Mid-range Research Articles

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

Urea-Selective Catalytic Reduction (SCR) is widely used to reduce nitrogen oxide (NOx) emissions. This paper presents a comprehensive experimental research work on aftertreatment emissions of NOx and ammonia (NH3) slip for three aftertreatment concepts by introducing the SCR sizing strategy on a 6-cylinder mid-range non-exhaust gas recirculation (EGR) diesel engine to meet China non-road Stage IV regulation limits. It can be observed that the three concepts could meet the regulation limits for NOx emissions and NH3 slip by selecting the appropriate length. There is little effect on emission results during a non-road transient cycle (NRTC) when the aftertreatment inlet/outlet with insulation and without insulation and the emission results on both strategies could meet non-road China Stage IV regulation limits. It is recommended to select Concept 2 which could meet regulation requirements considering multiple factors in the SCR sizing strategy. Substrate impact and NH3/NOx molar ratio (ANR) impact are investigated based on Concept 2. The results show that by applying the SCR substrate aftertreatment with a cell density of 600 cpsi, NOx conversion capability is stronger than that with cell density 400 cpsi for the same SCR size. Current dosing strategy is capable and recommended ANR is 0.9–1.1 if considering dosing strategy optimization. The methodology in this study provides an effective guidance and reference for future aftertreatment SCR sizing strategies in real applications.

LiGaS2 crystal growth under low temperature gradient conditions by the modified Bridgman method

LiGaS2 (LGS) is a promising nonlinear optical material for the generation of coherent radiation in the mid IR range. However, the production of large crystals of optical quality is complicated by the strong incongruent evaporation of volatile components at the temperatures above melting point. Such evaporation leads to deviations from the crystal stoichiometry during the growth process. In this paper the value of the LGS melt superheating in classical Bridgman–Stockbarger method was determined using the mathematical modeling. On the other hand, we designed a modified furnace and tested it: This allowed us to decrease the melt superheating down to 5 K.

Uplink transceiver design for coded GFDMA systems

In the generalized frequency division multiplexing (GFDM) technique, non-orthogonal pulse shapes are used to transmit data symbols on both time and frequency. This procedure causes self-interference among transmitted symbols. Recently, a modified version of GFDM, coded GFDM (CGFDM), has been introduced in which the transmitter matrix is unitary, avoiding the noise enhancement during self-interference cancellation. In this paper, we generalize the CGFDM for the multiuser uplink transmission scenario, and develop a zero-forcing (ZF) receiver to detect the data of multiple users. Simulation results show that the proposed ZF receiver outperforms the conventional ZF based generalized frequency division multiple access (GFDMA) receiver when the prototype filters are less localized and the number of subsymbols is high; however, with an increase in computational complexity. Moreover, a receiver with remarkably lower computational complexity is proposed based on the unitarity of the transmitter matrix in CGFDM and the assumption of relatively low frequency selectivity of the communication channels. This low-complexity receiver provides the same bit error rate (BER) performance of the ZF receiver in the low to mid range SNRs.

Abstract 6408: E3scan™ ligand binding assay platform for targeted protein degradation and PROTAC discovery

