victor I. O. , Adigbo Sunday O. , Olasantan Faucett O.
Published: December 2020

Intercropping is a major production strategy in the tropics. Sesame (Sesamum indicum L.) and sunflower (Helianthus annuus L.) are two resilient oilseed crops of high economic potential with contrasting growth and morphological characteristics, which may make them suitable candidates for intercropping. Two field trials were conducted during the late cropping season (July–November) of 2018 and 2019 at Abeokuta, Nigeria, to evaluate the effects of organic fertiliser application and varying the introduction date of sunflower into sesame fields on intercrop productivity and efficiency. Sunflower was sown at 0, 10 and 20 days after sowing (DAS) of two varieties of sesame. On average, mixtures that involved either sesame variety with sunflower interplanted at 0 or 10 DAS plus fertiliser application showed a high land-equivalent ratio of >1.00 (biological efficiency), high land-equivalent coefficient of >0.25 (intercrop compatibility), and high economic efficiency in terms of monetary advantage index and sesame yield equivalent. Weight of sesame capsules per plant increased significantly (P < 0.05) following application of organic fertiliser in both years. Similarly, aboveground plant weight of sesame was significantly (P < 0.05) enhanced irrespective of the date of introducing sunflower into sesame fields in both years. Sesame grain yield (543.4–636.5 kg/ha) during the wetter late season of 2019 compared favourably with mean values from Africa (473.5 kg/ha) and the world (512.3 kg/ha). Organic fertiliser application significantly (P < 0.05) enhanced sesame grain yield in both years. Delaying introduction of sunflower until 20 DAS of sesame resulted in significantly (P < 0.05) lower sunflower head weight and achene weight per head and depressed sunflower grain yield in both years. Therefore, mixtures of both sesame varieties with sunflower introduced at 0 or 10 DAS and with organic fertiliser applied achieved high intercrop productivity and land-use efficiency, and are hereby recommended for cultivation under humid tropical conditions.
Wild-type p53-induced phosphatase 1 (WIP1) regulates the proliferation of swine Sertoli cells through P53
Authors: Wang Bingyuan , Zhang Mingrui , Che Jingjing , Li Kui , Mu Yulian , Liu Zhiguo
Published: December 2020

Wild-type p53-induced phosphatase 1 (WIP1) plays an oncogenic function by increasing cell proliferation in various cancer types. Deficiency in WIP1 expression leads to male infertility, possibly by impairing the blood–testis barrier and spermatogenesis. However, how WIP1 functions in the Sertoli cells to affect male reproduction remains unclear. Thus, in the present study we used a swine Sertoli cell line to investigate whether WIP1 regulated the proliferation of Sertoli cells to participate in male reproduction. The WIP1 inhibitor GSK2830371, WIP1-short interference (si) RNAs and an upstream microRNA (miR-16) were used to inhibit the expression of WIP1, after which the proliferation of swine Sertoli cells, P53 expression and the levels of P53 phosphorylation were determined. Inhibiting WIP1 expression suppressed swine Sertoli cell proliferation, increased P53 expression and increased levels of P53 phosphorylation. In addition, overexpression of miR-16 in swine Sertoli cells resulted in a decrease in WIP1 expression and increases in both P53 expression and P53 phosphorylation. Together, these findings suggest that WIP1 positively regulates the proliferation of swine Sertoli cells by inhibiting P53 phosphorylation, and the miR-16 is likely also involved by targeting WIP1.
Why does D-linking reduce the need for inversion in Spanish
wh-questions?
Authors: Goodall Grant
Published: December 2020