Abstract E3 ligases have emerged as pivotal targets for a next generation protein degradation-based drug discovery paradigm. This new paradigm includes both ligand binding-directed “reprogramming” of E3 substrate specificity approaches and a more directed approach, using small molecule proteolysis-targeting chimeras (PROTACs), to selectively degrade disease-driving proteins. As there are hundreds of diverse putative E3 ligases with differentiated tissue expression, this new paradigm may well define a next dimension of precision medicine defined by an axis of tissue-specific activity. While there have been some early successes, the E3 drug discovery field has a significant unmet need for a standardized biochemical ligand binding assay platform. A platform is required that: 1) Can measure ligand binding across the E3 family using a standardized method enabling “apples to apples” comparisons; 2), Is highly scalable and rapid; 3) Has an exquisite dynamic range for the measurement of accurate KD values as low as digit picomolar (pM). Eurofins DiscoverX herein presents its novel E3scan™ technology that addresses each of these unmet needs. E3scan, based upon well-established KINOMEscan® technology, has been successfully applied to diverse E3 ligases, including CRBN, VHL, MDM2, MDMX, cIAP1, cIAP2, and XIAP, with many other E3 assays in progress. We shall present assay validation data for these targets, including data for ligands with KD values in the low to mid pM range. In conclusion, we present Eurofins DiscoverX's novel E3scan platform that shall enable accelerated screening and SAR analysis in the E3 drug discovery field, with rapid turnaround times for discovery library screens (20 business day TAT) and weekly SAR (5 business day TAT) and the largest assay panel available on a single technology platform. Citation Format: Ksenya Cohen Katsenelson, Luis Gonzalez, Gabriel Pallares, Alastair J. King, Daniel K. Treiber. E3scan™ ligand binding assay platform for targeted protein degradation and PROTAC discovery [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6408.

On the noise generated by a controlled-diffusion aerofoil at [formula omitted

A compressible direct numerical simulation of the flow and near-field acoustics over a Controlled-Diffusion aerofoil at 8∘ geometrical angle of attack, a Reynolds number of Rec=1.5×105 based on the chord and a free-stream Mach number of M=0.25, with a spanwise extent of 12% chord was conducted to produce a space-time database to determine the aerofoil noise generation mechanisms. Three main noise sources respectively from the flow separation and reattachment at the leading-edge on the suction side, the interaction between the attached turbulent flow on the suction side and the trailing-edge and an additional near-wake source due to secondary instability are observed. It should be noticed, however, that such an additional source may strongly depend on the aerofoil shape and also on the flow conditions. The contribution of these three noise sources to the noise radiation at different frequencies is analysed through a wavenumber-frequency filtering procedure. In the low to mid frequency range, the contribution of the traditional trailing-edge noise is significant, whereas at high frequencies, the noise radiation is shown to be related to the flow transition/reattachment in the leading-edge area and the flow in the near wake further downstream of the trailing-edge noise source center. The near-wake source is observed to dominate the high-frequency noise radiation.

Molecular Assembling in Mixtures of Hydrophilic 1-Butyl-1-Methylpyrrolidinium Dicyanamide Ionic Liquid and Water

The infrared absorbance spectrum of the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, mixed with water at two different concentrations, was measured between 160 and 300 K in the mid infrared range. Both mixtures do not crystallize on cooling; however, remarkably, the one with an ionic liquid (IL):water composition of 1:3 displays a cold crystallization process on heating in a restricted temperature range between 240 and 250 K. A portion of the water participates to the cold crystallization. On the contrary, with an IL:water composition of 1:6.6 no crystallization takes place. Upon water addition the vibration frequencies of the anion and of some lines of the cation are blue shifted, while the absorption lines of water are red shifted. These facts are interpreted as the evidence of the occurrence of the hydrogen bonding of water, as the hydrogen bonding acceptor with respect to the anion (anion∙∙∙O-H bonds develop) and as hydrogen donor for the cation (C-H∙∙∙O bonds can form). Microscopic inhomogeneities in the samples and their evolution with temperature are discussed.

Identifying Significance of Product Features on Customer Satisfaction Recognizing Public Sentiment Polarity: Analysis of Smart Phone Industry Using Machine-Learning Approaches

ABSTRACT The reality about human behavior is that how other people think and evaluate have strong influences on our beliefs and thinking. Consumers get rich information from online reviews that may reduce their uncertainty regarding purchases. Besides, product-developing companies analyze user demands from online reviews to design market-driven product. In this study, a comparison among five major market share holder smart phone brands - Samsung, Apple, Huawei, Xiaomi, and Oppo is performed in different price categories - high, mid, and low range, based on sentiment polarity score. Online public reviews are extracted and sentiment scores of reviews are calculated to construct public sentiment polarity toward the famous brands. By examining both quantitative and qualitative methodologies, we identified the most important smart phone features or attributes that have great significance on consumer satisfaction. By experimenting and comparing five efficient machine-learning algorithms in predicting sentiment polarity and three feature selection algorithms in reducing attributes, an optimal set of 21 smart phone attributes was found those play major roles in determining customer satisfaction.

Assessment of Right Ventricular Systolic Function in Heart Failure with Preserved, Reduced and Mid Range Ejection Fraction

Assessment of Right Ventricular Systolic Function in Heart Failure with Preserved, Reduced and Mid Range Ejection Fraction

Thermomechanical Response of Supported Hexagonal Boron Nitride Sheets of Various Thicknesses

Raman spectroscopy is employed to investigate the temperature dependence of the E2g phonon mode of single-layer, few-layer (FL), and bulk hexagonal boron nitride (hBN) sheets, situated over Si/SiO2 (90 nm). Depending on the sample, two temperature regimes are recorded. In the low to mid range of the examined temperatures, the monolayer and FL samples exhibit significantly higher slopes compared to the thicker ones because of the thermal expansion of the underlying substrate. In the high-temperature region, all the examined samples show almost the same temperature slope, indicating slippage of the hBN sheets relative to the substrate and providing strong evidence that the slopes of the monolayer, FL, and bulk hBN are quite similar of about −0.020 cm–1/K. This is further justified from the full width at half-maximum versus T of the studied samples and the observed similarities of the thermal expansion coefficient (TEC) of one to three layers and bulk hBN, revealing a comparable level of anharmonicity for the E2g mode from the monolayer up to bulk hBN. Moreover, using a finite element method, we have determined the TEC of the underling substrate and the strain induced by TEC mismatch between the single-layer hBN and the substrate. Consequently, the intrinsic frequency shift of the E2g mode for the monolayer hBN upon temperature change is extracted. Finally, the vibrational response of monolayer hBN upon temperature is also examined by means of computational simulations, and satisfactory agreement with the experiment is obtained.

Becas Escolares y su impacto en la percepción del promedio escolar: evidencia para la Ciudad de México

El presente artículo muestra los resultados de impacto de un Programa de Becas Escolares de la Ciudad de México sobre la percepción que las familias tienen del promedio escolar de sus hijas e hijos. El estudio emplea una nueva base de datos recolectada para la evaluación de dicho programa de transferencias monetarias condicionadas, que contiene información para una muestra aleatoria sobre un grupo de tratamiento y un grupo de control. Por medio de modelos de regresión lineal y probit ordenado, se encontró que la participación en el Programa de Becas Escolares aumentó 18.1% la percepción de promedios altos y redujo 11.3 y 6.7% la percepción de promedios de rango medio y bajo, respectivamente.