Spanish wh-questions without
inversion are much more acceptable when the
wh-phrase is D-linked. Standard semantic and
syntactic analyses of D-linking, developed for the more well-known
case of D-linking in weak islands, make incorrect predictions
regarding the Spanish case, while analyses based on working memory
fare better. In these analyses, the effect obtains because at the
time when the gap is posited, the processor is able to retrieve a
D-linked filler more easily, and this results in increased
acceptability. This type of analysis makes correct predictions about
D-linking in Spanish wh-questions, and the Spanish
facts provide new evidence that such an approach to D-linking based
on working memory is correct. The analysis adopted leaves open the
question of the proper analysis of inversion itself. Even if
D-linking results from properties of working memory, the inversion
phenomenon could still be the result of a grammatical
constraint.
Mechanisms of Change in Drinking following an Alcohol-Related Injury: A Qualitative Examination of the Sentinel Event Effect
Authors: Castro Yessenia , Najera Sarah N. , Robles Eden H. , Reddy Swathi M. , Holcomb Brianna N. , Field Craig A.
Published: December 2020

Background

Sentinel events are negative health-related events that trigger change in risky health behaviors. Despite its presumed major role in behavior change, the sentinel event effect has received little empirical attention. Through analysis of qualitative interviews, we explored how sentinel events trigger behavior change.

Methods

Thematic analysis and concept mapping were used to develop a preliminary model of the sentinel event effect among a sample of 24 adult heavy drinking Mexican-origin men previously admitted to a hospital due to injury. The model was checked against cases that did versus did not report change in alcohol use following an alcohol-related negative event.

Results

Findings suggest that sentinel events may arouse negative emotional reactions, encourage reflection on the negative consequences of drinking, and cause reevaluation of the severity and significance of drinking. These processes may increase motivation to change.

Conclusions

Findings support the concept of the sentinel event as a natural intervention, and identifies potential social-cognitive and motivational mechanisms through which it influences change. Findings stand to inform research on mechanisms underlying brief intervention effects, and research that seeks to identify treatment targets.
Origin of itinerant ferromagnetism in two-dimensional Fe3GeTe2
*
Authors: Chen Xi , Lin Zheng-Zhe , Cheng Li-Rong
Published: December 2020

Magnetic order in two-dimensional systems was not supposed to exist at finite temperature. In recent years, the successful preparation of two-dimensional ferromagnetic materials such as CrI3, Cr2Ge2Te6, and Fe3GeTe2 opens up a new chapter in the remarkable field of two-dimensional materials. Here, we report on a theoretical analysis of the stability of ferromagnetism in Fe3GeTe2. We uncover the mechanism of holding long-range magnetic order and propose a model to estimate the Curie temperature of Fe3GeTe2. Our results reveal the essential role of magnetic anisotropy in maintaining the magnetic order of two-dimensional systems. The theoretical method used here can be generalized to future research of other magnetic two-dimensional systems.
Water and nutrient recovery from urine: A lead up trail using nano-structured In2S3 photo electrodes*
Authors: Jayakrishnan R , Sreerev T R , Varma Adith
Published: December 2020

Developments of economic systems are critical for bio-regenerative life support systems in manned space missions. In this work we report on the feasibility of using two direct sunlight powered processes sequentially for the recovery of water and nutrients from urine. The work presents experimental evidence on nutrient and water recovery achieved using the proto-type designed and developed. We report the design and testing of a solar still which would serve on the nutrient recovery front. The cooled condensate from the solar still is fed into a solar powered electrolysis unit where nano-structured indium sulphide (In2S3) thin films coated over fluorine doped tin oxide (SnO2:F) substrate serve as one of the working electrodes. The electrolysis takes place in the absence of an electrolyte which manifests as a technical achievement of our work. Our results show that the COD level in the recycled water is very low. The In2S3 photo-electrodes are stable without any physical damage after the process.
Phase characteristics of hydrocarbons generated from different types of kerogen at different maturity levels in closed system
Authors: Chen Chengsheng , Deng Rui , Wang Yunpeng
Published: December 2020

For studying phase characteristics of hydrocarbons generated from different types of kerogen at different maturity levels, pyrolysis data of MM type-I and II kerogen (Maoming oil shale) and Coal type-III (Turpan coal) were collected and used for building phase models by PVT simulation technology. Then, phase diagrams, as well as physical properties (GOR, density, and viscosity) related to different kerogen types and along with maturity history, were output and carried out for comparative studies. The results show that three different types of kerogen perform different hydrocarbon generation processes, which form various yields and hydrocarbon compositions, leading to different petroleum types and diverse phase characteristics. The GORwt and the relative proportion of light and heavy hydrocarbons are two critical factors to shape the phase envelopes. The nature of kerogen with different maturity processes controls the changes of hydrocarbon compositions to form diverse phase characteristics. Their phase diagrams and physical properties on the ground conditions confirmed the different maturity ranges of black oils, light oils, and gas condensates generated by kerogen, respectively. Our study clarified that all types of kerogen at early generations (relatively low maturities) extensively generate black oils even though phase characteristics are different. In contrast, at a relatively high maturity by considering yields and expulsions of hydrocarbons, the MM type-II kerogen prefers to generate light oils, while the MM type-I kerogen prefers to generate black oils and the Coal/type-III kerogen prefers to generate gas condensates.
The main generation stage of organic acids during source-rock maturation: Implications for reservoir alteration in deep strata
Authors: Chen Jian , Xu Jie , Wang Qiang , Wang Susu , Sun Zhenyu , Peng Pingan
Published: December 2020

Generation of short-chain organic acids during source rock maturation was simulated over 72 h, using different kerogens at 220°C–360°C. A Youganwo Formation Type I kerogen sample had the highest organic acid yield (31.0 mg g−1 total organic carbon), twice that of the Yanchang and Kezilenuer formation samples (Type II and III kerogens, ∼15 mg g−1). The organic acids were generated mainly in the oil window, regardless of kerogen type. Type I and II kerogen-bearing source rocks produced organic acids with an equivalent vitrinite reflectance (EasyRo) of 1.16%, slightly later than the peak generation of liquid hydrocarbons. Type III kerogen-bearing source rocks produced acids at an early stage (0.95% EasyRo). Most organic acids dissolved in pore waters might have been expelled with hydrocarbons from source rocks containing type I and II kerogen, migrating to reservoirs. Pores and cavities in reservoirs along faults and conduits or near source rocks could be enlarged by mineral dissolution caused by organic acids, with the generated pore space being occupied by the migrated hydrocarbons. During continued burial, these porosities would be preserved, even in deep reservoirs.
Recovering the phase diagram of condensate gas reservoir in Well TZ86, Central Tarim Basin using PVTsim with geochemical inputs
Authors: Deng Rui , Zhang Haizu , Chen Chengsheng , Wang Yunpeng
Published: December 2020

The phase diagram of the condensate gas reservoir in the Ordovician lithologic trap of Well TZ86 was recovered using PVTsim software with geochemical inputs (well fluid components and experiment data). The results show the error between the recovery and measured phase diagrams is within a reasonable range, indicating the reliability of the recovery result. The recovery phase diagram shows an order of CP-Pm-Tm, and the current reservoir temperature and pressure (138.49°C, 65.10MPa) confirms that the fluid belongs to the condensate gas phase currently and turns to the condensate gas-condensate oil coexistence phase when it is mined to the surface condition. The components rich in gaseous hydrocarbons caused by the gas charging in the Late Himalayan and the temperature and pressure condition determined the formation of condensate gas reservoirs in the Tazhong Uplift.
Characteristics and accumulation period of Cambrian-Ordovician hydrocarbon inclusions in Yingmai 7 area, Tabei Uplift
Authors: Fan Shan , Zhang Huifang , Lou Hong , Shi Chaoqun , Zhou Siyu , Wang Zuotao , Ma Xiaodan , Jiang Jun
Published: December 2020