Глобальна проблема розмінування: стан та підходи до розв’язання

В останні роки міжнародне співтовариство все глибше усвідомлює масштаби і гостроту проблем, породжуваних наземними мінами та вибухонебезпечними залишками війни, у тому числі боєприпасами, що не розірвалися, поступово погоджуючись з тим, що мова йде про глобальну проблему, яка вимагає узгоджених заходів у відповідь на міжнародному рівні. При цьому ООН покликана зіграти ключову роль у формулюванні цих глобальних заходів у відповідь, а також у забезпеченні необхідної міжнародної підтримки і створенні відповідних координаційних механізмів. Як показує аналіз, жоден з розроблених раніше методів виявлення мін за своїми основними параметрами (чутливість, вибірковість, швидкодія) не відповідає ні вимогам стандартів ООН з гуманітарного розмінування, ні загальному завданню глобального розмінування планети. Метою статті є визначення сучасних підходів до розв’язання проблеми розмінування. На теперішній час зарубіжні країни розробили та використовують сучасні мобільні робототехнічні комплекси (далі – РТК) для розмінування і продовжують фінансувати роботи з розширення функціональних можливостей для їхнього застосування у нових напрямах за рахунок створення нових конструктивних схем або використання уніфікованих підсистем міжтипового призначення. Досвід експлуатації мобільних РТК у цьому випадку розглядається в якості базової основи для перспективних розробок. Разом з тим, одним з актуальних у світі напрямів розробки РТК, у зв’язку з розвитком різноманітних безпілотних літальних апаратів, стала активізація ідеї щодо застосування БПЛА для ведення розвідки мінної обстановки, виявлення мін і дистанційного їх знищення. Подальші дослідження можуть відбуватися за такими напрямами: розробка чи закупівля готових безпілотних авіаційних комплексів, здатних виконувати завдання розвідки мінної обстановки, виявлення мін і дистанційного їх знищення; дослідження можливостей застосування спектрозональної чи багатоспектральної апаратури на борту безпілотника для підвищення достовірності та забезпечення повноти інформації про мінну обстановку; створення спеціалізованих підрозділів у складі безпосередніх користувачів, діяльність яких буде пов’язана з використанням безпілотних авіаційних комплексів для розвідки мінної обстановки, виявлення мін і дистанційного їх знищення тощо.

Investigation of the Thermal Properties of Diesters from Methanol, 1-Pentanol, and 1-Decanol as Sustainable Phase Change Materials.

Esters present several advantages when compared to traditional materials used for thermal energy storage, amongst which are better sustainability and greater chemical stability. However, at present, their thermal properties remain mostly unknown or not well documented. In this study, 12 diesters from four dicarboxylic acids (oxalic, succinic, suberic, sebacic) and three alcohols (methanol, 1-pentanol, 1-decanol) have been assessed as bio-based phase change materials for thermal energy storage. All diesters have been synthesized via Fischer esterification to high purities, and their chemical structures, as well as thermal properties, have been fully characterized. The diesters investigated show phase change transitions in a low–mid temperature range between −32 and 46 °C with maximum enthalpies of 172 J/g and show higher degrees of supercooling compared to fatty monoesters. Similarly to other esters classes, some trends correlating the chemical structures to the thermal properties were identified, which would allow for the development of property prediction tools.

An accurate higher order plate theory for vibrations of cross-laminated timber panels

In this contribution, bending vibrations of cross-laminated timber (CLT) panels are addressed. The focus is on the low to mid audio frequency range in view of the sound radiation properties of CLT. To this end, a plate theory recently proposed by the authors is adapted by introducing a deformation ansatz for the transverse displacement and neglecting insignificant terms, yielding a theory with six degrees of freedom. From the governing equations of motion, dispersion relations for the propagation of bending wave are derived, which also allow to compute the natural frequencies and mode shapes of bounded plates. The weak formulation of the equations of motion is presented. The accuracy of the proposed theory is validated for a simply supported rectangular CLT panel for which an analytical solution is available. The results are compared with first order shear deformation theory, revealing the limitations of this simplified theory in the present context. Finally, finite element solutions for the rectangular plate with non-classical boundary conditions are presented, as well as incorporating a floating floor construction, underlining the importance of numerical solutions for the practical application of this plate theory.