According to the fluorescence characteristics of hydrocarbon inclusions under the microscope, the interpenetration relationship with the occurrence veins, and the homogenization temperature, the hydrocarbon inclusions developed in the Cambrian-Ordovician reservoir in Yingmian 7 area can be divided into four periods, which correspond to four hydrocarbon accumulation events respectively. The periods of accumulation determined by the analysis of homogenization temperature and burial history are as follows: late Caledonian to early Hercyian low mature heavy oil filling, late Hercyian medium mature normal oil filling, early Himalayan high mature light oil filling and late Himalayan over mature natural gas filling. Among them, periods of I, II hydrocarbon inclusions distribution range is limited, only visible in part of the wells in Yingmai 7 area; periods of III, IV hydrocarbon inclusions in Yingmai 7 area are widely distributed, which reveals the Himalayan period of the two-stage oil and gas filling on the reservoir formation.
The distribution of lithium in nature and the application of lithium isotope tracing
Authors: Liu Jiayi , Liu Quanyou , Meng Qingqiang , Zhu Dongya , Liang Xinping
Published: December 2020

In recent years, with the advancement of isotope analysis methods, lithium isotopes have been widely used in tracing geological processes. This article introduces the unique geochemical properties of lithium and the lithium content and isotope characteristics in all kinds of natural geological reservoirs, and analyzes the fractionation mechanism of lithium isotope in the geological process which happened on the surface and the inner part of the earth. Further, this article summarizes and analyzes the application of lithium isotopes in tracing continental chemical weathering and slab subduction process, and discusses the distribution of lithium among various reservoirs in the light of the material circulation process on the surface and underground.
The excursion of Nitrogen and Carbon isotope in the Lower Cambrian of Tarim Basin: Implication for the transformation of anaerobic and euxinic settling
Authors: Su J , Fang Y , Ma S H , Yang Y P , Wei C Y , Weng N , Xu L , Bi L N , Li H D , Lin K X
Published: December 2020

The Nitrogen (N) along with Carbon (C) isotopes, Rear earth elements (REEs) and trace elements (TEs) were detected in the lower Cambrian Yuertusi formation, Northwest Tarim Basin. Two sections of obvious isotopic and elemental cycles have been investigated, which reflects the sedimentary transformation from lower euxinic to upper anaerobic setting. The extreme negative excursion of kerogen δ13C emerged in the bottom layer silica shales. The lowest value of kerogen δ13C is up to -37‰, which is similar with the global “Base” excursion in the bottom of lower Cambrian. It could be inferred the deposition of Yuertusi formation might be occurred after the Neoproterozoic glacial. Consequently, the kerogen δ13C of upper Yuertusi formation mostly exceeded -32‰, which could inferred the rapid rise of atmosphere and oceanic temperature. Based on the typical theory of isotope fraction, the δ13C of bitumen should be lower than that of kerogen. The bitumen δ13C in the upper Yuertusi formation varies from -34‰ ∼ 31.5‰, which is lighter than the δ13C of kerogen. Nevertheless, the δ13C of bitumen in the bottom layer silica shales is heavier than the δ13C of kerogen. This phenomenon has been noticed by previous researchers. The nadir negative excursion of bulk δ15N occurred in the bottom of Yuertusi formation, which has been indicated the sedimentary environment of Euxinic photic zone. The assimilation of bioavailable nutrient N (either in form of NH4 + or NO3-) may have contributed to the persistently low δ15C values. Ammonium may have served as the dominant nutrient N source for this period. The recycled NH4+ can be used directly or was sometimes oxidized to nitrate and then quantitatively used by phytoplankton to fuel primary productivity, which finally resulted into accumulation of high TOC and negative excursion of carbon isotope in the bottom of Yuertusi formation. It could be alternative interpretation for the depositional conditions of TOC-rich shales around Ediacaran-Cambrian boundary.
Quantitative assessment of cracking gas generated by dispersed liquid hydrocarbon
Authors: Zhaoyun Wang , Hua Jiang , Yongxin Li , Deyu Gong , Dongliang Wang
Published: December 2020

The resource assessment of cracking gas generated by dispersed liquid hydrocarbons involves 5 aspects. Firstly, the study on the distribution ratio and amount of liquid hydrocarbon within and out of the source rock, the oil expulsion efficiency of different source rocks varied from 20% to 80%, and the data is less than 50% for source rocks with TOC lower 2% and more than 50% for those with high TOC (higher than 2%), which means that the source rocks with high organic matter abundance and excellent type will have high oil expulsion efficiency. Secondly, the dominant migration pathway and distribution zone of the liquid hydrocarbons were conducted by numerical modeling while the distribution zone could also be tested through inversion method including statistics on thermogenic bitumen and fluorescence characteristics of reservoir samples. Thirdly, the conversion ratio of cracking gas generated by liquid hydrocarbon of various occurrences should be known. The main gas generation periods of liquid hydrocarbon mixed with carbonate, mudstone and sandstone are 1.2%-3.2%, 1.3%-3.4% and 1.4%-3.6% respectively. Moreover, overpressure could inhibit the process of gas generation. The mixture temperature lag is about 30°C while comparing the experimental results of 200Mpa and 50Mpa. Fourthly, the study of petroleum system of the studied area, especially the analysis of key factors and critical moments for the late scale formation and accumulation of natural gas of the liquid hydrocarbon cracking gas. Fifthly, quantitative assessment and resource evaluation of cracking gas generated by dispersed liquid hydrocarbon. The quantitative assessment method of “five steps”, which is based on genetic method, realized the integrated and systematic assessment of cracking gas generated by dispersed liquid hydrocarbon inside and outside the source rock, by paleo-reservoirs, and degradation gas generated by kerogen.
Analysis of deep gas accumulation conditions of the Upper Paleozoic in the southern Huanghua Depression
Authors: Yang Runze , Zhao Changyi , Zhao Xianzheng , Liu Haitao , Pu Xiugang , Li Hongjun , Li Chuanming
Published: December 2020

Influenced by sedimentary and tectonic factors, the accumulation conditions and models of Permian reservoirs in southern Huanghua Depression are unclear. Based on geochemical data of source rocks and petrophysical property data of reservoirs, by means of seismic interpretation, geochemical testing and profile analysis of typical reservoirs, the accumulation conditions are clarified, and the accumulation model is put forward. The study show that the intensity of secondary hydrocanbon generation is a favorable condition for the formation of gas field. The thrust structural traps in Huanghua Depression were mainly formed in the Indosinian, and anticline traps were mainly developed in the Yanshanian and Himalayan. Several source-reservoir-cap assemblages were developed inside the buried hill. Strong tectonic activity created good migration paths for natural gas, and the matching of trap formation, tectonic activity and hydrocarbon expulsion is the key factor of the accumulation of gas. On this basis, the typical gas accumulation pattern is established.
Preparation and application of stochastic simulation for the sensitive parameters of oil-bearing reservoir
Authors: Zhang Shiqi , Wei Feifei , Li Shijie , Ma Junxia , Wang Yanjun
Published: December 2020

The petrol physical inversion, based on the parametric relations defined by the Archie’s formulas, revealed that oiliness of reservoir in the targeted zone increases along with the resistivity increment. U sing the different values of resistivity Rtf, and water saturation Sw=80% as the aqueous layer limit, we build up a theoretical chart of Rtf greater than 3.5Ω.m as the reference standard for Oil bearing sand body. Upon the statistical results of actual well data, we set “the cloud relationship” between Rtf and P-impedance under the constraint of geostatistics inversion data, and used the cooperative simulation algorithm to get a spatial prediction of oil-bearing sand body by means of inversion data of the P-impedance.
Wigner function analysis of high harmonic generation in atoms
Authors: Wells D J , Quiney H M
Published: December 2020