Mid Infrared Optical Gas Sensor Using Plasmonic Mach-Zehnder Interferometer

In this work, we propose an optimized design for on-chip gas sensor using metal-insulator (MI) plasmonic waveguide in the mid infrared range and utilizing a Mach-Zehnder Inetrferometer (MZI). The MI waveguide utilizes a high index dielectric layer on top of the metal to enhance the sensitivity of the sensor. The thickness and the refractive index of this layer are optimized to achieve high sensitivity. Using this layer, a design that exhibits high performance for both wavelength and intensity interrogation schemes is achieved. In addition, another one that furtherly enhances the sensor performance for intensity interrogation is also proposed. This design also minimizes the sensor sensitivity to wavelength variations. Intensity interrogation scheme has the advantage of eliminating the size and cost needed by wide wavelength band measurements including either spectrometer or tunable laser in wavelength interrogation. The first design sensitivity has reached 10000 nm/RIU with wavelength interrogation figure of merit (FOMλ) of 133RIU−1 and intensity interrogation FOMI of 239RIU−1. While the second one exhibit FOMI of 363RIU−1, both with length of 250 µm around 4.6 µm wavelength. Finally, these structures are cheap, compact, and easy to fabricate.

Nanostructuring SnTe to improve thermoelectric properties through Zn and Sb co-doping

A complex microstructure resulting in SnTe based thermoelectric materials with improved properties in the mid temperature range.

Exploring the boundaries of the passive greenhouse in Jordan: a modelling approach

Greenhouses are expanding fast in arid and semi-arid regions, among other reasons, because of the water savings that can be realized compared to open field cultivation. However, it is difficult for growers to recognize the optimum greenhouse design. Many competing aspects must be weighed against each other such as the structure, the cover and the climate control equipment. Obviously, the optimum design must be tailored for each specific crop and growing cycle and availability of resources (land, water, energy, labor, etc.). Simulation models can assist in this process, saving time and money. Wageningen University & Research, BU Greenhouse Horticulture has developed the Adaptive Greenhouse Methodology. It combines the use of greenhouse climate and resources simulation models, with crop growth and economic models, to solve the problem of designing the optimum greenhouse for each specific scenario in the world. In the present work we present the results of the application of this methodology to the specific case of the production of greenhouse soilless tomato in two regions in Jordan in the mid tech range: the highlands and the Jordan Valley. Results show that different mid tech designs could potentially provide yield levels of up to 35 and 27 kg m-2 in the Highlands and the Jordan Valley, respectively. The final design is similar in the two locations.

Dielectrically Loaded Quad-Ridge Flared Horn for Beamwidth Control Over Decade Bandwidth—Optimization, Manufacture, and Measurement

We present the design, manufacture, and measured performance of a dielectrically loaded quad-ridge flared horn (QRFH) feed for decade bandwidth radio astronomy application. The introduction of the dielectric load improves the QRFH beamwidth control in H-plane at the mid and upper frequency range. Consequently on the reflector, illumination efficiency, phase efficiency, and the intrinsic cross-polarization ratio (IXR) have been improved. The dielectric load is made from homogeneous low-loss polytetrafluoroethylene and has a low profile with a cylinder shape for simple installation at the center of the QRFH. The dielectrically loaded QRFH presented here covers 1.5–15.5 GHz with a calculated average aperture efficiency above 50% on a f/D = 0.3 prime-focus reflector. We present a calculation of system noise temperature and sensitivity for the QRFH on a 100 m prime-focus reflector. Measured beam patterns of the QRFH are in good agreement with the simulations over the full frequency band. The input reflection coefficient was predicted to be below −10 dB across the bandwidth. We present a tolerance analysis that explains why the measured one deviates.

Structural and electrical properties of Mg Silicide thin films deposited by RF sputtering

Mg2Si based thin films are a promising candidate for thermoelectric applications in the mid temperature range. The main advantages of these films are their low density, abundance of the elements used, good stability and environmental friendly nature. Nano structuring is considered to be useful tool to enhance the properties and hence thin films have been studied; although fabrication of Mg2Si thin film has been difficult due to difference in properties of magnesium and silicon. Semiconducting Mg2Si thin films were deposited on silicon substrate by radio frequency magnetron sputtering at low substrate temperature following a distinct approach. X-ray diffraction (XRD) and Field – Emission Scanning Electron Microscopy (FE-SEM) with EDS were done to study the phases, elemental composition and microstructure of these films. XRD results showed single phase Mg2Si formation. SEM results revealed granular nature of films and no cracks were observed. XPS was employed to study the chemical composition of films. The thin films were studied for their electrical transport behaviour through I-V and Hall measurements. Maximum conductivity of Mg2Si thin films was found to be ∼ 103 S/m and a carrier concentration of 5.14 + 19/cm3 was obtained for 300 nm thick film. The films showed n type nature.