The Wigner function provides the expression of phase space dynamics in quantum mechanics. In an application to non-linear optics, we describe its construction from time-dependent wavefunctions generated by numerical simulations, performed in both one and three dimensions, of the interaction of atoms with strong laser fields. From this analysis, the elements of the semi-classical three-step model of high-harmonic generation are extracted directly from the solution of the time-dependent Schrödinger equation. It is demonstrated that information contained in the Wigner function that is not relevant to this analysis may be removed by spatial filtering and state-projection operations.
National trends and outcomes of genetically inherited non-alcoholic chronic liver disease in the USA: estimates from the National Inpatient Sample (NIS) database
Authors: Sieloff Eric M , Rutledge Brian , Huffman Cuyler , Vos Duncan , Melgar Thomas
Published: December 2020

Background

Medical literature on the prevalence of genetic liver disease is lacking. In this study, we investigated the in-hospital healthcare and economic burden from genetic causes of non-alcoholic chronic liver disease (NACLD) and non-alcoholic liver cirrhosis (NALC) in the USA.

Methods

Data were abstracted from the National Inpatient Sample database between 2002 and 2014 using ICD9 codes for patients discharged with NACLD and NALC secondary to genetic diseases including alpha-1 antitrypsin deficiency (A1ATd), cystic fibrosis (CF), Wilson disease (WD), hereditary hemochromatosis (HHC), glycogen storage disease, and disorders of aromatic amino-acid metabolism (DAAAM).

Results

Throughout the study period, there were 19,332 discharges for NACLD associated with the six genetic diseases including 14,368 for NALC. There were $1.09 billion in hospital charges, 790 in-hospital deaths, and 955 liver transplants performed. Overall, A1ATd was associated with 8,983 (62.52%) hospitalizations for NALC followed by WD, CF, and HHC. The highest in-hospital mortality was seen with HHC. The greatest frequency of liver transplants was seen with DAAAM.

Conclusion

The number of hospitalizations for genetic liver diseases continues to increase. With increased funding and directed research efforts, we can aim to improve medical treatments and the quality of life for patients at risk for liver deterioration.
Whole-genome sequence-guided PCR for the rapid identification of thePseudomonas aeruginosaST175 high-risk clone directly from clinical samples
Authors: Cabot Gabriel , Lara-Esbrí Paula , Mulet Xavier , Oliver Antonio
Published: December 2020

Objectives

Pseudomonas aeruginosa frequently show MDR/XDR profiles, which are associated with worldwide-disseminated high-risk clones (HRCs). We developed a PCR assay for the detection in clinical samples of ST175, an HRC that is widespread in European countries.

Methods

The whole-genome sequence was obtained for one ST175 isolate using a PacBio RSII sequencer. Reads from multiple isolates belonging to ST175 and the PAO1 reference strain were mapped against the ST175 genome to identify potentially specific regions. Once curated, using the BLAST database to search for the presence of those regions in any other organism, we designed a specific PCR for the detection of ST175.

Results

Assembly of the ST175 PacBio-sequenced genome resulted in three contigs with a total length of 7 087 985 bases, encoding 6566 coding sequences. Specific regions for ST175 genomes were detected and a PCR targeting a 318 bp fragment located within a 3177 bp ORF coding for a putative reverse transcriptase was designed. The PCR test was first evaluated in silico against 229 XDR P. aeruginosa genomes (73 ST175) from two multicentre studies, yielding 100% sensitivity and specificity. Then, the PCR was evaluated in vitro in 25 isolates (12 ST175) and in 120 clinical samples (30 urine samples, 30 blood cultures, 30 sputum samples and 30 rectal swabs) of which 10% contained ST175, yielding again 100% sensitivity and specificity.

Conclusions

The PCR assay developed, showing high sensitivity and specificity for the detection of the ST175 HRC directly from clinical samples, could become a useful tool for guiding infection control and treatment strategies in areas with a high prevalence of this clone.