Application of vector flow mapping technique in the assessment of left intraventricular pressure gradients in heart failure patients

Objective To evaluate the changes of intraventricular pressure differences (IVPDs) and intraventricular pressure gradients (IVPGs) in different phases of cardiac cycle in patients with heart failure(HF) patients by relative pressure imaging based on vector flow imaging(VFM). Methods Forty-nine HF patients with left ventricular ejection fraction (LVEF) lower than 0.50 hospitalized in Qilu Hospital of Shandong University from November 2018 to January 2019, including thirty-three patients with HF with reduced ejection fraction (HFrEF group) and fifteen patients with midrange ejection fraction (HFmrEF group), and forty-three controls were enrolled in this study. Clinical data and echocardiographic images were collected and the conventional left ventricular diameter, mass, volume, and systolic and diastolic function parameters were measured. IVPDs and IVPGs during isovolemic systole (IC), rapid ejection (RE), isovolemic diastole (IR), rapid filling (RF) and atrial systole (AC) phases were obtained by the VFM technique. The changes of IVPDs and IVPGs in different phases between the HF and control groups, and their correlations with conventional ultrasound parameters were analyzed. Results IVPDs and IVPGs in heart failure group were significantly reduced compared with the control group especially in isovolumic relaxation phase(all P<0.001). IVPDs and IVPGs showed a decreasing trend in the control group, HFmrEF group and the HFrEF group(P<0.001). IVPDs and IVPGs were correlated with LVID, LVMI, ESV, LVEF, GLS and E/e′ (all P<0.01), among which IVPD-IR and IVPG-IR were best correlated. IVPD-IR and IVPG-IR had excellent diagnostic efficacy for HF patients with LVEF<0.5, with cut-off values of <0.73 mmHg (AUC=0.915, P<0.001) and <0.103 mmHg/cm (AUC=0.932, P<0.001), respectively. Conclusions Early diastolic hemodynamics are severely impaired when systolic function declines.IVPG-IR, as a marker of left ventricular diastolic function, significantly correlates with left ventricular systolic function, and can be used as a potential indicator for assessing left ventricular systolic and diastolic function in patients with heart failure and identifying patients with heart failure. Key words: Vector flow imaging; Relative pressure imaging; Intraventricular pressure gradients; Heart failure

An approach to explore for a sweet spot in randomized trials

ObjectiveThe objective of the study was to demonstrate how a conventional randomized trial can be analyzed through a stratified or a matched approach to identify a potential sweet spot where observed differences might be accentuated in the mid range of disease severity. Design and SettingWe review a landmark randomized trial of heart failure patients that tested whether implantable defibrillators reduce mortality (n = 2,521). ResultsOverall, 22% (182/829) of the patients in the defibrillator group died compared with 29% (484/1,692) of patients in the control group. Proportional hazards analysis yielded a modest 25% survival benefit (hazard ratio = 0.75, 95% confidence interval: 0.63 to 0.89). Stratified analysis of the trial yielded a larger 52% survival benefit for those in the middle quintile of disease severity (hazard ratio = 0.48, 95% confidence interval: 0.29 to 0.79). In contrast, little of the survival benefit was explained by patients with the greatest disease severity (hazard ratio = 0.89, 95% confidence interval: 0.69 to 1.15). The discrepancy between crude and stratified analyses could be visualized by graphical displays and replicated with matched comparisons. ConclusionOur approach for analyzing a randomized trial could help identify a potential sweet spot of an accentuated treatment effect.